Device for rapidly measuring high-resistance migration current

By arranging a migration current measurement circuit on each channel of the current testing equipment, the problem of inability to detect sample migration in time in the existing technology is solved, real-time monitoring and rapid capture of the migration current is achieved, and the accuracy of the test is improved.

CN222353981UActive Publication Date: 2025-01-14SHANGHAI XINCHONG ELECTRONIC TECH CO LTD
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Patent Information

Application Number
CN202420476052.5
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-03-12
Publication Date
2025-01-14
Estimated Expiration
2034-03-12

AI Technical Summary

Technical Problem

Existing current testing equipment cannot detect the migration of samples during scanning intervals in a multi-channel scanning test, resulting in partial migrations that may only be temporarily unmeasured for a few minutes, affecting the accuracy of the test results.

Method used

设计了一种包括N个样品测试通道和对应的迁移电流测量电路的装置，通过在每个通道上设置迁移电流测量电路，实时监测每个通道上的迁移电流，确保即使在扫描间隔期间发生的迁移也能被测量到。

Benefits of technology

It realizes the ability to quickly capture the migration current when the tested sample migrates, improves the real-time and accuracy of the test, and ensures the timely detection of migration that occurs in a short time.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to the technical field of current testing, in particular to a device for quickly measuring high-resistance migration current, which comprises N migration current measuring circuits, each migration current measuring circuit is connected with a corresponding sample testing channel, each migration current measuring circuit has the same structure, and each migration current measuring circuit comprises a sampling part, a signal processing part and a signal processing part, the first switch is connected between the second end of the corresponding channel switch and a common grounding end; the amplification part is connected with the sampling part; the filtering part is connected with the amplifying part; the collector is connected with the output end of the migration current measuring circuit and used for collecting the migration signals obtained by the migration current measuring circuit; according to the utility model, the migration current measurement circuit is arranged to be complementary with the original circuit, so that the original insulation measurement function is not influenced, and the migration current can be measured when the measured sample migrates.
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Description

Technical Field

[0001] The utility model relates to the technical field of current testing, in particular to a device for fast measurement of high-resistance migration current. Background Art

[0002] With the development of science and technology, the functions of electronic products are more advanced. The line density of PCB boards used in electronic products will be higher and the line spacing will be smaller. Smaller spacing and higher density will make it easier for ions to migrate. The insulation resistance test equipment used to evaluate the reliability of PCBs can measure the degree of insulation degradation, usually using a multi-way switch to measure by scanning. In multi-channel scanning tests, when the measuring instrument is in the scanning interval, the migration of the sample cannot be detected, and the abnormality can only be measured after the next scanning cycle. Partial migration may only occur for a few minutes, and there is a possibility that it cannot be measured, which will cause the test results to deviate from the actual state.

[0003] In the existing method of measuring by an ammeter, the measuring method is to first select the first channel through a relay and then start measuring; after the measurement is completed, select the second channel and start measuring; and so on until all channels are measured. Since only one channel value can be measured at any time, if migration occurs in other channels at this time, it cannot be measured. Due to the existence of this scanning interval, the migration of the measured sample cannot be discovered in time, and the migration that occurs in a short time may not be measured. Utility Model Content

[0004] The purpose of the utility model is to provide a device for rapid measurement of high-resistance migration current to solve the above technical problems;

[0005] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0006] A device for fast measurement of high-resistance migration current, comprising N sample test channels, each of which comprises a test sample and a channel switch having a first end connected to the test sample, and further comprising:

[0007] N migration current measurement circuits, one migration current measurement circuit is connected to a corresponding sample test channel, and each migration current measurement circuit has the same structure, including:

[0008] A sampling part connected between the second end of the corresponding channel switch and a common ground end; an amplifying part connected to the sampling part;

[0009] A filtering unit connected to the amplifying unit;

[0010] a collector, connected to the output end of the migration current measurement circuit, and collecting the migration signal obtained by the migration current measurement circuit;

[0011] Wherein N is a positive integer.

[0012] Preferably, it further comprises an ammeter and N measuring switches connected to the ammeter, and the two measuring ends of the ammeter are connected to the two ends of a corresponding channel switch through the measuring switch.

[0013] Preferably, the sampling portion comprises:

[0014] A sampling resistor, wherein a first end of the sampling resistor is connected to a second end of a corresponding channel switch, and a second end of the sampling resistor is connected to the common ground end;

[0015] a first diode, wherein a cathode of the first diode is connected to a first end of the sampling resistor;

[0016] a second diode, wherein an anode of the second diode is connected to an anode of the first diode, and a cathode of the second diode is connected to a second end of the sampling resistor;

[0017] A first capacitor, wherein a first end of the first capacitor is connected to a first end of the sampling resistor, and a second end of the first capacitor is connected to a second end of the sampling resistor.

[0018] Preferably, the amplifying portion comprises:

[0019] a first resistor, wherein a first end of the first resistor is connected to a second end of a corresponding channel switch;

[0020] a second resistor, wherein a first end of the second resistor is connected to the common ground end;

[0021] a first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to a second terminal of the first resistor, and a second input terminal of the first operational amplifier is connected to a second terminal of the second resistor;

[0022] a third resistor, wherein a first end of the third resistor is connected to the first input end of the first operational amplifier, and a second end of the third resistor is connected to the output end of the first operational amplifier;

[0023] A fourth resistor, wherein a first end of the fourth resistor is connected to the second input end of the first operational amplifier, and a second end of the fourth resistor is grounded.

[0024] Preferably, the filtering unit comprises:

[0025] a fifth resistor, a first end of which is connected to the output end of the amplifying unit;

[0026] a second capacitor, wherein a first end of the second capacitor is connected to a second end of the fifth resistor;

[0027] a sixth resistor, a first end of the sixth resistor being connected to the second end of the second capacitor;

[0028] a second operational amplifier, wherein a first input terminal of the second operational amplifier is connected to the second end of the sixth resistor, and a second input terminal of the second operational amplifier is grounded;

[0029] a seventh resistor, wherein a first end of the seventh resistor is connected to the first input end of the second operational amplifier, and a second end of the seventh resistor is connected to the output end of the second operational amplifier;

[0030] A third capacitor, wherein a first end of the third capacitor is connected to the output end of the second operational amplifier, and a second end of the third capacitor is connected to the second end of the fifth resistor.

[0031] Preferably, the filtering unit further includes:

[0032] An acquisition buffer, wherein a first input end of the acquisition buffer is connected to the second end of the third capacitor, and an output end of the acquisition buffer is connected to the collector;

[0033] An eighth resistor, wherein a first end of the eighth resistor is connected to the second input end of the acquisition buffer, and a second end of the eighth resistor is connected to the output end of the acquisition buffer.

[0034] Preferably, the acquisition buffer is an operational amplifier.

[0035] Preferably, it further comprises a controller, which is connected to the controlled end of the collector to output a control signal.

[0036] Preferably, the collector is a 16-bit 8-channel synchronous sampling chip.

[0037] Preferably, the first diode and the second diode are both voltage stabilizing diodes.

[0038] Beneficial effects of the utility model: Due to the adoption of the above technical solution, the utility model provides a migration current measurement circuit to complement the original circuit, which does not affect the original insulation measurement function and can also measure the migration current when the measured sample migrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the overall circuit of a device for rapid measurement of high-resistance migration current in an embodiment of the utility model;

[0040] Figure 2 This is a schematic diagram of the connection of N migration current measurement circuits in an embodiment of the utility model;

[0041] Figure 3 It is a specific circuit diagram of a single migration current measurement circuit in an embodiment of the utility model. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0043] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0044] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0045] A device for rapid measurement of high resistance migration current, such as Figures 1 to 3 As shown, it includes N sample test channels, each sample test channel includes a test sample Y and a channel switch K connected to the test sample Y at the first end, and also includes,

[0046] N migration current measurement circuits, one migration current measurement circuit is connected to a corresponding sample test channel, and each migration current measurement circuit has the same structure, including:

[0047] The sampling part F1 is connected between the second end of the corresponding channel switch K and a common ground end GND;

[0048] Amplifying part F2, connected to sampling part F1;

[0049] The filter part F3 is connected to the amplifier part F2;

[0050] A collector U4, connected to the output end of the migration current measurement circuit, collecting the migration signal obtained by the migration current measurement circuit;

[0051] Wherein N is a positive integer.

[0052] Specifically, the utility model sets a migration current measurement circuit on each channel, which can monitor the migration current on each channel in real time. Even the migration occurring during the scanning interval can be measured, and the current curve of the migration of the sample under test can be quickly captured.

[0053] In a preferred embodiment, it also includes an ammeter A and N measuring switches KA connected to the ammeter A, and two measuring ends of the ammeter A are connected to two ends of a corresponding channel switch K through a measuring switch KA.

[0054] For more details, please refer to Figure 1 As shown, the test samples Y are Y1, Y2, ..., YN, the channel switches K are K1, K2, ..., KN, each sample test channel includes a test sample Y and a channel switch K, the sample test channels are all connected to an input voltage terminal V, the measurement switches KA are KA1, KA2, ..., KAN, and the two measurement ends of the ammeter A are connected to the two ends of a corresponding channel switch K through a measurement switch KA.

[0055] Ammeter A is used to select a sample test channel for testing and monitor the current on the channel in real time. Since ammeter A can only select a single channel or a part of the channels, during the testing process of ammeter A, if migration occurs in the unselected sample test channel or if migration occurs when ammeter A switches the sample test channel, it cannot be measured by ammeter A. The utility model sets a migration current measurement circuit to monitor the migration signal that cannot be captured in time by ammeter A while ammeter A is working.

[0056] In this embodiment, N=8 is taken as an example, including 8 sample test channels, correspondingly equipped with 8 channel switches K and 8 measurement switches KA, the sampling resistors RS are RS1, RS2, ..., RSN respectively, and the sampling resistors RS of each migration current measurement circuit are correspondingly connected to the second end of a channel switch K, and the second end of each sampling resistor RS is connected to the common ground terminal GND. If N is 8, there are 8 migration current measurement circuits, and the collector U4 is a 16-bit 8-channel synchronous sampling chip.

[0057] In a preferred embodiment, the sampling portion F1 includes:

[0058] A sampling resistor RS, a first end of the sampling resistor RS is connected to the second end of a corresponding channel switch K, and a second end of the sampling resistor RS is connected to a common ground terminal GND;

[0059] A first diode D1, wherein a cathode of the first diode D1 is connected to a first end of the sampling resistor RS;

[0060] a second diode D2, wherein an anode of the second diode D2 is connected to an anode of the first diode D1, and a cathode of the second diode D2 is connected to a second end of the sampling resistor RS;

[0061] A first capacitor C1 , wherein a first end of the first capacitor C1 is connected to a first end of the sampling resistor RS, and a second end of the first capacitor C1 is connected to a second end of the sampling resistor RS.

[0062] Specifically, the first end of the sampling resistor RS of the present invention is connected to the corresponding channel switch K, and the first end of the sampling resistor RS is connected to the common ground terminal GND, so as to sample the migration current.

[0063] In a preferred embodiment, the amplifying part F2 includes:

[0064] A first resistor R1, wherein a first end of the first resistor R1 is connected to a second end of a corresponding channel switch K;

[0065] A second resistor R2, a first end of the second resistor R2 is connected to a common ground terminal GND;

[0066] A first operational amplifier U1, wherein a first input terminal of the first operational amplifier U1 is connected to a second terminal of the first resistor R1, and a second input terminal of the first operational amplifier U1 is connected to a second terminal of the second resistor R2;

[0067] A third resistor R3, wherein a first end of the third resistor R3 is connected to a first input end of the first operational amplifier U1, and a second end of the third resistor R3 is connected to an output end of the first operational amplifier U1;

[0068] A fourth resistor R4 , wherein a first end of the fourth resistor R4 is connected to the second input end of the first operational amplifier U1 , and a second end of the fourth resistor R4 is grounded.

[0069] Specifically, the amplifier F2 is a differential amplifier circuit composed of a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first operational amplifier U1, and is used to amplify the input signal.

[0070] In a preferred embodiment, the filter unit F3 includes:

[0071] a fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to an output end of the amplifier F2;

[0072] A second capacitor C2, a first end of the second capacitor C2 is connected to a second end of the fifth resistor R5;

[0073] a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to a second end of the second capacitor C2;

[0074] A second operational amplifier U2, wherein a first input terminal of the second operational amplifier U2 is connected to a second end of the sixth resistor R6, and a second input terminal of the second operational amplifier U2 is grounded;

[0075] a seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to a first input end of the second operational amplifier U2, and a second end of the seventh resistor R7 is connected to an output end of the second operational amplifier U2;

[0076] A third capacitor C3, wherein a first end of the third capacitor C3 is connected to the output end of the second operational amplifier U2, and a second end of the third capacitor C3 is connected to the second end of the fifth resistor R5.

[0077] Specifically, the filter unit F3 is used to filter out noise interference. The second capacitor C2 couples the AC noise to the input end of the second operational amplifier U2. The second operational amplifier U2 forms an amplifier circuit with an inverting gain of 1, which inverts the noise and couples it to the original signal through the third capacitor C3 to achieve a filtering function.

[0078] In a preferred embodiment, the filter unit F3 further includes:

[0079] A collection buffer U3, wherein a first input end of the collection buffer U3 is connected to a second end of a third capacitor C3, and an output end of the collection buffer U3 is connected to a collector U4;

[0080] An eighth resistor R8, a first end of the eighth resistor R8 is connected to the second input end of the acquisition buffer U3, and a second end of the eighth resistor R8 is connected to the output end of the acquisition buffer U3.

[0081] Specifically, the acquisition buffer U3 can make signal sampling more accurate.

[0082] In a preferred embodiment, the acquisition buffer U3 is an operational amplifier.

[0083] In a preferred embodiment, a controller U5 is further included. The controller U5 is connected to the controlled end of the collector U4 to output a control signal.

[0084] Specifically, the controller U5 is used to control the collector U4 to collect the migration signal.

[0085] In a preferred embodiment, the collector U4 is a 16-bit 8-channel synchronous sampling chip.

[0086] Specifically, in the present invention, N is taken as 8, and the collector U4 is a 16-bit 8-channel synchronous sampling chip, which can realize high-precision voltage collection.

[0087] In a preferred embodiment, the first diode D1 and the second diode D2 are both voltage-stabilizing diodes.

[0088] In summary, in order to solve the problem that when the ammeter A measures the current on each test sample Y by scanning, other test samples Y migrate, and the ammeter A is measuring in other channels, so the migration of multiple samples cannot be measured in real time, the utility model sets a migration current measurement circuit to complement the original circuit, which does not affect the original insulation measurement function and can also measure the migration current when the sample under test migrates.

[0089] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for fast measurement of high-resistance migration current, comprising N sample test channels, each of which comprises a test sample (Y) and a channel switch (K) having a first end connected to the test sample (Y), characterized in that: Also includes, N migration current measurement circuits, one migration current measurement circuit is connected to a corresponding sample test channel, and each migration current measurement circuit has the same structure, including: A sampling part (F1) connected between the second end of the corresponding channel switch (K) and a common ground terminal (GND); an amplifying part (F2), connected to the sampling part (F1); A filter unit (F3), connected to the amplifier unit (F2); a collector (U4), connected to the output end of the migration current measurement circuit, and collecting the migration signal obtained by the migration current measurement circuit; Wherein N is a positive integer.

2. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: It also includes an ammeter (A) and N measuring switches (KA) connected to the ammeter (A), and the two measuring ends of the ammeter (A) are connected to the two ends of a corresponding channel switch (K) through the measuring switch (KA).

3. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: The sampling part (F1) comprises: a sampling resistor (RS), wherein a first end of the sampling resistor (RS) is connected to a second end of a corresponding channel switch (K), and a second end of the sampling resistor (RS) is connected to the common ground terminal (GND); a first diode (D1), wherein a cathode of the first diode (D1) is connected to a first end of the sampling resistor (RS); a second diode (D2), wherein an anode of the second diode (D2) is connected to an anode of the first diode (D1), and a cathode of the second diode (D2) is connected to a second end of the sampling resistor (RS); A first capacitor (C1), wherein a first end of the first capacitor (C1) is connected to a first end of the sampling resistor (RS), and a second end of the first capacitor (C1) is connected to a second end of the sampling resistor (RS).

4. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: The amplifying part (F2) comprises: a first resistor (R1), wherein a first end of the first resistor (R1) is connected to a second end of a corresponding channel switch (K); a second resistor (R2), wherein a first end of the second resistor (R2) is connected to the common ground terminal (GND); A first operational amplifier (U1), wherein a first input end of the first operational amplifier (U1) is connected to a second end of the first resistor (R1), and a second input end of the first operational amplifier (U1) is connected to a second end of the second resistor (R2); a third resistor (R3), wherein a first end of the third resistor (R3) is connected to a first input end of the first operational amplifier (U1), and a second end of the third resistor (R3) is connected to an output end of the first operational amplifier (U1); A fourth resistor (R4), wherein a first end of the fourth resistor (R4) is connected to the second input end of the first operational amplifier (U1), and a second end of the fourth resistor (R4) is grounded.

5. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: The filtering unit (F3) comprises: a fifth resistor (R5), wherein a first end of the fifth resistor (R5) is connected to an output end of the amplifier (F2); a second capacitor (C2), wherein a first end of the second capacitor (C2) is connected to a second end of the fifth resistor (R5); a sixth resistor (R6), a first end of the sixth resistor (R6) being connected to a second end of the second capacitor (C2); a second operational amplifier (U2), wherein a first input terminal of the second operational amplifier (U2) is connected to a second end of the sixth resistor (R6), and a second input terminal of the second operational amplifier (U2) is grounded; a seventh resistor (R7), wherein a first end of the seventh resistor (R7) is connected to a first input end of the second operational amplifier (U2), and a second end of the seventh resistor (R7) is connected to an output end of the second operational amplifier (U2); A third capacitor (C3), wherein a first end of the third capacitor (C3) is connected to the output end of the second operational amplifier (U2), and a second end of the third capacitor (C3) is connected to the second end of the fifth resistor (R5).

6. The device for rapid measurement of high-resistance migration current according to claim 5, characterized in that: The filtering unit (F3) further includes: A collection buffer (U3), wherein a first input end of the collection buffer (U3) is connected to the second end of the third capacitor (C3), and an output end of the collection buffer (U3) is connected to the collector (U4); An eighth resistor (R8), wherein a first end of the eighth resistor (R8) is connected to a second input end of the acquisition buffer (U3), and a second end of the eighth resistor (R8) is connected to an output end of the acquisition buffer (U3).

7. The device for rapid measurement of high-resistance migration current according to claim 6, characterized in that: The acquisition buffer (U3) is an operational amplifier.

8. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: It also includes a controller (U5), which is connected to the controlled end of the collector (U4) to output a control signal.

9. The device for rapid measurement of high-resistance migration current according to claim 1, characterized in that: The collector (U4) is a 16-bit 8-channel synchronous sampling chip.

10. The device for rapid measurement of high-resistance migration current according to claim 3, characterized in that: The first diode (D1) and the second diode (D2) are both voltage-stabilizing diodes.