Circuit board detection circuit, device and method

Abstract

This application discloses a circuit board testing circuit, device, and method, relating to the field of circuit technology, to solve the problems of high false negative rate, long testing time, and low accuracy of current methods for detecting leakage current in circuit boards using a multimeter. The circuit board testing circuit includes: a constant current power supply, the output of which is electrically connected to the input of the circuit board under test; at least one driving unit, electrically connected to the output of the circuit board under test, wherein, in the event of leakage current in the circuit board under test, the driving unit is used to reflect the leakage current condition of the circuit board under test through a current-voltage characteristic curve; and at least one power consumption detection unit, disposed between the circuit board under test and the constant current power supply, wherein the power consumption data detected by the power consumption detection unit is used to reflect the leakage current condition of the circuit board under test.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a circuit board testing circuit, device and method. Background Technology

[0002] When the resistance value of a circuit board changes, the current in the circuit board will also change, causing leakage current. This results in poor current stability of the circuit board's output current, which in turn affects other connected electronic components. However, current methods for detecting leakage current in circuit boards involve using a multimeter to poke the board's voltage or resistance. But during the poke test, the multimeter probe can easily damage the PAD (pad) area of ​​the circuit board, and measurements can only be taken with the PAD area exposed. This can easily lead to missed detections, the testing time is long, and the requirements for the object being tested are high.

[0003] In display panels, current backlight circuits typically include a driver circuit board to drive the light-emitting devices. However, in practical applications, the presence of foreign objects between the positive and negative terminals of the driver circuit board increases its resistance, affecting the current and causing leakage. This results in the driver circuit board being unable to provide a stable drive current, thus impacting the brightness uniformity of the light-emitting devices. Furthermore, the positive and negative terminals of the driver circuit board in the backlight circuit exhibit a high-resistance state. Abnormal resistance has a relatively small impact on the output current, meaning that during multimeter testing, the accuracy of the multimeter significantly affects the test results, leading to lower overall accuracy. Summary of the Invention

[0004] This application provides a circuit board testing circuit, device, and method, relating to the field of circuit testing technology, to solve the problems of high false negative rate, long testing time, and low accuracy of test results when using a multimeter to detect leakage current in circuit boards.

[0005] A first aspect of this application provides a circuit board detection circuit, including:

[0006] A constant current power supply, the output terminal of which is used to electrically connect to the input terminal of the circuit board under test;

[0007] At least one driving object unit is used to be electrically connected to the output terminal of the circuit board under test, wherein, in the event of leakage current in the circuit board under test, the driving object unit is used to reflect the leakage current of the circuit board under test through the volt-ampere characteristic curve.

[0008] At least one power consumption detection unit is disposed between the circuit board under test and the constant current power supply. The power consumption data detected by the power consumption detection unit is used to reflect the leakage current of the circuit board under test.

[0009] In some implementations, the power consumption detection unit is used to reflect the leakage current of the circuit board under test based on the relationship between the detected power consumption data and the output power of the constant current power supply.

[0010] In some embodiments, the driving object unit includes a light-emitting device;

[0011] The light-emitting device is used to reflect the leakage current of the circuit board under test by the change in light intensity.

[0012] In some embodiments, the power consumption detection unit is disposed between the positive terminal of the constant current power supply and the circuit board under test; and / or,

[0013] All of the power consumption detection units are connected in parallel.

[0014] In some embodiments, the light-emitting device includes an LED.

[0015] A second aspect of this application provides a circuit board testing device, comprising:

[0016] At least one circuit board detection circuit as described in any of the first aspects above.

[0017] In some embodiments, where the driving object unit includes a light-emitting device, it further includes:

[0018] A brightness detection device is used to detect the brightness of the light-emitting device, and the brightness detection device includes an optical lens.

[0019] In some embodiments, the circuit board testing equipment further includes:

[0020] A platform for mounting at least one of the circuit board testing devices.

[0021] In some embodiments, the circuit board testing equipment further includes:

[0022] A limiting unit is disposed on the mounting platform for fixing the circuit board under test;

[0023] And / or,

[0024] A vacuum adsorption unit is disposed on the mounting platform and is used to vacuum adsorb the circuit board under test in order to fix the circuit board under test.

[0025] In some embodiments, the device for detecting leakage current of the circuit board under test further includes:

[0026] The first adapter is disposed on the mounting platform and is used to connect the constant current power supply and the circuit board under test;

[0027] And / or,

[0028] The second adapter is located on the mounting platform and is used to connect the driving object unit and the circuit board under test.

[0029] A third aspect of this application provides a circuit board testing method, applied to the circuit board testing equipment as described in the second aspect, comprising:

[0030] Power is applied to the circuit board under test;

[0031] The electrical parameters of the driving object unit are detected to obtain the current-voltage characteristic curve of the driving object unit;

[0032] Detect the power consumption data of the circuit board under test;

[0033] Based on the current-voltage characteristic curve and power consumption data of the driving object unit, the leakage current of the circuit board under test is analyzed.

[0034] In some implementations, the power consumption data includes actual current and actual power;

[0035] The step of analyzing the leakage current of the circuit board under test based on the current-voltage characteristic curve and power consumption data of the driving object unit includes:

[0036] The target output power of the constant current power supply is determined based on the volt-ampere characteristics of the driving object unit and the detection current output by the constant current power supply.

[0037] If the target output power is greater than the actual power, and the difference between the target output power and the actual power is greater than a preset power, it is determined that the circuit board under test has leakage.

[0038] In some embodiments, where the circuit board inspection equipment includes a brightness detection device, the method further includes:

[0039] Detect the brightness of all the light-emitting devices;

[0040] If the light-emitting devices are of the same model, and the brightness of at least one of the light-emitting devices is less than the brightness of the other light-emitting devices, and the difference between the two is greater than a preset brightness, it is determined that there is leakage in the branch of the circuit board under test that is electrically connected to the light-emitting device with lower brightness.

[0041] This embodiment of the application provides a constant and known current to the circuit board under test (PCB) via a constant current power supply. A driving unit receives the current output from the PCB and determines its input current based on its volt-ampere characteristic curve. Therefore, the leakage current of the PCB can be determined by comparing the current output from the constant current power supply with the input current of the driving unit. A power consumption detection unit detects the current power consumption of both the driving unit and the PCB. The difference between the current power consumption and a preset power consumption value can be used to determine the leakage current of the PCB. Therefore, by using the above-described PCB detection circuit for leakage current detection, it is possible to eliminate the need to disassemble the packaged PCB, thereby shortening the detection time, improving detection efficiency, preventing missed detections, and enhancing the accuracy of the detection results. Attached Figure Description

[0042] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A schematic structural diagram of a circuit board detection circuit provided in an embodiment of this application;

[0044] Figure 2 A schematic diagram of a circuit board detection circuit driving a light-emitting device provided in an embodiment of this application;

[0045] Figure 3 A schematic diagram of another circuit board detection circuit driving a light-emitting device provided in an embodiment of this application;

[0046] Figure 4 A schematic pin connection diagram of a circuit board under test provided for an embodiment of this application;

[0047] Figure 5 A current-voltage volt-ampere characteristic curve of an LED in a circuit board detection circuit provided in this application embodiment;

[0048] Figure 6 A current-power volt-ampere characteristic curve of an LED in another circuit board detection circuit provided in this application embodiment;

[0049] Figure 7 A schematic diagram of a circuit board detection circuit provided in an embodiment of this application;

[0050] Figure 8 A schematic structural diagram of a circuit board testing device provided in this application embodiment;

[0051] Figure 9This is a schematic diagram of a circuit board testing device provided in an embodiment of this application;

[0052] Figure 10 A schematic top view of a circuit board testing device provided in an embodiment of this application;

[0053] Figure 11 This is a schematic diagram of a backlight module provided in an embodiment of this application;

[0054] Figure 12 This is a schematic flowchart illustrating a circuit board testing method provided in an embodiment of this application. Detailed Implementation

[0055] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims. In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways, and the apparatus embodiments described below are merely exemplary.

[0056] A first aspect of this application provides a circuit board detection circuit. Figure 1 This is a schematic structural diagram of a circuit board detection circuit provided in an embodiment of this application. Figure 1 As shown, the circuit board testing circuit 100 provided in this embodiment includes: a constant current power supply 110, the output terminal of which is electrically connected to the input terminal of the circuit board under test 140; at least one driving object unit 120, which is electrically connected to the output terminal of the circuit board under test 140, wherein, in the event of leakage current in the circuit board under test 140, the driving object unit 120 is used to reflect the leakage current condition of the circuit board under test 140 through a current-voltage characteristic curve; and at least one power consumption detection unit 130, which is disposed between the circuit board under test 140 and the constant current power supply 110, and the power consumption data detected by the power consumption detection unit 130 is used to reflect the leakage current condition of the circuit board under test 140. This circuit board testing circuit 100 does not include the circuit board under test 140. For example, the circuit board under test provided in this embodiment can be used as a driving circuit board for a light-emitting device in a display panel backlight.

[0057] For example, there may be multiple driving object units 120, namely driving object unit 1, driving object unit 2 to driving object unit n. There may be multiple power consumption detection units 130, namely power consumption detection unit 1, power consumption detection unit 2 to power consumption detection unit m, where m and n are natural numbers greater than 0.

[0058] For example, the aforementioned driving object unit 120 is an electronic component whose electrical parameters, such as voltage, resistance, or power, change with the change in current. The actual input current of the driving object unit 120 can be determined by detecting its electrical parameters, such as voltage, resistance, or power, and combining this with its volt-ampere characteristic curve. The leakage current of the circuit board 140 under test can be determined based on the difference between the output current of the constant current power supply 110 and the actual input current.

[0059] For example, the aforementioned driving object unit 120 can be a driving object unit 120 with high current sensitivity. A driving object unit 120 with high current sensitivity can exhibit significant changes in electrical parameters such as voltage, resistance, or power even with small changes in the input current, making it easy to detect and thus improving the sensitivity and accuracy of the circuit board detection circuit. The type of driving object unit 120 can be determined based on the resistance value of the circuit board 140 under test. For instance, when the resistance value of the circuit board 140 under test is high, the output current of the circuit board 140 under test is less affected by abnormal resistance. Therefore, a driving object unit 120 with high current sensitivity to the volt-ampere characteristic curve can be selected to improve the detection capability of the circuit board detection circuit and enhance the accuracy of the detection results.

[0060] For example, the actual power in the circuit can be detected by the power consumption detection unit 130. The difference between the detected power consumption data and the preset power consumption can be used to determine whether the circuit board under test 140 has leakage current. If the power consumption data is less than the preset power consumption and the difference is greater than the preset leakage current threshold, it is determined that the circuit board under test 140 has leakage current. The preset leakage current threshold can be determined based on the sensitivity of the driving unit 120 to current. For example, if the driving unit 120 has low sensitivity to current, changes in the input current have a smaller impact on the resistance of the driving unit 120. If the leakage current of the circuit board under test 140 is small, the changes in the total resistance and total current of the entire circuit are small, resulting in a smaller difference between the actual power in the circuit and the power when no leakage current occurs. Therefore, the preset leakage current threshold should be lowered to improve the accuracy of the detection results of the circuit board detection circuit.

[0061] A constant and known current is supplied to the circuit board under test (DUT) 140 by a constant current power supply. The current output by the DUT 140 is received by the drive unit 120. The input current of the drive unit 120 is determined based on its volt-ampere characteristic curve. Therefore, the leakage current of the DUT 140 can be determined by the current output by the constant current power supply 110 and the input current of the drive unit 120. The power consumption detection unit 130 can detect the current power consumption data of the drive unit 120 and the DUT 140. The difference between the current power consumption data and the preset power consumption can be used to determine whether there is leakage current in the DUT. Therefore, leakage current detection of the circuit board using the above circuit board detection circuit does not require disassembly of the packaged circuit board, thereby shortening the detection time, improving detection efficiency, and increasing the accuracy of the detection results.

[0062] In some feasible implementations, the power consumption detection unit 130 is used to reflect the leakage current of the circuit board 140 under test based on the relationship between the detected power consumption data and the output power of the constant current power supply 110.

[0063] For example, the actual power in the current circuit can be determined based on the power consumption data detected by the power consumption detection unit 130. The output power of the constant current power supply 110 is the output power of the constant current power supply 110 when there is no leakage current in the circuit board under test 140. The resistance of the driving object unit 120 when there is no leakage current can be determined by the output current of the constant current power supply 110 and the volt-ampere characteristic curve of the driving object unit 120. The total circuit resistance when there is no leakage current can be determined by the resistance of at least one driving object unit 120 when there is no leakage current and the resistance of the circuit board under test 140. The output power of the constant current power supply 110 can be determined by the total circuit resistance and the output current of the constant current power supply 110. The leakage current of the circuit board under test 140 can be determined by the difference between the power consumption data detected by the power consumption detection unit 130 and the output power of the constant current power supply 110 and the volt-ampere characteristic curve of the driving object unit 120. For example, the leakage current of the circuit board under test 140 can be determined by the current-power volt-ampere characteristic curve of the driving object unit 120 and the resistance value of the circuit board under test 140.

[0064] The magnitude of leakage current in the circuit board under test 140 can be determined by the relationship between the power consumption data measured by the power consumption detection unit 130 and the output power of the constant current power supply 110, thereby improving the effectiveness and practicality of the detection data.

[0065] In some feasible implementations, the driving object unit 120 includes a light-emitting device; the light-emitting device is used to reflect the leakage current of the circuit board under test by the change in light intensity.

[0066] For example, Figure 2This is a schematic diagram of a circuit board detection circuit driving a light-emitting device, provided as an embodiment of this application. Figure 2 As shown, Figure 2 A schematic diagram is provided showing that the light emission brightness of each light-emitting device is consistent when there is no leakage current in the circuit board under test 140. The diagram includes multiple light-emitting devices 121, which are used to emit light according to the input current. Figure 2 The backlight shown is a side-lit type, with multiple light-emitting devices 121 forming a light strip. The light strip is converted into a surface light source through a light guide plate, resulting in a surface-emitting display area 210. The aforementioned emitting area 211 is the brightness area formed by the light-emitting devices 121 in the emitting display area 210 under the current emitting state. Since the opening angle of the emitting areas 211 formed by each light-emitting device 121 in the emitting display area 210 is the same under the current emitting current, it can be assumed that the circuit board under test is not experiencing leakage.

[0067] For example, Figure 3 This is a schematic diagram of another circuit board detection circuit driving a light-emitting device, provided in an embodiment of this application. Figure 3 As shown, when leakage occurs in the circuit board under test 140, the brightness of the light-emitting devices is inconsistent. The driving unit 120 includes multiple first light-emitting devices 122, which emit light according to the input current, forming multiple first light-emitting areas 211. The driving unit 120 also includes multiple second light-emitting devices 123, which emit light according to the input current, forming multiple second light-emitting areas 212, and a surface light source display area 210, which is used to highlight the light-emitting effect of the light-emitting devices and make the brightness of the light-emitting devices easy to observe. The first light-emitting area 211 is the brightness area formed by the light-emitting display area 210 corresponding to the first light-emitting device 122 in the current light-emitting state, and the second light-emitting area 212 is the brightness area formed by the light-emitting display area 210 corresponding to the second light-emitting device 123 in the current light-emitting state. Since the opening angle of the first light-emitting area 211 formed by the first light-emitting device 122 is greater than the opening angle of the second light-emitting area 212 formed by the second light-emitting device 123 under the current light-emitting current, it can be considered that leakage occurs in the branch electrically connected to the second light-emitting device 123 in the circuit board under test 140.

[0068] For example, the correlation between the brightness and power of the light-emitting device 121 and the current-voltage characteristic curve of the light-emitting device 121 can be obtained to determine the leakage current of the circuit board 140 under test by the change in the brightness of the light-emitting device 121. For example, when the brightness of the light-emitting device 121 is positively correlated with the power, and the resistance of the light-emitting device 121 decreases as the current decreases, the greater the brightness of the light-emitting device 121, the smaller the leakage current of the circuit board 140 under test.

[0069] By using the light-emitting device 121 as the driving object unit 120, the brightness of the light-emitting device 121 can intuitively represent the magnitude of the input current of the light-emitting device 121, thereby determining the leakage current of the circuit board 140 under test, reducing the difficulty of detection, improving the detection efficiency, and thus improving the practicality of the circuit board detection circuit.

[0070] In some feasible implementations, the power consumption detection unit 130 is disposed between the positive terminal of the constant current power supply 110 and the circuit board under test.

[0071] For example, Figure 4 This is a schematic pin connection diagram of a circuit board under test provided for an embodiment of this application. Figure 4 As shown, the circuit board under test 140 includes an input terminal 141 and an output terminal 142. The input terminal 141 includes a positive input port 143 connected to the positive terminal of the constant current power supply 110 and a negative input port 144 connected to the negative terminal of the constant current power supply 110. The output terminal 142 includes a positive output port 145 connected to the input terminal of the driving object unit 120 and a negative output port 146 connected to the output terminal of the driving object unit 120. The input terminal 141 of the circuit board under test 140 can be connected to the positive terminal of the constant current power supply 110 via a single wire through the positive input port 143. The input terminal 141 of the circuit board under test 140 can be connected to the negative terminal of the constant current power supply 110 via the negative input port 144, and the number of wires between them is equal to the number of wires in the negative input port 144.

[0072] Therefore, by placing the power consumption detection unit 130 between the positive terminal of the constant current power supply 110 and the circuit board under test 140, only one power consumption detection unit 130 needs to be set up to detect the total power in the entire circuit. This can reduce the number of electronic components, improve the integration level of the circuit board detection circuit, and further reduce the size and production cost of the circuit board detection circuit, thereby improving the economy and practicality of the circuit board detection circuit.

[0073] In some feasible implementations, all power consumption detection units 130 are connected in parallel with each other.

[0074] For example, a power consumption detection unit 130 can be set between each input port of the circuit board under test 140 and the negative terminal of the constant current power supply 110 to determine the power consumption of the internal branch corresponding to each input port of the circuit board under test 140, thereby determining the leakage current of each branch in the circuit board under test 140, and thus locating the leakage current in the circuit board under test 140.

[0075] For example, if a branch in the circuit board under test 140 is connected to the power consumption detection unit 130 but not to the driving target unit 120, the leakage current of that branch can be determined directly based on the power consumption data detected by the power consumption detection unit 130 and the branch power determined by the output current of the constant current power supply 110 and the branch resistance. If a branch in the circuit board under test 140 is connected to both the power consumption detection unit 130 and the driving target unit 120, the leakage current of that branch can be determined based on the detected power consumption data and the volt-ampere characteristic curve of the driving target unit 120.

[0076] By connecting a power consumption detection unit 130 in parallel between at least one input port of the circuit board under test 140 and the negative terminal of the constant current power supply 110, the power consumption data of each branch in the circuit board under test can be detected, which facilitates the location of leakage in the circuit board under test 140, reduces the difficulty of maintenance, and thus improves the practicality and effectiveness of the circuit board testing circuit.

[0077] In some feasible implementations, a power consumption detection unit 130 can be provided between the positive terminal of the constant current power supply 110 and the input terminal 141 of the circuit board under test 140 and between the negative terminal of the constant current power supply 110 and the input terminal 141 of the circuit board under test 140.

[0078] It should be noted that when the leakage current of the circuit board under test 140 is small, the measurement accuracy of the power consumption detection unit 130 has a significant impact on the detection results. Therefore, determining the leakage current state of the circuit board under test 140 solely through the power consumption detection unit 130 located between the negative terminal of the constant current power supply 110 and the input terminal of the circuit board under test 140 is somewhat inaccurate.

[0079] By setting a power consumption detection unit 130 between the positive terminal of the constant current power supply 110 and the input terminal of the circuit board under test 140, the power of each branch of the circuit board under test 140 can be summed to determine the leakage status of the circuit board under test 140 as a whole. This avoids the reduced accuracy of the detection results due to the small difference between the power of each branch of the circuit board under test 140 and the power of each branch in the non-leakage state. Furthermore, the power consumption data of the entire circuit can be used to correct the power consumption data of the power consumption detection unit 130 set between the negative terminal of the constant current power supply 110 and the input terminal 141 of the circuit board under test 140, so as to locate the leakage branch of the circuit board under test 140, thereby improving the detection quality and practicality of the circuit board detection circuit.

[0080] In some feasible implementations, the light-emitting device 121 includes an LED.

[0081] For example, the LEDs described above may be arranged in an array.

[0082] For example, Figure 5 This is a current-voltage volt-ampere characteristic curve of an LED in a circuit board detection circuit provided in an embodiment of this application. (See attached image.) Figure 5 As shown, the horizontal axis of the LED current-voltage volt-ampere characteristic curve represents the voltage value in V, and the vertical axis represents the current value in A. When the current is less than 0.1 mA, the ratio of LED voltage to current decreases as the current increases.

[0083] For example, Figure 6 This is a current-power volt-ampere characteristic curve of an LED in a circuit board detection circuit provided in an embodiment of this application. Figure 6 As shown, the horizontal axis of the LED's current-voltage characteristic curve represents the current value, and the vertical axis represents the power value. When the current is less than 0.1 mA, the LED's power increases with the increase of the current.

[0084] in, Figure 5 and Figure 6 These are the current-voltage volt-ampere characteristic curves and the current-power volt-ampere characteristic curves for the same type of LED. Since the resistance of an LED changes non-linearly with the current, it is difficult to determine the LED current by calculation when the LED's power or voltage is known. Therefore, by obtaining the LED's current-voltage volt-ampere characteristic curves or current-power volt-ampere characteristic curves in advance, the current can be directly looked up in the volt-ampere characteristic curves based on the detected LED's voltage or power and other electrical parameters. By obtaining the LED's current-voltage volt-ampere characteristic curves and current-power volt-ampere characteristic curves, various electrical parameter acquisition devices can be adapted to improve the practicality of the circuit board testing circuit.

[0085] Because LEDs have a PN junction structure, their current-voltage characteristic curve is non-linear when emitting light. Therefore, a slight change in the LED current will result in a significant change in the LED's power. Furthermore, since the luminous intensity of an LED is positively correlated with its power, a slight change in the LED current will cause a noticeable change in brightness, making it easy to observe. Due to the fast response speed of LEDs, the detection speed of circuit board testing circuits can be improved, increasing detection efficiency. Leakage branches in the circuit board under test can be quickly located based on the LED's luminous intensity, thereby reducing the difficulty of detection and improving the practicality and effectiveness of the test results.

[0086] For example, Figure 7 This is a schematic diagram of a circuit board detection circuit provided in an embodiment of this application. Figure 7As shown, the circuit board testing circuit includes a constant current power supply 110 and a driving object unit 120, wherein the driving object unit 120 is a light-emitting diode 124, and a power consumption detection unit 130 is connected between the positive terminal of the constant current power supply 110 and the circuit board 140 under test. Figure 7 As shown, multiple light-emitting diodes 124 are connected in parallel.

[0087] A second aspect of this application provides a circuit board testing device 300. Figure 8 This is a schematic structural diagram of a circuit board testing device provided in an embodiment of this application. Figure 8 As shown, the circuit board testing device 300 includes at least one circuit board testing circuit 100 as described in any of the first aspects above, namely circuit board testing circuit 1, circuit board testing circuit 2 to circuit board testing circuit k, where k is a natural number greater than 0.

[0088] The circuit board testing device 300 provided in this embodiment provides a constant and known current to the circuit board under test 140 via a constant current power supply 110. The drive unit 120 receives the current output from the circuit board under test 140. Based on the volt-ampere characteristic curve of the drive unit 120, the input current of the drive unit 120 is determined. Therefore, the leakage current of the circuit board under test 140 can be determined by the current output of the constant current power supply 110 and the input current of the drive unit 120. The power consumption detection unit 130 detects the current power consumption data of the drive unit 120 and the circuit board under test 140. The difference between the current power consumption data and the preset power consumption can be used to determine whether leakage current exists in the circuit board under test 140. Therefore, by using the above-described circuit board testing device to perform leakage current detection on the circuit board under test 140, it is not necessary to disassemble the packaged circuit board under test 140, thereby shortening the testing time, improving testing efficiency, and increasing the accuracy of the testing results.

[0089] In some feasible implementations, when the driving object unit 120 includes a light-emitting device 121, it further includes:

[0090] A brightness detection device is used to detect the brightness of a light-emitting device. The brightness detection device includes an optical lens.

[0091] The brightness value of the light-emitting device 121 can be directly obtained through the brightness detection device, which makes it easy to determine the power of the light-emitting device 121 based on its brightness. This allows for the determination of the leakage current of the circuit board 140 under test, thereby improving the detection level of the circuit board testing equipment 300, increasing detection efficiency and accuracy of detection results, and ultimately enhancing the practicality and effectiveness of the circuit board testing equipment 300.

[0092] In some feasible implementations, the circuit board testing device 300 further includes:

[0093] A platform for mounting at least one circuit board testing device 300.

[0094] By setting up a platform to mount at least one circuit board testing device 300, the integration level of the circuit board testing device 300 can be improved, as well as its convenience and practicality.

[0095] In some feasible implementations, the circuit board testing device 300 further includes:

[0096] A limiting unit is set on the mounting platform to fix the circuit board 140 under test.

[0097] By fixing the circuit board 140 under test by the limiting unit, it is possible to prevent the circuit board 140 under test from sliding on the mounting platform, which would cause poor contact between the circuit board 140 under test and the circuit board detection circuit, affect the detection results, and increase the false judgment rate. This can improve the accuracy of the detection results and thus improve the practicality of the circuit board detection equipment 300.

[0098] In some feasible implementations, the circuit board testing device 300 further includes:

[0099] A vacuum adsorption unit is mounted on a platform and is used to vacuum adsorb the circuit board 140 under test in order to fix the circuit board 140 under test.

[0100] For example, the vacuum adsorption unit described above may include at least one vacuum hole to evacuate the side of the circuit board 140 to be tested away from the PAD area, thereby adsorbing the circuit board 140 to be tested and protecting the electronic devices in the PAD area.

[0101] By using the vacuum adsorption unit to vacuum adsorb the circuit board 140 under test, the circuit board 140 under test can be further fixed. This can avoid the problem of poor contact between the circuit board 140 under test and the circuit board detection circuit 100 due to slippage, which would cause misjudgment and affect the accuracy of the test results. This can improve the accuracy and reliability of the test results, and thus improve the practicality of the circuit board testing equipment 300.

[0102] In some feasible implementations, the circuit board testing device 300 further includes:

[0103] The first adapter is located on the mounting platform and is used to connect the constant current power supply 110 and the circuit board under test 140.

[0104] For example, one end of the first adapter is electrically connected to the positive and negative terminals of the constant current power supply 110, and the other end is used to electrically connect to the input terminal of the circuit board under test 140. A power consumption detection unit 130 can be set between the first adapter and the positive and negative terminals of the constant current power supply 110.

[0105] By mounting the first adapter, power consumption detection unit 130, and constant current power supply 110 on the platform, the input terminal 141 of the circuit board 140 under test can be switched only at the first adapter during the testing of different circuit boards 140 under test. This simplifies the operation and avoids the impact of hot-swapping the constant current power supply 110 on its lifespan. It also prevents any discrepancy between the actual output current and the target output current, which would affect the output power and consequently the accuracy of the test results. Therefore, by using the first adapter, the lifespan of the constant current power supply 110 can be improved, the current stability in the circuit can be enhanced, the operation can be simplified, the accuracy of the test results can be improved, the lifespan of the circuit board testing equipment 300 can be extended, and the practicality of the circuit board testing equipment 300 can be increased.

[0106] In some feasible implementations, the circuit board testing device 300 further includes:

[0107] The second adapter is located on the mounting platform and is used to connect the drive object unit 120 and the circuit board under test 140.

[0108] For example, one end of the second adapter is electrically connected to the drive object unit 120, and the other end is used to electrically connect to the output terminal 142 of the circuit board under test 140.

[0109] By setting the second adapter and constant current power supply 110 on the mounting platform, the output of the circuit board under test 140 can be switched only at the second adapter during the testing of different circuit boards under test 140. This simplifies the operation steps, protects the transmission interface of the drive object unit 120, and extends the service life of the drive object unit 120, thereby improving the practicality of the circuit board testing equipment 300.

[0110] For example, Figure 9 This is a schematic diagram of a circuit board testing device provided in an embodiment of this application. Figure 9As shown, the circuit board testing equipment includes a constant current power supply 110, a driving object unit 120, a power consumption detection unit 130, a brightness detection device 410, a first adapter 420, a second adapter 430, a display device 440, a vacuum adsorption unit 450, a start switch 460, and a mounting platform 470. The constant current power supply 110 is electrically connected to the power consumption detection unit 130. The display device 440 displays the detection results of the power consumption detection unit 130 and the brightness detection device 410, and displays data such as the leakage status and leakage current of the circuit board 140 under test. The start switch 460 controls the total power supply of the mounting platform 470 and is electrically connected to the constant current power supply 110, the driving object unit 120, the power consumption detection unit 130, the brightness detection device 410, the display device 440, and the vacuum adsorption unit 450 to control their start-up state.

[0111] For example, Figure 10 This is a schematic top view of a circuit board testing device provided in an embodiment of this application. Figure 10 As shown, Figure 9 The circuit board testing equipment shown, viewed from above, includes a constant current power supply 110, a drive object unit 120, a power consumption detection unit 130, a brightness detection device 410, a first adapter 420, a second adapter 430, a display device 440, a start switch 460, and a mounting platform 470.

[0112] For example, Figure 11 This is a schematic diagram of a backlight module provided in an embodiment of this application. Figure 11 As shown, the circuit board under test 140 can drive the lamp board 125 composed of light-emitting devices 121. After the circuit board under test is tested, it can form a backlight module with the lamp board, such as... Figure 11 As shown, the backlight module may include a lamp board 125, a glass cover plate 510, a light diffuser 520, a light guide plate 530, and a support back plate 540. By adding a light guide plate 530 in the illumination direction of the lamp board 125, the line light source can be converted into a surface light source. By adding a light diffuser 520, the brightness uniformity of the surface light source can be improved, thereby improving the uniformity of the screen display of the liquid crystal display device.

[0113] A third aspect of this application provides a method for testing circuit boards. Figure 12 This is a schematic flowchart illustrating a circuit board testing method provided in an embodiment of this application. Figure 12 As shown, the circuit board testing method includes:

[0114] Step S610: Power on the circuit board 140 under test.

[0115] For example, a constant current is output to the circuit board under test 140 via a constant current power supply 110.

[0116] Step S620: Detect the electrical parameters of the driving object unit 120 to obtain the current-voltage characteristic curve of the driving object unit 120.

[0117] For example, before testing the circuit board 140 under test, the electrical parameters of the drive unit 120 are first tested. If the drive unit 120 is a device with constant resistance, its current-voltage characteristic curve can be obtained based on its resistance value. If the resistance of the drive unit 120 changes with the input current, its current-voltage characteristic curve can be determined by detecting the current and voltage or power of the drive unit 120.

[0118] Step S630: Detect the power consumption data of the circuit board under test 140.

[0119] For example, the power consumption data of the circuit board under test 140 can be detected by a power detection device or a current detection device.

[0120] Step S640: Analyze the leakage current of the circuit board under test 140 based on the current-voltage characteristic curve and power consumption data of the drive object unit 120.

[0121] For example, the actual power in the current circuit can be determined based on the power consumption data detected by the power consumption detection unit 130. The power of the circuit board under test 140 and the power of the driving unit 120 under the condition of no leakage can be determined based on the volt-ampere characteristic curve of the driving unit 120, the output current of the constant current power supply 110, and the resistance value of the circuit board under test 140, thereby determining the output power of the constant current power supply 110 under the condition of no leakage. If the difference between the output power of the constant current power supply 110 and the power consumption data is greater than a preset threshold, it can be determined that leakage has occurred in the circuit board under test 140. The magnitude of the leakage current of the circuit board under test 140 can be analyzed based on the sensitivity of the volt-ampere characteristic curve of the driving unit 120 to current.

[0122] A constant and known current is provided to the circuit board under test (TBD) 140 by a constant current power supply 110. The current output from the TBD 140 is received by the drive unit 120. The input current of the drive unit 120 is determined based on its volt-ampere characteristic curve. Therefore, the leakage current of the TBD 140 can be determined by the current output of the constant current power supply 110 and the input current of the drive unit 120. The power consumption detection unit 130 can detect the current power consumption data of the drive unit 120 and the TBD 140. The difference between the current power consumption data and the preset power consumption can be used to determine whether the TBD 140 has leakage current. Therefore, the above circuit board detection method does not require disassembling the packaged circuit board, thereby shortening the detection time, improving detection efficiency, and enhancing the accuracy, effectiveness, and practicality of the detection results.

[0123] In some feasible implementations, power consumption data includes actual current and actual power.

[0124] The leakage current of the circuit board 140 under test can be determined by comparing the actual current in the circuit with the current provided by the constant current power supply 110. The leakage current of the circuit board 140 under test can also be determined by comparing the actual power with the output power of the constant current power supply 110. This can improve the effectiveness and practicality of the test data, thereby enhancing the practicality of the circuit board testing method.

[0125] In some feasible implementations, the leakage current of the circuit board under test 140 is analyzed based on the volt-ampere characteristic curve and power consumption data of the driven object unit 120, including:

[0126] The target output power of the constant current power supply 110 is determined based on the volt-ampere characteristics of the drive object unit 120 and the detection current output by the constant current power supply 110.

[0127] If the target output power is greater than the actual power, and the difference between the target output power and the actual power is greater than the preset power, it is determined that the circuit board under test 140 has leakage.

[0128] It should be noted that if leakage occurs in the circuit board under test 140, the current in the circuit will be smaller than the detection current output by the constant current power supply 110, which will cause a reduction in the power of the circuit board under test 140 and the driven unit 120. This will result in the actual power being less than the target output power.

[0129] By using the above method to determine the leakage current of the circuit board 140 under test, the accuracy of the test results can be improved, the difficulty of the test can be reduced, and the efficiency of the test can be increased, thereby improving the practicality and convenience of the circuit board testing method.

[0130] In some feasible implementations, where the circuit board inspection equipment 300 includes a brightness detection device 410, the method further includes:

[0131] Detect the brightness of all light-emitting devices 121;

[0132] If the light-emitting devices are all of the same type 121, and the brightness of at least one light-emitting device 121 is less than the brightness of the other light-emitting devices 121, and the difference between the two is greater than the preset brightness, it is determined that there is leakage in the branch of the circuit board 140 under test that is electrically connected to the light-emitting device 121 with lower brightness.

[0133] For example, when the light-emitting devices 121 are of different models, the luminous power corresponding to the luminous brightness of the light-emitting device 121 can be determined according to the model of the light-emitting device 121. The preset brightness is determined based on the detection accuracy of the brightness detection device 410. The preset brightness can also be determined based on the usage status of light-emitting devices 121 of the same model. For example, the preset brightness can be determined based on the difference in usage time of the light-emitting devices 121. If the difference in usage time of each light-emitting device 121 is greater than the preset time, it can be considered that some light-emitting devices 121 have aged, and therefore the preset brightness should be increased.

[0134] When there is a large difference in brightness between light-emitting devices 121 of the same model, it can be assumed that there is a large difference in their power. Therefore, it can be determined that there is leakage in the branch of the circuit board 140 connected to the light-emitting device 121 with lower brightness. This causes the input current of the light-emitting device 121 to be less than the output current of the constant current power supply 110. Thus, the location of the leakage in the circuit board 140 can be determined, thereby improving the practicality of the circuit board testing method.

[0135] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0136] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A circuit board testing circuit, characterized in that, include: A constant current power supply, the output terminal of which is used to electrically connect to the input terminal of the circuit board under test, and the constant current power supply is used to provide a constant and known current to the circuit board under test; At least one driving object unit is used to be electrically connected to the output terminal of the circuit board under test, wherein, in the event of leakage current in the circuit board under test, the driving object unit is used to reflect the leakage current of the circuit board under test through the volt-ampere characteristic curve. At least one power consumption detection unit is disposed between the circuit board under test and the constant current power supply. The power consumption data detected by the power consumption detection unit is used to reflect the leakage current of the circuit board under test. The driving object unit includes a light-emitting device, which is used to reflect the leakage current of the circuit board under test by the change in light intensity. The light-emitting device includes an LED, and the current-voltage characteristic curve of the LED is non-linear. When the current of the LED changes slightly, the power of the LED will change significantly. The power consumption detection unit is used to reflect the leakage current of the circuit board under test based on the relationship between the detected power consumption data and the output power of the constant current power supply.

2. The circuit board detection circuit according to claim 1, characterized in that, The power consumption detection unit is positioned between the positive terminal of the constant current power supply and the circuit board under test; and / or, All of the power consumption detection units are connected in parallel.

3. A circuit board testing device, characterized in that, include: At least one circuit board detection circuit as described in any one of claims 1 to 2.

4. The circuit board testing equipment according to claim 3, characterized in that, When the driving object unit includes a light-emitting device, it further includes: A brightness detection device is used to detect the brightness of the light-emitting device, and the brightness detection device includes an optical lens.

5. The circuit board testing equipment according to claim 3, characterized in that, Also includes: A platform for mounting at least one of the circuit board testing devices.

6. The circuit board testing equipment according to claim 5, characterized in that, Also includes: A limiting unit is disposed on the mounting platform for fixing the circuit board under test; And / or, A vacuum adsorption unit is disposed on the mounting platform and is used to vacuum adsorb the circuit board under test in order to fix the circuit board under test.

7. The circuit board testing equipment according to claim 5, characterized in that, Also includes: The first adapter is disposed on the mounting platform and is used to connect the constant current power supply and the circuit board under test; And / or, The second adapter is located on the mounting platform and is used to connect the driving object unit and the circuit board under test.

8. A circuit board testing method, characterized in that, The circuit board testing equipment as described in any one of claims 3 to 7 comprises: Power is applied to the circuit board under test; The electrical parameters of the driving object unit are detected to obtain the current-voltage characteristic curve of the driving object unit; Detect the power consumption data of the circuit board under test; Based on the current-voltage characteristic curve and power consumption data of the driving object unit, the leakage current of the circuit board under test is analyzed.

9. The circuit board testing method according to claim 8, characterized in that, The power consumption data includes actual current and actual power; The step of analyzing the leakage current of the circuit board under test based on the current-voltage characteristic curve and power consumption data of the driving object unit includes: The target output power of the constant current power supply is determined based on the volt-ampere characteristics of the driving object unit and the detection current output by the constant current power supply. If the target output power is greater than the actual power, and the difference between the target output power and the actual power is greater than a preset power, it is determined that the circuit board under test has leakage.

10. The circuit board testing method according to claim 8, characterized in that, When the circuit board inspection equipment includes a brightness detection device and the driving object unit includes a light-emitting device, the method further includes: Detect the brightness of all the light-emitting devices; If the light-emitting devices are of the same model, and the brightness of at least one of the light-emitting devices is less than the brightness of the other light-emitting devices, and the difference between the two is greater than a preset brightness, it is determined that there is leakage in the branch of the circuit board under test that is electrically connected to the light-emitting device with lower brightness.

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