Thinning of semiconductor wafers
First Claim
1. A method of thinning a semiconductor wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, comprising the steps of:
- selecting a generally circular support tape for said wafer, said tape having a second diameter;
selecting said second diameter to be greater than said first diameter by an amount about equal to the length of said peripheral wafer rounding as obtained in said wafer after said thinning step is completed;
placing said first flat wafer surface on said tape; and
removing semiconductor material from said second wafer surface until the intended thickness is achieved.
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Accused Products
Abstract
A method for thinning a semiconductor wafer (201) to less than about 100 μ thickness (208). The wafer has two flat surfaces (206, 207) of a first diameter and a rounded periphery (204a) between the flat surfaces. A generally circular support tape (202) for the wafer is selected having a second diameter. The second diameter is selected to be greater than the first diameter by an amount about twice the length (204a) of the peripheral wafer rounding, as obtained after the thinning step is completed and measured along a radial line. Flat wafer surface 206 is placed on the tape and the wafer is thinned to the intended thickness less than about 100 μ. Specifically, the length (204b) along a radial line may be about 1 mm, making the second diameter about 2 mm larger than the first diameter. Furthermore, the wafer thickness (208) after thinning may specifically be between 10 and 30 μ.
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Citations
20 Claims
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1. A method of thinning a semiconductor wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, comprising the steps of:
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selecting a generally circular support tape for said wafer, said tape having a second diameter;
selecting said second diameter to be greater than said first diameter by an amount about equal to the length of said peripheral wafer rounding as obtained in said wafer after said thinning step is completed;
placing said first flat wafer surface on said tape; and
removing semiconductor material from said second wafer surface until the intended thickness is achieved. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of thinning a semiconductor wafer to a final thickness, said wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, said method comprising the steps of:
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placing said wafer on a generally circular support tape such that said first flat surface is adjacent to said tape, said tape having a second diameter wherein said second diameter is about equal to said first diameter plus a length measured along a radial line from the center of said wafer about equal to twice the length of said rounded periphery at said final thickness of said wafer; and
removing semiconductor material from said second surface of said wafer until said final thickness is achieved. - View Dependent Claims (12)
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13. A method of thinning a semiconductor wafer having first and second flat surfaces of a first diameter, comprising the steps of:
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selecting a generally circular support tape for said wafer, said tape having a second diameter;
selecting said second diameter about 2 mm greater than said first diameter;
placing said first flat wafer surface on said tape; and
removing semiconductor material from said second wafer surface until the intended thickness is achieved. - View Dependent Claims (14, 15)
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16. A method of mechanically grinding a semiconductor wafer to a final thickness, said wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, said method comprising the steps of:
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placing said wafer on a generally circular support tape such that said first flat surface is adjacent to said tape, said tape having a second diameter wherein said second diameter is about equal to said first diameter plus a length measured along a radial line from the center of said wafer about equal to twice the length of said rounded periphery at said final thickness of said wafer;
bringing a grinding tool into contact with said second surface of said wafer; and
abrading said second surface of said wafer until said final thickness is achieved. - View Dependent Claims (17, 18, 19)
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20. A method of mechanically grinding a semiconductor wafer to a final thickness of less than about 100 μ
- , said wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, said method comprising the steps of;
placing said wafer on a generally circular support tape such that said first flat surface is adjacent to said tape, said tape having a second diameter about 2 mm larger than said first diameter;
bringing a grinding tool into contact with said second surface of said wafer; and
abrading said second surface of said wafer until said final thickness is achieved.
- , said wafer having first and second flat surfaces of a first diameter and a rounded periphery between said flat surfaces, said method comprising the steps of;
Specification