TWI907099B - Device for laser etching thin wafers to form taiko structure and method thereof - Google Patents

Abstract

This invention relates to an apparatus and method for forming a drum-shaped wafer, wherein a wafer is placed on an operating table, and a femtosecond laser at one end of a cylindrical laser array is focused along its central axis, while a femtosecond laser extending to the other end of the cylindrical laser array is focused onto the groove radius _R1. The wafer is rotated or the elongated columnar laser array is rotated. In the rotating state, the elongated columnar laser array melts the wafer, forming a groove bottom surface in the center of the thinned wafer. The groove bottom surface forms a horizontal disk-shaped concave cross-section. The periphery around the center of the thinned wafer is not melted, forming the wafer frame. The wafer frame and the groove bottom surface together form the taiko structure of the wafer.

Description

Apparatus and method for forming drum-shaped structures from thin-film wafers by laser etching

An apparatus and method for forming a taiko-shaped wafer, particularly an apparatus and method for forming a taiko structure by laser etching a thin wafer.

As shown in Figure 1, the prior art uses a grinding machine with at least one grinding block to grind the wafer 1 to be thinned. The grinding block grinds a groove 11 at the center of the wafer, forming a groove bottom surface 13 and a ring-shaped frame 12 around its perimeter. The prior art grinding block grinds the wafer 1 into a taiko-shaped wafer with a wafer radius _R0 and a groove radius _R1 .

This invention relates to an apparatus for laser etching thin wafers to form a drum-like structure, comprising: a long cylindrical array laser with at least one femtosecond laser; an operating stage disposed below the long cylindrical array laser; and a wafer placed on the operating stage, wherein the wafer surface to be thinned has an outer perimeter of a wafer radius R_₀ and an inner perimeter of a groove radius R_₁, wherein the femtosecond laser at one end of the long cylindrical array laser is focused along the central axis, and the femtosecond laser extending to the other end of the long cylindrical array laser is focused onto the groove radius R _₁. ; and at least one control module to control the rotation of the wafer or the rotation of the elongated columnar array laser. In the rotating state, the elongated columnar array laser etches the wafer to form a thinned wafer with a groove bottom at the center. The groove bottom forms a horizontal disc-shaped concave cross-section, wherein the periphery around the thinned wafer center is not etched, forming the wafer frame. The wafer frame and the groove bottom together form the taiko structure of the wafer.

This invention is a device for laser etching thin wafers to form a drum structure, wherein the operating table is a rotary freezer.

This invention is a device for laser etching thin wafers to form a drum structure, wherein the femtosecond laser uses green light.

This invention is a device for laser etching thin wafers to form a drum structure, wherein the scanning spot of the femtosecond laser is 2μm.

This invention discloses a method for forming a drum structure from a thin wafer using laser etching. The steps include: Step 1, holding the wafer to be thinned to form a drum structure on an operating table; Step 2, using the operating table, synchronously rotating the wafer along its central axis; Step 3, using at least one femtosecond laser to form a long columnar array laser, the long columnar array laser having a linear arrangement. The wafer surface to be thinned has an outer perimeter of a wafer radius R _₀ and an inner perimeter of a groove radius R _₁ , wherein the femtosecond laser along one end of the long columnar array laser... Step 4: Focusing the central axis with at least one femtosecond laser, extending to the other end of the long columnar laser array, and focusing the femtosecond laser onto the groove radius _R1 ; Step 5: Using at least one femtosecond laser... In step 5, the long columnar laser array is used to etch a linear array of columnar laser points onto the wafer surface, which is then melted and etched. Simultaneously, a control module rotates the wafer at least once, melting and etching it to form a taiko structure. This results in a central groove bottom surface on the thinned wafer, with a horizontal, disc-shaped recessed section formed. The periphery surrounding the central portion of the thinned wafer remains un-etched, forming the wafer's frame. The wafer's frame and the groove bottom surface together form the taiko structure of the wafer.

This invention discloses a method for forming a drum structure from a thin wafer using laser etching. The steps include: Step 1, holding the wafer to be thinned to form a drum structure on an operating table; Step 2, using at least one femtosecond laser to form a long cylindrical laser array, the long cylindrical laser array having a linear arrangement. The wafer surface to be thinned has an outer perimeter of a wafer radius R _₀ and an inner perimeter of a groove radius R_₁ . A femtosecond laser at one end of the long cylindrical laser array focuses on the central axis, and a femtosecond laser extending to the other end of the long cylindrical laser array focuses on the groove radius R₁. ₁ ; Step 3, using the pulse of at least one femtosecond laser to form a linear array of columnar light spots to melt-etch the wafer surface; Step 4, using one end of the long columnar array laser positioned above the central axis of the wafer, rotating the other end of the long columnar array laser to scan; In step 5, the long columnar array laser is directed at the rotating wafer to be thinned to form a taiko structure. At the same time, a control module rotates the long columnar array laser at least once. In the rotating state, the wafer is etched to form a groove bottom surface in the center of the thinned wafer. The groove bottom surface forms a horizontal disk-shaped concave cross-section. The periphery around the center of the thinned wafer is not etched, forming the wafer frame. The wafer frame and the groove bottom surface together form the taiko structure of the wafer.

This invention relates to a method for laser etching thin wafers to form a drum-like structure, wherein the operating stage is equipped with a rotary freezer. The femtosecond laser used is green light. The scanning spot size of the femtosecond laser is 2 μm.

This invention relates to an apparatus and method for forming a taiko structure from a thin wafer using laser etching. The apparatus utilizes a femtosecond laser with a scanning spot size of 2μm, enabling rapid etching of the wafer surface and achieving the desired thinning effect to form a taiko structure. Furthermore, a rotary freezer reduces heat dissipation during the rapid etching process, thereby minimizing the risk of brittle fracture in the taiko structure wafer.

The above description and explanation are merely illustrative examples of the preferred embodiments of this invention. Those skilled in the art may make other modifications based on the scope of the patent application as defined below and the above explanation, but such modifications shall still be within the spirit of the invention and the scope of the claims of this invention.

As shown in Figures 2 and 3, an apparatus for laser etching a thin wafer 1 to form a drum structure includes: a cylindrical array laser 3 with at least one femtosecond laser 31; an operating stage 2 disposed below the cylindrical array laser 3; and a wafer 1 placed on the operating stage 2. The wafer surface 14 of the wafer 1 to be thinned has an outer perimeter of a wafer radius R _₀ and an inner perimeter of a groove radius R _₁ . The femtosecond laser 31 at one end of the cylindrical array laser 3 focuses on the central axis C, and the femtosecond laser 31 extending to the other end of the cylindrical array laser 3 focuses on the groove radius R_₁ . The system includes at least one control module 4, which controls the rotation of the wafer 1 or the rotation of the cylindrical array laser 3. During rotation, the cylindrical array laser 3 etches the wafer 1, resulting in a thinned wafer 1 with a groove bottom surface 13 at its center. This groove bottom surface 13 forms a horizontal, disc-shaped recessed section. The periphery surrounding the thinned wafer 1's center is not etched, forming the wafer 1's frame 12. The wafer 1's frame 12 and the groove bottom surface 13 of the groove 11 together form the taiko structure of the wafer 1. The frame 12 has a depth D1 and a width W1.

As shown in Figures 2 and 3, an apparatus for laser etching thin wafer 1 to form a drum structure is provided, wherein the operating table 2 is a rotary freezer.

As shown in Figures 2 and 3, an apparatus for laser etching a thin wafer 1 to form a drum structure is described, wherein the femtosecond laser 31 uses green light.

As shown in Figures 2 and 3, an apparatus for forming a drum structure by laser etching of a thin wafer 1 is provided, wherein the scanning spot 32 of the femtosecond laser 31 is 2 μm.

As shown in Figure 4, a method for forming a drum structure from a thin wafer 1 using laser etching includes the following steps: Step 1, holding the wafer 1 to be thinned to form a drum structure on an operating stage 2; Step 2, using the operating stage 2, synchronously rotating the wafer 1 to be thinned to form a drum structure along its central axis C; Step 3, using at least one femtosecond laser 31 to form a long columnar array laser 3, the long columnar array laser 3 having a linear arrangement structure, the wafer surface 14 of the wafer 1 to be thinned having an outer perimeter of a wafer radius R _₀ and an inner perimeter of a groove radius R _₁. In step 4, a femtosecond laser 31 along one end of the elongated columnar laser array 3 focuses on the central axis C, and a femtosecond laser 31 extending to the other end of the elongated columnar laser array 3 focuses on the groove radius _R1 ; step 4, using at least one femtosecond laser 31... In step 5, the long columnar array laser 3 is used to etch a linear array of columnar light spots 32 to melt and etch the wafer surface 14 of the wafer 1; and in step 6, the long columnar array laser 3 is used to etch the wafer 1, which is being thinned to form a taiko structure, while a control module 4 rotates the wafer 1 at least once. In the rotating state, the wafer 1 is etched to form a groove bottom surface 13 in the center of the thinned wafer 1. The groove bottom surface 13 forms a horizontal disk-shaped concave cross-section, in which the periphery around the center of the thinned wafer 1 is not etched to form the edge 12 of the wafer 1. The edge 12 of the wafer 1 and the groove bottom surface 13 of the groove 11 together form the taiko structure of the wafer 1.

As shown in Figure 5, a method for forming a drum structure from a thin wafer 1 by laser etching includes the following steps: Step 1, holding the wafer 1 to be thinned to form a drum structure on an operating table 2; Step 2, using at least one femtosecond laser 31 to form a long columnar array laser 3, the long columnar array laser 3 having a linear arrangement structure, the wafer surface 14 of the wafer 1 to be thinned having an outer perimeter of a wafer radius _R0 and an inner perimeter of a groove radius _R1 , wherein the femtosecond laser 31 along one end of the long columnar array laser 3... Step 3: A femtosecond laser 31, extending to the other end of the elongated columnar array laser 3, is focused onto the groove radius _R1 ; Step 4: Using the pulse of at least one femtosecond laser 31, a linear array of columnar light spots 32 is formed to melt-etch the wafer surface 14 of the wafer 1; Step 5: Using one end of the elongated columnar array laser 3 positioned above the central axis C of the wafer 1, the other end of the elongated columnar array laser 3 is rotated to scan. In step 5, the long columnar array laser 3 is directed at the rotating wafer 1 to be thinned to form a taiko structure. At the same time, a control module 4 rotates the long columnar array laser 3 at least once. In the rotating state, the wafer 1 is etched to form a groove bottom surface 13 in the center of the thinned wafer 1. The groove bottom surface 13 forms a horizontal disk-shaped concave cross-section. The periphery around the center of the thinned wafer 1 is not etched to form the edge frame 12 of the wafer 1. The edge frame 12 of the wafer 1 and the groove bottom surface 13 of the groove 11 together form the taiko structure of the wafer 1.

As shown in Figures 4 and 5, a method for forming a drum structure by laser etching a thin wafer 1 is described, wherein the operating stage 2 is equipped with a rotary freezer. The femtosecond laser 31 uses green light. The scanning spot 32 of the femtosecond laser 31 is 2 μm. However, this is not a limitation; at least one control module 4 controls the rotation of the wafer 1 or the rotation of the cylindrical array laser 3. In the rotational state, the cylindrical array laser 3 etches the wafer 1 to form a thinned wafer 1. Therefore, the control module 4 may only control the operating stage 2 to rotate the wafer 1, or the control module 4 may only control the rotation of the cylindrical array laser 3 to etch the wafer 1 fixed on the operating stage 2. Alternatively, at least one control module 4 can simultaneously control the rotation of the wafer 1 and the rotation of the long columnar array laser 3, forming a thinned tadpole structure wafer 1 in a state of mutual rotation.

The above description and explanation are merely illustrative examples of the preferred embodiments of this invention. Those skilled in the art may make other modifications based on the scope of the patent application as defined below and the above explanation, but such modifications shall still be within the spirit of the invention and the scope of the claims of this invention.

1: Wafer 2: Operating Table 3: Long Column Array Laser 31: Femtosecond Laser 32: Spot 4: Control Module 5: Grinding Machine 51: Grinding Block 11: Groove 12: Frame 13: Groove Bottom 14: Wafer Surface D1: Depth W1: Width _R0 : Wafer Radius _R1 : Groove Radius C: Central Axis

Figure 1 shows a wafer with a drum-shaped structure formed by grinding a wafer using a prior art grinder. Figure 2 is a schematic cross-sectional view of a wafer with a drum-shaped structure formed according to the present invention. Figure 3 is a schematic three-dimensional view of a wafer with a drum-shaped structure formed according to the present invention. Figure 4 is a schematic diagram of the method for forming a drum-shaped structure from a thin wafer using laser etching according to the present invention. Figure 5 is another schematic diagram of the method for forming a drum-shaped structure from a thin wafer using laser etching according to the present invention.

1: Wafer

2: Control Panel

3: Long column array laser

31: Femtosecond Laser

32: Light Spot

11: Groove

12: Border

13: Bottom surface of the groove

14: Wafer Surface

D1: Depth

W1: Width

_R0 : Wafer radius

R ₁ : Slot radius

C: Central axis

Claims (9)

An apparatus for laser etching a thin wafer to form a drum structure includes: a long cylindrical array laser with at least one femtosecond laser; an operating stage disposed below the long cylindrical array laser; and a wafer placed on the operating stage, wherein the wafer surface to be thinned has an outer perimeter that is a wafer radius ( _R0 ) and an inner perimeter that is a groove radius ( _R1 ), wherein the femtosecond laser at one end of the long cylindrical array laser is focused on a central axis, and the femtosecond laser extending to the other end of the long cylindrical array laser is focused on the groove radius ( _R1). The wafer is rotated or the elongated columnar laser array is rotated. In the rotating state, the elongated columnar laser array melts the wafer, forming a thinned wafer with a groove bottom at the center. The groove bottom forms a horizontal disk-shaped concave cross-section, wherein the periphery around the thinned wafer center is not melted, forming the wafer frame. The wafer frame and the groove bottom of the groove together form the taiko structure of the wafer. The apparatus for laser etching thin wafers to form a drum structure as described in claim 1, wherein the operating table is a rotary freezer. The apparatus for laser etching thin wafers to form a drum structure as described in claim 1, wherein the femtosecond laser uses green light. The apparatus for laser etching thin wafers to form a drum structure as described in claim 1, wherein the scanning spot of the femtosecond laser is 2 μm. A method for forming a drum structure from a thin wafer using laser etching, comprising the following steps: Step 1, holding the wafer to be thinned to form a drum structure on an operating table; Step 2, using the operating table, synchronously rotating the wafer to be thinned to form a drum structure along its central axis; Step 3, using at least one femtosecond laser to form a long columnar array laser, the long columnar array laser having a linear arrangement, the wafer surface to be thinned having an outer perimeter that is a wafer radius ( _R0 ) and an inner perimeter that is a groove radius ( _R1 ), wherein the femtosecond laser along one end of the long columnar array laser... Step 4 involves focusing at least one femtosecond laser onto the central axis of the wafer, extending to the other end of the columnar laser array, and focusing it onto the groove radius ( _R1 ); In step 5, the long columnar laser array is used to etch a linear array of columnar laser points onto the wafer surface, which is then melted and etched. Simultaneously, a control module rotates the wafer at least once, melting and etching the wafer as it rotates. This results in a central groove bottom surface on the thinned wafer, with a horizontal, disc-shaped recessed section formed. The periphery surrounding the central portion of the thinned wafer remains un-etched, forming the wafer's frame. The wafer's frame and the groove bottom surface together form the taiko structure of the wafer. A method for forming a drum structure from a thin wafer using laser etching, comprising the following steps: Step 1, holding the wafer to be thinned to form a drum structure on an operating table; Step 2, using at least one femtosecond laser to form a long columnar array laser, the long columnar array laser having a linear arrangement, the wafer surface to be thinned having an outer perimeter of the wafer as a wafer radius (R _₀ ) and an inner perimeter of the wafer as a groove radius (R _₁ ), wherein a femtosecond laser along one end of the long columnar array laser focuses on the central axis, and a femtosecond laser extending to the other end of the long columnar array laser focuses on the groove radius (R₁). ₁ ); Step 3, using the pulse of at least one femtosecond laser, a linear array of columnar light spots is formed to melt-etch the wafer surface; Step 4, one end of the elongated columnar array laser is positioned above the central axis of the wafer, and the other end of the elongated columnar array laser is rotated to scan. ; and step 5, the long columnar array laser is directed at the rotating wafer to be thinned to form a taiko structure, while a control module rotates the long columnar array laser at least once. In the rotating state, the wafer is etched to form a groove bottom surface in the center of the thinned wafer. The groove bottom surface forms a horizontal disk-shaped concave cross-section, wherein the periphery around the center of the thinned wafer is not etched to form the wafer frame. The wafer frame and the groove bottom surface together form the taiko structure of the wafer. The method for forming a drum structure by laser etching of a thin wafer as described in claim 5 or 6, wherein the operating table is equipped with a rotary freezer. The method for forming a drum structure by laser etching of a thin wafer as described in claim 5 or 6, wherein the femtosecond laser uses green light. The method for forming a drum structure by laser etching of a thin wafer as described in claim 5 or 6, wherein the scanning spot of the femtosecond laser is 2 μm.