Laser resistance trimming equipment and laser resistance trimming method

Abstract

The invention belongs to the technical field of laser resistance trimming, and particularly relates to laser resistance trimming equipment and a laser resistance trimming method. The laser emits laser to the TaN resistor, and the working wavelength is 808 nm or 980 nm; the temperature feedback system measures the temperature of laser on the surface of the TaN resistor; the resistance measuring system measures the resistance value of the TaN resistor; the control system is respectively in signal connection with the laser, the temperature feedback system and the resistance measurement system, receives target resistance setting, adjusts laser power of the laser according to the temperature of the TaN resistor measured by the temperature feedback system, receives the resistance of the TaN resistor measured by the resistance measurement system, compares the resistance with the target resistance, and outputs the target resistance. And when the measured resistance value of the TaN resistor reaches the target resistance value, turning off the laser, and finishing the resistance adjustment. Compared with the prior art, the resistance adjusting device and the resistance adjusting method have the advantages that the shape of the resistor is not changed, and the circuit has good high-frequency performance.

Description

Technical Field

[0001] The invention belongs to the technical field of laser resistance trimming, and in particular relates to a laser resistance trimming device and a laser resistance trimming method. Background Art

[0002] Thin film resistors are important components in thin film circuits, playing the role of voltage distribution, power attenuation and signal isolation. The accuracy of thin film resistors has an important impact on the performance of the circuit. Due to the influence of substrate surface morphology, sputtering uniformity, and patterning accuracy, the initial value of the resistor usually cannot meet the accuracy requirements, and the resistance adjustment method is required to make the resistance value meet the accuracy requirements.

[0003] The existing laser resistance trimming uses a small light spot with high energy density to hit the resistor on the surface of the substrate, the resistor material is vaporized, and the resistance value increases. Laser resistance trimming has the advantages of high resistance trimming accuracy and fast speed. The existing laser resistance trimming cutting methods include single-pole, double-pole, L-shaped, scanning cutting, dot cutting, etc. For DC and low-frequency circuits, single-pole, double-pole, and L-shaped cutting can meet the requirements. When the frequency increases, scanning cutting and dot cutting methods can be used. Both methods achieve the purpose of resistance trimming by changing the shape of the resistor. After the shape of the resistor changes, the performance indicators of the circuit deteriorate; in addition, when the size of the resistor is very small, when the size of the laser cutting is close to the width of the resistor, the resistance trimming accuracy decreases.

[0004] In microwave and millimeter wave circuits, the integrity of the resistor pattern has an important impact on the high-frequency performance of the circuit. It is required that the resistor pattern should not be destroyed during resistance adjustment. The existing laser resistance adjustment technology cannot meet this requirement. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a laser resistance trimming device and a laser resistance trimming method.

[0006] The present invention solves the technical problem by adopting the following technical solution: a laser resistance trimming device, comprising: a laser, emitting laser to a TaN resistor, with an operating wavelength of 808nm or 980nm; a temperature feedback system, measuring the temperature of the laser hitting the surface of the TaN resistor; a resistance measurement system, measuring the resistance value of the TaN resistor; a control system, which is respectively connected with the laser, the temperature feedback system and the resistance measurement system by signals, receives a target resistance setting, the control system adjusts the laser power of the laser according to the temperature of the TaN resistor measured by the temperature feedback system, the control system receives the resistance value of the TaN resistor measured by the resistance measurement system, and compares it with the target resistance value, and when the measured resistance value of the TaN resistor reaches the target resistance value, turns off the laser to complete the resistance trimming.

[0007] Preferably, it also includes: an optical focusing system, which is connected to the control system signal and is used to control the size of the laser spot falling on the TaN resistor.

[0008] Preferably, it also includes: a workbench movement system, which is connected to the control system signal and is used to control the workbench to the position of the next resistor for resistance adjustment.

[0009] Preferably, the laser is a semiconductor laser.

[0010] The laser resistance adjustment method comprises: adjusting the laser power of the laser according to the current temperature of the TaN resistor measured by the temperature feedback system: if the current temperature is lower than the resistance adjustment temperature, increasing the laser power; if the current temperature is higher than the resistance adjustment temperature, decreasing the laser power; if the current temperature is equal to the resistance adjustment temperature, maintaining the laser power; a resistance measurement system measures the current resistance value of the TaN resistor and compares it with the target resistance value, if the current resistance value does not reach the target resistance value, continuing the resistance adjustment; if the current resistance value reaches the target resistance value, turning off the laser to complete the resistance adjustment.

[0011] Preferably, the operating wavelength of the laser is 808 nm or 980 nm; and the resistance adjustment temperature is controlled at 350-450°C.

[0012] Preferably, a segmented resistance adjustment method is adopted.

[0013] Preferably, when the current resistance value is lower than 80% of the target resistance value, the resistance adjustment temperature is set to 400~450℃; when the current resistance value is 80%~90% of the target resistance value, the resistance adjustment temperature is set to 360~400℃; when the current resistance value is higher than 90% of the target resistance value, the resistance adjustment temperature is set to 350~360℃.

[0014] Preferably, when the current resistance value is lower than 90% of the target resistance value, the resistance adjustment temperature is set to 420-450°C; when the current resistance value reaches 90% of the target resistance value, the resistance adjustment temperature is set to 350-380°C.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The resistance trimming equipment integrates laser, temperature feedback system, optical focusing system, resistance measurement system, workbench motion system and control system. It can achieve precise resistance trimming through the collaborative work of multiple systems, and at the same time improve the accuracy and efficiency of resistance trimming; 2. The temperature feedback system is used to monitor in real time to adjust the laser power, ensuring that the temperature during the resistance adjustment process is controlled between 350℃ and 450℃, effectively controlling the oxidation process of the TaN resistor surface, thereby achieving precise adjustment of the resistance value; 3. The optical focusing system is used to control the size of the laser spot to adapt to resistors of different sizes, improve the applicability and flexibility of the equipment, and enable it to handle resistors of various specifications; 4. The control system automatically adjusts the laser power according to the feedback data of the resistance measurement system and turns off the laser when the target resistance value is reached. The automatic control reduces human intervention and improves the accuracy and consistency of resistance adjustment. 5. The workbench motion system can automatically move the resistor position to achieve continuous resistance adjustment of multiple resistors, which is beneficial to improve production efficiency and is suitable for mass production; In summary, the resistance adjustment device and the resistance adjustment method proposed in the present invention can adjust the resistance of the thin film resistor without destroying the resistor pattern and changing the shape of the resistor, thereby ensuring that the circuit has good performance when used at high frequencies; the segmented resistance adjustment can take into account both the resistance adjustment efficiency and the resistance adjustment accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of laser resistance trimming equipment.

[0017] Figure 2 It is a flow chart of the laser resistance trimming method. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0019] Embodiment 1: A laser resistance trimming device, such as Figure 1 As shown, it includes a laser, a temperature feedback system, an optical focusing system, a resistance measurement system, a workbench motion system and a control system.

[0020] Among them, the laser is a high-stability semiconductor laser to ensure the stability of output power, and the operating wavelength is 808nm or 980nm.

[0021] The temperature feedback system is used to measure the temperature of the laser hitting the resistor surface, monitor it in real time, and the control system adjusts the laser power according to the measured temperature. In the process of adjusting the resistance, the temperature is controlled at 350℃~450℃. In this temperature range, the surface of the TaN resistor begins to oxidize and the resistance increases.

[0022] The optical focusing system is used to control the size of the light spot and adjust the resistance of resistors of different sizes. The optical focusing system is equipped with an autofocus function to automatically adjust the focal length according to the size of the resistor. A beam shaper is set on the optical path to optimize the shape of the light spot so that the beam reaches the desired shape, such as circular, elliptical, rectangular, etc. At the same time, the distribution of laser energy can be adjusted, so that the energy density on the resistor to be adjusted can be more accurately controlled.

[0023] The resistance measurement system uses the Kelvin four-wire method to measure the resistance value, reducing the impact of contact resistance on the measurement accuracy, and feeding back the measured resistance value to the control system. The control system compares the measured resistance value with the target resistance value, and turns off the laser when the measured resistance value reaches the target resistance value to complete the resistance adjustment. The control system uses an industrial-grade PLC or embedded controller to achieve high-reliability control.

[0024] The workbench motion system controls the workbench to move to the next resistor position for resistance adjustment. The workbench motion system uses high-precision stepper motors or servo motors to achieve micron-level positioning accuracy. In addition, the workbench is equipped with an automatic level adjustment device to ensure stability during the resistance adjustment process; the workbench motion system supports multi-axis control to meet the resistance adjustment requirements of complex resistor arrays.

[0025] Description of the resistance adjustment process: input the target resistance value and the resistance adjustment temperature into the control system, turn on the laser, the working wavelength is 980nm, and the laser is emitted to the TaN resistor; the control system has two relatively independent control systems built in. First, the temperature feedback system measures the current temperature of the laser hitting the surface of the TaN resistor, and adjusts the laser power of the laser according to the current temperature of the TaN resistor measured by the temperature feedback system: if the current temperature is lower than the resistance adjustment temperature, increase the laser power; if the current temperature is higher than the resistance adjustment temperature, reduce the laser power; if the current temperature is equal to the resistance adjustment temperature, maintain the laser power; second, the resistance measurement system measures the current resistance value of the TaN resistor and compares it with the target resistance value. If the current resistance value does not reach the target resistance value, continue to adjust the resistance; if the current resistance value reaches the target resistance value, turn off the laser and complete the resistance adjustment.

[0026] In one embodiment, a segmented resistance adjustment method is used in the resistance adjustment process, that is, when the measured resistance value is lower than a certain proportion of the target resistance value, the laser power is increased to maintain a higher temperature range to accelerate oxidation, which is conducive to improving the resistance adjustment efficiency; when it is higher than this proportion, the laser power is lowered to maintain a lower temperature range to slow down the oxidation rate, which is conducive to improving the resistance adjustment accuracy. For example, if the current resistance value is lower than 80% of the target resistance value, the resistance adjustment temperature is set to 400~450℃; if the current resistance value is 80%~90% of the target resistance value, the resistance adjustment temperature is set to 360~400℃; if the current resistance value is higher than 90% of the target resistance value, the resistance adjustment temperature is set to 350~360℃. Alternatively, if the current resistance value is lower than 90% of the target resistance value, the resistance adjustment temperature is set to 420~450℃; if the current resistance value reaches 90% of the target resistance value, the resistance adjustment temperature is set to 350~380℃.

[0027] In this embodiment, the resistance adjustment device integrates a laser, a temperature feedback system, an optical focusing system, a resistance measurement system, a workbench motion system and a control system, and realizes precise resistance adjustment through the coordinated work of multiple systems, while improving the accuracy and efficiency of resistance adjustment; the temperature feedback system is used to monitor in real time to adjust the laser power, ensure that the temperature during the resistance adjustment process is controlled between 350°C and 450°C, and effectively control the oxidation process of the TaN resistor surface, thereby realizing precise adjustment of the resistance value; the optical focusing system is used to control the size of the laser spot to adapt to resistors of different sizes, improve the applicability and flexibility of the equipment, and enable it to handle resistors of various specifications; the control system automatically adjusts the laser power according to the feedback data of the resistance measurement system and turns off the laser when the target resistance value is reached. The automated control reduces human intervention and improves the accuracy and consistency of resistance adjustment; the workbench motion system can automatically move the resistor position to realize continuous resistance adjustment of multiple resistors, which is conducive to improving production efficiency and is suitable for mass production.

[0028] More importantly, by controlling the oxidation of the TaN resistor surface and implementing closed-loop control through an integrated system, the thin-film resistor can be adjusted without destroying the resistor pattern or changing the shape of the resistor, ensuring that the circuit has good performance when used at high frequencies.

[0029] Example 2: Combination Figure 2 Understand, the laser resistance adjustment method, first input the target resistance and adjustment temperature into the control system, turn on the laser, the working wavelength is 808nm, and emit the laser to the TaN resistor; then, the temperature feedback system measures the current temperature of the laser hitting the surface of the TaN resistor, and the resistance measurement system measures the current resistance of the TaN resistor and compares it with the target resistance. When the current resistance is lower than 90% of the target resistance, adjust the laser power to control the resistance temperature at 450℃. At this stage, the resistance oxidation speed is fast and the resistance adjustment efficiency is high; when the current resistance is higher than 90% of the target resistance, adjust the laser power to control the resistance temperature at 350℃. At this stage, the resistance oxidation speed is slow, but the resistance value is not easy to overshoot, and the resistance adjustment accuracy is high. In this way, the segmented resistance adjustment can take into account both the resistance adjustment efficiency and the resistance adjustment accuracy. It can be seen that when the resistance is adjusted in stages, the resistance adjustment temperature is not fixed. There is a corresponding resistance adjustment temperature and its corresponding control in each stage, respectively: if the current temperature is lower than the resistance adjustment temperature, increase the laser power; if the current temperature is higher than the resistance adjustment temperature, reduce the laser power; if the current temperature is equal to the resistance adjustment temperature, maintain the laser power and adjust the resistance. Finally, when the current resistance reaches the target resistance, turn off the laser and complete the resistance adjustment. During the entire resistance adjustment process, the measurement, comparison and judgment of temperature and resistance are continuous and relatively independent.

[0030] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A laser resistance trimming device, characterized in that: include: Laser, emitting laser to TaN resistor, with operating wavelength of 808nm or 980nm; Temperature feedback system, measuring the temperature of the TaN resistor surface when the laser hits it; Resistance measurement system, measuring the resistance value of TaN resistor; The control system is connected with the laser, the temperature feedback system and the resistance measurement system respectively by signals, receives the target resistance setting, and adjusts the laser power of the laser according to the temperature of the TaN resistor measured by the temperature feedback system. The control system receives the resistance value of the TaN resistor measured by the resistance measurement system and compares it with the target resistance value. When the measured resistance value of the TaN resistor reaches the target resistance value, the laser is turned off to complete the resistance adjustment.

2. The laser resistance trimming device according to claim 1, characterized in that: Also includes: The optical focusing system is connected to the control system signal and is used to control the size of the laser spot falling on the TaN resistor.

3. The laser resistance trimming device according to claim 2, characterized in that: Also includes: The workbench motion system is connected to the control system signal and is used to control the workbench to the position of the next resistor for resistance adjustment.

4. The laser resistance trimming device according to claim 3, characterized in that: The laser is a semiconductor laser.

5. A laser resistance trimming method, characterized in that: include: The laser power of the laser is adjusted according to the current temperature of the TaN resistor measured by the temperature feedback system: if the current temperature is lower than the resistor adjustment temperature, the laser power is increased; If the current temperature is higher than the resistance adjustment temperature, reduce the laser power; if the current temperature is equal to the resistance adjustment temperature, maintain the laser power; The resistance measurement system measures the current resistance value of the TaN resistor and compares it with the target resistance value. If the current resistance value does not reach the target resistance value, the resistance adjustment continues; if the current resistance value reaches the target resistance value, the laser is turned off to complete the resistance adjustment.

6. The laser resistance trimming method according to claim 5, characterized in that: The operating wavelength of the laser is 808nm or 980nm; the resistance adjustment temperature is controlled at 350~450℃.

7. The laser resistance trimming method according to claim 6, characterized in that: A segmented resistance adjustment method is adopted.

8. The laser resistance trimming method according to claim 7, characterized in that: If the current resistance value is lower than 80% of the target resistance value, set the resistance adjustment temperature to 400~450℃; if the current resistance value is 80%~90% of the target resistance value, set the resistance adjustment temperature to 360~400℃; if the current resistance value is higher than 90% of the target resistance value, set the resistance adjustment temperature to 350~360℃.

9. The laser resistance trimming method according to claim 7, characterized in that: When the current resistance value is lower than 90% of the target resistance value, the resistance adjustment temperature is set to 420~450℃; when the current resistance value reaches 90% of the target resistance value, the resistance adjustment temperature is set to 350~380℃.

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