U.S. patent application number 11/797714 was filed with the patent office on 2008-01-03 for sheet for mounting polishing workpiece and method for making the same.
Invention is credited to Chen-Hsiang Chao, Chung-Chih Feng, I-Peng Yao.
Application Number | 20080003927 11/797714 |
Document ID | / |
Family ID | 38877300 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080003927 |
Kind Code |
A1 |
Feng; Chung-Chih ; et
al. |
January 3, 2008 |
Sheet for mounting polishing workpiece and method for making the
same
Abstract
The present invention relates to a sheet for mounting a
polishing workpiece. The sheet comprises a substrate, a surface
layer and a slightly rough layer. The substrate has a surface. The
surface layer is located on the surface of the substrate, with no
hole structure existing in the interior thereof, and has a surface.
The slightly rough layer is located on the surface of the surface
layer to carry and mount the polishing workpiece, with no hole
structure existing in the interior thereof. Accordingly, when the
polishing workpiece contacts the slightly rough layer, the air
therebetween is easily vented out via the slightly rough layer,
without the phenomenon of air wrapping, which increases the
adsorption force between the polishing workpiece and the sheet.
Inventors: |
Feng; Chung-Chih;
(Kaohsiung, TW) ; Yao; I-Peng; (Kaohsiung, TW)
; Chao; Chen-Hsiang; (Kaohsiung, TW) |
Correspondence
Address: |
VOLENTINE & WHITT PLLC
ONE FREEDOM SQUARE, 11951 FREEDOM DRIVE SUITE 1260
RESTON
VA
20190
US
|
Family ID: |
38877300 |
Appl. No.: |
11/797714 |
Filed: |
May 7, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11478601 |
Jul 3, 2006 |
|
|
|
11797714 |
|
|
|
|
Current U.S.
Class: |
451/56 |
Current CPC
Class: |
B24B 37/30 20130101;
B24B 41/068 20130101 |
Class at
Publication: |
451/56 |
International
Class: |
B24B 1/00 20060101
B24B001/00 |
Claims
1. A method for making a sheet for mounting a polishing workpiece,
comprising the following steps of: (a) forming a surface layer on a
release paper, the surface layer having no hole structure in the
interior thereof; (b) forming a substrate on the surface layer; (c)
drying the surface layer and the substrate; (d) removing the
release paper; and (e) printing a slightly rough layer on the
surface layer, the slightly rough layer having no hole structure in
the interior thereof.
2. The method as claimed in claim 1, wherein the substrate has a
plurality of holes in the interior thereof.
3. The method as claimed in claim 2, wherein the holes of the
substrate are of a continuous type.
4. The method as claimed in claim 2, wherein the holes of the
substrate are of a discontinuous type.
5. The method as claimed in claim 1, wherein the surface layer is
formed on the release paper in a manner of coating in the step
(a).
6. The method as claimed in claim 1, wherein the substrate is
formed on the surface layer in a manner of coating in the step
(b).
7. The method as claimed in claim 1, wherein the slightly rough
layer is printed on the surface layer in a manner of screen
printing in the step (e).
8. The method as claimed in claim 1, further comprising a step of
performing a water repellent treatment for the slightly rough
layer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of application Ser. No. 11/478,601,
filed Jul. 3, 2006, which is incorporated herein by reference in
its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a sheet for mounting a
polishing workpiece and the method for making the same, and more
particularly, to a sheet for mounting a polishing workpiece and the
method for making the same which are used in the chemical
mechanical polishing process.
[0004] 2. Description of the Related Art
[0005] Polishing generally refers to a wear control for a
preliminary coarse surface in the process of chemical mechanical
polishing (CMP), which makes the slurry containing fine particles
evenly dispersed on the upper surface of a polishing pad, and at
the same time places a polishing workpiece against the polishing
pad and then rubs the workpiece repeatedly with a regular motion.
The polishing workpiece may be objects such as a semiconductor, a
storage medium substrate, an integrated circuit, an LCD flat-panel
glass, an optical glass and a photoelectric panel. During the
polishing, a sheet must be used for carrying and mounting the
polishing workpiece, and the quality of the sheet directly
influences the polishing effect of the polishing workpiece.
[0006] Referring to FIG. 1, a schematic view of a polishing device
with a conventional sheet disclosed in U.S. Patent No. U.S. Pat.
No. 5,781,393 is shown. The polishing device 1 comprises a lower
base plate 11, a sheet 12, a polishing workpiece 13, an upper base
plate 14, a polishing pad 15 and slurry 16. The sheet 12 is adhered
to the lower base plate 11 through an adhesive layer 17 and is used
for carrying and mounting the polishing workpiece 13. The polishing
pad 15 is mounted on the upper base plate 14.
[0007] The operation mode of the polishing device 1 is as follows.
First, the polishing workpiece 13 is mounted on the sheet 12, and
then both the upper and lower base plates 14 and 11 are rotated and
the upper base plate 14 is simultaneously moved downwards, such
that the polishing pad 15 contacts the surface of the polishing
workpiece 13. A polishing operation for the polishing workpiece 13
may be performed by continuously supplementing the slurry 16 and
using the polishing pad 15.
[0008] Referring to FIG. 2, a local schematic view of the sheet of
FIG. 1 is shown. The sheet 12 is of a single-layer structure, the
material of which is generally PU (polyurethane), a kind of foaming
material. The sheet 12 is formed by a wet process, and thus a
plurality of continuous foaming holes 121 exists in the interior of
the sheet 12. The disadvantage of the sheet 12 is that the slurry
16 tends to be inhaled through the foaming holes 121 during the
polishing process, which causes changes in the hardness and
physical property of the sheet 12, such that the polishing
condition needs to be readjusted. Furthermore, the lifetime of the
sheet 12 is reduced. In addition, the sheet 12 is formed by the wet
process which results in an excessively low planarity, and it is
very difficult to achieve a generally uniform thickness above 0.5
mm. Finally, the foaming holes 121 within the sheet 12 cause the
phenomenon of air wrapping when the sheet 12 adsorbs the polishing
workpiece 13, thus resulting in a poor adhesion and a possible
crack during the polishing process as well as an uneven polished
surface after the polishing of the polishing workpiece 13.
[0009] Consequently, there is an existing need for a sheet for
mounting a polishing workpiece and the method for making the same
to solve the above-mentioned problems.
SUMMARY OF THE INVENTION
[0010] The objective of the present invention is to provide a sheet
for mounting a polishing workpiece. The sheet of the present
invention comprises a substrate, a surface layer and a slightly
rough layer. The substrate has a surface. The surface layer is
located on the surface of the substrate, with no hole structure
existing in the interior thereof, and has a surface. The slightly
rough layer is located on the surface of the surface layer to carry
and mount the polishing workpiece, with no hole structure existing
in the interior thereof. Accordingly, when the polishing workpiece
contacts the slightly rough layer, the air therebetween is easily
vented out via the slightly rough layer, without the phenomenon of
air wrapping, which increases the adsorption force between the
polishing workpiece and the sheet, thereby improving the polishing
effect of the polishing workpiece. Additionally, since no hole
structure exists in the interior of both the surface layer and the
slightly rough layer, the slurry will not be inhaled during the
polishing, thus prolonging the lifetime of the sheet.
[0011] Another objective of the present invention is to provide a
method for making the sheet for mounting a polishing workpiece,
which comprises the following steps:
[0012] (a) forming a surface layer on a release paper, the surface
layer having no hole structure in the interior thereof;
[0013] (b) forming a substrate on the surface layer;
[0014] (c) drying the surface layer and the substrate;
[0015] (d) removing the release paper; and
[0016] (e) printing a slightly rough layer on the surface layer,
the slightly rough layer having no hole structure in the interior
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a schematic view of the polishing device with a
conventional sheet disclosed in U.S. Patent No. U.S. Pat. No.
5,781,393;
[0018] FIG. 2 shows a local schematic view of the sheet of FIG.
1;
[0019] FIG. 3 shows a local schematic view of the sheet for
mounting the polishing workpiece according to the present
invention; and
[0020] FIGS. 4 to 6 show schematic views of each process step of
the method for making the sheet for mounting the polishing
workpiece according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring to FIG. 3, a local schematic view of the sheet for
mounting the polishing workpiece according to the present invention
is shown. The sheet 2 of the present invention is of a
three-layered structure, which comprises a substrate 21, a surface
layer 22 and a slightly rough layer 23. The substrate 21 has a
first surface 211 and a second surface 212, wherein the second
surface 212 is used for being adhered on the lower base plate (not
shown) of a polishing device. In this embodiment, the material of
the substrate 21 is high solid PU, with a plurality of continuous
or discontinuous type holes 213 existing in the interior of the
substrate 21, and the thickness of the substrate 21 can be larger
than 0.5 mm. However, it is to be understood that the material of
the substrate 21 may also be acrylic resin or another kind of
resin.
[0022] The surface layer 22 is located on the first surface 211 of
the substrate 21, and has a surface 221. The surface layer has no
hole structure in the interior thereof. The material of the surface
layer 22 is a polymeric elastomer without foam (for example PU,
acrylic resin or another kind of resin). The surface layer 22 has a
uniform thickness which is less than that of the substrate 21. The
materials of the surface layer 22 and substrate 21 may be the same
or different.
[0023] The slightly rough layer 23 is located on the surface 221 of
the surface layer 22, and is used for carrying and mounting a
polishing workpiece (not shown). No hole structure exists in the
interior of the slightly rough layer 23, and the material of the
slightly rough layer 23 is a polymeric elastomer without foam (for
example PU, acrylic resin or another kind of resin). The materials
of the slightly rough layer 23 and surface layer 22 may be the same
or different. A vent space 232 is formed between any two
protrusions 231 of the slightly rough layer 23, and when the
polishing workpiece contacts the slightly rough layer 23, the air
therebetween may be easily vented out via the vent space 232,
without the phenomenon of air wrapping, which increases the
adsorption force between the polishing workpiece and the sheet 2,
thereby improving the polishing effect of the polishing workpiece.
Additionally, since no hole structure exists in the interior of
both the surface layer 22 and the slightly rough layer 23, the
slurry will not be inhaled during the polishing, thus prolonging
the lifetime of the sheet 2.
[0024] The present invention further relates to a method for making
the sheet for mounting a polishing workpiece, which comprises the
following steps.
[0025] At first, referring to FIG. 4, a surface layer 22 is formed
on a release paper 30. The surface layer 22 has no hole structure
existing in the interior thereof. The surface layer 22 has a
surface 221. The material of the surface layer 22 is a polymeric
elastomer without foam (for example PU, acrylic resin or another
kind of resin), and the surface layer 22 has a uniform thickness.
Preferably, the surface layer 22 is formed on the release paper 30
in a manner of coating.
[0026] Then, referring to FIG. 5, a substrate 21 is formed on the
surface layer 22, the substrate 21 has a first surface 211 and a
second surface 212. In this embodiment, the material of the
substrate 21 is high solid PU, with a plurality of continuous or
discontinuous type holes 213 existing in the interior of the
substrate 21, and the thickness of the substrate 21 is larger than
0.5 mm. However, it is to be understood that the material of the
substrate 21 may also be acrylic resin or another kind of resin.
The materials of the surface layer 22 and the substrate 21 may be
the same or different. Preferably, the substrate 21 is formed on
the surface layer 22 in a manner of coating. Therefore, compared
with the conventional wet process, the substrate 21 of the
invention can remain a uniform thickness when the thickness thereof
is larger than 0.5 mm.
[0027] Then, the substrate 21 and surface layer 22 are dried for
one day. After that, the release paper 30 is removed.
[0028] At last, referring to FIG. 6, after turning the substrate 21
and the surface layer 22 upside-down for 180 degrees, a slightly
rough layer 23 is printed on the surface 221 of the surface layer
22 to form the sheet 2 (the same as FIG. 3). No hole structure
exists in the interior of the slightly rough layer 23, and the
material of the slightly rough layer 23 is a polymeric elastomer
without foam (for example PU, acrylic resin or another kind of
resin). The materials of the slightly rough layer 23 and surface
layer 22 may be the same or different. In this embodiment, the
printing step is screen printing.
[0029] Preferably, a water repellent treatment may also be
performed for the slightly rough layer 23 to prolong the lifetime
of the sheet 2.
[0030] While several embodiments of the present invention have been
illustrated and described, various modifications and improvements
can be made by those skilled in the art. The embodiments of the
present invention are therefore described in an illustrative but
not restrictive sense. It is intended that the present invention
may not be limited to the particular forms as illustrated, and that
all modifications which maintain the spirit and scope of the
present invention are within the scope as defined in the appended
claims.
* * * * *