Wafer splitting manufacturing method

Abstract

This provides an innovative wafer splitting method. [Solution] Multiple dies with non-perpendicular interior angles are distributed on a wafer. The manufacturing method includes the following steps. First, the dies on the wafer are arranged, and the edges of each die are aligned in a straight line to form a separation region between adjacent dies. Next, multiple markers are set in the separation region. Then, the position of each marker is confirmed by initial image position confirmation, and the wafer is divided along the straight line of the aligned edges of the dies. The wafer is rotated by a specific angle, the position of each marker is confirmed again by image position confirmation, and the wafer is divided along the straight line of the edges of the aligned dies that have not yet been divided. The previous step is repeated until the straight line division of all edges of each die is completed.

Description

Technical Field

[0001] The present invention relates to a manufacturing method for wafer dicing, and particularly to a manufacturing method for dicing a wafer into non-rectangular dies.

Background Art

[0002] A photosensitive chip is a photoelectric conversion element that generates a corresponding current or voltage when irradiated with light. The application scope of photosensitive chips includes various optical devices such as optical communication, photoelectric detection, automatic brightness adjustment, spectrum analysis, optical sensing circuits, photodetectors, and cameras. Such chips are mainly used for light intensity detection, spectrum measurement, or optical signal detection. FIG. 1 is a schematic diagram showing how a wafer is linearly diced by a dicing saw. After dicing, standard rectangular chips are generated. When applying rectangular chips to the photosensitive module of a popular wearable device in recent years, the requirement for the maximum distribution area cannot be satisfied. In order to meet the requirement for the maximum distribution area of photosensitive chips, the development of chips with various shapes has begun, and the most common among them is the hexagonal die shown in FIG. 2.

[0003] FIG. 2 shows a hexagonal die layout on a wafer 1 in the prior art. The layout of die 本発明は、ウェハの分割に関する製造方法であり、特に非矩形ダイへのウェハの分割に関する製造方法である。10 in the figure is the densest arrangement, which can maximize the usage area of the wafer. However, since the contours of the hexagonal dies cannot form continuous straight lines with each other, after the growth process of die 10 is completed, the wafer cannot be diced with the conventional low-cost dicing saw shown in FIG. 1, and the wafer cannot be diced with the conventional cleavage process even after a line is drawn with a laser saw. It is necessary to adopt a plasma etching process to dice the wafer. However, when plasma etching a wafer with a thickness of 100 to 300 micrometers (μm), the plasma process has the disadvantages of high cost and time-consuming. There is also a problem of low yield of finished products. These drawbacks need to be improved urgently.

Summary of the Invention

[0004] The main objective of the present invention is to provide an innovative wafer splitting method, which is particularly applicable to the splitting of non-rectangular shaped dies on a wafer. This manufacturing method introduces a conventional linear splitting process to wafer splitting, sets markers in the separation regions between each die on the wafer, ensures the matching of recognition images acquired by the splitting device at different angles, improves the recognition accuracy of image position confirmation by the wafer splitting device, ensures the accuracy of the splitting device at different angles, and improves the precision of wafer splitting.

[0005] To achieve the above objective, the present invention provides a manufacturing method for dividing a wafer. Multiple dies with non-perpendicular interior angles are distributed on the wafer. The manufacturing method includes the following steps: First, the dies on the wafer are arranged, and the edges of each die are aligned in a straight line with each other to form separation regions between adjacent dies. Next, multiple markers are set in the separation regions. Next, the initial image positioning of the markers is performed, and the wafer is divided along the straight line of the aligned edges of the dies. The wafer is rotated by a specific angle, the image positioning of the markers is performed, and the wafer is divided along the straight line of the edges of the dies that are aligned but not yet divided. The previous step is repeated until the straight line division of all edges of each die is completed.

[0006] In the wafer division manufacturing method according to an embodiment of the present invention, if each die has an internal angle of 120°, each edge of the die on the wafer is aligned with a plurality of first diagonal lines, a plurality of second diagonal lines, and a plurality of third diagonal lines.

[0007] In the manufacturing method for dividing a wafer according to an embodiment of the present invention, each of the first diagonal lines is made horizontal, the position of each marker is confirmed by initial image position confirmation, and the wafer is divided in a straight line along each of the first diagonal lines.

[0008] In the wafer division manufacturing method of an embodiment of the present invention, the steps of rotating the wafer by a specific angle, confirming the position of each marker by image position confirmation, and dividing the wafer include the steps of rotating the wafer by 60° to make each second diagonal line horizontal, and then dividing the wafer in a straight line along each second diagonal line on the wafer, and rotating the wafer by 60° again to make each third diagonal line horizontal, and then dividing the wafer in a straight line along each third diagonal line on the wafer.

[0009] In the wafer splitting manufacturing method of the embodiment of the present invention, the step of linearly splitting the wafer is performed using a splitting saw.

[0010] In the wafer division manufacturing method of the embodiment of the present invention, the step of setting multiple markers in separation regions involves forming markers in each separation region using an exposure and development process.

[0011] In the manufacturing method for dividing a wafer according to an embodiment of the present invention, the step of arranging the dies on the wafer to form a separation region between adjacent dies is to arrange adjacent dies on the wafer to form a triangular region.

[0012] To achieve the above objective, the present invention provides a manufacturing method for dividing a wafer. The wafer has a plurality of hexagonal dies. The manufacturing method includes the following steps: Arrange the hexagonal dies on the wafer and align the edges of each die to form a plurality of first diagonal lines, a plurality of second diagonal lines, and a plurality of third diagonal lines. Form separation regions between adjacent hexagonal dies. The area of ​​each separation region is smaller than the area of ​​each hexagonal die. Set a plurality of markers in the separation region. Perform initial image position confirmation of the markers so that the first diagonal lines are horizontal, and then divide the wafer linearly along the first diagonal lines. Rotate the wafer by 60°, perform image position confirmation of the markers so that the second diagonal lines are horizontal, and then divide the wafer linearly along the second diagonal lines. Rotate the wafer by another 60°, perform image position confirmation of the markers so that the third diagonal lines are horizontal, and then divide the wafer linearly along the third diagonal lines.

[0013] In the wafer splitting manufacturing method of the embodiment of the present invention, the step of linearly splitting the wafer is performed using a splitting saw.

[0014] In the wafer division manufacturing method of the embodiment of the present invention, the step of setting multiple markers in separation regions involves forming markers in each separation region using an exposure and development process.

[0015] In the wafer division manufacturing method of an embodiment of the present invention, the step of arranging the hexagonal dies on the wafer to form a separation region between adjacent hexagonal dies is performed by arranging adjacent hexagonal dies on the wafer to form a triangular region.

[0016] Those skilled in the art will be able to understand other objects of the present invention, as well as the technical means and embodiments of the present invention, by referring to the drawings and the embodiments described later. [Brief explanation of the drawing]

[0017] [Figure 1] Top view of a wafer layout with a conventional rectangular die [Figure 2] Top view of a conventional wafer layout with a hexagonal die. [Figure 3] Top view of the wafer layout of a hexagonal die in an embodiment of the present invention. [Figure 4] Partial enlarged view of Figure 3 [Figure 5A] A magnified view of the figure showing the result when rotated at a different angle. [Figure 5B] A magnified view of the figure showing the result when rotated at a different angle. [Figure 5C] A magnified view of the figure showing the result when rotated at a different angle. [Figure 6] Top view of the wafer layout of a hexagonal die in another embodiment of the present invention [Figure 7A] A magnified view of the figure showing the result when rotated at a different angle. [Figure 7B] A magnified view of the figure showing the result when rotated at a different angle. [Figure 7C]Partial enlarged view showing the state of rotation at different angles from FIG. 6 [Figure 8] Flowchart of wafer dicing in the present invention

Mode for Carrying Out the Invention

[0018] Hereinafter, the content of the present invention will be described through examples. Note that the examples of the present invention show examples of embodiments and are not intended to be limited to the environments, applications, or specific aspects as described in the examples. Therefore, the description of the examples is for explaining the present invention but does not limit the present invention. In the embodiments and the drawings, components not directly related to the present invention are omitted and not shown. The dimensional relationships of the components in the drawings are for facilitating understanding and do not limit the actual dimensions.

[0019] FIG. 3 is a top view of a wafer 50. There are a large number of photosensitive dies before dicing on the wafer 50, and a separation region 30 is formed between adjacent dies 20. The area of the separation region 30 is smaller than the area of each die 20. The shape of the die 20 is a hexagon with non-vertical interior angles. Specifically, the die 20 has an interior angle of 120°. The separation region 30 formed by the hexagonal dies is a triangular region. As shown in the partial enlarged view of FIG. 4, there are two electrodes 22 used as contacts for positive and negative electrodes on the upper edge of each die 20. The arrangement of the dies 20 on the wafer 50 shown in FIG. 3 is not the densest arrangement, but its feature is that the six sides of each hexagonal die are aligned to form a large number of straight lines, facilitating the straight-line dicing of the wafer by subsequent dicing saws. Based on the gradient, these straight lines are classified into three types: the first slant line L1, the second slant line L2, and the third slant line L3. Specifically, as shown in FIG. 3, the gradient of the first slant line L1 is 0, the gradient of the second slant line L2 is JPEG2026085237000002.jpg10163, and the gradient of the third slant line L3 is JPEG2026085237000003.jpg10160.

[0020] The die arrangement method shown in FIG. 3 is such that the edges of the dies form continuous straight lines, which is advantageous for the linear division of the wafer by a dicing saw, and since there is no need for laser division or plasma division, the cost is reduced. Also, before dividing the wafer with a dicing saw, the dividing device uses image position confirmation to identify the direction of the die edges, and division is only carried out after confirming that the direction of the die edges is accurate, and it is necessary to avoid damage to the dies due to incorrect division. As shown in FIGS. 4, 5A to 5C, when performing image position confirmation of the die edges, as shown in the frame of FIG. 4, one of the two electrodes 22 of the die 20 can be used as a reference position confirmation point.

[0021] Specifically, at the initial image position confirmation, the position of one electrode 22 of the die 20 is selected as the position confirmation reference point. After confirming that there is no error in the direction of the die edges, a horizontal linear division is performed. If there is no error in the image position confirmation, the first diagonal line L1 is in a horizontal state with a gradient of 0, and the dividing device performs a linear division. As shown in FIG. 5A, on the wafer 50, each die 20 is aligned and divided along each edge forming the first diagonal line L1. Next, as shown in FIG. 5B, the wafer 50 is rotated at a specific angle, for example, 60°, to make the gradient of the second diagonal line L2 from the original JPEG2026085237000004.jpg10163 to a horizontal state. After confirming that there is no error in the image position confirmation, the wafer is linearly divided again using the dividing device, and each die 20 on the wafer 50 is aligned and divided along each edge forming the second diagonal line L2. Finally, the wafer is rotated 60° again so that, as shown in FIG. 5C, the third diagonal line L3 is in a horizontal state after two rotations. After confirming that there is no error in the image position confirmation, the wafer is linearly divided again using the dividing device, and each die 20 on the wafer 50 is aligned and divided along each edge forming the third diagonal line L3.

[0022] While the wafer splitting method described above solves the problem of needing to employ laser or plasma methods for splitting conventional non-rectangular dies, the method of using die electrodes as image recognition reference points can still lead to recognition failures. Specifically, as shown in Figures 5A to 5C, after using the position of one electrode 22 as a confirmation reference point, when the wafer is rotated at angles of 0°, 60°, and 120°, the orientation of each die 20 on the wafer 50 changes accordingly. This difference in orientation makes image recognition difficult. Three different images are generated by dies in three different orientations. This causes confusion in the grayscale values ​​of image recognition, leading to misrecognition and negatively impacting the accuracy of wafer splitting.

[0023] Based on this, Figure 6 shows a wafer splitting method in a preferred embodiment of the present invention. In this preferred embodiment, markers 40 are set in the separation region 30 between each adjacent die 20 on the wafer 50 to support image position confirmation during wafer splitting. The markers 40 are formed in each separation region 30 using an exposure and development process during the wafer processing stage. Specifically, as shown in Figure 6, since the markers 40 are set in the center of the separation region 30 between each adjacent die 20 as a position confirmation reference point for image recognition, when performing the wafer splitting process described above, the images at each angle substantially coincide, avoiding the problem of confusion in grayscale values ​​for image recognition and improving the recognition accuracy of image position confirmation. This design can improve the accuracy of recognition of a rotated wafer and, as a result, improve the accuracy of wafer splitting.

[0024] Specifically, during the initial image position verification, the positions of the markers 40 between the dies 20 are selected as reference points, and after confirming that there are no errors in the direction of the die edges, a horizontal linear division is performed. At this time, as shown in Figure 7A, the first diagonal line L1 is horizontal with a slope of 0. The wafer 50 is divided along each edge where each die 20 aligns to form the first diagonal line L1. Next, the wafer is rotated 60° so that the second diagonal line L2 is horizontal. After confirming that there are no errors in the image position verification, the wafer is again linearly divided using the dividing device as shown in Figure 7B, dividing along each edge where each die 20 on the wafer 50 aligns to form the second diagonal line L2. Finally, the wafer is rotated 60° again so that the third diagonal line L3 is horizontal. After confirming that there are no errors in the image position verification, the wafer is again divided using the dividing device as shown in Figure 7C, dividing along each edge where each die 20 on the wafer 50 aligns to form the third diagonal line L3. After three divisions, the edges of each die 20 on the wafer 50 are successfully divided linearly by the dividing saw. Subsequently, the wafer can be divided into non-rectangular dies using a conventional wafer cleavage method. Although this invention describes a wafer division method using a hexagonal die as an example, it is not limited to this shape. In fact, this invention can be applied to the division of dies of other shapes, such as parallelograms and octagons.

[0025] Figure 8 is a flowchart of the wafer splitting method of the present invention. First, in step S01, multiple dies are arranged on the wafer, the edges of each die are aligned to form a straight line, and a separation region is formed between adjacent dies. The area of ​​each separation region is smaller than the area of ​​each die. In step S02, multiple markers are set in the separation region. Next, in step S03, after initial image position confirmation of the markers is performed, the wafer is linearly split along the edges where the dies are arranged in a straight line. In step S04, the wafer is rotated by a specific angle, the image position confirmation of the markers is performed, and the wafer is linearly split along the edges where the dies are arranged in a straight line but have not yet been split. Finally, in step S05, the previous step is repeated until the linear splitting of all edges of each die is completed. The explanation of the related elements in the process described above can be found in the above content and will not be repeated here.

[0026] The above-described embodiments illustrate embodiments of the present invention and describe the characteristic configuration of the present invention. The present invention is not limited to the above embodiments. Modifications or equivalent arrangements that can be easily made by those skilled in the art are also within the scope of the present invention. The scope of protection of the rights of the present invention shall be based on the claims. [Explanation of Symbols]

[0027] 1 wafer 10 Dies 20 Dies 22 electrodes 30 separation area 40 markers 50 wafers L1 1st diagonal line L2 second diagonal line L3 Third Slope

Claims

1. A manufacturing method for dividing wafers, Multiple dies with non-vertical interior angles are distributed on the wafer. The aforementioned manufacturing method is The steps include arranging the dies on the wafer, aligning the edges of each die in a straight line, and forming a separation region between adjacent dies with an area smaller than the area of ​​the die, The steps include setting multiple markers in the aforementioned separation region, The process involves performing an initial image position check of the marker and dividing the wafer along the straight line of the edge where the die is aligned, The process involves rotating the wafer by a specific angle, confirming the image position of the marker, and dividing the wafer along a straight line of the edge where the die is aligned and has not yet been divided. A manufacturing method for dividing a wafer, comprising the step of repeating the preceding process until the linear division of all the edges of each die is completed.

2. A wafer splitting manufacturing method according to claim 1, characterized in that, when each die has an internal angle of 120°, each edge of the die on the wafer is aligned with a plurality of first diagonal lines, a plurality of second diagonal lines, and a plurality of third diagonal lines.

3. A manufacturing method for dividing a wafer according to claim 2, characterized in that each of the first diagonal lines is made horizontal, the position of each of the markers is confirmed by initial image position confirmation, and the wafer is divided in a straight line along each of the first diagonal lines.

4. The steps of rotating the wafer by a specific angle, confirming the position of each marker by image position confirmation, and dividing the wafer are as follows: The process involves rotating the wafer by 60° to make each of the second diagonal lines horizontal, and then linearly dividing the wafer along each of the second diagonal lines. A wafer division manufacturing method according to claim 3, characterized by comprising the steps of: rotating the wafer again by 60° to make each of the third diagonal lines horizontal, and then linearly dividing the wafer along each of the third diagonal lines.

5. The manufacturing method for dividing a wafer according to claim 4, characterized in that the step of linearly dividing the wafer is performed by dividing it using a dividing saw.

6. The manufacturing method for dividing a wafer according to claim 1, characterized in that the step of setting a plurality of markers in the separation region is used to form the markers in each of the separation regions using an exposure and development process.

7. The manufacturing method for dividing a wafer according to claim 2, characterized in that the step of arranging the dies on the wafer to form the separation region between adjacent dies is arranging adjacent dies on the wafer to form a triangular region.

8. A manufacturing method for dividing wafers, Multiple hexagonal dies are distributed on the wafer, The aforementioned manufacturing method is The process involves arranging hexagonal dies on the wafer, aligning the edges of each hexagonal die to form a plurality of first diagonal lines, a plurality of second diagonal lines, and a plurality of third diagonal lines, and forming a separation region between adjacent hexagonal dies with an area smaller than the area of ​​the hexagonal die. The steps include setting multiple markers in the aforementioned separation region, The process involves performing an initial image position check of the marker, ensuring that the first diagonal line is horizontal, and then linearly dividing the wafer along the first diagonal line. The wafer is rotated 60°, the image position of the marker is confirmed, and after the second diagonal line is made horizontal, the wafer is linearly divided along the second diagonal line. A manufacturing method for dividing a wafer, comprising the steps of: rotating the wafer by 60°, confirming the image position of the marker, ensuring that the third diagonal line is horizontal, and then linearly dividing the wafer along the third diagonal line.

9. The manufacturing method for dividing a wafer according to claim 8, characterized in that the step of linearly dividing the wafer is performed by dividing it using a dividing saw.

10. The manufacturing method for dividing a wafer according to claim 8, characterized in that the step of setting a plurality of markers in the separation region is to form the markers in each of the separation regions using an exposure and development process.

11. The manufacturing method for dividing a wafer according to claim 8, wherein the step of arranging the hexagonal dies on the wafer to form the separation region between adjacent hexagonal dies is characterized in that the adjacent hexagonal dies on the wafer are arranged to form a triangular region.

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