A grinding device and method for reducing the impact of a pressure membrane on a wafer

Abstract

The present invention discloses a grinding device and method for reducing the impact of a pressure film on a wafer, relating to the technical field of wafer processing, including a magnetizing component, a grinding head, a pressure film, a first electromagnet and a second electromagnet. The magnetizing component and the grinding head are installed at the bottom of the machine table. The pressure film is arranged inside the grinding head. The first electromagnets are evenly installed inside the grinding head, and the second electromagnets are evenly installed inside the pressure film. The magnetizing component magnetizes the first electromagnet and the second electromagnet respectively to change the magnetic force magnitudes of the first electromagnet and the second electromagnet. The present invention can improve the grinding effect and reduce the influence of the impact force generated when the grinding head descends on the wafer.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and particularly relates to a grinding device and method for reducing the impact of a pressure film on a wafer. Background Art

[0002] In the current semiconductor chip processing field, a polishing head is required to polish a wafer. The pressure film is an important component among many components of the polishing head. The polishing head makes the pressure film contact the wafer by moving up and down, applying pressure, and rotating, removing the uneven parts on the wafer surface to achieve the grinding effect and providing a basis for subsequent processes.

[0003] With the development of modern industry, although traditional grinding tools can meet the basic grinding requirements, they have many limitations when facing high-precision requirements. In the semiconductor industry, the pressure film is one of the most widely used grinding tools. After the polishing head reaches the working position, the up and down movement of the pressure film of the polishing head is controlled by air flow. During this rapid movement, due to the structural problems of the polishing head itself and the fact that the pressure film is made of soft rubber, inertial forces will inevitably be generated when the pressure film moves up and down, which will cause certain impact damage to the wafer and the pressure film itself, and more seriously, the wafer may be broken. Secondly, during the grinding process, the bottom surface of the pressure film will also be unevenly stressed due to various reasons, resulting in uneven grinding of the wafer surface.

[0004] Therefore, those skilled in the art urgently need to provide a grinding device and method for reducing the impact of a pressure film on a wafer, which can improve the grinding effect and reduce the impact of the impact force generated when the polishing head descends on the wafer. Summary of the Invention

[0005] The object of the present invention is to provide a grinding device and method for reducing the impact of a pressure film on a wafer, which can improve the grinding effect and reduce the impact of the impact force generated when the polishing head descends on the wafer.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A grinding device for reducing the impact of a pressure film on a wafer according to the present invention includes a magnetizing component, a polishing head, a pressure film, a first electromagnet, and a second electromagnet. The magnetizing component and the polishing head are installed at the bottom of the machine table. The pressure film is arranged inside the polishing head. The first electromagnets are evenly installed inside the polishing head. The second electromagnets are evenly installed inside the pressure film. The magnetizing component magnetizes the first electromagnet and the second electromagnet respectively to change the magnetic force magnitudes of the first electromagnet and the second electromagnet.

[0008] Preferably, a wafer is adsorbed on the bottom of the pressure film, and the wafer contacts the upper surface of the grinding pad.

[0009] Preferably, the magnetizing assembly includes a first magnetizing assembly and a second magnetizing assembly, and both the first magnetizing assembly and the second magnetizing assembly are arranged on the outer wall of the electromagnetic cover; the first magnetizing assembly controls the magnetic force of the first electromagnet, and the second magnetizing assembly controls the magnetic force of the second electromagnet, so as to control the acting force between the grinding head and the pressure film.

[0010] Preferably, the first electromagnet and the second electromagnet are arranged opposite to each other vertically, and the magnetic poles of the adjacent surfaces of the first electromagnet and the second electromagnet are N pole and S pole respectively.

[0011] Preferably, the first magnetizing assembly and the second magnetizing assembly are symmetrically arranged on the outer wall of the electromagnetic cover respectively.

[0012] Preferably, the electromagnetic cover is located outside the grinding head and surrounds the grinding head.

[0013] Preferably, the first electromagnets are arranged in an annular distribution inside the grinding head, and the second electromagnets are arranged in an annular distribution inside the pressure film.

[0014] Preferably, the first electromagnet and the second electromagnet are arranged in a single-layer or multi-layer annular arrangement structure.

[0015] Preferably, the size of the first electromagnet installed inside the grinding head with a size of 200 mm is Ф4 mm to Ф6 mm, and the number of circumferentially evenly distributed is 12 or 16; the size of the first electromagnet installed inside the grinding head with a size of 300 mm is Ф6 mm to Ф8 mm, and the number of circumferentially evenly distributed is 16 or 20.

[0016] A method for using a grinding device for reducing the impact of a pressure film on a wafer includes the following steps

[0017] S1: Positioning and regulation stage, driving the grinding head to be accurately positioned at a preset grinding station through a displacement control system, and then regulating the downward movement of the pressure film by an air flow control system;

[0018] S2: Buffer control stage, only magnetizing the first electromagnets arranged inside the grinding head through the first magnetizing assembly to increase the magnetic force of the grinding head, and the grinding head will generate an attractive force on the pressure film, so as to reduce the impact force generated by the pressure film on the wafer due to inertia when the grinding head moves downward;

[0019] S3: Grinding optimization stage. At the same time, the grinding head and the pressure film are magnetized through the first magnetizing component and the second magnetizing component to change the magnetic force. The first electromagnet and the second electromagnet interact with each other. Since the second electromagnet is uniformly arranged in the pressure film, the force on the bottom surface of the pressure film during the grinding work of the grinding head can be controlled simultaneously, improving the grinding uniformity and efficiency.

[0020] S4: Quick separation control stage. Only the second magnetizing component is used to magnetize the second electromagnet inside the pressure film to increase the magnetic force of the pressure film. Thus, during the rising process of the grinding head, the grinding head has an attractive force on the pressure film, enabling the pressure film to quickly leave the wafer and reducing damage to the wafer.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0022] (1) In the present invention, only the first magnetizing component is used to magnetize the first electromagnet arranged inside the grinding head to increase the magnetic force of the grinding head. The grinding head will generate an attractive force on the pressure film, thereby reducing the impact force generated by the inertia of the pressure film on the wafer during the downward movement of the grinding head.

[0023] (2) In the present invention, only the second magnetizing component is used to magnetize the second electromagnet inside the pressure film to increase the magnetic force of the pressure film. Thus, during the rising process of the grinding head, the grinding head has an attractive force on the pressure film, enabling the pressure film to quickly leave the wafer and reducing damage to the wafer.

[0024] (3) In the present invention, the grinding head and the pressure film are magnetized simultaneously through the first magnetizing component and the second magnetizing component to change the magnetic force. The first electromagnet and the second electromagnet interact with each other. Since the second electromagnet is uniformly arranged in the pressure film, the force on the bottom surface of the pressure film during the grinding work of the grinding head can be controlled simultaneously, improving the grinding uniformity and efficiency. Description of the Drawings

[0025] The present invention will be further described below in conjunction with the drawings.

[0026] Figure 1 It is a schematic diagram of the overall structure of a grinding device for reducing the impact of the pressure film on the wafer according to the present invention;

[0027] Figure 2 It is a side view of the overall structure of a grinding device for reducing the impact of the pressure film on the wafer according to the present invention;

[0028] Figure 3 It is a schematic diagram of the structure of the present invention after removing the electromagnetic cover, the first electromagnetic generator and the second electromagnetic generator;

[0029] Figure 4 It is a perspective view of the structure of the grinding head and the pressure film according to the present invention;

[0030] Figure 5Schematic diagram of the grinding head structure of the present invention;

[0031] Figure 6 Schematic diagram of the pressure film structure of the present invention;

[0032] Figure 7 Schematic diagram of one arrangement of the first electromagnet and the second electromagnet of the present invention;

[0033] Figure 8 Schematic diagram of another arrangement of the first electromagnet and the second electromagnet of the present invention.

[0034] Explanation of reference numerals: 1, grinding head; 2, pressure film; 3, first magnetizing component; 4, second magnetizing component; 5, first electromagnet; 6, second electromagnet; 7, electromagnetic cover; 8, wafer; 9, grinding pad. Detailed implementation manners

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] As Figures 1-8 shown, a grinding device for reducing the impact of a pressure film on a wafer includes a magnetizing component, a grinding head 1, a pressure film 2, a first electromagnet 5 and a second electromagnet 6. The magnetizing component and the grinding head 1 are installed at the bottom of the machine table. The pressure film 2 is arranged inside the grinding head 1. The first electromagnet 5 is evenly installed inside the grinding head 1. The second electromagnet 6 is evenly installed inside the pressure film 2. The magnetizing component magnetizes the first electromagnet 5 and the second electromagnet 6 respectively to change the magnetic force magnitudes of the first electromagnet 5 and the second electromagnet 6.

[0037] The bottom of the pressure film 2 adsorbs a wafer 8, and the wafer 8 contacts the upper surface of the grinding pad 9.

[0038] Specifically, the first electromagnet 5 is installed inside the hard part of the grinding head 1 by bolts to form an integral body. The pressure film 2 is made of rubber. A hole is reserved in the rubber part of the pressure film, and then the second electromagnet 6 is installed. Then, it is combined into an integral body through a special transparent rubber adhesive, and the durability of the pressure film and the second electromagnet is ensured by using a one-time molding process.

[0039] The magnetizing component includes a first magnetizing component 3 and a second magnetizing component 4. The first magnetizing component 3 and the second magnetizing component 4 are both arranged on the outer wall of the electromagnetic cover 7. The first magnetizing component 3 controls the magnetic force of the first electromagnet 5. The second magnetizing component 4 controls the magnetic force of the second electromagnet 6, thereby controlling the acting force between the grinding head 1 and the pressure film 2.

[0040] The first electromagnet 5 and the second electromagnet 6 are arranged opposite to each other vertically, and the magnetic poles of the adjacent surfaces of the first electromagnet 5 and the second electromagnet 6 are N pole and S pole respectively.

[0041] Specifically, the N pole of the second electromagnet 6 inside the pressure film 2 faces upward, and the S pole of the first electromagnet 5 inside the grinding head faces downward.

[0042] The first magnetizing component 3 and the second magnetizing component 4 are symmetrically arranged on the outer wall of the electromagnetic cover 7 respectively.

[0043] Specifically, multiple groups of the first magnetizing component 3 and the second magnetizing component 4 are arranged in pairs respectively, and can be set as needed. In this embodiment, the first magnetizing component 3 and the second magnetizing component 4 are respectively arranged as a pair on the outer wall of the electromagnetic cover 7.

[0044] The electromagnetic cover 7 is located outside the grinding head 1 and surrounds the grinding head 1.

[0045] The first electromagnets 5 are arranged in a circular pattern inside the grinding head 1, and the second electromagnets 6 are arranged in a circular pattern inside the pressure film 2.

[0046] The first electromagnet 5 and the second electromagnet 6 are arranged in a single-layer or multi-layer circular arrangement structure.

[0047] The usage process of the present invention includes the following steps.

[0048] The first step is the positioning and regulation stage. The grinding head 1 is driven by the displacement control system to be accurately positioned at the preset grinding station, and then the pressure film 2 is regulated to move downward by the air flow control system.

[0049] The second step is the buffering control stage. Only the first magnetizing component 3 magnetizes the first electromagnets 5 arranged inside the grinding head 1 to increase the magnetic force of the grinding head 1. The grinding head 1 will generate an attractive force on the pressure film 2, so as to reduce the impact force generated by the inertia of the pressure film 2 on the wafer 8 when the grinding head 1 moves downward.

[0050] The third step is the grinding optimization stage. The first magnetizing component 3 and the second magnetizing component 4 magnetize the grinding head 1 and the pressure film 2 simultaneously to change the magnetic force. The first electromagnet 5 and the second electromagnet 6 interact with each other. Since the second electromagnets 6 are uniformly arranged in the pressure film 2, the force on the bottom surface of the pressure film 2 during the grinding operation of the grinding head 1 can be controlled simultaneously, improving the grinding uniformity and efficiency.

[0051] The fourth step is the rapid separation control stage. Only the second magnetizing component 4 magnetizes the second electromagnets 6 inside the pressure film 2 to increase the magnetic force of the pressure film 2. Thus, during the upward movement of the grinding head, the grinding head has an attractive force on the pressure film 2, so that the pressure film 2 quickly leaves the wafer 8, reducing the damage to the wafer.

[0052] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0053] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method of using a grinding device for reducing the impact of a pressure membrane on a wafer, characterized in that: The grinding device includes a magnetizing component, a grinding head (1), a pressure film (2), a first electromagnet (5) and a second electromagnet (6). The magnetizing component and the grinding head (1) are installed at the bottom of the machine table. The pressure film (2) is arranged inside the grinding head (1). The first electromagnets (5) are evenly installed inside the grinding head (1). The second electromagnets (6) are evenly installed inside the pressure film (2). The magnetizing component magnetizes the first electromagnet (5) and the second electromagnet (6) respectively to change the magnetic force of the first electromagnet (5) and the second electromagnet (6). A wafer (8) is adsorbed on the bottom of the pressure film (2), and the wafer (8) is in contact with the upper surface of the grinding pad (9). The magnetizing component includes a first magnetizing component (3) and a second magnetizing component (4). The first magnetizing component (3) and the second magnetizing component (4) are both arranged on the outer wall of the electromagnetic cover (7). The first magnetizing component (3) controls the magnetic force of the first electromagnet (5), and the second magnetizing component (4) controls the magnetic force of the second electromagnet (6), so as to control the acting force between the grinding head (1) and the pressure film (2). The first electromagnets (5) are arranged in a circular pattern inside the grinding head (1), and the second electromagnets (6) are arranged in a circular pattern inside the pressure film (2). A method for using a grinding device that reduces the impact of the pressure film on the wafer includes the following steps S1: Positioning and regulation stage. The grinding head (1) is driven by a displacement control system to accurately position at a preset grinding station, and then the pressure film (2) is regulated to move downward by an air flow control system. S2: Buffer control stage. Only the first magnetizing component (3) magnetizes the first electromagnets (5) arranged inside the grinding head (1) to increase the magnetic force of the grinding head (1). The grinding head (1) will generate an attractive force on the pressure film (2), so as to reduce the impact force generated by the pressure film (2) on the wafer (8) due to inertia when the grinding head (1) moves downward. S3: Grinding optimization stage. The first magnetizing component (3) and the second magnetizing component (4) magnetize the grinding head (1) and the pressure film (2) at the same time to change the magnetic force. The first electromagnet (5) and the second electromagnet (6) interact with each other. Since the second electromagnets (6) are evenly arranged inside the pressure film (2), the force on the bottom surface of the pressure film (2) during the grinding work of the grinding head (1) can be controlled at the same time, improving the grinding uniformity and efficiency. S4: Quick separation control stage. Only the second magnetizing component (4) magnetizes the second electromagnets (6) inside the pressure film (2) to increase the magnetic force of the pressure film (2). Thus, during the rising process of the grinding head, the grinding head has an attractive force on the pressure film (2), so that the pressure film (2) quickly leaves the wafer (8), reducing the damage to the wafer.

2. The usage method of a grinding device for reducing the impact of a pressure membrane on a wafer according to claim 1, characterized in that: The first electromagnet (5) and the second electromagnet (6) are arranged opposite to each other up and down, and the magnetic poles of the adjacent surfaces of the first electromagnet (5) and the second electromagnet (6) are N pole and S pole respectively.

3. The usage method of a grinding device for reducing the impact of a pressure membrane on a wafer according to claim 1, characterized in that: The first magnetizing assembly (3) and the second magnetizing assembly (4) are symmetrically arranged on the outer wall of the electromagnetic cover (7) respectively.

4. The usage method of a grinding device for mitigating the impact of a pressure membrane on a wafer according to claim 3, characterized in that: The electromagnetic cover (7) is located outside the grinding head (1) and surrounds the grinding head (1).

5. The usage method of a grinding device for reducing the impact of a pressure membrane on a wafer according to claim 4, characterized in that: The first electromagnet (5) and the second electromagnet (6) are arranged in a single-layer or multi-layer ring structure.

6. The usage method of a grinding device for reducing the impact of a pressure film on a wafer according to claim 1, characterized in that: The size of the first electromagnet (5) installed inside the grinding head (1) is Ф4mm - Ф8mm, and the number evenly distributed in the circumference is 12 - 20.

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