Functional structure integrated optimization polishing pad capable of uniformly removing materials

Abstract

The invention discloses a functional structure integrated optimization polishing pad capable of uniformly removing materials. The functional structure integrated optimization polishing pad comprises a polishing layer and an elastic layer, the polishing layer is composed of a plurality of protrusions, and the protrusions are arranged in a honeycomb shape. The elastic layer is of a concentric partition structure and comprises a soft area and a hard area. By designing surface patterns of the polishing pad, abrasive particle tracks on the surface of the workpiece are uniformly distributed; by designing the polishing pad structure, the contact pressure on the surface of the workpiece is uniformly distributed. The surface pattern and structure of the polishing pad are subjected to comprehensive optimization design, integrated optimization of the functional structure of the polishing pad is achieved, the abrasive particle motion trail and contact pressure distribution can be cooperatively regulated and controlled, and the material removal uniformity of the surface of a workpiece is improved.

Description

Technical Field

[0001] This invention relates to a precision and ultra-precision machining technology, and more particularly to a polishing pad for grinding and polishing, specifically a functional structure-integrated optimized polishing pad that can uniformly remove material. Background Technology

[0002] Grinding and polishing technology, due to its ability to achieve high surface accuracy and excellent surface quality, has become an important processing method in fields such as integrated circuits, optical components, and semiconductor materials. With the continuous increase in workpiece diameter, the requirements for planarization are becoming increasingly stringent. Among the consumables used for overall planarization, polishing pads are one of the key consumables determining the stability of the manufacturing process. Currently, existing polishing pads have relatively simple surface patterns during the polishing process, resulting in uneven distribution of abrasive particle movement trajectories on the workpiece surface. Their structures are mostly vertical single-layer or multi-layer composite structures, making it difficult to achieve zoned control of the contact pressure on the workpiece surface. Uneven pressure distribution and the tendency to generate edge effects lead to uneven material removal.

[0003] Chinese patent CN101327577B discloses a bonded abrasive polishing pad with self-sharpening function and good wear uniformity. By setting three annular zones of unequal density on the polishing layer, it can maintain surface accuracy for a long time during polishing, thereby improving the surface accuracy of the workpiece. Chinese patent CN114770372B discloses a composite surface pattern polishing pad with uniform material removal function. By designing the arrangement of protrusions on the polishing pad surface and the distribution density of composite small patterns on the protrusion surface, it combines macroscopic effects with microscopic effects, improving the uniformity of material removal from the workpiece. Chinese patent CN114193319B discloses a polishing pad with a buffer layer. By establishing the relationship between the ratio of the restoring force to the applied pressure during the stress relaxation stage and time, and selecting a suitable buffer layer formula, it has stable compression recovery characteristics, which can reduce the impact applied to the polishing pad during polishing and improve the overall uniformity of the workpiece. The above polishing pad designs are based on a single factor such as surface pattern or structure, which limits the ability to control the uniformity of material removal. It is difficult to simultaneously achieve a uniform distribution of abrasive particle movement trajectory and contact pressure on the workpiece surface, resulting in limited material removal uniformity and failing to meet the requirements of efficient and high-quality polishing of workpieces. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention aims to provide a functionally optimized polishing pad that can uniformly remove materials. By comprehensively optimizing the surface pattern and structure of the polishing pad, a uniform distribution of abrasive particle movement trajectory and contact pressure on the workpiece surface is achieved. This ensures that the pad meets the functional requirements for uniform material removal while also taking into account structural conditions such as support and yielding, thus realizing the integrated optimization of the functional structure of the polishing pad.

[0005] The technical solution of this invention is:

[0006] An integrated optimized polishing pad with a functional structure capable of uniform material removal is provided. The polishing pad includes, from top to bottom, a polishing layer 1 and an elastic layer 2. The polishing layer 1 is composed of multiple protrusions arranged in a honeycomb pattern. The elastic layer 2 has a concentric partitioned structure, including soft regions 21 and 23 and a hard region 22.

[0007] Furthermore, the shape of the protrusion is one or more combinations of triangle, square, pentagon, hexagon, and circle, the diameter of the outer circle of the protrusion is 5-15 mm, and the gap between adjacent protrusions is 1-2 mm.

[0008] Furthermore, the center of the protrusion satisfies the following relationship:

[0009]

[0010] In the formula, i and j are both integers, (x ij , y ij ) represents the center coordinates of the protrusion in the i-th row and j-th column; d represents the diameter of the circumscribed circle of the protrusion; w represents the gap between adjacent protrusions; and R represents the radius of the polishing pad.

[0011] Furthermore, the thickness of the polishing layer is 0.5-3 mm, and the thickness of the elastic layer is the same as the thickness of the polishing layer.

[0012] Furthermore, the elastic modulus of the soft regions 21 and 23 is 0.3-0.5 times that of the polished layer, and the elastic modulus of the hard region 22 is the same as that of the polished layer.

[0013] Furthermore, the width of the hard region 22 is 0.8-0.9 times the diameter of the workpiece's circumscribed circle, and the radius of the soft region 21 and the width of region 23 are both half the difference between the radius of the polishing pad and the width of the annular region 22.

[0014] The beneficial effects of this invention are:

[0015] The surface pattern of the polishing layer of this invention is arranged in a honeycomb pattern, which has a high space utilization rate. During the polishing process, this arrangement helps to reduce the periodic distribution of the abrasive movement trajectory on the workpiece surface, making the abrasive trajectory more dispersed and random, thereby improving the coverage of abrasive trajectory and the uniformity of the engraving on the workpiece surface.

[0016] The elastic layer of the present invention has a concentric partition structure, with soft and hard regions having different elastic moduli and widths. During the polishing process, it can achieve partitioned control of the contact pressure on the workpiece surface, making the contact pressure distribution more uniform, or compensating for uneven material removal caused by differences in speed distribution, thereby improving the uniformity of material removal.

[0017] This invention achieves a uniform distribution of abrasive particle movement trajectory and contact pressure on the workpiece surface by comprehensively optimizing the surface pattern and structure of the polishing pad, thereby greatly improving the uniformity of material removal from the workpiece. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional schematic diagram of the polishing pad of the present invention.

[0019] Figure 2 This is one of the schematic diagrams of the surface pattern of the polishing layer of the present invention.

[0020] Figure 3 This is a schematic diagram of the concentric partitioned structure of the elastic layer of the present invention.

[0021] Figure 4 This is a comparison diagram of the surface contours of workpieces processed by the polishing pad (b) of the present invention and the unoptimized polishing pad (a). Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] A functionally optimized polishing pad capable of uniform material removal, comprising a polishing layer 1 and an elastic layer 2, such as... Figure 1 As shown; the polishing layer 1 is composed of multiple protrusions, such as Figure 2 As shown, the protrusions are arranged in a honeycomb pattern; the elastic layer 2 has a concentric partitioned structure, as... Figure 3 As shown, the system includes soft regions 21 and 23 and a hard region 22. The thickness of the polishing layer is 0.5-3 mm, and the thickness of the elastic layer is the same as that of the polishing layer. The elastic modulus of the soft regions 21 and 23 is 0.3-0.5 times that of the polishing layer, and the elastic modulus of the hard region 22 is the same as that of the polishing layer. The width of the hard region 22 is 0.8-0.9 times the diameter of the workpiece's circumscribed circle. The radius of the soft region 21 and the width of region 23 are both half the difference between the radius of the polishing pad and the width of the annular region 22.

[0024] In specific implementation, the shape of the protrusion can be one or more of the following: triangle, square, pentagon, hexagon, and circle. The diameter of the outer circle of the protrusion is 5-15 mm, and the gap between adjacent protrusions is 1-2 mm.

[0025] The center of the protrusion satisfies the following relationship:

[0026]

[0027] In the formula, i and j are both integers, (x ij , y ij) represents the center coordinates of the protrusion in the i-th row and j-th column; d represents the diameter of the circumscribed circle of the protrusion, which is 5-15 mm; w represents the gap between adjacent protrusions, which is 1-2 mm; and R represents the radius of the polishing pad.

[0028] like Figure 2 As shown, the surface pattern of the polishing layer is honeycomb-like, which improves space utilization and makes the abrasive grain movement trajectory more dispersed and random during processing, thereby improving the coverage of abrasive grain trajectory and the uniformity of the engraving on the workpiece surface. The raised shape is circular, ensuring uniform force distribution in each area during rotary machining and continuous chip removal path. The polishing layer is a homogeneous mixture of hydrophilic resin and abrasive, possessing excellent self-cleaning properties, which suppresses subsurface damage and improves machining quality while ensuring machining accuracy.

[0029] like Figure 3 As shown, the elastic layer has a concentric partitioned structure, which allows for partitioned control of the contact pressure on the workpiece surface, resulting in a more uniform contact pressure distribution and effectively reducing edge effects. Through comprehensive optimization of the surface pattern and structure of the polishing pad, the uniform distribution of abrasive particle movement trajectory and contact pressure on the workpiece surface is achieved, thereby significantly improving material removal uniformity. Based on the actual processing requirements of the workpiece, the appropriate polishing layer formulation is selected, and the material of the elastic layer is also determined accordingly, saving preparation time for the polishing pad.

[0030] A comparison of the workpiece surface contours obtained during processing using the polishing pad of the present invention and the unoptimized polishing pad is shown below. Figure 4 As shown, in the unoptimized polishing pad processing, the material removal from the workpiece surface is uneven, and due to the concentration of edge stress, there is an obvious edge collapse phenomenon, and the PV value of the workpiece surface profile is 14.02 µm; in the polishing pad processing of the present invention, the uniformity of workpiece material removal is significantly improved, the edge effect is weakened, and the PV value of the workpiece surface profile is reduced to 6.91 µm.

[0031] The above description is merely a preferred embodiment of the present invention. For those skilled in the art, any changes, modifications, and substitutions made to these embodiments without departing from the principles and spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A functionally optimized polishing pad with integrated structure capable of uniform material removal, characterized in that, The polishing pad includes a polishing layer (1) and an elastic layer (2) from top to bottom. The polishing layer (1) is composed of multiple protrusions arranged in a honeycomb pattern. The elastic layer (2) has a concentric partition structure, including a central soft area (21), an outer soft area (23), and a hard area (22) located between the central soft area (21) and the outer soft area (23).

2. The polishing pad according to claim 1, characterized in that, The shape of the protrusion is one or more of the following: triangle, square, pentagon, hexagon, and circle. The diameter of the circumscribed circle of the protrusion is 5-15 mm, and the gap between adjacent protrusions is 1-2 mm.

3. The polishing pad according to claim 1 or 2, characterized in that, The center of the protrusion satisfies the following relationship: In the formula, i and j are both integers, (x ij , y ij ) represents the center coordinates of the protrusion in the i-th row and j-th column; d represents the diameter of the circumscribed circle of the protrusion; and w represents the gap between adjacent protrusions. R is the radius of the polishing pad.

4. The polishing pad according to claim 1, characterized in that, The thickness of the polishing layer is 0.5-3 mm, and the thickness of the elastic layer is the same as that of the polishing layer.

5. The polishing pad according to claim 1, characterized in that, The elastic modulus of the central soft region (21) and the outer soft region (23) is 0.3-0.5 times that of the polished layer, and the elastic modulus of the hard region (22) is the same as that of the polished layer.

6. The polishing pad according to claim 1, characterized in that, The width of the hard region (22) is 0.8-0.9 times the diameter of the workpiece's outer circle, and the radius of the soft region (21) and the width of the region (23) are both half the difference between the radius of the polishing pad and the width of the annular region (22).

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