A high-precision laser resistance adjusting method with parabolic grading

Abstract

The present application relates to the technical field of laser resistance adjustment, and particularly relates to a high-precision laser resistance adjustment method with parabolic regulation grading. By setting resistance increments changing according to a parabolic law, establishing a data table of each resistance adjustment increment and error before resistance adjustment, and the corresponding relationship between the resistance adjustment point and the resistance increment, the increment of resistance adjustment is selected automatically in real time during the resistance adjustment process, so that the resistance to be adjusted can quickly approach the target resistance value, and then a short fine adjustment line is cut to complete the resistance adjustment. By setting the resistance increments changing according to a parabolic law, the number of resistance adjustment is effectively reduced, and in the graded resistance adjustment, only the pattern line of the resistance adjustment point needs to be cut, without continuous cutting, and in the fine adjustment process, a long fine adjustment line does not need to be cut, but only a short fine adjustment line needs to be cut by laser, so that the resistance adjustment process is simplified, the heat generated in the resistance adjustment process is greatly reduced, and the resistance adjustment precision and efficiency are improved.

Description

Technical Field

[0001] This invention relates to laser trimming, and more particularly to a high-precision laser trimming method that uses a parabolic gradient. Background Technology

[0002] A typical resistance value of a thin-film platinum resistance temperature sensor at 0 ℃ is 100.000 ± 0.059 Ω. Common thin-film batch forming processes often fail to meet this requirement directly, necessitating adjustments in subsequent processes. Laser cutting of the thin-film pattern for adjustment is a common method, theoretically achieving both efficiency and accuracy. However, continuous laser cutting generates significant heat, causing temperature variations that alter the resistance of the film being adjusted, thus affecting the adjustment process and its accuracy. Therefore, minimizing heat generation during laser adjustment is a crucial consideration for improving accuracy.

[0003] Patent CN113284688A discloses a method for adjusting the resistance of a high-temperature thin-film platinum resistance thermometer with dual fine-tuning lines. This method involves cutting a short fine-tuning line after cutting a long fine-tuning line to compensate for the error caused by the heat generated during the first cutting of the long fine-tuning line, thereby improving the accuracy of the resistance adjustment. However, it only discloses the fine-tuning process, not the coarse-tuning process, or that coarse-tuning is unnecessary. This requires high precision in thin-film pattern preparation and still necessitates cutting the long fine-tuning line, generating a large amount of heat. Therefore, during the resistance adjustment process, it is necessary to wait for the resistor being adjusted to cool down, which is detrimental to improving the efficiency of mass production.

[0004] Patent CN111609947A discloses a method for adjusting the resistance of a high-precision temperature sensor chip. This method involves cutting pre-designed short-circuit resistor strips from a thin-film pattern, connecting these fixed-value resistor strips in series with the main resistor strips to raise the resistance to near the target value. Multiple adjustment pieces are then cut to achieve fine-tuning. However, in this method, the resistances of the multiple fixed-value resistor strips in the adjustment circuit are equal or decreasing. Adjustment requires continuously cutting multiple short-circuit resistor strips, and this process is repeated for each stage of the adjustment circuit. After cutting the multiple short-circuit resistor strips, multiple adjustment pieces still need to be cut for fine-tuning, resulting in a large number of cuts. Summary of the Invention

[0005] This invention aims to address the aforementioned shortcomings by providing a high-precision laser trimming method based on a parabolic gradient. This invention sets a parabolic resistance increment and establishes a data table of the resistance increment and error for each trimming stage before trimming. During the trimming process, the method automatically selects the adjustment increment in real time, allowing the tuned resistor to quickly approach the target resistance value. Finally, a short fine-tuning line is cut to complete the trimming. By setting a parabolic resistance increment, the number of trimming operations is effectively reduced. In the graded trimming, the laser only needs to cut the pattern lines at the trimming points, eliminating the need for continuous cutting. Furthermore, during the fine-tuning process, only a short fine-tuning line needs to be cut, simplifying the trimming process and significantly reducing the heat generated, thereby improving trimming accuracy and efficiency.

[0006] To overcome the deficiencies in the prior art, the technical solution adopted by the present invention to solve its technical problem is: a high-precision laser trimming method with parabolic graded steps, comprising the following steps:

[0007] S1. Determine the parameters before adjusting the resistance, including the following steps:

[0008] S101. Determine the target resistance R0 at 0 ℃;

[0009] S102. Determine the temperature coefficient of resistance α of the resistor being adjusted;

[0010] S103. Determine the ambient temperature T of the area where the resistor is located;

[0011] S104. Determine the target resistance value R1 at the current temperature T based on the temperature coefficient of resistance;

[0012] S105. Determine the required range of the target resistance R1 at the current temperature T;

[0013] S106. Establish a data table of resistance increment and error at each resistance adjustment point under the current temperature T, where the resistance increment changes parabolically;

[0014] S107. Establish a program to correlate the position of the resistance adjustment point with the resistance increment, so as to automatically select the resistance adjustment point;

[0015] S2. Graded resistance adjustment, including the following steps:

[0016] S201. Measure the current value of the controlled resistor;

[0017] S202. Determine whether the current adjusted resistor value is within the design range. If yes, proceed to S203; otherwise, proceed to step S4.

[0018] S203. Automatically select and laser-cut the trimming point according to the data table in step 106;

[0019] S204. Measure the resistance value;

[0020] S205. Determine whether it is less than 99% of the target resistance value at the current temperature. If yes, proceed to step S206; otherwise, proceed to step S207.

[0021] S206. Determine if there is a usable resistance adjustment point. If yes, proceed to step S203; otherwise, proceed to step S4.

[0022] S207. Determine whether the resistance is greater than the target upper limit. If yes, proceed to step S4; otherwise, proceed to step S208.

[0023] S208. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S301.

[0024] S3. Continuous fine-tuning, including the following steps:

[0025] S301. Cutting short fine-tuning lines: Due to the multi-level micro-resistance increments set in the graded resistance adjustment, the continuous fine-tuning process only requires cutting one short fine-tuning line, and the continuous laser cutting path is short, so as to reduce the generation of heat.

[0026] S302. Monitor resistance value;

[0027] S303. Determine whether the resistance is less than the target lower limit. If yes, proceed to step S301; otherwise, proceed to step S304.

[0028] S304. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S4.

[0029] S4. Scrapped;

[0030] S5. Complete the resistance adjustment.

[0031] According to another embodiment of the present invention, step S103 further includes determining the ambient temperature at which the resistance is adjusted by means of a standard resistance temperature sensor or by measuring a general resistor with a high-precision resistance value of the target resistance value.

[0032] According to another embodiment of the present invention, step S105 further includes determining the required range of the target resistance at the current temperature by means of the required range of the target resistance R0 at 0 °C, the range of the resistance temperature coefficient of the adjusted resistance, and the current temperature error range.

[0033] According to another embodiment of the present invention, the resistance increment achieved by laser cutting each trimming point in step S203 varies parabolically. Because the resistance increment in the graded trimming varies parabolically, the target resistance value can be quickly approached during the graded trimming process, eliminating the need for multiple laser cuts. Because the resistance increment in the graded trimming varies parabolically, the cutting of long fine-tuning lines can be eliminated during continuous fine-tuning. The process of cutting long fine-tuning lines is replaced by the small resistance increment achieved by cutting a portion of the trimming points in the graded trimming, thereby avoiding the large amount of heat generated by cutting long fine-tuning lines.

[0034] According to another embodiment of the present invention, the step S2 of graded resistance adjustment further includes the selection of the resistance adjustment point being automatically performed by a pre-set program. The selection of the resistance adjustment point can be automatically performed by a pre-set program using a pre-established table of resistance increments and errors achieved by cutting the resistance adjustment point, as well as a table of data corresponding to the position of the resistance adjustment point and the resistance increment.

[0035] According to another embodiment of the present invention, the step S2 graded resistance adjustment further includes real-time monitoring of the adjusted resistance value to improve efficiency and automatic selection of the adjustment point, and the step S3 continuous fine adjustment requires real-time monitoring of the adjusted resistance value to control the continuous laser cutting of short fine adjustment line paths.

[0036] According to another embodiment of the present invention, the laser cutting method in step S203 is further included as linear cutting or laser point cutting.

[0037] According to another embodiment of the present invention, the cutting method in step S301 is further included as straight cutting, L-shaped cutting or laser point cutting.

[0038] The beneficial effects of this invention are as follows: By setting a resistance increment that changes parabolically, and establishing a data table of resistance increment and error for each stage of adjustment before adjustment, the adjustment increment is judged in real time and automatically selected during the adjustment process, allowing the adjusted resistor to quickly approach the target resistance value. Then, a short fine-tuning line is cut to complete the adjustment. By setting a parabolically changing resistance increment, the number of adjustment steps is effectively reduced. Furthermore, in the staged adjustment, only the resistance line needs to be cut, not continuously. In the fine-tuning process, only a short fine-tuning line needs to be cut, and the laser continuous cutting path is short. Therefore, the adjustment process is simplified, the heat generated during adjustment is greatly reduced, and the adjustment accuracy and efficiency are improved. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 This is a flowchart of the present invention;

[0041] Figure 2 This is a schematic diagram of the circuit pattern used in the embodiments of the present invention;

[0042] Figure 3 This is a graph showing the resistance increment changes at each level in the graded resistance adjustment scheme of this invention.

[0043] Figure 4 This is a graph showing the change in resistance during the resistance adjustment process according to an embodiment of the present invention;

[0044] Wherein: 100 is the substrate, 200 is the electrode, 300 is the setpoint circuit, 400 is the graded resistance adjustment circuit, 401 ~ 410 are the adjustment points of the graded resistance adjustment circuit, and 500 is the continuous fine adjustment circuit. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] This embodiment provides a high-precision laser trimming method based on a parabolic gradient, the flowchart of which is shown below. Figure 1 As shown, it includes the following steps:

[0047] S1. Determine the parameters before adjusting the resistance, including the following steps:

[0048] S101. Determine the target resistance R0 at 0 ℃;

[0049] S102. Determine the temperature coefficient of resistance α of the resistor being adjusted;

[0050] S103. Determine the ambient temperature T of the area where the resistor is located;

[0051] S104. Determine the target resistance value R1 at the current temperature T based on the temperature coefficient of resistance;

[0052] S105. Determine the required range of the target resistance R1 at the current temperature T;

[0053] S106. Establish a data table of resistance increment and error at each adjustable point under the current temperature T, where the adjustable points are as follows: Figure 2 As shown in the figure, 401 to 410 are different levels of resistance adjustment points. The resistance increment achieved by laser cutting of resistance adjustment points 401 to 410 exhibits a parabolic variation, as follows: Figure 3 As shown;

[0054] S107. Establish a program to correspond the position of the resistance adjustment point to the resistance increment, so as to automatically select the resistance adjustment point.

[0055] S2. Graded resistance adjustment, including the following steps:

[0056] S201. Measure the current value of the controlled resistor;

[0057] S202. Determine whether the current adjusted resistor value is within the design range. If yes, proceed to S203; otherwise, proceed to step S4.

[0058] S203. Automatically select and cut the adjustment point according to the data table to achieve resistance increase, and the resistance increase curve is as follows: Figure 4 As shown, Figure 4 The left half of the curve represents the resistance increase achieved through stepped resistance adjustment;

[0059] S204. Measure the resistance value;

[0060] S205. Determine whether it is less than 99% of the target resistance value at the current temperature. If yes, proceed to step S206; otherwise, proceed to step S207.

[0061] S206. Determine if there is a usable resistance adjustment point. If yes, proceed to step S203; otherwise, proceed to step S4.

[0062] S207. Determine whether the resistance is greater than the target upper limit. If yes, proceed to step S4; otherwise, proceed to step S208.

[0063] S208. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S301.

[0064] S3. Continuous fine-tuning, including the following steps:

[0065] S301. Cut short adjustment leads to achieve fine resistance adjustment, such as... Figure 4 As shown, Figure 4 The right half of the curve represents the resistance increase achieved through continuous fine-tuning;

[0066] S302. Monitor resistance value;

[0067] S303. Determine whether the resistance is less than the target lower limit. If yes, proceed to step S301; otherwise, proceed to step S304.

[0068] S304. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S4.

[0069] S4. Scrapped.

[0070] S5. Complete the resistance adjustment.

[0071] Preferably, in step S1, which determines the parameters before adjusting the resistance, step S103, which determines the ambient temperature at which the resistance is adjusted, can be achieved using a standard resistance temperature sensor.

[0072] Preferably, in step S1, determining the parameters before adjusting the resistance, step S103, determining the ambient temperature at which the resistance is adjusted can be replaced by measuring a general resistor with a high-precision resistance value that is the target resistance value.

[0073] Preferably, in step S1, which determines the parameters before resistance adjustment, step S105, which determines the required range of the target resistance at the current temperature, can be determined by the required range of the target resistance R0 at 0 ℃, the range of the resistance temperature coefficient of the adjusted resistance, and the current temperature error range.

[0074] Preferably, in step S2 graded resistance adjustment, the resistors to be adjusted whose resistance values ​​are within the design range are screened before resistance adjustment through steps S201 and S202, so as to avoid the resistance adjustment process of the resistors to be adjusted outside the design range, thereby improving efficiency.

[0075] Preferably, in step S2 graded resistance adjustment, the resistance increment achieved by laser cutting each resistance adjustment point in step S203 changes in a parabolic manner.

[0076] Preferably, in step S2, the resistance increment changes parabolically during the graded resistance adjustment, allowing the target resistance value to be quickly approached, thus eliminating the need for multiple laser cuts.

[0077] Preferably, in step S2 graded resistance adjustment, the resistance increment and error achieved by the pre-established cutting resistance adjustment point, as well as the data table corresponding to the position of the resistance adjustment point and the resistance increment, can be automatically performed by the set program in step S203.

[0078] Preferably, in step S2, the resistance increment changes parabolically during the graded resistance adjustment. Therefore, the cutting of the long fine adjustment wire can be omitted during the continuous fine adjustment process in step S3. The process of cutting the long fine adjustment wire is replaced by the small resistance increment achieved by cutting part of the adjustment point in step S203 of the graded resistance adjustment, thereby avoiding the large amount of heat generated by cutting the long fine adjustment wire.

[0079] Preferably, in the continuous fine-tuning step S3, due to the multi-level micro-resistance increments set in the graded resistance adjustment step S2, the continuous fine-tuning process in step S301 only needs to cut a short fine-tuning line, and the laser continuous cutting path is short, so as to reduce the generation of heat.

[0080] Preferably, in step S2, the resistance value being adjusted is monitored in real time to improve efficiency and enable automatic selection of the resistance adjustment point in step S203.

[0081] Preferably, in step S3 continuous fine-tuning, the value of the tuned resistance is monitored in real time so as to control the short fine-tuning line path of laser continuous cutting in step S301.

[0082] Preferably, in step S2 graded resistance adjustment, the laser cutting method in step S203 is linear cutting or laser point cutting.

[0083] Preferably, in the continuous fine-tuning step S3, the laser cutting method in step S301 is either straight-line cutting or L-shaped cutting.

[0084] Preferably, steps S2 (gradual resistance adjustment) and S3 (continuous fine adjustment) include multiple resistance measurements and automatic judgment processes to perform screening before and after resistance adjustment.

[0085] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision laser trimming method based on a parabolic gradient, characterized in that, The resistance adjustment method includes the following steps: S1. Determine the parameters before adjusting the resistance, including the following steps: S101. Determine the target resistance R0 at 0 ℃; S102. Determine the temperature coefficient of resistance α of the resistor being adjusted; S103. Determine the ambient temperature T of the area where the resistor is located; S104. Determine the target resistance value R1 at the current temperature T based on the temperature coefficient of resistance; S105. Determine the required range of the target resistance R1 at the current temperature T; S106. Establish a data table of resistance increment and error at each resistance adjustment point under the current temperature T, where the resistance increment changes parabolically; S107. Establish a program to correlate the position of the resistance adjustment point with the resistance increment, so as to automatically select the resistance adjustment point; S2. Graded resistance adjustment, including the following steps: S201. Measure the current value of the controlled resistor; S202. Determine whether the current adjusted resistor value is within the design range. If yes, proceed to S203; otherwise, proceed to step S4. S203. Automatically select and laser-cut the trimming point according to the data table in step 106; S204. Measure the resistance value; S205. Determine whether it is less than 99% of the target resistance value at the current temperature. If yes, proceed to step S206; otherwise, proceed to step S207. S206. Determine if there is a usable resistance adjustment point. If yes, proceed to step S203; otherwise, proceed to step S4. S207. Determine whether the resistance is greater than the target upper limit. If yes, proceed to step S4; otherwise, proceed to step S208. S208. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S301. S3. Continuous fine-tuning, including the following steps: S301. Cut short fine-tuning lines; S302. Monitor resistance value; S303. Determine whether the resistance is less than the target lower limit. If yes, proceed to step S301; otherwise, proceed to step S304. S304. Determine whether the resistance is within the target resistance requirement range. If yes, proceed to step S5; otherwise, proceed to step S4. S4. Scrapped; S5. Complete the resistance adjustment.

2. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: The step S103 determines the ambient temperature at which the resistance is adjusted by using a standard resistance temperature sensor or by measuring a general resistor with a high-precision resistance value that is the target resistance value.

3. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: Step S105 determines the required range of the target resistance at the current temperature by using the required range of the target resistance R0 at 0 ℃, the range of the resistance temperature coefficient of the adjusted resistance, and the current temperature error range.

4. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: The resistance increment achieved by laser cutting at each adjustment point in step S203 changes in a parabolic manner.

5. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: During the step S2 graded resistance adjustment process, the selection of the resistance adjustment point can be automatically performed by the set program.

6. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: In step S2, graded resistance adjustment, and in step S3, continuous fine adjustment, the value of the adjusted resistance needs to be monitored in real time.

7. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: The laser cutting method in step S203 is either linear cutting or laser point cutting.

8. The high-precision laser trimming method based on parabolic gradient as described in claim 1, characterized in that: The cutting method in step S301 is straight cutting, L-shaped cutting, or laser point cutting.

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