Chip pick-and-place method and die bonding method

Abstract

This application provides a chip pick-and-place method and a die bonding method, relating to the field of chip technology. The method includes: controlling a pick-up nozzle to pick up chips and place them at a target position; controlling the pick-up nozzle to rotate around its axis by a preset angle after each preset number of chip pick-ups and placements, establishing a coordinate system with the center of the nozzle as the origin, a straight line passing through the origin as the X-axis, and a straight line passing through the origin and perpendicular to the X-axis as the Y-axis. The coordinates of a positioning point after the nozzle rotation are different from all previous coordinates, where the positioning point is any point on the nozzle surface. In this application, by rotating the nozzle after picking up a certain number of chips, and ensuring that the position of the nozzle after rotation is different from its previous position, the wear of the nozzle can be changed from a fixed area to uniform wear across the entire adsorption surface of the nozzle. This avoids the formation of wear marks on the adsorption surface of the nozzle, preventing downtime for nozzle replacement, and thus improving chip production efficiency.

Description

Technical Field

[0001] This application relates to the field of chip technology, specifically to a chip pick-and-place method and a die bonding method. Background Technology

[0002] Mini LED (Miniature Light Emitting Diode) displays are display devices that utilize miniature LED backlighting technology. Because the chips in Mini LED displays are small, typically between 100 and 300 micrometers in size, they can be arranged more densely, enabling finer local dimming areas. This allows Mini LED displays to offer higher contrast, deeper blacks, and a wider color gamut.

[0003] Chips are one of the most crucial components of Mini LED displays. In the chip manufacturing process of Mini LEDs, such as the die bonding process, the chip needs to be picked up and fixed in position using the nozzles of the die bonder. These nozzles pick up chips frequently, typically hundreds of thousands or even millions of times. Therefore, such high-frequency picking causes wear to the nozzles due to repeated contact with the chips. Because chips have a long, narrow structure, elongated wear marks will appear on the nozzle's surface. This results in poor chip quality and an increase in defective chips processed through that nozzle. Therefore, it is necessary to replace the nozzles to ensure chip quality.

[0004] However, changing the nozzle will cause the die bonder to stop, which will reduce chip production efficiency and increase the time cost of chip production. Summary of the Invention

[0005] The embodiments of this application provide a chip pick-and-place method and a die bonding method, which can improve the problem of low chip production efficiency.

[0006] In a first aspect, embodiments of this application provide a chip pick-and-place method.

[0007] A chip picking and placing method includes: controlling a nozzle to pick up a chip and placing the picked-up chip at a target position; controlling the nozzle to rotate around its axis by a preset angle after each preset number of chip picking and placing operations, establishing a coordinate system with the center of the nozzle as the origin, a straight line passing through the origin as the X-axis, and a straight line passing through the origin and perpendicular to the X-axis as the Y-axis, wherein the coordinates of a positioning point after the nozzle rotation are different from all the coordinates before the positioning point, wherein the positioning point is any point on the surface of the nozzle.

[0008] In one embodiment, the suction nozzle rotates about its axis in the same direction of rotation by a predetermined angle.

[0009] In one embodiment, the total number of rotations of the suction nozzle is less than 100 per revolution.

[0010] In one embodiment, within one cycle, the coordinates of the positioning point after the nozzle rotates are different from all the coordinates of the positioning point before.

[0011] In one embodiment, the nozzle completes one cycle of rotation, and the positioning point returns to the initial position.

[0012] In one embodiment, the preset angle is α, which satisfies: 5°≤α≤170°.

[0013] In one embodiment, the preset number of times is N, which satisfies: 500 times ≤ N ≤ 20,000 times.

[0014] In one embodiment, the chip picking and placing method further includes: controlling the nozzle to perform position calibration after each rotation.

[0015] In one embodiment, the nozzle position calibration step includes: acquiring position image information of the current position of the nozzle; determining the deviation of the current position relative to a reference position based on the position image information; and compensating and correcting the nozzle drive based on the deviation; wherein the initial position of the nozzle is the reference position.

[0016] Secondly, embodiments of this application provide a die bonding method, which includes the aforementioned chip pick-and-place method.

[0017] The beneficial effects of the embodiments of this application are as follows:

[0018] In the embodiments of this application, by rotating the nozzle after each certain number of chips are picked up, and making the position of the nozzle after rotation different from the previous position, the wear of the nozzle can be changed from a fixed area to uniform wear of the entire adsorption surface of the nozzle. This can avoid the formation of wear marks on the adsorption surface of the nozzle, which would lead to downtime and nozzle replacement, thereby improving chip production efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the first chip pick-and-place process provided in the embodiments of this application;

[0021] Figure 2 This is a schematic diagram of the second chip pick-and-place process provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the third chip pick-and-place process provided in the embodiments of this application;

[0023] Figure 4 This is a schematic diagram of the fourth chip pick-and-place process provided in the embodiments of this application;

[0024] Figure 5 This is a schematic diagram of the structure of the suction nozzle provided in an embodiment of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 001 - Suction nozzle;

[0027] 011-Base; 012-Multi-stage stepped shaft; 013-Cone. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] In the description of the embodiments of this application, the words "example" or "for example" are used to indicate exemplification, illustration, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this application is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0031] Please see Figure 1 , Figure 1 This is a schematic diagram of a first chip pick-and-place process provided by an embodiment of this application. An embodiment of this application provides a chip pick-and-place method, which includes:

[0032] Control the suction nozzle 001 to pick up the chip and place the picked-up chip at the target location;

[0033] The control nozzle 001 rotates around its axis by a preset angle every time it completes the chip picking and placing a preset number of times.

[0034] A coordinate system is established with the center of the nozzle 001 as the origin, a straight line passing through the origin as the X-axis, and a straight line passing through the origin and perpendicular to the X-axis as the Y-axis. The coordinates of the positioning point after the nozzle 001 is rotated are different from all the coordinates before the positioning point. The positioning point is any point on the surface of the nozzle 001.

[0035] The suction nozzle 001 includes, but is not limited to, a ceramic suction nozzle 001, a metal suction nozzle 001, and a ceramic-metal suction nozzle 001. Optionally, the suction nozzle 001 is a ceramic-metal suction nozzle 001. The ceramic-metal suction nozzle 001 is a suction nozzle 001 that combines the properties of ceramic and metal materials. This suction nozzle 001 possesses the wear resistance, corrosion resistance, and high-temperature stability of ceramics, while also possessing the strength and impact resistance of metals, thus meeting the operational requirements for adsorbing and fixing chips.

[0036] In addition, the preset number of times is a parameter that can be adjusted according to the actual working conditions during operation; for example, it can be 50 times or 100 times. The preset angle is also a parameter that can be adjusted according to the actual working conditions during operation; for example, it can be 5°, 15°, or 30°.

[0037] In this embodiment, by rotating the suction nozzle 001 after each certain number of chips are picked up, and making the position of the suction nozzle 001 after rotation different from its previous position, the wear of the suction nozzle 001 can be changed from a fixed area to uniform wear on the entire adsorption surface of the suction nozzle 001. This avoids the formation of wear marks on the adsorption surface of the suction nozzle 001, which would lead to downtime and replacement of the suction nozzle 001. In this way, chip production efficiency can be improved and the maintenance cost of the suction nozzle 001 can be reduced.

[0038] In addition, the above settings can improve chip quality and avoid chip defects that occur during the period when the nozzle 001 has wear marks and the wear marks deepen and the nozzle 001 needs to be replaced, thereby improving the chip yield.

[0039] Please see Figure 2 , Figure 2 This is a schematic diagram of a second chip pick-and-place process provided in an embodiment of this application. In one embodiment, the suction nozzle 001 rotates about its axis in the same direction of rotation by a preset angle.

[0040] For example, the nozzle 001 can rotate clockwise about its axis and also rotate counterclockwise about its axis.

[0041] In this embodiment, by setting the suction nozzle 001 to rotate around its axis in the same direction of rotation, the control of the suction nozzle 001 can be simplified, making the control of the suction nozzle 001 simpler.

[0042] In one embodiment, the total number of rotations of the nozzle 001 is less than 100 per revolution.

[0043] It is understandable that the total number of rotations of the suction nozzle for each revolution includes, but is not limited to, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 28, 40, 42, 45, 48, 50, 60, 70, 80, 90, and 99.

[0044] Furthermore, the nozzle 001 rotates a total of 5 to 12 times per revolution.

[0045] For example, the suction nozzle 001 rotates a total of 12 times per revolution. After completing 2000 pick-up and drop-off operations of the target chip, the suction nozzle 001 rotates around its axis by 30° relative to its current position. After rotating 12 times in one cycle, the positioning point returns to its initial position.

[0046] In this embodiment, the above settings can prevent the nozzle from rotating too many times within a week, thus reducing the control precision and lowering the control cost.

[0047] In one embodiment, within one cycle, the coordinates of the positioning point after the nozzle 001 rotates are different from all the coordinates where the positioning point was before.

[0048] In this embodiment, the above settings can simplify the control process of the nozzle 001 and reduce the difficulty of controlling the nozzle 001.

[0049] In one embodiment, the nozzle 001 completes one cycle of rotation, and the positioning point returns to the initial position.

[0050] In this embodiment, the working process of the suction nozzle 001 is divided into cycles for control, which simplifies the working process of the suction nozzle 001 and improves the ease of operation of the suction nozzle 001.

[0051] In one embodiment, the preset angle is α, which satisfies: 5°≤α≤170°.

[0052] It can be understood that α includes, but is not limited to, 5°, 10°, 15°, 22°, 25°, 35°, 45°, 55°, 65°, 78°, 90°, 100°, 105°, 120°, 135°, 147°, 150°, 160°, and 170°.

[0053] It is understandable that when α is between 180° and 360°, there is a possibility that the position of the nozzle 001 relative to the chip before rotation of the α angle will remain in contact with the chip after rotation, thus increasing the complexity of controlling the rotation angle of the nozzle 001.

[0054] Based on this, in this embodiment, the above-mentioned limitations can simplify the difficulty of controlling the rotation angle of the suction nozzle 001, and facilitate the smooth operation of the related rotation of the suction nozzle 001.

[0055] In one embodiment, α satisfies: 25°≤α≤45°.

[0056] For example, α includes, but is not limited to, 25°, 26°, 27.5°, 28°, 29°, 30°, 33°, 35°, 36°, 38°, 40°, 42°, 44°, 44.3°, and 45°.

[0057] In this embodiment, the above-mentioned limitations can, on the one hand, prevent the suction nozzle 001 from rotating too small an angle, which would result in a large overlap between the surface of the suction nozzle 001 in contact with the chip after rotation and the surface of the suction nozzle 001 in contact with the chip before rotation, thereby improving the uniformity of wear on the suction surface of the suction nozzle 001; on the other hand, can prevent the suction nozzle 001 from rotating too large an angle, which would result in a long time to adjust the position of the suction nozzle 001, thereby facilitating the efficient operation of the suction nozzle 001.

[0058] In one embodiment, the preset number of times is N, which satisfies: 500 times ≤ N ≤ 20,000 times.

[0059] It is understandable that N can be, but is not limited to, 505, 589, 599, 600, 700, 800, 900, 1,000, 2,000, 3,000, 4,000, 5,000, 6,000, 8,000, 10,000, 15,000, and 20,000.

[0060] Furthermore, N satisfies: 2,000 times ≤ N ≤ 10,000 times.

[0061] In this embodiment, the above-mentioned limitations allow the nozzle 001 to rotate to the next angle to contact the chip without significant wear, thereby avoiding the formation of dents on the adsorption surface of the nozzle 001 and further improving the uniformity of wear on the entire adsorption surface. On the other hand, it also prevents the high rotation frequency of the nozzle 001 from affecting the chip production efficiency.

[0062] Please see Figure 3 , Figure 3This is a schematic diagram of a third chip pick-and-place process provided in an embodiment of this application. In one embodiment, the chip pick-and-place method further includes: controlling the suction nozzle 001 to perform position calibration after each rotation.

[0063] It is understandable that the installation of nozzle 001 has a coaxiality deviation, so when nozzle 001 is rotated, the coaxiality deviation will change.

[0064] Therefore, in this embodiment, by performing a position calibration step for the suction nozzle 001 after rotating it, the control accuracy of the suction nozzle 001 can be improved, thereby improving the quality of the chip.

[0065] There are several ways to calibrate the nozzle 001, such as confirming the positional deviation through ultrasound, determining the actual position of the nozzle 001 based on the deviation, and then compensating for it by the drive device of the nozzle 001.

[0066] The nozzle 001 position calibration step can also be confirmed through image analysis. Specifically, such as... Figure 4 As shown, Figure 4 This is a schematic diagram of the fourth chip pick-and-place process provided in the embodiments of this application. The nozzle 001 position calibration step includes:

[0067] Obtain the current position image information of nozzle 001;

[0068] Determine the deviation of the current position relative to the reference position based on the position image information;

[0069] The drive device of nozzle 001 compensates and corrects the drive of nozzle 001 according to the deviation.

[0070] The initial position of the nozzle 001 is the reference position.

[0071] In addition, the position image information of the nozzle 001 at its current position can be obtained by a CCD (Charge-Coupled Device) positioning camera, and the deviation of the current position from the reference position can be determined based on the position image information.

[0072] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a suction nozzle 001 provided in an embodiment of this application. In one embodiment, the suction nozzle 001 includes a base 011, a multi-stage stepped shaft 012, and a cone 013 connected coaxially in sequence. The diameter of the multi-stage stepped shaft 012 decreases sequentially in the direction away from the base. The large-diameter end of the cone 013 is connected to one end of the multi-stage stepped shaft 012. The air passage of the suction nozzle 001 extends from the base 011 to the cone 013 and passes through the end face of the small-diameter end of the cone 013.

[0073] Among them, the multi-stage stepped shaft 012 is a three-stage stepped shaft, with its two ends connected to the base 011 and the cone 013 respectively, and the diameter of its smallest diameter shaft is the same as the diameter of the largest diameter end of the cone 013.

[0074] In this embodiment, through the above-mentioned limitations, on the one hand, the size of the adsorption surface of the base 011 relative to the nozzle 001 can be set to be larger, thereby improving the reliability of the nozzle 001 installation; on the other hand, a progressive support can be formed by gradually changing to a smaller adsorption surface through the multi-stage stepped shaft 012 and the cone 013, thereby helping to reduce stress concentration and thus improving the structural reliability of the nozzle 001.

[0075] In addition, the cone design of 013 can provide good centering and positioning accuracy between the nozzle 001 and the object being suctioned, and make it easy for staff to observe the situation of the nozzle 001 adsorbing the chip.

[0076] Based on the foregoing embodiments, the following is a summary of the embodiments of the chip pick-and-place method: The chip pick-and-place method includes:

[0077] Control the suction nozzle 001 to pick up the chip and place the picked-up chip at the target location;

[0078] Each time the control nozzle 001 completes the chip picking and placing a preset number of times, it rotates around its axis in the same direction by a preset angle.

[0079] A coordinate system is established with the center of the nozzle 001 as the origin, a straight line passing through the origin as the X-axis, and a straight line passing through the origin and perpendicular to the X-axis as the Y-axis. The coordinates of the positioning point after the nozzle 001 is rotated are different from all the coordinates before the positioning point. The positioning point is any point on the surface of the nozzle 001.

[0080] The nozzle rotates less than 100 times per revolution. Within one cycle, the coordinates of the positioning point after the nozzle's rotation are different from all its previous coordinates. After completing one cycle, the positioning point returns to its initial position. The preset angle is α, satisfying: 5° ≤ α ≤ 170°. The preset number of rotations is N, satisfying: 500 ≤ N ≤ 20,000.

[0081] Position calibration is performed after each rotation of the suction nozzle. The position calibration steps for suction nozzle 001 are as follows: acquire the position image information of the current position of suction nozzle 001; determine the deviation of the current position relative to the reference position based on the position image information; and compensate and correct the drive of suction nozzle 001 based on the deviation.

[0082] Accordingly, embodiments of this application provide a die bonding method, which includes the aforementioned chip pick-and-place method.

[0083] It is understandable that the die bonding method is primarily implemented using a die bonder. The nozzle 001 is fixed to the swing arm of the die bonder. Specifically, the nozzle 001 is fixed to the drive end of a rotary motor located on the swing arm. The rotation of the nozzle 001 can be controlled using this rotary motor.

[0084] In this embodiment, by adopting the aforementioned pick-and-place method, the nozzle 001 can contact the chip through different parts, thereby avoiding the formation of wear marks on the adsorption surface of the nozzle 001, which would lead to downtime and replacement of the nozzle 001, and thus improving the die bonding efficiency.

[0085] The technical solutions and effects of this application will be described in detail below through specific embodiments. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0086] This embodiment aims to examine the wear and tear of the suction nozzle 001 during its operation.

[0087] The specific details of the test content for the embodiment are as follows:

[0088] I. Test-related instructions

[0089] (1) The dimensions of the adsorption surface of nozzle 001 are: inner diameter 70um, outer diameter 200um;

[0090] (2) The measuring device for the depth of the dent in the nozzle 001 is a two-dimensional measuring instrument.

[0091] II. Test Results

[0092] (1) Set the scale

[0093] The comparative examples show experimental data for nozzle 001 not rotating throughout the entire working process in related technologies. Details are shown in the table below:

[0094]

[0095] Table 1. Experimental data for the comparative example

[0096] As shown in Table 1, in the comparative example, when the number of chip pick-up and drop cycles is 200,000, the depth of the wear mark on the suction surface of nozzle 001 is 20 μm; when the number of chip pick-up and drop cycles is 1.5 million, the depth of the wear mark on the suction surface of nozzle 001 is 30 μm; and when the number of chip pick-up and drop cycles is 2 million, the depth of the wear mark on the suction surface of nozzle 001 is 40 μm.

[0097] (2) The verification results of the embodiments of this application are shown in Table 2.

[0098]

[0099]

[0100] in,

[0101] Example 1 shows the test results of rotating the nozzle 001 by 15° after picking up 500 chips before picking up the chips again.

[0102] Example 2 shows the test results of rotating the nozzle 001 by 30° after picking up 500 chips before picking up the chips again.

[0103] Example 3 shows the test results of rotating the nozzle 001 by 30° after picking up 2000 chips before picking up the chips again.

[0104] Example 4 shows the test results of rotating the nozzle 001 by 30° after picking up 3000 chips before picking up the chips again.

[0105] Example 5 shows the test results of rotating the nozzle 001 by 30 degrees after picking up 10,000 chips before picking up the chips again.

[0106] As can be seen from the embodiments 1-5 above, by rotating the suction nozzle 001 after each certain number of chips are picked up, and ensuring that the position of the suction nozzle 001 after rotation is different from its previous position, the suction nozzle 001 can contact the chips through different parts, thereby ensuring that the entire adsorption surface of the suction nozzle 001 can contact the chips. This changes the wear of the suction nozzle 001 from a fixed area to uniform wear across its entire adsorption surface, thus avoiding the formation of wear marks on the adsorption surface of the suction nozzle 001 that would require downtime for replacement, and ultimately improving chip production efficiency.

[0107] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A chip pick-and-place method, characterized in that, include: Control the nozzle to pick up the chip and place the picked-up chip at the target location; The nozzle rotates around its axis by a preset angle after each preset number of chip pick-ups and put-downs. A coordinate system is established with the center of the nozzle as the origin, a straight line passing through the origin as the X-axis, and a straight line passing through the origin and perpendicular to the X-axis as the Y-axis. The coordinates of the positioning point after the nozzle rotates are different from all the coordinates before the positioning point. The positioning point is any point on the surface of the nozzle. The preset angle is α, which satisfies: 5°≤α≤170°.

2. The chip pick-and-place method according to claim 1, characterized in that, The suction nozzle rotates around its axis in the same direction of rotation by a preset angle.

3. The chip pick-and-place method according to claim 1, characterized in that, The total number of rotations of the suction nozzle is less than 100 per revolution.

4. The chip pick-and-place method according to claim 1, characterized in that, Within one cycle, the coordinates of the positioning point after the nozzle rotates are different from all the coordinates of the positioning point before that.

5. The chip pick-and-place method according to claim 4, characterized in that, The suction nozzle completes one cycle of rotation, and the positioning point returns to its initial position.

6. The chip pick-and-place method according to any one of claims 1-5, characterized in that, The preset number of times is N, which satisfies: 500 times ≤ N ≤ 20,000 times.

7. The chip pick-and-place method according to any one of claims 1-5, characterized in that, The chip picking and placing method further includes: controlling the nozzle to perform position calibration after each rotation.

8. The chip pick-and-place method according to claim 7, characterized in that, The nozzle position calibration step includes: Obtain the position image information of the current position of the suction nozzle; The deviation of the current position relative to the reference position is determined based on the position image information; The drive of the suction nozzle is compensated and corrected according to the deviation; The initial position of the suction nozzle is the reference position.

9. A method for solidification, characterized in that, Includes the chip pick-and-place method as described in any one of claims 1-8.

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