Microminiature DFN chip torque protection method

Abstract

The invention relates to the technical field of torque control, and discloses a microminiature DFN chip torque protection method, which comprises the following steps: S1, setting a torque control parameter of a servo motor, and ensuring that the downward pressure of the servo motor is kept in a set safety range, namely 13N + / -10% in a chip detection process; s2, monitoring an external force value borne by the servo motor in a pressing process in real time through a software test system, and when the external force value is detected to exceed a set safety range, immediately executing a power-off protection measure to enable the servo motor to stop working, and lifting a pressing mechanism by a certain distance through the acting force of a spring to prevent a chip or a suction pen from being damaged; the external force borne by the motor can be monitored in real time, and if the external force exceeds an effective collision interval range, power-off protection is carried out; and in an effective pressing range, according to the real-time torque, the pressing force of the motor is controlled to be kept constant (13N + / -10%), and the chip is protected from being damaged during testing.

Description

Technical Field

[0001] The invention relates to the technical field of torque control, and in particular to a torque protection method for an ultra-small DFN chip. Background Art

[0002] In the semiconductor industry, with the continuous advancement of technology, the performance requirements for semiconductor equipment are also constantly increasing. Especially in the testing and sorting of chips, equipment needs to have high precision and high efficiency to meet the growing market demand. As the size of semiconductor components continues to shrink, traditional testing and sorting equipment can no longer meet the needs of precise chip operations. In this context, ultra-small DFN (Dual Flat No leads) chips are widely used in various high-density electronic devices due to their small size, light weight, and few pins.

[0003] However, when using traditional sorting equipment to test DFN chips, due to the tiny size of the chips, the operation requires extremely high precision, and the chips may be damaged if not handled with care. For example, during the chip suction process, if the downward pressure applied by the suction pen is too large, the suction pen may break or the chip may be damaged, resulting in product scrapping and reduced production efficiency. Therefore, how to effectively protect the chips during the inspection process and avoid damage caused by improper operation has become a technical problem that needs to be solved urgently for semiconductor test and sorting equipment.

[0004] In order to solve the above problems, the present invention proposes a torque protection method for ultra-small DFN chips. The method introduces motor torque control technology to accurately control the actuator of the sorting equipment to ensure that the torque applied during the chip detection process remains within a safe range. By real-time monitoring and adjusting the output torque of the motor, chip damage caused by excessive torque can be effectively avoided, thereby improving the chip detection efficiency and yield rate. The application of this technology can not only improve the performance of semiconductor test and sorting equipment, but also reduce production costs, and has important practical value and market prospects. Summary of the invention

[0005] The object of the present invention is to provide a torque protection method for an ultra-small DFN chip to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A technical solution for a torque protection method of an ultra-small DFN chip includes the following steps:

[0008] S1. Set the torque control parameters of the servo motor to ensure that during the chip detection process, the downward force of the servo motor remains within the set safety range, i.e. 13N±10%;

[0009] S2. Use the software test system to monitor the external force value of the servo motor in real time during the pressing process. When it is detected that the external force value exceeds the set safety range, the power-off protection measures are immediately implemented to stop the servo motor from working, and the pressing mechanism is lifted up a certain distance through the spring force to avoid damage to the chip or the suction pen;

[0010] S3. Before chip testing, the preset pressure is calibrated by a pressure measuring gauge to ensure that the servo motor can automatically adjust the torque output according to different pressing distances during the pressing process to keep the pressure constant;

[0011] S4. During chip testing, after the servo motor is pressed down to the test station, it is determined whether a stacking collision occurs according to the torque control and external force value display. If a stacking collision is detected, the power-off protection measures are executed. If no collision is detected, the electrical performance test is continued until the servo motor is reset;

[0012] S5. After the chip detection is completed, the servo motor is reset and the pressing mechanism returns to the initial position to prepare for the next chip detection.

[0013] As a preferred technical solution, the pressing mechanism includes a fixed plate, a servo motor is installed on the top of the fixed plate, a cam is connected to the output end of the servo motor, a slider assembly is connected below the cam, a suction pen is arranged below the slider assembly, a DFN chip is arranged below the suction pen, and a turntable is arranged on the adjacent side of the suction pen.

[0014] As a preferred technical solution, the cam is used to drive the slider assembly to move up and down in a straight line, so as to realize the downward pressing and upward lifting action of the suction pen, thereby sucking the chip to complete the corresponding detection.

[0015] As a preferred technical solution, the output torque of the servo motor in S2 varies with the rotation angle of the motor (i.e., the pressing distance), and the specific operation steps are as follows:

[0016] (1) Rotate the motor to a certain angle and record the first downward pressure position, denoted as P 1 ;

[0017] (2) Adjust the height of the pressure gauge so that it contacts the suction pen and fine-tune P 1 position until the pressure reaches 13N;

[0018] (3) Record the current torque of the motor, denoted as T 1 ;

[0019] (4) Repeat steps (1) and (2) and record P 1 ~P 5 , T 1 ~T 5 .

[0020] As a preferred technical solution, the torque calculation formula is as follows:

[0021]

[0022] As a preferred technical solution, the relationship between the motor torque and the pressing position is determined by a linear fitting or curve fitting method based on the recorded pressing position and the corresponding torque value, so that during the chip detection process, the motor torque output is automatically adjusted according to the real-time pressing position to maintain the set pressure value.

[0023] As a preferred technical solution, in S4, the step of determining whether a stacking collision occurs by torque control and external force value display includes:

[0024] (a) Setting a collision detection threshold range, when the external force value exceeds the range, it is considered that a stacking collision has occurred;

[0025] (b) When a stack collision is detected, power-off protection measures are immediately implemented to stop the servo motor and lift the pressing mechanism up a certain distance through the spring force to avoid damage to the chip or the suction pen;

[0026] (c) When no stack collision is detected, continue the electrical performance test until the servo motor is reset.

[0027] As a preferred technical solution, in S5, the servo motor resetting step includes:

[0028] (a) After the chip detection is completed, the servo motor stops working and the pressing mechanism returns to its initial position under the action of the spring;

[0029] (b) A reset command is issued through the software test system, and the servo motor readjusts the torque output to prepare for the next chip test.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention is a torque protection method for ultra-small DFN chips, which effectively avoids chip damage caused by excessive torque by accurately controlling the output torque of the servo motor. This method not only improves the detection efficiency and yield rate of the chip, but also significantly reduces the production cost, providing strong support for the technical upgrade of semiconductor testing and sorting equipment. In addition, the technical solution of the present invention is also highly flexible and scalable, and can be adjusted and optimized according to actual needs to meet the detection needs of DFN chips of different specifications and types. The present invention has broad application prospects and important practical value in the semiconductor industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a pressing mechanism for a torque protection method for an ultra-small DFN chip;

[0033] Figure 2 A schematic diagram of the collision velocity structure of a torque protection method for an ultra-small DFN chip;

[0034] Figure 3 A schematic diagram of the structure of a normal DFN chip image taken by an industrial camera for a torque protection method of an ultra-small DFN chip;

[0035] Figure 4 A schematic diagram of the structure of an image of a DFN chip damaged by a suction pen captured by an industrial camera using a torque protection method for an ultra-small DFN chip;

[0036] Figure 5 A schematic diagram of a collision detection structure of a super-small DFN chip torque protection method;

[0037] Figure 6 This is a force analysis diagram of the pressing mechanism of a super-small DFN chip torque protection method;

[0038] Figure 7 A schematic diagram of a chip pressing process of a torque protection method for an ultra-small DFN chip;

[0039] Figure 8 A proportional relationship diagram of motor torque and position for a super-small DFN chip torque protection method;

[0040] Fig. 9 The figure is a flow chart of chip detection at a test station for a torque protection method for an ultra-small DFN chip.

[0041] In the accompanying drawings: 1. fixed plate; 2. servo motor; 3. cam; 4. slider assembly; 5. suction pen; 6. turntable. DETAILED DESCRIPTION

[0042] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by illustrating examples of the present invention.

[0043] The present invention provides a technical solution for a torque protection method of an ultra-small DFN chip, which comprises the following steps:

[0044] S1. Set the torque control parameters of the servo motor to ensure that during the chip detection process, the downward force of the servo motor remains within the set safety range, i.e. 13N±10%;

[0045] S2. Use the software test system to monitor the external force value of the servo motor in real time during the pressing process. When it is detected that the external force value exceeds the set safety range, the power-off protection measures are immediately implemented to stop the servo motor from working, and the pressing mechanism is lifted up a certain distance through the spring force to avoid damage to the chip or the suction pen;

[0046] S3. Before chip testing, the preset pressure is calibrated by a pressure measuring gauge to ensure that the servo motor can automatically adjust the torque output according to different pressing distances during the pressing process to keep the pressure constant;

[0047] S4. During chip testing, after the servo motor is pressed down to the test station, it is determined whether a stacking collision occurs according to the torque control and external force value display. If a stacking collision is detected, the power-off protection measures are executed. If no collision is detected, the electrical performance test is continued until the servo motor is reset;

[0048] The steps of judging whether a stacking collision occurs by torque control and external force value display include:

[0049] (a) Setting a collision detection threshold range, when the external force value exceeds the range, it is considered that a stacking collision has occurred;

[0050] (b) When a stack collision is detected, power-off protection measures are immediately implemented to stop the servo motor and lift the pressing mechanism up a certain distance through the spring force to avoid damage to the chip or the suction pen;

[0051] (c) When no stacking collision is detected, continue the electrical performance test until the servo motor is reset.

[0052] S5. After the chip detection is completed, the servo motor is reset, and the pressing mechanism returns to the initial position to prepare for the next chip detection;

[0053] The steps for resetting the servo motor include:

[0054] (a) After the chip detection is completed, the servo motor stops working and the pressing mechanism returns to its initial position under the action of the spring;

[0055] (b) A reset command is issued through the software test system, and the servo motor readjusts the torque output to prepare for the next chip test.

[0056] Specifically, Figure 1The figure shows the schematic diagram of the pressing mechanism. The servo motor drives the cam to rotate, and the cam drives the slider mechanism to move up and down linearly, so as to realize the pressing and lifting action of the suction pen, thereby sucking the chip to complete the corresponding detection.

[0057] During the test, sometimes there will be material overlap. If there is no protective measure, the chip will be squeezed and damaged or the suction pen will break. When a collision occurs, the torque may not change much, but the motor speed will change greatly due to the collision. Figure 2 As shown, this is a schematic diagram of the change in motor speed when a collision occurs.

[0058] The pressing process is similar to the motor speed change process, first accelerating and then decelerating. 0 Stop. When there is only one chip, due to the error, the collision point is at P 0 Nearby 1 At this time, the speed is small, and the external force value after collision is F 1 Smaller; when two chips are stacked, the collision point is at P 0 Farther away 2 , at this time the speed is relatively large, and the external force value after the collision is F 2 Larger. Figure 3 As shown in the figure, the images of a normal DFN chip taken by an industrial camera and a DFN chip damaged by a suction pen are shown. If there is no anti-collision protection, the chip will be obviously damaged.

[0059] In order to protect the chip from being damaged when stacking occurs, the present invention proposes an anti-collision protection method. When the stacking collision occurs, the motor loses power and an alarm is sounded. At the same time, the pressing mechanism is lifted up a certain distance under the action of the spring. By developing a software testing system, an effective interval range is set to monitor the external force value of the motor when pressing down. Once the external force value exceeds the collision detection threshold setting parameter range, a collision is detected, the motor loses power and an alarm is sounded, and anti-collision protection is performed. Figure 4 The figure shows a schematic diagram of collision detection. Within the collision detection range, if the external force value exceeds the set threshold range, it means that a stacking collision occurs.

[0060] In order to accurately detect the electrical performance of the chip, the chip needs to be pressed down to the test station and kept for a period of time. To ensure that the chip is not damaged by the pressure, the pressure should be controlled to remain constant within a certain range. Therefore, before the chip test, a pressure measuring instrument should be used to perform a measurement experiment, such as Figure 5 The figure shows the force analysis diagram of the pressing mechanism. According to the field test data, when the servo torque remains unchanged, the larger the motor rotation angle (i.e., the smaller the angle θ), the greater the pressing force. Therefore, in the measurement experiment, in order to ensure that the pressure remains unchanged during the pressing process, the servo output torque must change with the motor rotation angle (i.e., the pressing distance). The specific operation steps are as follows:

[0061] (1) Rotate the motor to a certain angle and record the first downward pressure position, denoted as P 1 ;

[0062] (2) Adjust the height of the pressure gauge so that it contacts the suction pen and fine-tune P 1 position until the pressure reaches 13N;

[0063] (3) Record the current torque of the motor, denoted as T 1 ;

[0064] (4) Repeat steps (1) and (2) and record P 1 ~P 5 , T 1 ~T 5 .

[0065] like Figure 6 The figure shows the schematic diagram of the chip pressing process. Before the motor presses down, the positions of the five points and the corresponding output torque at 15N are measured. The torque output is changed according to the current position using the information of the five points, thereby maintaining a constant pressure. No matter how position B changes, without the help of external sensors and upper-level instructions, each time the chip being tested collides with the test station, it can automatically maintain a certain downward pressure (13N±10%) until the test is completed and the motor is reset. Based on the on-site test data, the motor torque change curve can be simulated, such as Figure 7 As shown in the figure, it is a proportional relationship diagram between motor torque and position. It can be seen from the figure that when the motor just starts to move, its instantaneous torque is large, and it tends to be stable in the second half. Therefore, when calculating the motor torque, the instantaneous torque is not considered, and the stable downward pressure interval is selected, which can be approximated as a linear change. Assuming that the motor position P∈(P n ,P n+1 ), and T n >T n+1 , the torque formula is as follows:

[0066]

[0067] According to the recorded pressing position and corresponding torque value, the relationship between the motor torque and the pressing position is determined by linear fitting or curve fitting method, so that during the chip detection process, the motor torque output is automatically adjusted according to the real-time pressing position to maintain the set pressure value.

[0068] Therefore, through anti-collision protection methods and pressure maintenance methods, it can be ensured that the DFN chip under test is not damaged, such as Figure 8 As shown, it is a flow chart of chip detection at the test station, according to which the electrical performance of the chip is tested and the chip is protected from being damaged.

[0069] Among them, the pressing mechanism includes a fixed plate 1, a servo motor 2 is installed on the top of the fixed plate 1, a cam 3 is connected to the output end of the servo motor 2, a slider assembly 4 is connected below the cam 3, a suction pen 5 is arranged below the slider assembly 4, a DFN chip is arranged below the suction pen 5, and a turntable 6 is arranged on the adjacent side of the suction pen 5.

[0070] The cam 3 is used to drive the slider assembly 4 to make a linear motion up and down, so as to realize the downward pressing and upward lifting action of the suction pen 5, thereby sucking the chip to complete the corresponding detection.

[0071] The present invention can monitor the size of the external force applied to the motor in real time. If it exceeds the effective collision range, power-off protection is performed. Within the effective downward pressure range, the downward pressure of the motor is controlled to remain constant (13N±10%) according to the real-time torque size to protect the chip from being damaged during testing.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0073] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0074] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0075] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for torque protection of an ultra-small DFN chip, characterized in that: The following steps are involved: S1. Set the torque control parameters of the servo motor to ensure that during the chip detection process, the downward force of the servo motor remains within the set safety range, i.e. 13N±10%; S2. Use the software test system to monitor the external force value of the servo motor in real time during the pressing process. When it is detected that the external force value exceeds the set safety range, the power-off protection measures are immediately implemented to stop the servo motor from working, and the pressing mechanism is lifted up a certain distance through the spring force to avoid damage to the chip or the suction pen; S3. Before chip testing, the preset pressure is calibrated by a pressure measuring gauge to ensure that the servo motor can automatically adjust the torque output according to different pressing distances during the pressing process to keep the pressure constant; S4. During chip testing, after the servo motor is pressed down to the test station, it is determined whether a stacking collision occurs according to the torque control and external force value display. If a stacking collision is detected, the power-off protection measures are executed. If no collision is detected, the electrical performance test is continued until the servo motor is reset; S5. After the chip detection is completed, the servo motor is reset and the pressing mechanism returns to the initial position to prepare for the next chip detection.

2. The ultra-small DFN chip torque protection method according to claim 1, characterized in that: The pressing mechanism comprises a fixed plate (1), a servo motor (2) is mounted on the top of the fixed plate (1), a cam (3) is connected to the output end of the servo motor (2), a slider assembly (4) is connected below the cam (3), a suction pen (5) is arranged below the slider assembly (4), a DFN chip is arranged below the suction pen (5), and a turntable (6) is arranged on the adjacent side of the suction pen (5).

3. The ultra-small DFN chip torque protection method according to claim 2 is characterized in that: The cam (3) is used to drive the slider assembly (4) to perform vertical linear motion, thereby achieving the downward pressing and upward lifting action of the suction pen (5), thereby sucking the chip to complete the corresponding detection.

4. The ultra-small DFN chip torque protection method according to claim 1, characterized in that: The output torque of the servo motor in S2 varies with the rotation angle of the motor (i.e., the pressing distance), and the specific operation steps are as follows: (1) Rotate the motor by a certain angle and record the first downward pressing position, which is recorded as P1; (2) Adjust the height of the pressure gauge so that it contacts the suction pen and fine-tune the position of P1 until the pressure reaches 13N; (3) Record the current torque of the motor, denoted as T1; (4) Repeat steps (1) and (2) and record P1 to P5 and T1 to T5.

5. The ultra-small DFN chip torque protection method according to claim 4 is characterized in that: The torque calculation formula is as follows:

6. The ultra-small DFN chip torque protection method according to claim 5, characterized in that: According to the recorded pressing position and the corresponding torque value, the relationship between the motor torque and the pressing position is determined by a linear fitting or curve fitting method, so that during the chip detection process, the motor torque output is automatically adjusted according to the real-time pressing position to maintain the set pressure value.

7. The ultra-small DFN chip torque protection method according to claim 1, characterized in that: In S4, the step of determining whether a stacking collision occurs by torque control and external force value display includes: (a) Setting a collision detection threshold range, when the external force value exceeds the range, it is considered that a stacking collision has occurred; (b) When a stack collision is detected, the power-off protection measure is immediately executed to stop the servo motor and lift the pressing mechanism up a certain distance through the spring force to avoid damage to the chip or the suction pen; (c) When no stack collision is detected, continue the electrical performance test until the servo motor is reset.

8. The ultra-small DFN chip torque protection method according to claim 1, characterized in that: In S5, the servo motor resetting step includes: (a) After the chip detection is completed, the servo motor stops working and the pressing mechanism returns to its initial position under the action of the spring; (b) A reset command is issued through the software test system, and the servo motor readjusts the torque output to prepare for the next chip detection.

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