JP5908315B2 - Semiconductor wafer marking device and marking method - Google Patents

Description

  The present invention relates to a method for marking a defective chip on a semiconductor wafer as a defective chip and a semiconductor wafer marking apparatus used therefor.

  When a chip that is a semiconductor device is arranged on the surface of the semiconductor wafer, the area inside several mm from the outermost periphery of the semiconductor wafer is insufficient for the area for one chip, and a complete circuit pattern cannot be imposed on the arrangement, Since the chip itself is not arranged, marking must be performed with an area of several mm from the outer periphery of the wafer as a defective chip regardless of whether the electrical characteristics inspection is good or defective. Further, even in an area where a complete chip is arranged in a surface inside a portion several mm from the outermost peripheral part, a chip determined to be defective by the electrical characteristic inspection must be marked. This is to eliminate the waste of forming defective chips into a package by selecting defective chips by image recognition using this marking and not picking them up in the die bonding process, which is a part of the package assembly process.

  The procedure for marking a defective chip in a wafer according to the prior art will be described with reference to FIG. First, the marker 9 used for marking the defective chip is fixed. Next, the wafer 2 is placed on the chuck 3, and the chuck 3 is rotated so that the chip arrangement and the X axis are parallel to each other. Thereafter, the chuck 3 moves the defective chip 4 directly below the marker 9 by operating the X-axis Y-axis moving stage 13. By protruding the needle 10 built in the marker 9 onto the upper surface of the defective chip, the ink attached to the needle is transferred onto the defective chip in a substantially circular shape, and the marking 4 is applied. This operation is repeated for each defective chip, and marking of all defective chips completes the defective chip marking for one wafer.

  In the marking of defective chips on a semiconductor wafer, especially when tens of thousands of chips are arranged in the wafer surface, if the processing as described in the background art above is performed, defective chips in the outer peripheral portion and the inner surface thereof are removed. Since one chip is processed at a time, it takes a lot of time to process one wafer. In recent years, as the wafer diameter increases, the amount of movement of the chuck also increases, and as a result, it takes a lot of time to mark defective chips on the outer peripheral portion, reducing productivity.

  As a method for shortening the processing time of defective chip marking, for example, as shown in FIG. 5, Patent Document 1 performs marking for each group of defective chips, moves between defective chips at the shortest distance, and successively chips. An algorithm for marking is proposed.

JP-A-2005-244142

  However, in the method disclosed in Patent Document 1, since there is no defective chip group in the wafer surface for a wafer with good yield and almost all good chips, the defective chip marking is only for defective defective chips on the outer periphery of the wafer. Only marking is performed, and the effect of shortening the processing time is small. That is, defective chip marking by this method is effective in the case of a wafer with a low yield.

  Accordingly, it is an object of the present invention to provide a defective chip marking method that exhibits an effect even when the yield is good, and a semiconductor wafer marking device used therefor.

In order to solve the above problems, the following means were used.
First, an ink roller having a driving unit composed of a uniaxial moving stage and a rotating shaft, a chuck unit placed on the driving unit, a marking unit for marking an outer peripheral part of a semiconductor wafer placed on the chuck unit, and a needle A semiconductor wafer marking device characterized by comprising an attached marker.

The marking unit has a rotation mechanism and an ink replenishment mechanism, and is made of a material having a step coverage.
In addition, the marking portion is made of a sponge and a grooved resin.
The width of the marking portion of the ink roller is in the range of 0.5 to 5 mm.

  In addition, an ink roller having a driving unit including a uniaxial moving stage and a rotating shaft, a chuck unit placed on the driving unit, a marking unit marking the outer peripheral portion of the semiconductor wafer placed on the chuck unit, and a needle A marking method by a semiconductor wafer marking device, wherein a defective chip on a non-peripheral portion of the semiconductor wafer is marked with a marker with a needle, and an outer peripheral portion of the semiconductor wafer is ink-printed The marking method by the semiconductor wafer marking device characterized by comprising the step of marking with a roller.

  The step of marking with the ink roller includes the step of contacting the ink roller at a predetermined distance from the center of the semiconductor wafer, and the outer peripheral portion of the semiconductor wafer is marked while rotating the driving unit in the direction of the rotation axis. And a marking method using a semiconductor wafer marking device.

According to the present invention, defective chip marking on the outer peripheral portion can be greatly speeded up, and the time for defective chip marking can be shortened.
Further, since the moving axes of the chuck are only the X-axis and the θ-axis, a complicated mechanism is not necessary for the marking device, and the marking device can be reduced in cost and size.

It is a schematic diagram of the marking device of the present invention. It is a figure which marks a wafer outer peripheral part with the marking apparatus of this invention. It is a figure explaining the marking of the semiconductor wafer mounted in the marking apparatus of this invention. It is a schematic diagram of the conventional marking apparatus. It is a figure which shows the marking order in the conventional marking apparatus.

Embodiments of the present invention will be described with reference to the following drawings.
FIG. 1 is a schematic view of an apparatus that can be used in the defective chip marking method of the present invention. FIG. 2 is a diagram for explaining the operation of the marker portion of the present invention, and FIG. 3 is a conceptual diagram showing the concept of the procedure for moving the chuck.
As shown in FIG. 1, a large number of non-defective chips are arranged on the semiconductor wafer 2.

The semiconductor wafer 2 is placed on the chuck 3, and the chuck 3 has a θ rotation shaft 12 that can rotate the semiconductor wafer clockwise and counterclockwise.
An X-axis moving stage 7 which is a uniaxial moving stage is provided at the lower part of the chuck 3, and the chuck 3 can be moved in a uniaxial direction.
A marker 9 with a needle for marking a defective chip 4 inside the wafer and an ink roller 1 for marking a defective area 6 on the outer periphery of the wafer are provided at a position above the semiconductor wafer 2.

  As shown in the partial enlarged view of FIG. 2, the ink roller 1 for marking while rotating the outer peripheral portion of the wafer has a structure in which the ink can be solidly applied with a width of several millimeters. It is desirable that marking can be performed with a width of 5 to 5 mm. In addition, since the outer periphery of the semiconductor wafer has a large step, it is necessary to apply a solid coating on the outer periphery of the semiconductor wafer. Therefore, the marking part of the ink roller can hold ink such as sponge and grooved resin and is made of a material with a step coverage. It is desirable that Further, although not shown, the ink roller is provided with an ink replenishing mechanism so that ink can be replenished to the marking portion so that the ink coating film thickness is constant.

In order to perform marking on the defective chip 4 using this apparatus, first, the distance from the center of the defective chip 4 to the center of the semiconductor wafer 2 is calculated. From FIG. 3, the distance r between the center of the defective chip 4 and the center of the semiconductor wafer 2 is r = √ (x ² + y ² ) (Formula 1)
Can be calculated. The chuck 3 is moved by the X-axis moving stage 7 so that the distance between the center of the marker 9 and the semiconductor wafer 2 is equal to the distance r.

Next, the chuck 3 is rotated by a predetermined angle θ on the θ rotation shaft 12 so that the center of a predetermined defective chip is adjusted to be directly below the needle 10. The rotation angle θ of the θ rotation shaft 12 is θ = tan ⁻¹ (x / y) (Formula 2)
Can be calculated.

  By these operations, the defective chip 4 comes directly under the marker 9, so that the needle 10 can be protruded and ink can be attached. Similarly, other defective chips can be marked by moving the chuck with the X-axis moving stage and the θ rotation axis.

  When marking the outer peripheral portion 6, the distance r ′ from the center of the semiconductor wafer 2 to the inner periphery of the outer peripheral marking area is calculated, and the distance between the marking portion at the tip of the ink roller 1 and the center position of the semiconductor wafer 2 is calculated. The chuck 3 is moved by the X-axis moving stage 7 so as to be equivalent. As a result, the outer peripheral portion of the wafer comes directly under the ink roller 1, so that the outer peripheral portion of the wafer can be marked by transferring the ink by rotating the roller while rotating the θ rotation shaft 12.

  The present invention can be used alone as a semiconductor wafer marking device. Further, it can be used as a probe device having a semiconductor wafer marking mechanism.

DESCRIPTION OF SYMBOLS 1 Ink roller 2 Semiconductor wafer 3 Chuck 4 Defective chip on semiconductor wafer 6 Peripheral part 7 of semiconductor wafer X-axis moving stage 8 Peripheral chip 9 of semiconductor wafer Marker 10 for marking Ink transfer needle 11 Marking 12 θ rotation axis 13 X-axis Y-axis moving stage

Claims (3)

A drive unit comprising a uniaxial moving stage and a rotating shaft;
A chuck portion mounted on the driving portion;
An ink roller having a marking portion for marking the outer peripheral portion of the semiconductor wafer placed on the chuck portion;
A marker with a needle,
Consists of
A semiconductor wafer marking device for marking a semiconductor wafer only by movement by the uniaxial moving stage and rotation around the rotation axis ,
2. The semiconductor wafer marking apparatus according to claim 1, wherein the marking unit has a rotation mechanism and an ink replenishment mechanism and is made of a material having a step coverage .   2. The semiconductor wafer marking device according to claim 1, wherein the marking portion is made of a sponge or a grooved resin. Calculating a first distance from the center of the defective chip to the center of the semiconductor wafer;
Moving the chuck with a uniaxial moving stage so that the distance between the marker with needle and the center of the semiconductor wafer is the same as the first distance;
Rotating the chuck around a rotation axis so that the center of the defective tip is directly below the needle;
Marking the defective chip with the needle;
Calculating a second distance between the inner periphery of the outer peripheral marking area and the center of the semiconductor wafer;
A step of moving the chuck by the uniaxial moving stage so that a distance from the marking portion at the tip of the ink roller to the center of the semiconductor wafer is the same as the second distance; and the marking portion by rotating the chuck Transferring the ink to the outer peripheral marking area by:
A marking method comprising:

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