Plate vibration capacitance detection apparatus and method

Abstract

The application provides a board vibration capacitor detection device and method. The board vibration capacitor detection device comprises a plurality of board vibration detection devices and a signal processing device electrically connected with the plurality of board vibration detection devices respectively; the plurality of board vibration detection devices are respectively used for detecting the board vibration of the corresponding detection point of the to-be-detected circuit board and outputting the corresponding board vibration electric signal to the signal processing device; and the signal processing device is used for determining the position information of the board vibration capacitor causing the board vibration on the to-be-detected circuit board according to the plurality of input board vibration electric signals. Through the above board vibration capacitor detection device and method, the plurality of board vibration detection devices and the signal processing device are respectively arranged, so that the board vibration of the plurality of detection points of the to-be-detected circuit board can be detected, and the plurality of board vibration electric signals respectively corresponding to the plurality of detection points can be generated, and then the positioning of the board vibration capacitor causing the board vibration can be realized according to the plurality of board vibration electric signals, and finally the position information of the board vibration capacitor is obtained.

Description

Technical Field

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

[0002] Board vibration, also known as capacitor howling, is a noise caused by the deformation and expansion of a capacitor, which in turn causes the circuit board to vibrate. In this case, the capacitor can be considered a board-vibrating capacitor. However, not all capacitors have this problem; board vibration issues typically occur in multilayer ceramic capacitors (MLCCs). This is because, under an applied electric field, the ceramic dielectric itself undergoes significant expansion and contraction. If an alternating voltage is applied across the capacitor, the deformation of the ceramic capacitor will become periodic. Since the capacitor is in close contact with the circuit board, this periodic deformation of the capacitor will cause the circuit board to vibrate periodically.

[0003] In existing technologies, from early optical inspection (foreign object / defect identification) to electron beam inspection and X-ray measurement technology, modern inspection equipment has achieved nanometer-level precision. However, there is still a lack of dedicated inspection methods for board vibration capacitors on circuit boards, which makes it impossible to locate board vibration capacitors on circuit boards that exhibit board vibration. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a plate vibration capacitance detection device and method.

[0005] In a first aspect, in one embodiment, the present invention provides a plate vibration capacitance detection device, which includes a plurality of plate vibration detection devices and a signal processing device electrically connected to the plurality of plate vibration detection devices respectively.

[0006] Multiple board vibration detection devices are used to detect the board vibration at corresponding detection points of the circuit board under test, and output the corresponding board vibration electrical signal to the signal processing device.

[0007] The signal processing device is used to determine the location information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals received.

[0008] In one embodiment, the plurality of plate vibration detection devices each include a signal conversion unit;

[0009] Multiple signal conversion units are used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signals, and to convert the sensed board vibration mechanical signals into corresponding board vibration electrical signals and output them to the signal processing device.

[0010] In one embodiment, the plurality of signal conversion units each include a mechanical sensing device and a signal conversion device that is mechanically connected to the corresponding mechanical sensing device and electrically connected to the signal processing device.

[0011] Multiple mechanical sensing devices are used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signals, and to transmit the sensed board vibration mechanical signals to the corresponding signal conversion devices.

[0012] Multiple signal conversion devices are used to convert the incoming mechanical signals of the plate vibration into corresponding electrical signals of the plate vibration and output them to the signal processing device.

[0013] In one embodiment, the plurality of plate vibration detection devices further include signal amplification units that are electrically connected to corresponding signal conversion units and signal processing devices.

[0014] Multiple signal amplification units are used to amplify the board vibration electrical signals output by the corresponding signal conversion units and output them to the signal processing device.

[0015] In one embodiment, four plate vibration detection devices are provided;

[0016] Four board vibration detection devices are used to detect the board vibration at corresponding corner points of the circuit under test, with each corner point serving as a detection point.

[0017] In one embodiment, the signal processing apparatus includes a processing unit and a signal acquisition unit that is electrically connected to a plurality of plate vibration detection devices and the processing unit, respectively.

[0018] The signal acquisition unit is used to condition the electrical signals of the plate vibration output from multiple plate vibration detection devices and output them to the processing unit.

[0019] The processing unit is used to determine the location information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals output by the signal acquisition unit.

[0020] In one embodiment, the signal processing apparatus further includes a display unit electrically connected to the processing unit;

[0021] The display unit is used to display the position information of the plate resonator capacitor according to the display signal sent by the processing unit.

[0022] Secondly, in one embodiment, the present invention provides a plate resonator capacitance detection method, which is applied to the plate resonator capacitance detection device in any of the above embodiments; the plate resonator capacitance detection method includes the following steps performed by a signal processing device:

[0023] Connect to the plate vibration electrical signals output by multiple plate vibration detection devices;

[0024] Based on multiple board vibration electrical signals, determine the location information of the board vibration capacitors on the circuit board under test that cause board vibration.

[0025] In one embodiment, determining the location information of the board vibration capacitors on the circuit board under test that cause board vibration based on multiple board vibration electrical signals includes:

[0026] Based on multiple board vibration electrical signals, the vibration intensity of multiple detection points on the circuit board under test is determined;

[0027] The location information of the plate vibration capacitor is determined based on the location information of multiple detection points and vibration intensity.

[0028] In one embodiment, determining the vibration intensity of multiple detection points on the circuit board under test based on multiple board vibration electrical signals includes:

[0029] For each plate vibration signal, a fast Fourier transform is performed on the filtered plate vibration signal to obtain the corresponding frequency domain signal. The component signal with the largest amplitude in the frequency domain signal is obtained, and the vibration intensity corresponding to the component signal is taken as the vibration intensity of the detection point corresponding to the plate vibration signal.

[0030] In one embodiment, determining the location information of the plate vibration capacitor based on the location information of multiple detection points and the vibration intensity includes:

[0031] For one of the detection points,

[0032] Using the location information of this detection point as the reference location information, determine the ratio of the vibration intensity of at least two other detection points to that detection point;

[0033] The distance between the plate vibration capacitor and the detection point is obtained based on the ratio of the vibration intensity of at least two other detection points to that of the detection point.

[0034] The position information of the plate resonant capacitor is determined based on the distance between the plate resonant capacitor and the detection point, as well as the position information of multiple detection points.

[0035] In one embodiment, there are four detection points, three of which are used to determine the position information of the plate resonant capacitor, and the remaining detection point is used to verify the position information of the plate resonant capacitor.

[0036] By using the above-mentioned board vibration capacitor detection equipment and method, multiple board vibration detection devices and signal processing devices are set up respectively, so as to detect the board vibration at multiple detection points of the circuit board under test and generate multiple board vibration electrical signals corresponding to the multiple detection points. Then, the board vibration capacitor that causes the board vibration can be located based on the multiple board vibration electrical signals, and finally the position information of the board vibration capacitor can be obtained. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a plate vibration capacitance detection device in one embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of a plate vibration detection device including a signal conversion unit in one embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of a signal conversion unit including a signal conversion device and a mechanical sensing device in one embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram showing that the plate vibration detection device further includes a signal amplification unit in one embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of a signal processing device including a signal acquisition unit and a processing unit in one embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram showing that, in one embodiment of the present invention, the signal processing device further includes a power supply unit, a storage unit, a display unit, and a button unit;

[0044] Figure 7 This is a schematic diagram of a plate vibration detection device in one embodiment of the present invention, which includes four probe clips, microphones and amplifiers respectively;

[0045] Figure 8 This is a schematic diagram illustrating the coordinate calculation principle using four detection points as an example in one embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use the invention. In the following description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0048] Firstly, such as Figure 1 As shown, in one embodiment, the present invention provides a plate vibration capacitance detection device, which includes a plurality of plate vibration detection devices and a signal processing device electrically connected to the plurality of plate vibration detection devices respectively.

[0049] Multiple board vibration detection devices are used to detect the board vibration at corresponding detection points of the circuit board under test, and output the corresponding board vibration electrical signal to the signal processing device.

[0050] The plate vibration detection device can be implemented in different ways. For example, it can be visually detected to detect the plate vibration at the corresponding detection point. Specifically, the corresponding plate vibration electrical signal can be obtained by analyzing the plate vibration frequency and amplitude at the corresponding detection point in the image. Of course, in other embodiments, the plate vibration detection device can also use other methods, which will not be elaborated here.

[0051] The signal processing device is used to determine the location information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals received.

[0052] When board vibration occurs on the circuit board under test, it can be determined that there is a board vibration capacitor on the circuit board that is causing the vibration. The board vibration capacitor then acts as a vibration source, transmitting the vibration to each detection point on the circuit board under test.

[0053] Since the board resonant capacitor transmits vibration to each detection point through the vibration transmission path on the circuit board under test, the distance between each detection point and the board resonant capacitor affects the degree of vibration attenuation during transmission. Generally, the greater the distance, the greater the attenuation and the smaller the vibration intensity at the detection point; conversely, the smaller the distance, the smaller the attenuation and the greater the vibration intensity at the detection point.

[0054] In other words, if the vibration intensity of the plate vibrating capacitor, which is the vibration source, remains constant, and the position of the plate vibrating capacitor changes, the vibration intensity at each detection point will change. Based on this characteristic, the position information of the plate vibrating capacitor can ultimately be determined based on the vibration intensity at each detection point.

[0055] It is important to note that since only the vibration intensity at each detection point can be obtained, while the vibration intensity of the plate resonator capacitor is unknown, the distance between each detection point and the plate resonator capacitor cannot be directly determined based on the vibration intensity at each detection point. In this embodiment, since the vibration intensity of the plate resonator capacitor is constant relative to the vibration intensity at each detection point, the difference in vibration intensity between each detection point can characterize the difference in distance between each detection point and the plate resonator capacitor. The more detection points set, the more "distance differences" are characterized, and ultimately, the location information of the plate resonator capacitor can be determined based on these "distance differences." For example, in... Figure 1 Three plate vibration detection devices can be set up in the middle.

[0056] The aforementioned board vibration capacitor detection equipment is equipped with multiple board vibration detection devices and signal processing devices, which can detect board vibration at multiple detection points on the circuit board under test and generate multiple board vibration electrical signals corresponding to the multiple detection points. Then, the location of the board vibration capacitor that causes the board vibration can be realized based on the multiple board vibration electrical signals, and finally the position information of the board vibration capacitor can be obtained.

[0057] like Figure 2 As shown, in one embodiment, the plurality of plate vibration detection devices each include a signal conversion unit.

[0058] Multiple signal conversion units are used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signals, and to convert the sensed board vibration mechanical signals into corresponding board vibration electrical signals and output them to the signal processing device.

[0059] As mentioned in the above embodiments, board vibration detection can be achieved through non-contact methods such as visual inspection. In this case, the obtained image data in the form of electrical signals can be directly output to the signal processing device, which can process the image data in the form of electrical signals.

[0060] In this embodiment, a signal conversion unit that directly contacts the detection point can also be used. When the signal conversion unit contacts the detection point, it can sense the mechanical signal of the plate vibration at the detection point. Since the signal processing device cannot process the mechanical signal of the plate vibration, it is necessary to convert it into a plate vibration electrical signal in the form of an electrical signal.

[0061] like Figure 3 As shown, in one embodiment, the plurality of signal conversion units each include a mechanical sensing device and a signal conversion device that is mechanically connected to the corresponding mechanical sensing device and electrically connected to the signal processing device.

[0062] Among them, Figure 3 In the diagram, solid lines represent electrical connections, and dashed lines represent mechanical connections.

[0063] Multiple mechanical sensing devices are used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signals, and to transmit the sensed board vibration mechanical signals to the corresponding signal conversion devices.

[0064] When using a contact-based method, it is necessary to ensure the accuracy of vibration sensing. Therefore, a dedicated mechanical sensing device (such as a probe clip or probe with high sensitivity) can be set up. Mechanical sensing devices are specifically designed to sense vibrations, so they cannot perform signal conversion. Therefore, an additional signal conversion device is required.

[0065] Multiple signal conversion devices are used to convert the incoming mechanical signals of the plate vibration into corresponding electrical signals of the plate vibration and output them to the signal processing device.

[0066] The signal conversion device needs to be mechanically connected to the mechanical sensing device to receive the corresponding board vibration mechanical signal. Therefore, the connection between the signal conversion device and the mechanical sensing device needs to be reliable. Specifically, the shape or type of the input part of the signal conversion device can be selected according to the mechanical sensing device. For example, when the mechanical sensing device is a probe clip, the signal conversion device can be a microphone.

[0067] like Figure 4 As shown, in one embodiment, the plurality of plate vibration detection devices further include signal amplification units that are electrically connected to the corresponding signal conversion unit and signal processing device.

[0068] Multiple signal amplification units are used to amplify the board vibration electrical signals output by the corresponding signal conversion units and output them to the signal processing device.

[0069] The amplitude of the board resonant electrical signal directly output by the signal conversion unit may be small, which may cause some problems. For example, it may not meet the amplitude requirements of the signal processing device, or it may be easily interfered with by noise during subsequent transmission. In order to solve the above problems, this embodiment specifically adds a signal amplification unit (such as an amplifier), which can directly amplify the board resonant electrical signal output by the signal conversion unit and output the amplified board resonant electrical signal to the signal processing device.

[0070] like Figure 5 As shown, in one embodiment, the signal processing apparatus includes a processing unit and a signal acquisition unit that is electrically connected to a plurality of plate vibration detection devices and the processing unit, respectively.

[0071] The signal acquisition unit is used to condition the electrical signals of the plate vibration output from multiple plate vibration detection devices and output them to the processing unit.

[0072] Since the plate vibration detection device outputs an analog electrical signal, the signal acquisition unit is mainly used for analog-to-digital conversion to convert the analog electrical signal into a digital electrical signal and output the digital electrical signal to the processing unit.

[0073] The processing unit is used to determine the location information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals output by the signal acquisition unit.

[0074] Since the plate vibration electrical signal output by the plate vibration detection device has been converted from an analog signal to a digital signal by the signal acquisition unit, the processing unit can perform relevant processing after receiving the plate vibration electrical signal output by the signal acquisition unit. For specific details, please refer to the above-mentioned related embodiments, which will not be repeated here.

[0075] like Figure 6 As shown, in one embodiment, the signal processing apparatus further includes a display unit electrically connected to the processing unit.

[0076] The display unit is used to display the position information of the plate resonator capacitor according to the display signal sent by the processing unit.

[0077] In this embodiment, after the processing unit determines the position information of the board resonant capacitor on the circuit board under test, it can use the circuit board under test as a display background, highlighting it in the background and displaying the highlighted background on the display unit. This allows the testing personnel to clearly understand the current testing results based on the information displayed on the display unit. In other embodiments, the display unit can also use text to display the position coordinates of the circuit board under test and the position coordinates of the board resonant capacitor, allowing the testing personnel to clearly understand the current testing results based on the position coordinates as well.

[0078] Specifically, the display unit can be in the form of LCD (Liquid Crystal Display) or LED (Light Emitting Diode Display), which can be selected according to actual needs and cost.

[0079] In other embodiments, other methods can be used to inform the testing personnel of the current test results, such as an indicator light combination (the circuit board to be tested can be pre-divided into areas, each area corresponding to a lighting state; once the location of the board resonant capacitor on the circuit board to be tested is determined, the indicator light combination can be controlled to work in the corresponding lighting state, so that the testing personnel can know the current test results based on the lighting state).

[0080] like Figure 6 As shown, in one embodiment, the signal processing apparatus further includes a power supply unit electrically connected to the processing unit.

[0081] The power supply unit is used to provide the operating voltage to the processing unit according to the power supply connected to it.

[0082] The power supply unit can be a switching power supply circuit, which uses PWM (Pulse Width Modulation) control as its core to convert a relatively high-voltage power supply into a relatively low-voltage operating voltage. Of course, in other embodiments, the power supply unit can also adopt other types of circuit topologies, which will not be elaborated here.

[0083] like Figure 6 As shown, in one embodiment, the signal processing apparatus further includes a storage unit electrically connected to the processing unit.

[0084] The storage unit is used to store the location information sent by the processing unit for later tracing.

[0085] The storage unit can be made of flash memory, ROM, etc., which will not be elaborated here.

[0086] like Figure 6 As shown, in one embodiment, the signal processing apparatus further includes a button unit electrically connected to the processing unit.

[0087] The button unit is used to acquire the operation instructions input by the inspector and output the operation instructions to the processing unit.

[0088] Among them, the button unit serves as a human-machine interaction unit between the testing personnel and the plate vibration capacitance testing equipment, enabling the testing personnel to control the processing unit to perform corresponding operations through different button combinations.

[0089] In other embodiments, touch screens, voice units, etc. may also be used, which will not be described in detail here.

[0090] like Figure 7 As shown, in one embodiment, there are four plate vibration detection devices, each of which includes a probe clip as a mechanical sensing device, a microphone as a signal conversion device, and an amplifier as a signal amplification unit.

[0091] The four probe clips are used to contact the four corners of the circuit board under test and are mechanically connected to the corresponding microphones. The four microphones are also electrically connected to the corresponding amplifiers. The four amplifiers are also electrically connected to the signal acquisition interface in the signal processing device, so as to be electrically connected to the signal acquisition unit through the signal acquisition interface.

[0092] Four board vibration detection devices are used to detect the board vibration at corresponding corner points of the circuit under test, with each corner point serving as a detection point.

[0093] In this embodiment, the circuit board under test is rectangular with four corner points, and the positional relationship between the four corner points is relatively balanced. Therefore, using the four corner points as detection points can improve the accuracy of subsequent position detection.

[0094] In other embodiments, other numbers of plate vibration detection devices and other layouts of detection points may also be used.

[0095] Secondly, in one embodiment, the present invention provides a plate resonator capacitance detection method, which is applied to the plate resonator capacitance detection device in any of the above embodiments; the plate resonator capacitance detection method includes the following steps performed by a signal processing device:

[0096] Connect to the plate vibration electrical signals output by multiple plate vibration detection devices;

[0097] Based on multiple board vibration electrical signals, determine the location information of the board vibration capacitors on the circuit board under test that cause board vibration.

[0098] The signal processing device includes a processing unit capable of processing signals. This processing unit can perform relevant processing, analysis, and calculation on the plate vibration electrical signal to obtain the position information of the plate vibration capacitor.

[0099] The board vibration capacitance detection equipment used in the above-mentioned board vibration capacitance detection method is equipped with multiple board vibration detection devices and signal processing devices, which can detect board vibration at multiple detection points of the board under test and generate multiple board vibration electrical signals corresponding to the multiple detection points. Then, the board vibration capacitor that causes board vibration can be located based on the multiple board vibration electrical signals, and finally the position information of the board vibration capacitor can be obtained.

[0100] In one embodiment, determining the location information of the board vibration capacitors on the circuit board under test that cause board vibration based on multiple board vibration electrical signals includes:

[0101] The vibration intensity at multiple detection points on the circuit board under test is determined based on multiple board vibration electrical signals.

[0102] As mentioned in the above embodiments, the core of the present invention is to realize position detection based on the distance difference between each detection point and the plate vibration capacitor. The distance difference between each detection point and the plate vibration capacitor is reflected by the difference in vibration intensity of each detection point. Therefore, in this embodiment, after obtaining multiple plate vibration electrical signals, it is necessary to process the plate vibration electrical signals to obtain the vibration intensity represented by the plate vibration electrical signals.

[0103] The location information of the plate vibration capacitor is determined based on the location information of multiple detection points and vibration intensity.

[0104] Once the vibration intensity is obtained, the distance between each detection point and the plate vibration capacitor can be obtained through relevant calculations (such as solving the equations related to the vibration intensity). Then, combined with the position information of each detection point, the position information of the plate vibration capacitor can be obtained.

[0105] In one embodiment, determining the vibration intensity of multiple detection points on the circuit board under test based on multiple board vibration electrical signals includes:

[0106] For each plate vibration signal, a fast Fourier transform is performed on the filtered plate vibration signal to obtain the corresponding frequency domain signal.

[0107] It is understandable that when board vibration occurs on the circuit board under test, there is at least one board vibration capacitor on it.

[0108] When there is only one plate resonator capacitor, the frequency and amplitude of the plate resonator electrical signals obtained at each detection point are relatively regular. For each detection point, the amplitude of the plate resonator electrical signal detected at that detection point can be directly used as the vibration intensity of that detection point. Therefore, based on the vibration intensity and position information of each detection point, the position information of the plate resonator capacitor can be determined.

[0109] When there are multiple plate-mounted resonant capacitors, the frequency and amplitude of the plate-mounted resonant electrical signals obtained at each detection point are not very regular. Each plate-mounted resonant electrical signal is obtained by superimposing the plate-mounted resonants of multiple plate-mounted capacitors. For each detection point, directly taking the amplitude of the plate-mounted resonant electrical signal detected at that detection point as the vibration intensity corresponding to that detection point will cause a large error.

[0110] Therefore, in this embodiment, after obtaining the plate resonant electrical signal, a fast Fourier transform is performed on it to convert it from the time domain to the frequency domain. Since the plate resonant frequencies caused by different plate resonant capacitors are usually different, the plate resonant separation of each plate resonant capacitor can be achieved in the frequency domain. Finally, multiple component signals of different frequencies are obtained through fast Fourier transform, and each component signal corresponds to the plate resonant of one plate resonant capacitor.

[0111] For each frequency domain signal, the component signal with the largest amplitude in that frequency domain signal is obtained, and the vibration intensity corresponding to the component signal is taken as the vibration intensity of the detection point corresponding to the plate's electro-optic signal.

[0112] The purpose of detecting the board vibration capacitor is to determine its location so that relevant treatment measures can be taken. The greater the vibration intensity caused by the board vibration capacitor, the greater its impact on the circuit board under test. Therefore, the board vibration capacitor that causes the greatest vibration intensity should be detected first.

[0113] Therefore, in this embodiment, after obtaining the frequency domain signal, the component signal with the largest amplitude in the frequency signal is directly obtained. This component signal corresponds to the plate resonating capacitor with the largest vibration intensity. Thus, the vibration intensity corresponding to this component signal is taken as the vibration intensity of the detection point. After obtaining the vibration intensity of each detection point, the position information of the plate resonating capacitor can be determined by combining the position information of each detection point. Of course, in other embodiments, the position information of other plate resonating capacitors can be determined in the same way, which will not be elaborated here.

[0114] In one embodiment, determining the location information of the plate vibration capacitor based on the location information of multiple detection points and the vibration intensity includes:

[0115] The relative positions of the plate vibration capacitor and the multiple detection points are obtained based on the vibration intensity at multiple detection points.

[0116] The difference in vibration intensity between each detection point can characterize the difference in distance between each detection point and the plate resonating capacitor, thereby determining the distance between each detection point and the plate resonating capacitor, and finally obtaining the relative position of the plate resonating capacitor and multiple detection points.

[0117] The position information of the plate resonant capacitor is obtained based on the relative position of the plate resonant capacitor and multiple detection points, as well as the position information of the multiple detection points.

[0118] Among them, since the size parameters of the circuit board to be measured can be determined in advance, the position information of each detection point on it can also be determined in advance. For example, the position coordinates of a certain detection point can be used as the origin to establish a corresponding coordinate system. Based on the established coordinate system, after obtaining the relative positions of the board vibration capacitor and multiple detection points, the position coordinates of the board vibration capacitor in the coordinate system can be determined according to the position coordinates of the detectable points in the coordinate system, and the position coordinates of the board vibration capacitor in the coordinate system are used as the position information of the board vibration capacitor.

[0119] Specifically, for one detection point, the position information of this detection point is used as the reference position information to determine the ratio of the vibration intensities of at least two other detection points to this detection point; according to the ratio of the vibration intensities of at least two other detection points to this detection point, the distance between the board vibration capacitor and this detection point is obtained; according to the distance between the board vibration capacitor and this detection point and the position information of multiple detection points, the position information of the board vibration capacitor is determined.

[0120] More specifically, there are four detection points, three of which are used to determine the position information of the board vibration capacitor, and the remaining one is used to verify the position information of the board vibration capacitor.

[0121] To make the above-mentioned signal processing process clearer, a detailed description is given below taking four detection points as an example. Refer to Figure 8 , assuming that the circuit board to be measured is a rectangle with a length of L and a width of W, and the coordinates of the four corner points are A(0,0), B(L,0), C(L,W), D(0,W) respectively. The board vibration capacitor is located at the unknown coordinates of α(x,y) as the vibration source, where 0 < x < L and 0 < y < W, and the vibration intensity is assumed to be k. The vibration intensities measured at the four corner points are I A 、I B 、I C 、I D .

[0122] According to the Wellhausen attenuation theory, the vibration intensity is inversely proportional to the square of the distance, that is:

[0123]

[0124] Therefore, for each corner point:

[0125]

[0126] Using I A as a reference, calculate the ratios relative to I B and I C :

[0127]

[0128] Given I A I B I C Given the length L and width W, the coordinates x and y of the vibration source can be calculated. This can be verified by substituting the fourth point D(0,W) into the solution.

[0129] Meanwhile, assuming T is the square of the distance from the vibration source to point A(0,0), then T = X 2 +y 2 Then we can define constants A, B, C, and D as follows:

[0130]

[0131] Substituting x and y into the expression, we have:

[0132] x = AT + B, y = CT + D

[0133] Substitute T = x 2 +y 2 The quadratic equation is obtained as follows:

[0134] T = (AT + B) 2 +(CT+D) 2

[0135] Expand and organize:

[0136] T = A 2 T 2 +2ABT+B 2 +C 2 T 2 +2CDT+D 2

[0137] 0 = (A 2 +C 2 )T 2 +(2AB+2CD-1)T+(B 2 +D 2 )

[0138] Constant terms U, V, and W can be defined. e As follows:

[0139] U = A 2 +C 2 V = 2AB + 2CD - 1, W e =B 2 +D 2

[0140] The equation is:

[0141] UT 2 +VT+W e =0

[0142] The solution to this quadratic equation is the distance from the vibration source coordinates to the origin A(0,0). The solution has the following form:

[0143]

[0144] Since T = x 2 +y 2 If the value is greater than 0, then multiple solutions have only one positive real root. After obtaining T, the coordinate values ​​can be calculated as follows:

[0145] x = AT + B, y = CT + D

[0146] Finally, we can substitute I. D Let's verify the results:

[0147]

[0148] In summary, the vibration intensity I at the four corner points A, B, C, and D of the rectangle was recorded. A I B I C I D Using point A as the reference, calculate... and Eliminate the vibration intensity k of the vibration source.

[0149] Transform the ratio into a relationship with respect to the square of the distance from the vibration source to point A (T = x). 2 +y 2 The quadratic equation of T is expressed by auxiliary variables A, B, C, and D, where x and y are represented by auxiliary variables A, B, C, and D. Solving for the positive real roots of the quadratic equation of T and substituting them into x = AT + B and y = CT + D, the coordinates (x, y) of the vibration source can be obtained.

[0150] As can be seen from the detailed process above, only three detection points are needed to determine the spatial coordinates of the plate resonator capacitor. When four detection points are used, four triangular regions can be formed respectively, thereby improving the accuracy of the determined spatial coordinates.

[0151] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0152] The above provides a detailed description of the plate resonant capacitance detection device and method provided by the present invention. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0153] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A plate resonant capacitance detection device, characterized in that, The plate vibration capacitance detection equipment includes multiple plate vibration detection devices and a signal processing device that is electrically connected to each of the multiple plate vibration detection devices. The multiple board vibration detection devices are used to detect the board vibration at corresponding detection points of the circuit board under test, and output the corresponding board vibration electrical signal to the signal processing device; The signal processing device is used to determine the position information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals received. Each of the aforementioned plate vibration detection devices includes a signal conversion unit; The multiple signal conversion units are respectively used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signal, and to convert the sensed board vibration mechanical signal into the corresponding board vibration electrical signal and output it to the signal processing device. The signal processing device is specifically used to perform a fast Fourier transform on each of the plate vibrating electrical signals after filtering, to obtain the frequency domain signal corresponding to the plate vibrating electrical signal, to obtain the component signal with the largest amplitude in the frequency domain signal, and to take the vibration intensity corresponding to the component signal as the vibration intensity of the detection point corresponding to the plate vibrating electrical signal; to obtain the relative position of the plate vibrating capacitor and the multiple detection points based on the vibration intensity of the multiple detection points, and to obtain the position information of the plate vibrating capacitor based on the relative position of the plate vibrating capacitor and the multiple detection points and the position information of the multiple detection points.

2. The plate vibration capacitance detection device according to claim 1, characterized in that, Each of the signal conversion units includes a mechanical sensing device and a signal conversion device that is mechanically connected to the corresponding mechanical sensing device and electrically connected to the signal processing device; The plurality of mechanical sensing devices are respectively used to contact the corresponding detection points of the circuit board under test and sense the corresponding board vibration mechanical signals, and to transmit the sensed board vibration mechanical signals to the corresponding signal conversion devices. The plurality of signal conversion devices are used to convert the incoming mechanical signals of plate vibration into corresponding electrical signals of plate vibration and output them to the signal processing device.

3. The plate resonant capacitance detection device according to claim 1, characterized in that, The plurality of plate vibration detection devices further include signal amplification units that are electrically connected to the corresponding signal conversion unit and the signal processing device, respectively; The multiple signal amplification units are used to amplify the board vibration electrical signals output by the corresponding signal conversion units and output them to the signal processing device.

4. The plate vibration capacitance detection device according to any one of claims 1 to 3, characterized in that, The plate vibration detection device is provided with four units; The four board vibration detection devices are used to detect the board vibration at corresponding corner points of the circuit under test, with each corner point serving as a detection point.

5. The plate vibration capacitance detection device according to any one of claims 1 to 3, characterized in that, The signal processing device includes a processing unit and a signal acquisition unit that is electrically connected to the plurality of plate vibration detection devices and the processing unit respectively; The signal acquisition unit is used to condition the electrical signals of the plate vibration output by the multiple plate vibration detection devices and output them to the processing unit. The processing unit is used to determine the location information of the board vibration capacitor that causes board vibration on the circuit board under test based on the multiple board vibration electrical signals output by the signal acquisition unit.

6. The plate resonant capacitance detection device according to claim 5, characterized in that, The signal processing device further includes a display unit electrically connected to the processing unit; The display unit is used to display the position information of the plate resonant capacitor according to the display signal sent by the processing unit.

7. A method for detecting plate resonant capacitance, characterized in that, The plate vibration capacitance detection method is applied to the plate vibration capacitance detection device according to any one of claims 1 to 6; the plate vibration capacitance detection method includes the following steps performed by the signal processing device: The plate vibration electrical signals output by multiple plate vibration detection devices are connected; For each of the plate vibration electrical signals, a fast Fourier transform is performed on the plate vibration electrical signal after filtering to obtain the frequency domain signal corresponding to the plate vibration electrical signal. The component signal with the largest amplitude in the frequency domain signal is obtained, and the vibration intensity corresponding to the component signal is taken as the vibration intensity of the detection point corresponding to the plate vibration electrical signal. Based on the vibration intensity of the multiple detection points, the relative position of the plate vibration capacitor and the multiple detection points is obtained. Based on the relative position of the plate vibration capacitor and the multiple detection points and the position information of the multiple detection points, the position information of the plate vibration capacitor is obtained.

8. The plate resonant capacitance detection method according to claim 7, characterized in that, The step of obtaining the relative position of the plate-vibrating capacitor with respect to the multiple detection points based on the vibration intensity of the multiple detection points, and obtaining the position information of the plate-vibrating capacitor based on the relative position of the plate-vibrating capacitor with respect to the multiple detection points and the position information of the multiple detection points, includes: For one of the detection points, Using the location information of this detection point as the reference location information, determine the ratio of the vibration intensity of at least two other detection points to that detection point; The distance between the plate vibration capacitor and the detection point is obtained based on the ratio of the vibration intensity of at least two other detection points to that of the detection point. The position information of the plate resonating capacitor is determined based on the distance between the plate resonating capacitor and the detection point, as well as the position information of multiple detection points.

9. The plate resonant capacitance detection method according to claim 8, characterized in that, There are four detection points, three of which are used to determine the position information of the plate resonant capacitor, and the remaining detection point is used to verify the position information of the plate resonant capacitor.

Images