Laser setting method

Abstract

A laser setting method, which is applied to a laser processing apparatus for processing a semiconductor material using a laser, executes the following steps: a first step of performing mechanism calibration so that a position value of a reference point corresponding to a transfer command value of a motor for transferring a chuck table is confirmed by a visual device, and a mechanism offset value is corrected; a second step of performing a viewer calibration to transfer and image the reference point within an FOV region of the viewer to correct distortion and axis of the viewer; a third step of performing laser calibration to irradiate the laser light a plurality of times within an irradiation region of the laser light to correct distortion and axis of the laser light; and a fourth step of performing integration calibration so that the laser performs machining at the commanded position of the motor, checking the machining position by the visual device to calculate an offset value, and performing remachining by correcting the calculated offset value, and repeating the remachining until the offset value falls within a preset error range.

Description

Technical Field

[0001] The present invention relates to a laser setting method, and more particularly to a laser setting method that can improve the setting precision of the entire processing area of ​​a semiconductor material, realize the integrated calibration of a mechanism, a visual device, and a laser in an automated manner to improve reliability, and shorten the calibration time. Background Art

[0002] Solder balls are very small spherical components that connect semiconductor chips and substrates to transmit electrical signals. They are protected by molding based on molding compounds during the semiconductor manufacturing process. In semiconductor packaging, in order to connect the solder balls and substrates, the molding at the solder ball locations needs to be removed by laser. This process is called laser ablation.

[0003] That is, the laser ablation device is a device that uses laser to form vias at the solder ball position to expose the solder ball hidden inside the molding to the outside. It includes a suction cup table for transferring the semiconductor material to be processed, a laser that irradiates the solder ball position in the molding of the semiconductor material to locally remove the molding, a visual device for confirming the position of the laser to be irradiated in the molding of the semiconductor material, and a mechanism (motor) that horizontally moves the suction cup table with the semiconductor material transferred to the processing area of ​​the laser and the inspection area of ​​the visual device on the xy plane.

[0004] Although the positions of the solder balls to be irradiated with the laser are pre-input into the laser ablation device based on the design drawings of the semiconductor material, due to the expansion or contraction of the semiconductor material during the manufacturing process, errors may occur such that the positions of the solder balls in the design drawings of the semiconductor material are inconsistent with the positions of the solder balls in the semiconductor material actually manufactured.

[0005] Furthermore, it is necessary to correct the image distortion caused by the lens inside the laser irradiator arranged in the laser processing section and the scanning distortion caused by the lens inside the visual device camera arranged in the visual section. When the laser and the visual device are arranged at positions separated from each other, in order for the laser to be accurately irradiated to the position inspected by the visual device, it is necessary to align the inspection position of the visual device and the laser irradiation position.

[0006] Furthermore, even if the above-mentioned operations are performed, misalignment may occur due to deformation caused by wear or friction of the mechanism parts as the processing is repeated. When the operation time is prolonged, the laser irradiation position may be misaligned due to thermal deformation caused by continuous accumulation of heat in the optical instrument constituting the laser, requiring operations and maintenance to correct the errors caused by the above-mentioned misalignment.

[0007] In addition, a problem with lasers is that since there is a certain working distance between the lens and the object to be processed, even a slight change in the laser will cause a large change in the position of the laser irradiating the object to be processed. Therefore, even a slight misalignment or deformation will result in a large difference in the processing error.

[0008] The laser setting method of the laser ablation device in the prior art is composed of the steps of vision device calibration, laser calibration and system teaching. Among them, the vision device calibration is to use the vision device camera of the vision unit to photograph the glass substrate to confirm the distortion state and degree of the lens image, thereby performing the step of coordinate transformation of the vision device camera, wherein the glass substrate is loaded on the suction cup table and marked with a plurality of alignment marks (fiducialmarks) spaced at a certain interval.

[0009] Furthermore, laser calibration is a step of irradiating a jig loaded on a suction cup stage with laser light, thereby performing coordinate transformation of the laser scanner using information on the direction and distance between the position to be irradiated with the laser light and the position actually irradiated with the laser light.

[0010] In addition, the system teaching is a step of irradiating a total of three points with laser light in a certain area in a fixture loaded on a suction cup table, wherein the three points include the center point of the coordinate axis of the laser processing part and two points separated from the center point at a certain interval to the left and right, and aligning the coordinate axes of the laser and the visual device based on information related to the degree of separation and misalignment between the three points irradiated by the laser and the center of the coordinate axis of the visual device.

[0011] However, the laser setting method of the above-mentioned existing laser ablation device, since only the distortion of the visual device lens and the laser lens are considered in the visual device calibration step and the laser calibration step respectively to perform coordinate transformation, it is unable to correct the misalignment and position error between the coordinate axis of the semiconductor material and the coordinate axes of the laser scanner and the visual device camera caused by the misalignment of the suction cup table loaded with the semiconductor material, and is unable to consider the inconsistency between the coordinate axis of the semiconductor material in the inspection area and the coordinate axis of the semiconductor material in the processing area caused by the misalignment of the mechanism for moving the suction cup table. In addition, since the system teaching step is only performed in a part of the area of ​​the semiconductor material, there is a problem that the processing precision in the entire area cannot be guaranteed.

[0012] Furthermore, in the laser setting method of the laser ablation device of the prior art, since each step is performed manually by the operator, the setting accuracy becomes different depending on the operator's proficiency, thereby causing problems such as reduced setting reliability and delayed setting time.

[0013] Therefore, there is an urgent need to provide a laser setting method that can improve the reliability of setting and shorten the calibration time by automating the calibration method for laser processing while improving the machining accuracy of the entire machining area of ​​the semiconductor material. Summary of the invention

[0014] Technical issues

[0015] The object of the present invention is to provide a laser setting method which can improve the processing precision of the entire processing area of ​​a semiconductor material while improving the precision and shortening the calibration time by automating the calibration.

[0016] Furthermore, the present invention aims to use a fixture having specifications larger than the semiconductor material to be processed to perform correction and axis alignment operations for the entire area, thereby providing a basis for correction data preparation even for the outer contour area of ​​the semiconductor material transferred in a misaligned state.

[0017] Furthermore, the purpose of the present invention is to not only correct the lens distortion of the visual instrument and the lens distortion of the laser within the FOV area, but also to calibrate the mechanism part by calculating the structural offset value and misalignment value information for each area unit on the xy plane for the inspection area of ​​the visual instrument and the processing area of ​​the laser as a whole, and then align the coordinates of the visual instrument and the laser with respect to the mechanism part, thereby improving the precision.

[0018] Technical Solution

[0019] In order to solve the technical problem, the present invention provides a laser setting method, which is suitable for a laser processing device that uses laser to process semiconductor materials, and is characterized in that the laser setting method performs the following steps: a first step, performing a mechanical part calibration to use a visual device to confirm the position value of a reference point corresponding to the transfer instruction value of a motor for transferring a suction cup table to correct the mechanical offset value; a second step, performing a visual device calibration to transfer and image the reference point within the FOV area of ​​the visual device to correct the distortion and axis of the visual device; a third step, performing a laser calibration to irradiate the laser multiple times within the irradiation area of ​​the laser to correct the distortion and axis of the laser; and a fourth step, performing an integrated calibration to allow the laser to perform processing at the command position of the motor, use the visual device to confirm the processing position to calculate the offset value, and correct the calculated offset value to perform reprocessing, and repeat the reprocessing until the offset value reaches a preset error range.

[0020] Among them, the present invention provides a laser setting method, characterized in that, in the first step, the suction cup table is transferred so that any reference point among a plurality of reference points formed at equal intervals on a reference fixture is located in the inspection area of ​​the visual device, the suction cup table is transferred according to a preset transfer instruction value, and the visual device is used to check the position value of any reference point separated from any reference point located in the inspection area of ​​the visual device by a distance of the transfer instruction value to obtain a structural offset value related to the inspection area of ​​the visual device; when any reference point among a plurality of reference points formed at equal intervals on the reference fixture is located in the processing area of ​​the laser, and another arbitrary reference point is located in the inspection area of ​​the visual device, the suction cup table is transferred according to the preset transfer instruction value, and the visual device is used to check the position of any reference point separated from any reference point located in the inspection area of ​​the visual device by the transfer instruction value to obtain a structural offset value related to the processing area of ​​the laser.

[0021] Furthermore, the present invention provides a laser setting method, characterized in that the suction cup table is moved using n pitches (n is an integer) of reference points formed at equal intervals as the transfer command value of the motor, and the transfer is performed in an interval from the inspection area of ​​the visual device to the interval before the processing area corresponding to the laser and a structural offset value is obtained.

[0022] In addition, the present invention provides a laser setting method, characterized in that the second step includes: step a), moving the reference fixture within the FOV of the visual device according to the transfer instruction value of the motor, and using the visual device to shoot the same reference point and obtain an image at each position; step b), integrating the various images obtained by the visual device; and step c), correcting the lens distortion of the visual device based on the integrated image, and correcting the visual device coordinates based on the mechanism part so that the mechanism part coordinates obtained by the integrated image are consistent with the visual device coordinates.

[0023] Furthermore, the present invention provides a laser setting method, characterized in that, in the step a), the reference fixture is moved on the FOV of the visual device according to the transfer instruction value of the motor reflecting the structural offset value obtained by the calibration of the mechanism part, and the reference point is photographed by the visual device and the image of the reference point is obtained at each position.

[0024] In addition, the present invention provides a laser setting method, characterized in that the third step includes: the step of irradiating the laser to the fixture on the suction cup table multiple times within the laser irradiation area; the step of moving the irradiated fixture to the inspection area of ​​the visual device, and using the visual device to inspect the processing status of the laser; and the step of correcting the distortion of the laser according to the inspection result of the visual device, and aligning the coordinates of the laser with the coordinates of the visual device as a reference so that the coordinates of the visual device and the coordinates of the laser are consistent with each other.

[0025] In addition, the present invention provides a laser setting method, characterized in that the fourth step includes: step a), moving the fixture on the suction cup table so that the laser irradiates the command position of the motor and performs the first laser processing on the entire area of ​​the fixture; step b), moving the fixture that has completed the first laser processing to the inspection area of ​​the visual device, using the visual device to image the processing status of the first laser and calculate the offset value of the first processing position; step c), reflecting the calculated offset value and performing a second laser processing on the entire area of ​​the fixture; and step d), moving the fixture that has completed the second laser processing to the inspection area of ​​the visual device, using the visual device to check the processing status of the second laser, calculating the offset value of the second processing position and verifying the correction status; in the step of verifying the correction status, repeatedly executing steps b) to d) until the offset value of the second processing position meets the preset error range.

[0026] Furthermore, the present invention provides a laser setting method, characterized in that, in the step of executing the first laser processing and the step of executing the second laser processing, the laser is irradiated to two or more points in each inspection area to find the center, the offset value of the laser processing position is calculated, and the laser irradiation position is corrected with the center of the visual device as a reference to make it consistent with the center of the visual device.

[0027] In addition, the present invention provides a laser setting method, characterized in that, in the first laser processing of the step b), the laser is irradiated in a specified shape to two or more points in each inspection area; and in the second laser processing of the step c), the laser is irradiated in a shape that accommodates the shape or the same size as the shape performed by the first laser processing.

[0028] Furthermore, the present invention provides a laser setting method, characterized in that, in the first laser processing of the step b), laser is irradiated in a specified shape to two or more points in each inspection area; and in the second laser processing of the step c), laser is irradiated to positions separated by specified intervals from the points where the first laser processing is performed.

[0029] In addition, the present invention provides a laser setting method, characterized in that in the third step and the fourth step, the laser is irradiated onto the fixture automatically supplied and transferred from the gate box in which the fixtures formed with a larger specification than the semiconductor material to be processed are stacked.

[0030] Furthermore, the present invention provides a laser setting method, characterized in that in the third step and the fourth step, laser is irradiated onto one of the clamps having a thermal tape attached to a fluorine-coated plate, a plate clamp coated by cold electroplating, and a clamp made of PCB material.

[0031] In addition, the present invention provides a laser setting method, characterized in that the following steps are also performed: a fifth step, performing laser processing in an area outside the processing area of ​​the suction cup table, using the visual device to check the laser processing position, and calculating the offset value to correct the laser processing position.

[0032] Technical Effects

[0033] According to the laser setting method of the present invention, not only the lens distortion of the visual device is corrected in the fov area, and the lens distortion of the laser is corrected in the irradiation area, but also the error of the mechanism is corrected for the inspection area of ​​the visual device and the processing area of ​​the laser as a whole, so that the actual movement amount of the motor can be verified for the entire processing area to improve the precision. In particular, after the calibration of the mechanism for correcting the mechanical offset value is performed, the visual device calibration for correcting the distortion of the mechanism, the visual device, and the axis, the laser calibration for correcting the distortion of the laser and the axis, the offset value between the inspection position of the visual device and the laser processing position is calculated and corrected, and the reprocessing is repeated until the integrated calibration within the preset error range is reached, thereby showing the excellent effect of being able to improve the processing precision of the entire processing area of ​​the semiconductor material, while minimizing the error caused by the operator through the automation of the visual device calibration and the integrated calibration, improving the reliability of the setting, and shortening the setting time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a top view of an embodiment of a laser processing device applicable to the present invention.

[0035] Figure 2 The process of performing the fourth step of performing integrated calibration in the laser setting method according to one embodiment of the present invention is schematically shown.

[0036] Figure 3 A process of executing another embodiment of the fourth step of executing integrated calibration in the laser setting method according to the present invention is schematically shown.

[0037] Description of Reference Numerals

[0038] 10: loading unit; 20: first loading picker;

[0039] 30: second loading picker; 40: suction cup platform;

[0040] 50: Imported visual device; 60: Visual device;

[0041] 70: Laser; 80: Cleaning picker;

[0042] 90: cleaning unit; 100: first unloading picker;

[0043] 110: second unloading picker; 120: drying block;

[0044] 130: QC visual device; 140: Rework and recycling department;

[0045] 150: Unloading Department DETAILED DESCRIPTION

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein, but may also be embodied in other forms. On the contrary, the embodiments introduced herein are provided to make the disclosed contents sufficient and complete, and to fully convey the ideas of the present invention to those skilled in the art.

[0047] Figure 1 This is a top view of an embodiment of a laser processing device applicable to the present invention, and a laser ablation device is used as an example to explain various laser processing devices. At this time, the laser ablation device is only used as an example to explain, and the laser setting method of the present invention can be applied to various laser processing devices.

[0048] like Figure 1As shown, the laser ablation device includes: a loading part 10, which is loaded with semiconductor materials to be processed; a first loading picker 20, which draws out semiconductor materials from the loading part 10 and loads them onto a suction cup table 40; a second loading picker 30, which picks up the processed semiconductor materials from the suction cup table 40 and transfers them to a cleaning part 90; an inlet visual device (inlet a first unloading picker 100 for picking up the semiconductor material cleaned in the second cleaning section and transferring it to a drying block 120 for drying the semiconductor material; a QC visual device 130 for confirming the processing state of the semiconductor material dried in the drying block 120; a second unloading picker 110 for picking up the semiconductor material dried in the drying block 120 and transferring it to an outlet track; a second unloading picker 110 for picking up the semiconductor material cleaned ... The exit rail (not shown) transfers the semiconductor material to a rework recovery section 140 for loading defective products or an unloading section 150 for loading qualified products.

[0049] The chuck stage 40, the visual device 60 and the laser 70 are arranged in a row in plurality, so that a plurality of semiconductor materials can be processed simultaneously. Since the field of view (FOV) of the visual device camera of the visual device 60 and the laser irradiator of the laser 70 and the irradiation area of ​​the laser irradiator of the laser 70 are smaller than the area of ​​the semiconductor material, when performing the operation, the chuck stage loaded with the semiconductor material is moved in the inspection area below the visual device 60 and the processing area below the laser 70 on the xy plane and the operation is performed.

[0050] Therefore, the suction cup stage 40 can be moved on the xy plane by a mechanism (not shown) including a driving motor for moving the suction cup stage 40 and a rail forming a moving path of the suction cup stage 40 .

[0051] The laser setting method according to the present invention is generally composed of four steps, and each step of the laser setting method of the present invention includes: a first step, executing the mechanical part calibration; a second step, executing the visual device calibration; a third step, executing the laser calibration; and a fourth step, executing the integrated calibration.

[0052] Since the vision device 60 and the laser 70 are spaced apart from each other, the chuck stage 40 moves between the inspection area below the vision device 60 and the processing area below the laser 70 and performs processing position confirmation and processing of the semiconductor material loaded on the chuck stage 40 .

[0053] However, since the moving path formed by the rails and the like in the mechanism for transferring the suction cup table 40 cannot be guaranteed to be a complete straight line, and the prevention of tilting or flatness during stacking and fastening between the components of the various mechanism parts provided on the mover cannot be ensured, the coordinate axes of the suction cup table 40 and the semiconductor material loaded therein in the inspection area and the coordinate axes of the suction cup table 40 and the semiconductor material loaded therein in the processing area will not be consistent with each other. For example, even if the motor of the mechanism sends a command to transfer 1 pitch, the actual transferred position of the suction cup table transferred by the actual mechanism may be different.

[0054] In order to correct the above-mentioned mechanical offset value, the laser setting method of the present invention performs mechanical part calibration as the first step.

[0055] Mechanism calibration is a step of correcting the mechanism offset value by using a visual device to confirm the position value of a reference point corresponding to the transfer instruction value of a motor used to transfer a suction cup table. Specifically, it is a step of correcting the inconsistency of the coordinate axes of the semiconductor material in the inspection area of ​​the visual device and the processing area of ​​the laser.

[0056] First, in order to perform the mechanical part calibration, a reference jig is loaded on the chuck stage 40. As the reference jig, a large-area glass substrate having a plurality of reference points formed at equal intervals can be used.

[0057] The reference fixture is formed to be larger than the semiconductor material so that it can be used to obtain the mechanical offset value related to the inspection area of ​​the visual device and the mechanical offset value related to the laser inspection area. In particular, since there is no visual device in the laser, the reference fixture needs to be formed larger so that when the reference fixture is located in the processing area of ​​the laser, the reference point of the reference fixture can be observed by the visual device. The reference fixture can be loaded and stored in the loading part 10. Each time the mechanical part calibration is required, it can be drawn out from the loading part 10 and loaded onto the suction cup table 40 by the first loading pickup 20, or it can be supplied in a state where the operator places it on the suction cup table. The reference fixture can have an area that can be located in the inspection area of ​​the visual device and the processing area of ​​the laser at the same time, and a plurality of alignment marks (fiducial marks) are marked on the entire surface at regular intervals.

[0058] First, the suction cup stage is moved so that any reference point among a plurality of reference points formed at equal intervals on a reference fixture is located in the inspection area of ​​the visual device, the suction cup stage is moved according to a preset transfer instruction value, and the visual device is used to inspect the position value of any reference point that is spaced apart from any reference point located in the inspection area of ​​the visual device by a size equivalent to the transfer instruction value, so as to obtain a structural offset value related to the inspection area of ​​the visual device.

[0059] Furthermore, when any reference point among a plurality of reference points formed at equal intervals on a reference fixture is located in a processing area of ​​the laser, and another arbitrary reference point is located in an inspection area of ​​the visual device, the suction cup table is transferred according to a preset transfer instruction value, and the visual device is used to inspect the position of any reference point separated by the transfer instruction value from any reference point located in the inspection area of ​​the visual device, so as to obtain a structural offset value for the laser processing area.

[0060] When obtaining the mechanical offset value related to the processing area of ​​the laser, the suction cup stage is moved so that any reference point among the plurality of reference points is located in the processing area of ​​the laser, and at this time, the position of another arbitrary reference point located below the visual device is checked by the visual device. Next, the suction cup stage is moved according to the preset motor transfer command value, and the position value of another reference point spaced apart from another arbitrary reference point located in the inspection area of ​​the visual device by a distance equivalent to the motor transfer command value is checked by the visual device to obtain the offset value.

[0061] At this time, the motor transfer command value may be the interval of the reference points. Since the reference points are formed at equal intervals on the reference fixture, the 1st pitch of the reference points may be set as the motor transfer command value, and the 2nd and 3rd pitches of the reference points may be set as the motor transfer command value. That is, the suction cup stage may be transferred at intervals of n pitches (where n is an integer) of the reference points, and in particular, when the suction cup stage is transferred at intervals of 1 pitch of the reference points, the most precise data may be obtained.

[0062] The suction cup table is moved in an area from the inspection area of ​​the visual instrument to an area before the processing area corresponding to the laser, and at this time, based on the position of the reference point located below the visual instrument, the structural offset value of the suction cup table can be calculated by the motor's transfer command value and the actual measured position of the reference point within the entire range of the inspection area of ​​the visual instrument and the processing area of ​​the laser.

[0063] For example, by setting the motor's transfer command value to 1 pitch interval of the reference point, the suction cup table is moved 1 pitch each time in the visual inspection area and the laser processing area. At this time, the coordinates of the suction cup table related to the entire xy plane of the visual inspection area and the laser processing area, that is, the coordinates of the mechanism part, can be obtained through the position change of the reference point detected below the visual device.

[0064] Specifically, even if the motor sends a command to move 1 pitch at a time, the actual suction cup may be tilted or the axis deformed, and the position of the reference point measured in the visual device may be different from the motor's transfer command value. Therefore, for the motor's transfer command value, the offset value is corrected based on the position of the reference fixture checked by the actual visual device.

[0065] The vision device will sequentially check all the reference points formed on the reference fixture, moving n pitches each time from the first line of the reference fixture and starting to check the reference points. The last line of reference points checked by the vision device can be the last line of reference points configured in the area to be processed by the laser.

[0066] Therefore, the visual device 60 is used to analyze the image related to the position and arrangement of the alignment mark (fiducialmark) arranged in the inspection area in the reference fixture, so that the image related to the position and arrangement of the alignment mark arranged in the processing area can be inferred. Through the inferred information related to the position and arrangement of the alignment mark in the processing area, the state and degree of inconsistency of the coordinate axes of the semiconductor material in the inspection area and the processing area can be confirmed and corrected.

[0067] By calibrating the mechanism in this way, it is possible to calculate a transfer command value of the motor required to transfer the suction cup stage at one pitch interval.

[0068] Of course, at this time, since the transfer instruction value is an instruction value for correcting the mechanical offset value according to different positions, the motor transfer instruction value used to transfer 1 pitch in the inspection area of ​​the visual device and the motor transfer instruction value used to transfer 1 pitch in the laser processing area may be different.

[0069] That is, through the calibration of the mechanical part, the visual inspection area of ​​the suction cup table loaded with actual semiconductor materials and the structural offset value of the laser processing area can be corrected. For the fixture loaded on the suction cup table, the entire area from the visual inspection area to the laser processing area is moved and the corresponding operation is performed. At this time, the various changed positions are inspected by the visual device, and the transfer instruction value of the suction cup table and the offset value of the position actually transferred and measured can be obtained.

[0070] Furthermore, the acquired offset value is corrected to perform calibration of the mechanism for transferring the inspection area of ​​the vision device and the processing area of ​​the laser.

[0071] The mechanical offset value is corrected by calibrating the mechanism, and the motor transfer command value is changed based on the reference point position of the fixture on the suction cup table that is transmitted to the visual device for inspection. Therefore, the motor reflects the offset value of the straightness, flatness, yaw, etc. of the xy plane state moved by the mechanism (not the scale reference), so the transfer command value is corrected based on the position value that the actual mechanism moves and is inspected by the visual device.

[0072] After the calibration of the execution mechanism, the laser setting method of the present invention may perform a visual device calibration as a second step to correct the distortion and axis of the visual device.

[0073] In vision calibration, the reference jig is moved in accordance with the movement command value of the motor within the FOV area of ​​the vision system, and the same reference point is photographed by the vision system at each position to acquire an image.

[0074] At this time, the reference jig used can be the same as the reference jig used when calibrating the actuator unit. With the reference jig loaded on the suction cup stage, the suction cup stage is moved according to the transfer command value and the reference point is detected.

[0075] That is, the same reference fixture is used, and any one of the multiple reference points formed on the reference fixture is set as the target, and the corresponding reference point is moved within the FOV area of ​​the visual device, and the moving interval can be the n-pitch (n is an integer) interval of the reference point.

[0076] For example, when n is 1, the reference point set as the target in the FOV area of ​​the visual device is moved at 1 pitch intervals, and the image of the moved reference point is acquired by the visual device. Since the visual device calibration is performed after the actuator unit calibration, the motor can move the reference point at 1 pitch intervals of the reference fixture.

[0077] That is, the reference jig is moved at one-pitch intervals according to the transfer command value of the motor. At this time, the transfer command value of the motor is a value reflecting the mechanical offset value acquired by the mechanical unit calibration.

[0078] Therefore, the reference jig is moved according to the transfer instruction value, and the images of the reference points captured by the vision device at various positions can be integrated into one image.

[0079] At this time, the integrated image may be an image reflecting the lens distortion of the visual organ.

[0080] Therefore, the distortion of the lens can be corrected based on the integrated image, and the coordinates of the mechanism part can be obtained by moving the fixture at n pitch intervals in the FOV area using the mechanism part and photographing it. The coordinates of the visual device are corrected based on the mechanism part so that the coordinates of the visual device are consistent with the coordinates of the mechanism part.

[0081] That is, after the vertical state relative to the moving direction of the motor is ensured by calibrating the mechanism, the image modification operation of changing the coordinate axis of the visual device can be performed based on the moving coordinates of the mechanism to complete the visual device calibration.

[0082] By aligning the vision device based on the movement coordinates of the mechanism unit, the same reference values ​​can be ensured for each.

[0083] The visual device calibration is described in more detail. When a reference fixture marked with reference points is loaded on the suction cup table 40, the suction cup table 40 is moved according to the transfer command value of the motor, so that any one of the multiple reference points is transferred along the xy plane together with the reference fixture within the FOV area of ​​the visual device, and the corresponding reference point is photographed by the visual device 60. The process of moving the suction cup table and imaging the reference points separated by the transfer command value using the visual device is repeated multiple times. When the multiple images taken are integrated into one image, an image marked with multiple alignment marks can be obtained.

[0084] When analyzing the positions and arrangements of multiple alignment marks in such an image, the difference between the coordinate axes of the visual device 60 and the coordinate axes of the mechanism in the inspection area, the degree of image distortion caused by the lens of the visual device, and other factors can be confirmed and corrected, such as the coordinate difference between the coordinates of the visual device 60 and the coordinate difference of the reference point detected by moving the suction cup table in the inspection area of ​​the visual device.

[0085] Furthermore, at this time, the coordinate correction of the visual device is performed based on the mechanism unit, so that the distortion and axis of the visual device can be corrected.

[0086] After the vision device calibration is completed, the laser calibration is performed as the third step to correct the distortion and axis of the laser.

[0087] To perform laser calibration, load the fixture on the chuck stage and shine the laser multiple times within the laser's illumination area.

[0088] The steps of moving the fixture that has been irradiated with the laser to the inspection area of ​​the visual device and using the visual device to inspect the processing status of the laser, correcting the distortion of the laser based on the inspection result of the visual device, and aligning the coordinates of the laser based on the coordinates of the visual device so that the coordinates of the visual device and the coordinates of the laser are consistent with each other are executed.

[0089] To be more specific, in laser calibration, the fixture is loaded on the suction cup stage 40, the suction cup stage 40 is moved to the processing area, and the laser is irradiated to multiple points in the irradiation area of ​​the laser 70. At this time, the laser 70 and the fixture are fixed, and the laser is irradiated multiple times to the preset processing positions of the fixture in the irradiation area of ​​the laser using a scanner.

[0090] At this time, multiple laser irradiations do not mean irradiating the same area multiple times, but rather irradiating preset processing positions sequentially within the laser irradiation area and performing laser processing at multiple points. The preset processing positions can be multiple points with a certain interval.

[0091] At this time, any clamp can be used as long as it can confirm the processing status of the laser. Preferably, a clamp with a heat-sensitive tape attached to a fluorine-coated plate can be used, a plate clamp with surface treatment using cold electroplating can be used, and a clamp made of PCB material can also be used.

[0092] The reason for coating the jig with fluorine is to facilitate the peeling of the thermal tape and to reuse the jig. Since the portion of the thermal tape irradiated with the laser changes color and is marked as a mark, when analyzing the position and arrangement of the mark, the difference between the coordinate axis of the laser 70 and the coordinate axis of the semiconductor material in the processing area, the degree of scanning distortion caused by the lens of the laser irradiator, and the coordinate difference between the laser 70 and the semiconductor material can be confirmed and corrected.

[0093] Furthermore, a plate fixture that is surface treated by cold electroplating (raydent) can be used, which is a composite surface treatment method based on a coating treated by electroplating and a functional coating, or a fixture made of PCB material can be used. In this case, in order to prevent shrinkage caused by laser, a copper plate can be formed inside the fixture made of PCB material, and the surface of the copper plate can be coated with PCB material.

[0094] In the laser setting method of the present invention, laser calibration can be automatically performed. To this end, when a plurality of fixtures to be processed are stacked on the gate box, the first loading picker 20 picks up the fixtures drawn from the gate box and automatically supplies them to each suction cup table, the suction cup table moves to the laser and irradiates the fixture on the suction cup table with the laser multiple times within the irradiation area of ​​the laser, and the irradiated fixture is moved to the inspection area of ​​the visual device and the processing state of the laser is inspected by the visual device.

[0095] because Figure 1 The laser processing device shown has four suction cup stages, a vision device, and a laser. When the first loading picker 20 picks up the fixture and transfers it to each suction cup stage, the respective vision device and laser can be used to perform laser calibration.

[0096] After the laser irradiation is completed, the processing status of the laser is checked by using a visual device, and while the distortion of the laser is corrected based on the inspection result of the visual device, the coordinates of the laser are adjusted based on the coordinates of the visual device so that the coordinates of the visual device and the coordinates of the laser are consistent with each other.

[0097] At this time, since the coordinates of the visual device are calibrated based on the calibrated mechanical part, the coordinates of the visual device and the coordinates of the mechanical part are consistent with each other, the laser can also modify the coordinates on the scanner based on the coordinates of the visual device to correct the coordinates.

[0098] As described above, when the 2D vertical and horizontal errors of the mechanism part are corrected and verified by calibrating the mechanism part, the coordinates of the visual device are corrected based on the mechanism part, and the coordinates of the laser are aligned to be consistent with the coordinates of the corrected visual device, thereby completing each individual correction operation.

[0099] After the individual calibration operations are completed, the fourth step, which is the final step of the present invention, performs integrated calibration of the vision device and the laser so that the laser can perform processing to the command position of the motor.

[0100] In the laser setting method of the present invention, in the step of performing integrated calibration, the laser performs processing at the command position of the motor, uses a visual device to confirm the processing position to calculate the offset value, and corrects the calculated offset value to perform reprocessing, and repeats the reprocessing until the offset value reaches a preset error range.

[0101] To explain more specifically, in the integrated calibration, the jig on the chuck stage is moved so that the laser is irradiated to the command position of the motor, and the first laser processing is performed on the entire area of ​​the jig.

[0102] The jig used here can be the same jig as that used when performing laser calibration. In addition, it is preferable to use a jig with a larger size than the semiconductor material to be processed, so that even if the material is not supplied to the correct position of the chuck table, laser processing data for the entire area of ​​the material can be ensured.

[0103] As mentioned above, any jig can be used as long as it can confirm the processing status of the laser. Preferably, a jig with a heat-sensitive tape attached to a fluorine-coated plate can be used, a plate jig coated by cold electroplating can be used, or a jig made of PCB material can be used.

[0104] In addition, in the first laser processing, laser is irradiated in a predetermined shape at two or more points in each inspection area. In addition, the fixture that has been processed by the first laser is moved to the inspection area of ​​the vision device, and the processing state of the first laser for the entire inspection area is imaged by the vision device and the offset value of the first processing position is calculated. The calculated offset value is reflected in the laser, and the second laser processing is performed on the entire area of ​​the fixture.

[0105] At this time, in the secondary laser processing, the laser is irradiated in a shape that accommodates the first laser processing or in a shape of the same size as the accommodation, or the laser is irradiated at a position spaced a predetermined distance from the interval of the points where the first laser processing was performed.

[0106] The integrated calibration of the present invention is a step of confirming the positional errors of the visual device 60 and the laser 70 in the processing area for the entire area of ​​the semiconductor material, performing correction in the event of positional errors, and confirming and verifying the correction results.

[0107] Figure 2 The process of performing integrated calibration in the laser setting method according to one embodiment of the present invention is schematically illustrated.

[0108] The integrated calibration is described in more detail with reference to the accompanying drawings. Figure 2 As shown in part (a), after the fixture to be laser processed is loaded onto the suction cup table 40, the suction cup table 40 is moved to the processing area and the laser is irradiated to the fixture, thereby generating a plurality of mark pairs consisting of a first mark a and a second mark b on the entire surface of the fixture. Figure 2 Part (a) of FIG. 1 shows, as an example, a case where the laser is irradiated to two points in each inspection area, but the number of processing points in each inspection area may be more than that. Although the first laser processing is performed by irradiating the entire area of ​​the fixture with the laser at two points in each inspection area, one inspection area is enlarged and shown as a representative example. Figure 2 part (a) of the

[0109] The first mark a and the second mark b are processed into a predetermined shape by sequentially irradiating a plurality of laser beams. At this time, the predetermined shape can be a circular laser trajectory whose center is easily inferred.

[0110] For reference, in the first laser processing step, although only one mark can be processed in each inspection area, the angle and slope from the center can be calculated by processing more than two marks, so that more diverse position errors can be obtained. However, if too much processing is performed in each inspection area, it may take more processing time, so it is most preferred to process two marks in each inspection area.

[0111] The jig is formed with a larger area than the semiconductor material to be processed, so that processing data can be sufficiently ensured to the outer contour or peripheral portion of the semiconductor material, thereby improving precision.

[0112] Then, if Figure 2 As shown in part (b), the suction cup table 40 is moved to the inspection area of ​​the visual device to image the processing state of the first laser so that the jig processed with the mark is located below the visual device. When imaging the processing state, the inconsistency state and degree of inconsistency between the center c of the visual device 60 and the center of the laser 70 are confirmed for multiple pairs of marks. Among them, the laser center can be the center point on the line connecting the center straight lines of the two marks. That is, the center of the laser 70 can be set to the center of the first mark a and the second mark b, that is, the center of the straight line connecting the center of the first mark a and the center of the second mark b.

[0113] The offset value of the first laser processing position is calculated by comparing the center of the visual instrument with the center of the laser. When the offset value of the first processing position is calculated, in order to correct the calculated offset value, the offset value of the laser processing position is calculated so that the center of the visual instrument is consistent with the center of the laser, and the irradiation position of the laser is corrected based on the center of the visual instrument.

[0114] That is, after changing the irradiation position of the laser 70 according to the inconsistency state and degree, verification is performed to confirm whether the laser offset value is well reflected. When performing verification, the calculated offset value is reflected in the irradiation position of the laser and a second laser processing is performed on the entire area of ​​the jig for confirmation.

[0115] At this time, since the first laser processing and the second laser processing are respectively performed on the entire area of ​​the fixture, during the aforementioned second laser processing, in order to distinguish it from the first laser processing, the processing is performed in a shape that is the same as the shape of the first laser processing and only different in size, or the processing is performed at a specified position separated from the processing position of the first laser processing area.

[0116] First, the case where the second laser processing is performed in the same shape as the first laser processing but in a different size is described as an example. Figure 2As shown in part (c) of the embodiment, a comparison mark pair consisting of a third mark a' and a fourth mark b' is generated by irradiating a laser to the fixture. The third mark a' and the fourth mark b' can be formed to be the same size as the first mark a and the second mark b and to be relatively larger in size, so that they can be distinguished from the first mark a and the second mark b. If the center of the comparison mark pair is consistent with the center of the visual device 60, the center of the visual device 60 and the center of the mark pair are corrected to be consistent in the area of ​​the corresponding mark pair, and if the centers are still inconsistent, the process is repeated.

[0117] Among them, the process of marking the mark pair by irradiating the fixture with laser, the process of judging whether the center of the visual device 60 and the center of the mark pair are consistent, etc. can be automatically executed by a separate control unit.

[0118] Figure 3 The process of performing integrated calibration in another embodiment of the laser setting method according to the present invention is schematically shown.

[0119] Figure 3 The method shown in Figure 2 The process of the embodiment shown in is the same as a whole, but the difference is that when performing the second laser processing, a predetermined interval is spaced to a position different from the processing position of the first laser processing area to distinguish it from the first laser processing. Figure 3 As shown in part (c) of FIG. 1 , in order to distinguish the mark pair of the first mark a and the second mark b from the comparison mark pair of the fifth mark a" and the sixth mark b", the intervals between the marks can be formed to be relatively larger.

[0120] Figure 3 In part (c), the intervals between the marks are formed to be relatively larger, but if the marks can be distinguished from the first mark a and the second mark b, the intervals between the marks can also be formed to be relatively smaller.

[0121] In the laser setting method according to the present invention, in the integrated calibration step, by automatically and simultaneously performing calibration on a plurality of semiconductor materials in the plurality of visual devices 60 and lasers 70, it is possible to improve setting reliability and shorten setting time.

[0122] That is, in the laser setting method of the present invention, the integrated calibration is automatically performed, and for this purpose, a plurality of fixtures to be processed are stacked on the gate box respectively, and the first loading picker 20 picks up the fixtures drawn from the gate box and automatically supplies them to each suction cup stage. At this time, the suction cup stage performs the first laser processing on the entire area of ​​the fixture, and moves the fixture that has been processed by the first laser processing to the inspection area of ​​the visual device. Subsequently, the offset value of the processing position is calculated by imaging the first laser processing state with the visual device, and after reflecting the calculated offset value and performing the second laser processing on the entire area of ​​the fixture, the calibration state is verified by the visual device.

[0123] At this time, it is necessary to repeatedly perform calibration and reprocessing until the offset value of the second laser processing position meets the preset error range. The integrated calibration of the present invention is automatically performed, so that repeated compensation can be performed, and since laser processing is performed until the required error range is met, it can be repeatedly performed multiple times using multiple fixtures other than one fixture.

[0124] Of course, the fixture used at this time can be the same as the fixture used when performing laser calibration, and can be a fixture with a heat-sensitive tape attached to a fluorine-coated plate, a plate fixture coated by cold electroplating, or a PCB material fixture.

[0125] In addition, as mentioned above, the settings for laser processing are completed through the calibration of the mechanism, the visual device, the laser, and the integrated calibration. At this time, in the laser calibration and the integrated calibration, since the fixture is automatically supplied from the gate box and transferred to the suction cup table, and the laser processing of the fixture transferred to the suction cup table can be performed, the setting time can be shortened and the error caused by the difference in the ability of the operator can be minimized.

[0126] In addition, laser calibration and integrated calibration are automatically performed, and pass / fail can be confirmed based on the error range of the processing result. If it is confirmed as a fail, the problem is confirmed by confirming the position data and image, and measures are taken and reprocessing is performed after the cause is confirmed.

[0127] As described above, when the setting and offset value verification is completed, laser processing can be performed on the actual semiconductor material instead of the jig. For reference, by performing the above calibration work on the jig which is not a high-priced semiconductor material, not only the cost required for calibration can be minimized, but also in the case of using a jig with a thermal tape attached to the plate to be coated, it has the advantage that when the thermal tape that has been processed is removed and a new thermal tape is attached, the jig can be reused.

[0128] In addition, when performing laser processing on semiconductor materials, as the processing is repeated, the heat generated in the laser will accumulate in the lens part, and errors may occur in the laser. As the suction cup table is repeatedly transferred, errors may also occur in the mechanism part of the transfer suction cup table. Therefore, a correction operation is required to correct the errors.

[0129] To this end, the laser setting method of the present invention can also execute: the fifth step, performing laser processing in an area outside the processing area of ​​the suction cup table, using a visual device to check the laser processing position, and calculating an offset value to correct the laser processing position.

[0130] In the fifth step, the misalignment can be compensated by a reference check of the laser processing position. The reference check can be performed before, during, or after the semiconductor material is processed.

[0131] At this time, the inspection may be performed as an intermediate inspection when the number of times the semiconductor material is processed using the laser exceeds a predetermined number of times or when the laser processing time on the semiconductor material exceeds a predetermined time.

[0132] Specifically, in order to perform the fifth step of the present invention, a heat-sensitive tape is attached to an area other than the processing area of ​​the chuck table to confirm the processing state. Generally speaking, the processing area of ​​the chuck table is performed in the central area, so the heat-sensitive tape can be attached to one side or the outer contour area of ​​the chuck table, and the semiconductor material can be processed in a state where the heat-sensitive tape is pre-attached to the corresponding area on the chuck table before processing.

[0133] Then, when a reference check is required, laser processing is performed at a certain point of the thermal tape attached to one side of the suction cup table. The suction cup table after laser processing is moved to the inspection area of ​​the vision device, and the center of the laser processing position is detected by the vision device. The offset value between the center of the vision device and the center of the detected processing position is calculated, and the laser processing position is corrected based on the vision device.

[0134] At this time, when the operator sets the execution time point in advance, the reference check function can be automatically executed according to the set conditions, so that precise processing can be maintained.

[0135] Therefore, according to the laser setting method of the present invention, in addition to simply detecting the distortion of the lens in each of the visual device 60 and the laser 70, the processing precision can be further improved by performing integrated calibration of the visual device 60, the laser 70 and the mechanism part in the inspection area of ​​the visual device and the processing area of ​​the laser, taking into account the different coordinate axes of the semiconductor material based on the mechanism part. By calculating the correction value of the processing area of ​​the semiconductor material as a whole through integrated calibration, the laser 70 can be irradiated to the position of the command value of the motor, and the coordinates of the command value can be confirmed using the visual device to align the coordinate axes, thereby improving the processing precision.

[0136] According to the laser setting method of the present invention, it can not only be executed after the initial installation of the laser processing device, but also in order to be able to use the QC visual device to execute it immediately when defective products occur during operation, a reference fixture and a fixture lamp with a heat-sensitive tape attached above the fluorine coating can be loaded in the loading part.

[0137] Furthermore, by attaching a heat-sensitive tape to a specific area other than the processing area of ​​the suction cup stage, the state of the laser 70 can be checked and corrected at any time during laser processing using the laser 70 .

[0138] The above description is made with reference to the preferred embodiments of the present invention, but those skilled in the art may make various modifications and changes to the present invention without departing from the concept and scope of the present invention as described in the attached claims. Therefore, if the implementation of the modification basically includes the constituent elements of the claims of the present invention, it shall be considered to fall within the technical scope of the present invention.

Claims

1. A laser setting method, which is applicable to a laser processing device for processing semiconductor materials using laser, characterized in that: The laser setting method performs the following steps: The first step is to perform a mechanical part calibration, by confirming the position value of the reference point corresponding to the transfer instruction value of the motor for transferring the suction cup table through a visual device, thereby correcting the mechanical offset value; The second step is to perform visual calibration to move and image the reference point within the FOV area of ​​the visual device to correct the distortion and axis of the visual device; The third step is to perform laser calibration to irradiate the laser multiple times within the irradiation area of ​​the laser to correct the distortion and axis of the laser; as well as The fourth step is to perform integrated calibration so that the laser performs processing at the command position of the motor, use the visual device to confirm the processing position to calculate the offset value, and correct the calculated offset value to perform reprocessing, and repeat the reprocessing until the offset value reaches a preset error range.

2. The laser setting method according to claim 1, characterized in that: In the first step, The suction cup stage is moved so that any reference point among a plurality of reference points formed at equal intervals on a reference fixture is located in the inspection area of ​​the visual device, the suction cup stage is moved according to a preset transfer instruction value, and a position value of any reference point spaced apart from any reference point located in the inspection area of ​​the visual device by a distance of the transfer instruction value is checked by the visual device to obtain a structural offset value for the inspection area of ​​the visual device, When any reference point among the multiple reference points formed at equal intervals on the reference fixture is located in the processing area of ​​the laser, and another arbitrary reference point is located in the inspection area of ​​the visual device, the suction cup table is transferred according to the preset transfer instruction value, and the visual device is used to inspect the position of any reference point that is separated from any reference point located in the inspection area of ​​the visual device by a distance equal to the transfer instruction value, so as to obtain the structural offset value related to the processing area of ​​the laser.

3. The laser setting method according to claim 2, characterized in that: The suction cup table is moved using n pitches of reference points formed at equal intervals as the motor's transfer command value, where n is an integer, and the transfer is performed in the interval from the inspection area of ​​the visual device to the interval before the processing area equivalent to the laser to obtain a structural offset value.

4. The laser setting method according to claim 1, characterized in that: The second step comprises: Step a), moving the reference fixture within the FOV of the visual device according to the transfer instruction value of the motor, and photographing the same reference point at each position using the visual device to obtain an image; Step b), integrating the images acquired by the visual device; and Step c) corrects the lens distortion of the visual device based on the integrated image, and corrects the visual device coordinates based on the mechanism part so that the mechanism part coordinates obtained from the integrated image are consistent with the visual device coordinates.

5. The laser setting method according to claim 4, characterized in that: In the step a), the reference fixture is moved on the FOV of the visual device according to the motor transfer command value reflecting the mechanical offset value obtained by the mechanical unit calibration, and the reference point is photographed by the visual device to obtain an image of the reference point at each position.

6. The laser setting method according to claim 4, characterized in that: The third step comprises: The step of irradiating the fixture on the chuck table with laser light multiple times within the irradiation area of ​​the laser light; The step of moving the irradiated fixture to the inspection area of ​​the visual device and using the visual device to inspect the processing status of the laser; and A step of correcting the distortion of the laser light based on the inspection result of the visual instrument and aligning the coordinates of the laser light with the coordinates of the visual instrument so that the coordinates of the visual instrument and the coordinates of the laser light are consistent with each other.

7. The laser setting method according to claim 1, characterized in that: The fourth step comprises: Step a), moving the fixture on the suction cup table so that the laser irradiates the command position of the motor, and performing the first laser processing on the entire area of ​​the fixture; Step b), moving the fixture that has been processed by the first laser to the inspection area of ​​the visual device, using the visual device to image the processing state of the first laser and calculate the offset value of the first processing position; Step c), reflecting the calculated offset value and performing a second laser processing on the entire area of ​​the fixture; and Step d), moving the fixture that has been processed by the second laser to the inspection area of ​​the visual device, using the visual device to inspect the processing status of the second laser, calculating the offset value of the second processing position and verifying the correction status, In the step of verifying the correction state, The steps b) to d) are repeatedly performed until the offset value of the second processing position meets a preset error range.

8. The laser setting method according to claim 7, characterized in that: In the step of executing the first laser processing and the step of executing the second laser processing, the laser is irradiated to two or more points in each inspection area to find the center, the offset value of the laser processing position is calculated, and the laser irradiation position is corrected with the center of the visual device as a reference to make it consistent with the center of the visual device.

9. The laser setting method according to claim 7, characterized in that: In the first laser processing of step b), laser light is irradiated in a predetermined shape at two or more points in each inspection area. In the second laser processing of the step c), laser light is irradiated in a shape that accommodates the shape or the same size as that in which the first laser processing was performed.

10. The laser setting method according to claim 7, characterized in that: In the first laser processing of step b), laser light is irradiated in a predetermined shape at two or more points in each inspection area. In the second laser processing in step c), laser light is irradiated to positions spaced a predetermined distance apart from the points where the first laser processing was performed.

11. The laser setting method according to any one of claims 1 to 10, characterized in that: In the third step and the fourth step, the laser is irradiated onto the jig automatically supplied and transferred from a gate box in which jigs formed in a larger size than the semiconductor material to be processed are stacked.

12. The laser setting method according to any one of claims 1 to 10, characterized in that: In the third step and the fourth step, laser light is irradiated onto one of a jig having a heat-sensitive tape attached to a fluorine-coated plate, a plate jig coated by cold plating, and a jig made of PCB material.

13. The laser setting method according to any one of claims 1 to 10, characterized in that: A fifth step is also performed, wherein the laser processing is performed in an area other than the processing area of ​​the chuck table, the laser processing position is checked using the vision device, and an offset value is calculated to correct the laser processing position.

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