Method for detecting failure of silver alloy sheet-shaped electric contact sheet corrosion inhibition treatment and regulation system

Abstract

The application discloses a silver alloy sheet-shaped electric contact piece corrosion inhibition treatment failure detection method and a regulation and control system, and comprises the following steps: S1: obtaining the thickness d of an organic protective film on the surface of the electric contact piece in real time through an ellipsometric spectrum org and the thickness d of an oxide film ox ; S2: inputting the thickness d of the organic protective film org or the thickness d of the oxide film ox into a preset film thickness-contact resistance correlation model to obtain a predicted contact resistance value R c ; S3: when the predicted contact resistance R c is less than or equal to 25 mΩ, the electric contact piece is determined to be qualified, and when the predicted contact resistance R c is greater than 25 mΩ, the electric contact piece is determined to be failed, a back-end processing flow is triggered, and a front-end cleaning process is returned. The application utilizes the dynamic change effect of the predicted contact resistance value R c to determine the failure of the electric contact piece in the front-end cleaning process, to timely investigate the causes of the failure of the cleaning tank, and to improve the timeliness and reliability of the electric contact piece failure detection.

Description

Technical Field

[0001] This invention relates to the field of surface treatment production technology for electrical contact pieces used in the manufacture of electrical switches, relays, contactors, circuit breakers and other equipment, and particularly to a failure detection method and control system for corrosion inhibition treatment of silver alloy electrical contact pieces. Background Technology

[0002] Electrical contacts are key components in the manufacture of electrical switches, relays, contactors, circuit breakers, and other equipment, responsible for carrying current and breaking circuits. Their quality is a major factor determining the service life of electrical equipment. Silver-based contacts, due to their excellent thermal and electrical conductivity, resistance to arc erosion, and low self-loss, have long been the preferred material for high-end contacts. Silver alloy sheet electrical contact devices, as core electrical contact components in electrical equipment, typically use silver-based materials to achieve excellent conductivity. However, during production and use, their surfaces are susceptible to corrosion from environmental media. H2O molecules in the environmental medium react with Cl... - Corrosive ions can also penetrate to the interface through silver layer defects, exacerbating corrosion and worsening contact resistance stability. This type of corrosion is insidious and is often only discovered during the finished product inspection stage. The residual corrosive contaminants themselves have high resistivity characteristics and may induce subsequent continuous corrosion (including accelerating the oxidation of alloying elements), ultimately leading to a significant increase in contact resistance and deterioration in stability, affecting the reliability of equipment switching.

[0003] To address the aforementioned electro-corrosion problem, corrosion inhibitors are typically added during the cleaning process of silver alloy sheet-shaped electrical contacts. These inhibitors form an effective slow-release film on the surface of the silver alloy sheet-shaped electrical contacts, constructing a dense protective layer on the metal surface. This protective layer effectively isolates the metal from H2O and Cl-. - Direct contact with corrosive media inhibits metal corrosion, effectively protecting the metal surface of the silver alloy sheet electrical contact. During the post-processing cleaning and protection of the silver alloy sheet electrical contact, contact resistance testing is performed on a sample basis to ensure the formation of an effective slow-release film on the surface, thus guaranteeing effective protection. However, current technology relies on destructive sampling for contact resistance testing, which is inefficient, lacks full coverage, and is prone to delays. During testing, if a worker discovers that the slow-release film on one silver alloy sheet electrical contact has failed, the slow-release film on the remaining contacts in the post-processing cleaning has already failed in batches. Summary of the Invention

[0004] In view of the existing problems, the present invention needs to design a detection method that can quickly and real-time judge the failure of the corrosion inhibition film during the cleaning process of the silver alloy sheet-shaped electrical contact piece, so as to ensure the quality of the cleaning process of the silver alloy sheet-shaped electrical contact piece and improve the yield rate of the silver alloy sheet-shaped electrical contact piece.

[0005] In view of this, the technical solution provided by the present invention is: a failure detection method for the corrosion inhibition treatment of a silver alloy electrical contact piece, including the following steps:

[0006] S1: Obtain the thickness of the organic protective film on the surface of the electrical contact piece as d org and the thickness of the oxide film as d ox ;

[0007] S2: Input the thickness of the organic protective film d org or the thickness of the oxide film d ox into the preset film thickness-contact resistance correlation model, and output the predicted contact resistance value R c ;

[0008] S3: When the predicted contact resistance R c ≤25 mΩ, it is determined that the electrical contact piece is qualified. When the predicted contact resistance R c >25 mΩ, it is determined that the electrical contact piece fails, trigger the back-end processing flow, and return to the front-end cleaning process.

[0009] The preset film thickness-contact resistance correlation model is constructed based on Holm contact theory and satisfies the following general form: R c =R const +R org +R ox (1)

[0010] In formula (1), the R const is the contraction resistance independent of the film layer, with the unit of mΩ, and its calculation is as follows:

[0011] R const =500×ρ×sqrt(π×H / F) (2)

[0012] ρ is the resistivity of the electrical contact piece material, with the unit of Ω·m, H is the hardness of the electrical contact piece material, with the unit of Pa, and F is the contact pressure, with the unit of N.

[0013] In formula (1), the R org is the resistance function related to the organic film thickness, with the unit of mΩ, and its calculation is as follows:

[0014] R org =ρ org ×d org ×10 -6 / Anom (3)

[0015] ρ org The resistivity of the organic film is expressed in Ω·m and d. org The thickness of the organic film is expressed in nm (A). nom The nominal contact area of ​​the electrical contact piece, in meters (m²). 2 .

[0016] (1) In the formula, R ox The resistance function related to the oxide film thickness, in mΩ, is calculated as follows:

[0017] R ox =h 2 ×d ox ×exp[4×π×d ox ×sqrt(2×m×Phi) / h] / [A nom ×e 2 ×sqrt(2×m×Phi )] (4)

[0018] Phi is the barrier height, measured in exV, and h is Planck's constant, h = 6.62607015 × 10⁻⁶. -34 J·s, where m is the electron mass, m = 9.1093837139 × 10 -28 g and e are the electron charges, e = 1.6 × 10⁻⁶ -19 C (Coulomb).

[0019] Further, in step S3, the backend processing flow is performed according to the following method:

[0020] S4: When d ox If the value is greater than d1, it is determined that the pickling is insufficient; where d1 is the oxide film threshold in nm.

[0021] S5: When d org< d2, determined to be the failure of the corrosion inhibitor, when d org If the value is greater than d3, it is determined that the corrosion inhibitor concentration is too high. Here, d2 and d3 are the organic film thresholds, with units of nm.

[0022] The values ​​of d1, d2, and d3 are determined based on the application scenario of the silver alloy sheet electrical contact device (such as high-voltage circuit breakers and low-voltage switches) and the corrosion inhibitor system. Typical values ​​are d1 (0.8~1.2nm), d2 (2.0~2.8nm), and d3 (3.4~4.0nm).

[0023] This invention also includes a detection and control system designed for the failure detection method of corrosion inhibition treatment of silver alloy electrical contact sheets, comprising:

[0024] The ellipsometry detection unit includes a station for positioning electrical contact pieces and a detection device for performing ellipsometry scanning at the station. The detection device is electrically connected to a control motherboard, which displays in real time the measured thickness d of the organic protective film detected by the detection device. org and oxide film thickness d ox The control motherboard sets the thickness d of the organic protective film. org and the oxide film thickness d ox Transmitted to the following processing unit;

[0025] The resistance prediction unit has a built-in preset film thickness-contact resistance correlation model and receives the organic protective film thickness d transmitted from the control motherboard. org and the oxide film thickness d ox And based on the preset film thickness-contact resistance correlation model, through R c =R const +R org +R ox The predicted R c Value, and predict the R c The value is transmitted to the next processing unit;

[0026] The process decision unit receives R transmitted from the resistance prediction unit. c Value, when predicting contact resistance R c When the impedance is >25 mΩ, the transmission execution signal is sent to the next processing unit;

[0027] The actuator receives the execution signal from the process decision unit and sorts the defective electrical contact pieces to the corresponding rework process tank.

[0028] This invention utilizes the predicted contact resistance value R c To determine the quality of the cleaning process for silver alloy sheet electrical contacts and predict the contact resistance value R. c The dynamic changes in the electrical contact pieces are observed, and the failure status of the electrical contact pieces in the front-end cleaning process is comprehensively judged. Thus, in the actual cleaning process, the cause of the malfunction in the cleaning tank can be investigated in a timely manner, improving the timeliness and reliability of electrical contact piece failure detection. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the failure detection method for the corrosion inhibition treatment of silver alloy electrical contact sheets according to the present invention. Detailed Implementation

[0030] The embodiments of the present invention will now be briefly described with reference to the accompanying drawings.

[0031] See attached document Figure 1, A failure detection method for corrosion inhibition treatment of silver alloy electrical contact sheets, comprising the following steps:

[0032] S1: Obtain the thickness of the organic protective film on the surface of the electrical contact sheet as d org and the thickness of the oxide film as d ox ;

[0033] S2: Input the thickness d org of the organic protective film or the thickness d ox of the oxide film into a preset film thickness-contact resistance correlation model, and output the predicted contact resistance value R c ;

[0034] S3: When the predicted contact resistance R c ≤ 25 mΩ, determine that the electrical contact sheet is qualified. When the predicted contact resistance R c > 25 mΩ, determine that the electrical contact sheet fails, trigger the back-end processing flow, and return to the front-end cleaning process;

[0035] The preset film thickness-contact resistance correlation model is constructed based on Holm contact theory and satisfies the following general form: R c =R const +R org +R ox (1)

[0036] In formula (1), the R const is the constriction resistance independent of the film layer, with the unit of mΩ, and its calculation is as follows:

[0037] R const =500×ρ×sqrt(π×H / F) (2)

[0038] ρ is the resistivity of the electrical contact sheet material, with the unit of Ω·m, H is the hardness of the electrical contact sheet material, with the unit of Pa, F is the contact pressure, with the unit of N, and sqrt in formula (2) represents the square root symbol;

[0039] In formula (1), the R org is the resistance function related to the organic film thickness, with the unit of mΩ, and its calculation is as follows:

[0040] R org =ρ org ×d org ×10 -6 / A nom (3)

[0041] ρ org is the resistivity of the organic film, with the unit of Ω·m, d org is the thickness of the organic film, with the unit of nm, A nomThe nominal contact area of ​​the electrical contact piece, in meters (m²). 2 ;

[0042] (1) In the formula, R ox The resistance function related to the oxide film thickness, in mΩ, is calculated as follows:

[0043] R ox =h 2 ×d ox ×exp[4×π×d ox ×sqrt(2×m×Phi) / h] / [A nom ×e 2 ×sqrt(2×m×Phi)] (4)

[0044] Phi is the barrier height, measured in exV, and h is Planck's constant, h = 6.62607015 × 10⁻⁶. -34 J·s, where m is the electron mass, m = 9.1093837139 × 10 -28 g and e are the electron charges, e = 1.6 × 10⁻⁶ -19 C (Coulomb), in equation (4), sqrt represents the square root symbol.

[0045] In step S3, the backend processing flow is performed as follows:

[0046] S4: When d ox If the value is greater than d1, it is determined that the pickling is insufficient; where d1 is the oxide film threshold in nm.

[0047] S5: When d org< d2, determined to be the failure of the corrosion inhibitor, when d org If the value is greater than d3, it is determined that the corrosion inhibitor concentration is too high. Here, d2 and d3 are the organic film thresholds, with the unit being nm.

[0048] d1 is the oxide film threshold, and d2 and d3 are the organic film thresholds, which are determined by the type of corrosion inhibitor and the type of electrical contact. In this embodiment, specifically, when AgSnO2In2O3 contacts are used and the corrosion inhibitor is a methylimidazolium corrosion inhibitor system, d1 is 1.0 nm, d2 is 2.4 nm, and d3 is 3.5 nm.

[0049] This invention also includes a detection and control system designed for the failure detection method of corrosion inhibition treatment of silver alloy sheet-like electrical contacts, comprising:

[0050] The ellipsometry detection unit includes a station for positioning electrical contact pieces and a detection device for performing ellipsometry scanning at the station. The detection device is electrically connected to a control motherboard, which displays in real time the measured thickness d of the organic protective film detected by the detection device.org and oxide film thickness d ox The control motherboard sets the thickness d of the organic protective film. org and the oxide film thickness d ox Transmitted to the following processing unit;

[0051] The resistance prediction unit has a built-in preset film thickness-contact resistance correlation model and receives the organic protective film thickness d transmitted from the control motherboard. org and the oxide film thickness d ox And based on the preset film thickness-contact resistance correlation model, through R c =R const +R org +R ox The predicted R c Value, and predict the R c The value is transmitted to the next processing unit;

[0052] The process decision unit receives R transmitted from the resistance prediction unit. c Value, when predicting contact resistance R c When the impedance is >25 mΩ, the transmission execution signal is sent to the next processing unit;

[0053] The actuator receives the execution signal from the process decision unit and sorts the defective electrical contact pieces to the corresponding rework process tank.

[0054] Example 1

[0055] No corrosion inhibitors were added during the initial cleaning process. The silver alloy sheet-like electrical contacts after cleaning were then inspected. These contacts were AgSnO2In2O3 contacts with a diameter of 4 mm. An elliptic polarization spectrometer (SENTECH, SEUV800, Germany) was used to characterize the surface of the contacts. This instrument is equipped with both xenon and halogen lamps and measures in the 701 wavelength unit (200–900 nm). The thickness d of the organic protective film on the contact surface was obtained in real-time using elliptic polarization spectroscopy. org =0nm, oxide film thickness is d ox =1.22nm, where R const The calculation formula is as follows:

[0056] R const =500×ρ×sqrt (π×H / F) (2)

[0057] (2) In the formula, ρ is the resistivity of silver, 1.59 × 10⁻⁶. -8 Ω·m, where H is the hardness of silver (7.8456 × 10⁻⁶). 8Pa and F represent contact pressure. In electrical switches, relays, contactors, circuit breakers, and other equipment, the contact pressure is usually calculated as 7g. In this embodiment, the contact pressure is calculated as 7g, i.e., F = 0.0686 N.

[0058] R is calculated using equation (1). const =1.507mΩ, the magnitude of which is determined by the inherent properties of the material and the contact pressure, and is independent of the film layer.

[0059] (1) In the formula, R org The calculation is as follows:

[0060] R org =ρ org ×d org ×10 -6 / A nom (3)

[0061] ρ org ρ is the resistivity of the organic film. org =0.78Ω·m, A nom Given the nominal contact area of ​​the electrical contact piece, and a diameter of 4 mm, the nominal contact area can be calculated to be 1.256 × 10⁻⁶ mm. -5 m 2 R is calculated using equation (3). org =0 mΩ.

[0062] (1) In the formula, R ox The resistance function is related to the oxide film thickness and is dominated by the quantum tunneling effect of the oxide layer on the metal surface. Its calculation is as follows:

[0063] R ox =h 2 ×d ox ×exp[4×π×d ox ×sqrt(2×m×Phi) / h] / [A nom ×e 2 ×sqrt(2×m×Phi)] (4)

[0064] Phi is the barrier height, measured in eV. The barrier height for Ag₂O is taken as 3.0 eV. h is Planck's constant, h = 6.62607015 × 10⁻⁶. -34 J·s, where m is the electron mass, m = 9.1093837139 × 10 -28 g and e are the electron charges, e = 1.6 × 10⁻⁶ -19 C (Coulomb), after simplification, can be obtained as equation (5):

[0065] R ox =26×d ox×exp(9.8×d ox ) / A nom (5)

[0066] After calculation, R is obtained. ox =39.33 mΩ. In conclusion, using the detection method of the present invention, the predicted resistance value R can be obtained. c =R const +R org +R ox =40.84 mΩ, R c A resistance greater than 25 mΩ indicates a failure of the electrical contact piece. This suggests that the cleaning process at the front end did not include an etching agent, leading to excessive corrosion of the contact piece in acidic conditions. The resulting thick oxide film on the contact piece further contributes to the failure of the R... ox The value is significantly higher than expected, thus the predicted resistance value R is higher. c The critical value is greater than 25 mΩ, which is further determined through the back-end processing. The value of d2 is 2.4 nm. org< d2 indicates that the corrosion inhibitor has failed, meaning that the concentration of the corrosion inhibitor is too low or there is no corrosion inhibitor. In the cleaning process, because the corrosion inhibitor is not effective enough for the electrical contact piece, it is necessary to add corrosion inhibitor or increase the concentration of corrosion inhibitor in the cleaning process to achieve a better corrosion inhibition effect on the electrical contact piece.

[0067] The above-treated silver alloy sheet-shaped electrical contact was tested using existing contact resistance testing methods, referring to GB / T 15078-2021. The contact resistance was measured using the four-terminal resistance measurement method under DC conditions: a current of 0.1 A, an open-circuit voltage of 6 V, and a static contact pressure of 7 g. The contact resistance was calculated by measuring the ratio of the voltage drop across the probe and the contact sheet to the loop current, using the following formula:

[0068] R=Delta(U) / I (6)

[0069] In the formula, R is the contact resistance in Ω; Delta(U) is the voltage drop between the probe and the electrical contact in mV; and I is the contact current in mA.

[0070] The actual measured and calculated contact resistance R = 3.909 × 10⁻⁶ -2 Ω, actual measured resistance value R of the present invention c Compared to 40.84 mΩ, the error value is 4.3%, and the error is less than 5%, indicating good reliability.

[0071] It should be noted that during the process of measuring the contact resistance of the silver alloy sheet-shaped electrical contact piece by the existing method, in order to ensure good contact between the four terminals and the silver alloy sheet-shaped electrical contact piece, the silver alloy sheet-shaped electrical contact piece is inevitably damaged to a certain extent. Therefore, the existing contact resistance measurement is a destructive test. The reliability of the silver alloy sheet-shaped electrical contact piece after the contact resistance measurement is greatly reduced, and it is usually scrapped or repaired after the test.

[0072] Example 2

[0073] Add 20 ppm of methylimidazole as a corrosion inhibitor to the cleaning solution in the front-end cleaning process, and detect the silver alloy sheet-shaped electrical contact piece after the cleaning process. The contact is an AgSnO2In2O3 contact, the diameter of the electrical contact piece used is 4 mm, and an ellipsometer (SENTECH, SEUV800, Germany) is used to characterize the surface of the electrical contact piece. This instrument is equipped with a xenon lamp and a halogen lamp, and the measurement range is 701 wavelength units from 200 to 900 nm. The thickness d of the organic protective film on the surface of the electrical contact piece is obtained in real time through ellipsometry org = 3.10 nm, the thickness of the oxide film is d ox = 0.45 nm, R const Calculate in the same way as in Example 1, and obtain R const = 1.507 mΩ, and obtain R org = 19.25 mΩ, and obtain R ox = 0.01 mΩ. To sum up, by using the detection method of the present invention, the predicted resistance value R c = R const + R org + R ox = 20.77 mΩ, R c < 25 mΩ, and it is judged that the electrical contact piece is qualified.

[0074] For the above-mentioned treated contacts, the existing contact resistance measurement method is used, and the test method is the same as in Example 1. The actually measured and calculated contact resistance R = 1.896×10 -2 Ω. Compared with the predicted resistance value R c = 20.77 mΩ of the present invention, the error value is 8.71%, the error is less than 10%, and the reliability is good.

[0075] Example 3

[0076] Add 40 ppm of methylimidazole as a corrosion inhibitor to the cleaning solution in the front-end cleaning process, and detect the silver alloy sheet-shaped electrical contact piece after the cleaning process. The contact is an AgSnO2In2O3 contact. The diameter of the electrical contact piece used is 4 mm. Use an ellipsometer (SENTECH, SEUV800, Germany) to characterize the surface of the electrical contact piece. This instrument is equipped with a xenon lamp and a halogen lamp, and has a 701 wavelength unit with a measurement range of 200 - 900 nm. Obtain the thickness d of the organic protective film on the surface of the electrical contact piece in real time through ellipsometry org = 3.29 nm, and the thickness of the oxide film is d ox = 0.29 nm, R const Calculate as in Example 1 to obtain R const = 1.507 mΩ, obtain R org = 20.43 mΩ, obtain R ox = 0.001 mΩ. In summary, by using the detection method of the present invention, the predicted resistance value R c = R const + R org + R ox = 21.94 mΩ, R c < 25 mΩ, it is judged that the electrical contact piece is qualified

[0077] For the above-mentioned treated contacts, use the existing contact resistance measurement method. The measurement method is the same as in Example 1. The actually measured and calculated contact resistance R = 2.04×10 -2 Ω. Compared with the predicted resistance value R c = 21.94 mΩ of the present invention, the error value is 8.66%, and the error is less than 10%, with good reliability

[0078] Example 4

[0079] Add 60 ppm of methylimidazole as a corrosion inhibitor to the cleaning solution in the front-end cleaning process, and detect the silver alloy sheet-shaped electrical contact piece after the cleaning process. The contact is an AgSnO2In2O3 contact. The diameter of the electrical contact piece used is 4 mm. Obtain the thickness d of the organic protective film on the surface of the electrical contact piece in real time through ellipsometry org = 4.46 nm, and the thickness of the oxide film is d ox = 0.69 nm, R const Calculate as in Example 1 to obtain R const = 1.507 mΩ, obtain R org = 27.69 mΩ, obtain R ox = 0.12 mΩ. In summary, by using the detection method of the present invention, the predicted resistance value R c = R const + Rorg +R ox =29.32 mΩ, R c >25 mΩ indicates a failure of the electrical contact. Further analysis in the back-end processing reveals that d3 has a value of 3.5 nm. org If the value is greater than d3, it is determined that the corrosion inhibitor concentration is too high. In other words, when the concentration of the corrosion inhibitor is too high, the corrosion inhibitor will cause localized corrosion on the surface of the electrical contact piece during the cleaning process. It is necessary to reduce the concentration of the added corrosion inhibitor during the cleaning process in order to achieve the protective effect of forming a corrosion inhibitor film on the electrical contact piece during the cleaning process.

[0080] The contact points treated as described above were tested using existing contact resistance testing methods, the same as in Example 1. The actual measured and calculated contact resistance R = 3.098 × 10⁻⁶. -2 Ω, actual measured resistance value R of the present invention c Compared to 29.33 mΩ, the error value is -5.6%, and the error is less than 10%, indicating good reliability.

[0081] Example 5

[0082] 80 ppm methylimidazole was added as a corrosion inhibitor to the cleaning solution in the front-end cleaning process. The silver alloy sheet-like electrical contacts after the cleaning process were then tested. The contacts were AgSnO2In2O3 contacts, and the diameter of the electrical contacts was 4 mm. An elliptic polarization spectrometer (SENTECH, SEUV800, Germany) was used to characterize the surface of the electrical contacts. This instrument is equipped with both xenon and halogen lamps and measures in the 701 wavelength unit from 200 to 900 nm. The thickness d of the organic protective film on the surface of the electrical contacts was obtained in real time using elliptic polarization spectroscopy. org =4.76nm, oxide film thickness is d ox =1.16 nm, R const The calculation is the same as in Example 1, and R is obtained. const =1.507 mΩ, thus obtaining R org =29.56 mΩ, thus obtaining R ox =20.77 mΩ. In conclusion, using the detection method of the present invention, the predicted resistance value R can be obtained. c =R const +R org +R ox =51.84 mΩ, R c >25 mΩ indicates a failure of the electrical contact piece. Further analysis is performed in the back-end processing flow. d1 is set to 1.0 nm. ox >d1,d orgA value greater than d3 indicates insufficient pickling and an excessively high concentration of corrosion inhibitor. When the corrosion inhibitor concentration is too high, the excessive protection provided by the inhibitor to the electrical contacts hinders the removal of the oxide film formed on the contact surface by the acidifier during the cleaning process. Therefore, a high oxide film concentration leads to contact failure. It is necessary to reduce the corrosion inhibitor concentration or increase the acidifier concentration during the cleaning process to achieve the desired corrosion inhibition effect on the electrical contacts.

[0083] The contact points treated as described above were tested using existing contact resistance testing methods, the same as in Example 1. The actual measured and calculated contact resistance R = 5.321 × 10⁻⁶. -2 Ω, actual measured resistance value R of the present invention c Compared to 51.84 mΩ, the error value is 2.57%, and the error is less than 10%, indicating good reliability.

[0084] Compared to Example 1, in Examples 2-5, the oxide layer thickness d of the electrical contact sheet after methylimidazole corrosion inhibition treatment... ox Significantly reduced corrosion, with the electrical contact piece in Example 3 showing the best corrosion inhibition effect, d ox The oxide layer thickness was reduced by 76.23%, but in Examples 4 and 5, when the concentration of the corrosion inhibitor was increased to a certain extent, the d of the electrical contact sheet... ox The oxide layer thickness may actually increase, indicating that there is localized corrosion on the surface of the electrical contact piece. A high concentration of corrosion inhibitor can also cause the electrical contact piece to fail to inhibit corrosion during the cleaning process.

[0085] The above embodiments merely illustrate implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A failure detection method for corrosion-inhibiting treatment of silver alloy sheet-shaped electrical contacts, characterized in that, Includes the following steps: S1: The thickness d of the organic protective film on the surface of the electrical contact piece is obtained in real time using elliptic polarization spectroscopy. org And the oxide film thickness is d ox ; S2: The thickness d of the organic protective film org Or oxide film thickness d ox Input a preset film thickness-contact resistance correlation model, and output the predicted contact resistance value R. c ; S3: When predicting contact resistance R c When the resistance is ≤25mΩ, the electrical contact piece is considered qualified. The predicted contact resistance R... c When the resistance is >25mΩ, the electrical contact piece is determined to be faulty, triggering the back-end processing flow and returning to the front-end cleaning process. In step S3, the backend processing flow is performed according to the following method: S4: When d ox If the value is greater than d1, it is determined that the pickling is insufficient; where d1 is the oxide film threshold, and the unit is nm. S5: When d org< d2, determined to be the failure of the corrosion inhibitor, when d org If the value is greater than d3, it is determined that the corrosion inhibitor concentration is too high. Here, d2 and d3 are the organic film thresholds, in nm. The preset film thickness-contact resistance correlation model, based on Holm contact theory, satisfies the following general form: R c =R const +R org +R ox (1) Where: R const R is the shrinkage resistance independent of the film layer, measured in mΩ. org R is the resistance function related to the thickness of the organic film, in mΩ. ox This is a resistance function related to the oxide film thickness, with units of mΩ.

2. The failure detection method for corrosion inhibition treatment of silver alloy sheet electrical contact sheet according to claim 1, wherein in formula (1), R const The calculation is as follows: R const =500×ρ×sqrt(π×H / F) (2) ρ is the resistivity of the electrical contact material, in Ω·m; H is the hardness of the electrical contact material, in Pa; and F is the contact pressure, in N.

3. The failure detection method for corrosion inhibition treatment of silver alloy sheet electrical contact sheet according to claim 1, wherein in formula (1), R org The calculation is as follows: R org =ρ org ×d org ×10 -6 / A nom (3) ρ org The resistivity of the organic film is expressed in Ω·m and d. org The thickness of the organic film is expressed in nm (A). nom The nominal contact area of ​​the electrical contact piece, in meters (m²). 2 .

4. The failure detection method for corrosion inhibition treatment of silver alloy sheet electrical contact sheet according to claim 1, wherein in formula (1), R ox The calculation is as follows: R ox =h 2 ×d ox ×exp[4×π×d ox ×sqrt(2×m×Phi) / h] / [A nom ×e 2 ×sqrt(2×m×Phi)](4) Phi is the barrier height in eV, h is Planck's constant, m is the electron mass, and e is the electron charge.

5. A failure control system for corrosion inhibition treatment of silver alloy sheet electrical contacts, employing the failure detection method for corrosion inhibition treatment of silver alloy sheet electrical contacts as described in claim 1, characterized in that, The ellipsometry detection unit includes a station for positioning electrical contact pieces and a detection device for performing ellipsometry scanning at the station. The detection device is electrically connected to a control motherboard, which displays in real time the measured thickness d of the organic protective film detected by the detection device. org and oxide film thickness d ox The control motherboard sets the thickness d of the organic protective film. org and the oxide film thickness d ox Transmitted to the following processing unit; The resistance prediction unit has a built-in preset film thickness-contact resistance correlation model and receives the organic protective film thickness d transmitted from the control motherboard. org and the oxide film thickness d ox And based on the preset film thickness-contact resistance correlation model, through R c =R const +R org +R ox The predicted R c Value, and predict the R c The value is transmitted to the next processing unit; The process decision unit receives R transmitted from the resistance prediction unit. c Value, when predicting contact resistance R c When the resistance is >25mΩ, the transmission execution signal is sent to the next processing unit; The actuator receives the execution signal from the process decision unit and sorts the defective electrical contact pieces to the corresponding rework process tank.

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