Semiconductor wafer laser cutting power calibration method

Abstract

The invention discloses a semiconductor wafer laser cutting power calibration method. A shifting piece is arranged between the laser and the light outlet and is provided with a shifting piece motor output end; setting related parameters of a laser and a plectrum motor which need to be calibrated; aligning a light outlet to a laser power meter, driving a plectrum to rotate by a plectrum motor, rotating the plectrum motor to a plectrum motor calibration starting angle, starting a laser, and recording an initial laser power value measured by the laser power meter; when the plectrum motor rotates to the next angle, recording a process laser power value measured by the laser power meter until the plectrum motor rotates to the calibrated end angle of the plectrum motor, recording an end laser power value measured by the laser power meter, and then turning off the laser; the pick motor marks an angle and a laser power value corresponding to the angle to generate an angle-power curve; required laser power is input, and the required rotation angle of the plectrum motor is calculated. The laser is short in response time and long in service life.

Description

Technical field:

[0001] The invention belongs to the technical field of semiconductor wafer production, and in particular relates to a semiconductor wafer laser cutting power calibration method. Background technology:

[0002] In the semiconductor chip manufacturing process, wafer laser cutting is one of the most important processes in the packaging and testing stage. According to the manufacturing requirements of the semiconductor chip, the laser output power is set, and the laser output is used to cut the wafer along the set cutting path.

[0003] When the wafer material changes or the cutting accuracy requirements change, the output power of the laser needs to be adjusted. The existing adjustment method is to directly control the laser to adjust the power. In this adjustment method, the laser response speed is slow, and frequent adjustment of the laser output power will also affect the service life of the laser.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention:

[0005] The purpose of the present invention is to provide a method for calibrating power of semiconductor wafer laser cutting, so as to overcome the defects in the above-mentioned prior art.

[0006] To achieve the above-mentioned object, the present invention provides a semiconductor wafer laser cutting power calibration method, the steps of which are: (1) a paddle is arranged between a laser and a light outlet, the paddle is provided with an output end of a paddle motor, and the laser, the paddle, and the light outlet are located on the same optical path;

[0007] (2) Setting the laser power, laser frequency, paddle motor calibration start angle, paddle motor calibration end angle, paddle motor calibration step angle, and paddle motor calibration stabilization time parameters of the laser to be calibrated;

[0008] (3) Align the light outlet with the laser power meter, and the paddle motor drives the paddle to rotate until the paddle motor rotates to the paddle motor calibration start angle, turn on the laser, and measure the laser power with the laser power meter. Read the measured value of the laser power meter in real time, and after the paddle motor calibration stabilization time has passed, record the initial laser power value measured by the laser power meter.

[0009] (4) The paddle motor continues to rotate according to the paddle motor calibration step angle. Each time the paddle motor rotates to the next angle, after waiting for the paddle motor calibration stabilization time, the process laser power value measured by the laser power meter is recorded, until the paddle motor rotates to the paddle motor calibration end angle, after waiting for the paddle motor calibration stabilization time, the end laser power value measured by the laser power meter is recorded, and then the laser is turned off;

[0010] (5) Generate calibration data points in a coordinate graph according to the paddle motor calibration start angle, the paddle motor calibration step angle, the paddle motor calibration end angle, and the initial laser power value, process laser power value, and end laser power value corresponding to the angles. In the coordinate graph, the X-axis represents the paddle motor angle value, and the Y-axis represents the laser power value. Fit the calibration data points into a curve, and select a valid interval from the fitting curve as an angle-power curve;

[0011] (6) Input the required laser output power into the angle-power curve, and calculate the angle that the paddle motor needs to rotate according to the angle-power curve.

[0012] Preferably, in the technical solution, in step (5), the effective interval is the interval from the minimum laser power to the maximum laser power.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The paddle motor drives the paddle to rotate, changing the pass rate of the laser output laser, and then changing the laser power. The response time is greatly reduced, replacing the original direct control of the laser to change the laser output power, and extending the service life of the laser. Description of the drawings:

[0015] Figure 1 It is a schematic diagram of the process flow of the semiconductor wafer laser cutting power calibration method of the present invention;

[0016] Figure 2 An angle-power coordinate diagram of the power calibration method for laser cutting of semiconductor wafers of the present invention;

[0017] Figure 3 This is the output diagram of the semiconductor wafer laser cutting power calibration method of the present invention. Specific implementation method:

[0018] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0019] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0020] like Figure 1 As shown, a semiconductor wafer laser cutting power calibration method, the steps of which are: (1) a paddle is arranged between a laser and a light outlet, the paddle is arranged with an output end of a paddle motor, and the laser, the paddle, and the light outlet are located on the same optical path;

[0021] (2) Set the laser power (Power), laser frequency (Frequence), paddle motor calibration start angle (StartAngle), paddle motor calibration end angle (StopAngle), paddle motor calibration step angle (StepAngle), and paddle motor calibration stabilization time (StepTime) parameters of the laser to be calibrated;

[0022] (3) Align the light outlet with the laser power meter, and the paddle motor drives the paddle to rotate until the paddle motor rotates to the paddle motor calibration start angle, turn on the laser, and measure the laser power with the laser power meter. Read the measured value of the laser power meter in real time, and after the paddle motor calibration stabilization time has passed, record the initial laser power value measured by the laser power meter.

[0023] (4) The paddle motor continues to rotate according to the paddle motor calibration step angle. Every time the paddle motor rotates to the next angle, after waiting for the paddle motor calibration stabilization time, the process laser power value measured by the laser power meter is recorded, until the paddle motor rotates to the paddle motor calibration end angle, after waiting for the paddle motor calibration stabilization time, the end laser power value measured by the laser power meter is recorded, and then the laser is turned off; the laser power meter measurement results are shown in Table 1:

[0024] Table 1. Correspondence between the angle of the paddle motor and the laser power

[0025]

[0026]

[0027] (5) Generate calibration data points in a coordinate graph according to the paddle motor calibration start angle, paddle motor calibration step angle, paddle motor calibration end angle, and the initial laser power value, process laser power value, and end laser power value corresponding to the angle. In the coordinate graph, the X-axis represents the paddle motor angle value, and the Y-axis represents the laser power value. Fit the calibration data points into a curve, and select the interval from the minimum laser power to the maximum laser power from the fitting curve as the angle-power curve, such as Figure 2As shown, the paddle motor angle is selected in the range of 18°-64°;

[0028] (6) Input the required laser output power into the angle-power curve, and calculate the angle that the paddle motor needs to rotate according to the angle-power curve, such as Figure 3 shown.

[0029] The paddle motor drives the paddle to rotate, changing the pass rate of the laser output laser, and then changing the laser power. The response time is greatly reduced, replacing the original direct control of the laser to change the laser output power, and extending the service life of the laser.

[0030] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A semiconductor wafer laser cutting power calibration method, characterized in that: The steps are as follows: (1) a paddle is arranged between the laser and the light outlet, the paddle is provided with an output end of a paddle motor, and the laser, the paddle and the light outlet are located on the same optical path; (2) Setting the laser power, laser frequency, paddle motor calibration start angle, paddle motor calibration end angle, paddle motor calibration step angle, and paddle motor calibration stabilization time parameters of the laser to be calibrated; (3) Align the light outlet with the laser power meter, and the paddle motor drives the paddle to rotate until the paddle motor rotates to the paddle motor calibration start angle, turn on the laser, and measure the laser power with the laser power meter. Read the measured value of the laser power meter in real time, and after the paddle motor calibration stabilization time has passed, record the initial laser power value measured by the laser power meter. (4) The paddle motor continues to rotate according to the paddle motor calibration step angle. Each time the paddle motor rotates to the next angle, after waiting for the paddle motor calibration stabilization time, the process laser power value measured by the laser power meter is recorded, until the paddle motor rotates to the paddle motor calibration end angle, after waiting for the paddle motor calibration stabilization time, the end laser power value measured by the laser power meter is recorded, and then the laser is turned off; (5) Generate calibration data points in a coordinate graph according to the paddle motor calibration start angle, the paddle motor calibration step angle, the paddle motor calibration end angle, and the initial laser power value, process laser power value, and end laser power value corresponding to the angles. In the coordinate graph, the X-axis represents the paddle motor angle value, and the Y-axis represents the laser power value. Fit the calibration data points into a curve, and select a valid interval from the fitting curve as an angle-power curve; (6) Input the required laser output power into the angle-power curve, and calculate the angle that the paddle motor needs to rotate according to the angle-power curve.

2. The semiconductor wafer laser cutting power calibration method according to claim 1, characterized in that: In step (5), the effective interval is the interval from the minimum laser power to the maximum laser power.

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