Non-contact electrostatic warning system and method for memory testing environment

Abstract

The application provides a non-contact electrostatic early warning system and method for a memory test environment, and belongs to the technical field of electrostatic detection. The non-contact electrostatic early warning system comprises: a proximity identification module, which identifies whether a charged target enters a preset monitoring area and outputs a distance signal; an electrostatic induction module, which senses changes in a space electrostatic field and outputs an electrostatic induction signal; a signal processing and control module, which receives the distance signal and the electrostatic induction signal, generates or freezes background baseline data, performs comprehensive determination, and outputs a determination result; an alarm module, which receives the determination result and performs a prompt action; an interlock control module, which receives the determination result and performs an interlock action; and the signal processing and control module uses the distance signal as a gating condition, maintains a standby monitoring state when the distance signal indicates that the charged target has not entered the preset monitoring area, and determines the determination result when the distance signal indicates that the charged target has entered the preset monitoring area and the electrostatic induction signal meets preset conditions. The application solves the false alarm problem of distinguishing between near and far targets in electrostatic detection.

Description

Technical Field

[0001] This invention relates to the technical field of electrostatic detection, and in particular to a non-contact electrostatic warning system and method for memory testing environments. Background Technology

[0002] In DRAM chip testing, board debugging, chip insertion and removal, probe contact, rework analysis, and laboratory operations, personnel may accumulate static electricity due to walking, clothing friction, packaging materials, plastic tooling, cable movement, or container handling friction. When charged personnel or objects come into contact with chip pins, test sockets, fixtures, board-level circuits, or sensitive test points, electrostatic discharge (ESD) events may occur, causing chip damage, functional abnormalities, parameter drift, malfunctions, or potential reliability degradation.

[0003] Existing electrostatic discharge (ESD) protection solutions mainly include: establishing ESD protection areas, requiring operators to wear wrist straps and anti-static shoes, placing grounding posts or discharge balls at workstations, using ionizers for neutralization, and using handheld electrostatic field strength meters for manual inspection. However, the above solutions have the following drawbacks:

[0004] First, the contact discharge scheme requires personnel to touch the grounded structure before operating, and the risk control point lags behind the approach action, making it impossible to achieve pre-contact warning.

[0005] Second, handheld field strength meters rely on manual operation, making it impossible to continuously monitor the entire testing process online, and it is also difficult to form a real-time interlock with fixtures or host computers.

[0006] Third, existing non-contact electrostatic detection solutions rely solely on electrostatic field strength or a single threshold as the basis for judgment. Since the electrostatic field strength is inversely proportional to the square of the distance, the system has difficulty distinguishing between "a distant target with a strong charge" and "a nearby target with a weak charge". It is easily affected by changes in the distance between the human body and the sensor, environmental drift, charged tooling, and background electric field, resulting in false alarms or missed alarms.

[0007] Fourth, there is still a lack of specialized non-contact early warning modules for highly sensitive workstations such as memory testing fixtures, motherboards, and Field Programmable Gate Array (FPGA) boards, and there is a lack of commercially viable small structures and supporting interface solutions.

[0008] In view of this, a novel non-contact electrostatic discharge (ESD) warning system and method for memory testing environments is proposed to solve all or part of the above problems. Summary of the Invention

[0009] To address at least one of the aforementioned problems and deficiencies in the existing technology, embodiments of the present invention provide a non-contact electrostatic discharge (ESD) early warning system and method for memory testing environments. Through a dual-channel fusion decision based on proximity detection and ESD induction, using distance signal as the gating condition and ESD induction signal as the risk condition, an early warning or interlock is triggered only when a target enters a preset monitoring area and the ESD induction meets the corresponding threshold. This effectively solves the problem of false alarms caused by the inverse proportionality between electrostatic field strength and the square of the distance. Through dynamic management and freezing of background baseline data, distance-weighted risk mapping, multi-level threshold determination and de-jittering, and a monitoring hysteresis recovery design, a closed-loop protection mechanism of "proximity detection - risk identification - graded alarm - control blocking - event recording - monitoring recovery" is achieved, significantly improving the reliability of early warnings and workstation safety. The technical solution is as follows:

[0010] According to one aspect of the present invention, a non-contact electrostatic discharge (ESD) warning system for a memory testing environment is provided, the non-contact ESD warning system comprising:

[0011] The proximity detection module is configured to detect whether a charged target has entered a preset monitoring area and output a distance signal;

[0012] The electrostatic induction module is configured to sense changes in the spatial electrostatic field and output an electrostatic induction signal.

[0013] The signal processing and control module is configured to communicate with the proximity recognition module and the electrostatic induction module, receive distance signals and electrostatic induction signals, generate or freeze background baseline data, and make a comprehensive judgment based on the distance signals, electrostatic induction signals and background baseline data, and output the judgment result.

[0014] The alarm module is configured to communicate with the signal processing and control module, receive the judgment result, and execute prompt actions.

[0015] The interlocking control module is configured to communicate with the signal processing and control module, receive the judgment result, and execute the interlocking action; wherein...

[0016] The signal processing and control module uses the distance signal as the gating condition.

[0017] When the distance signal indicates that the charged target has not entered the preset monitoring area, the signal processing and control module maintains a standby monitoring state.

[0018] When the distance signal indicates that a charged target has entered the preset monitoring area and the electrostatic induction signal meets the preset conditions, the signal processing and control module outputs the judgment result.

[0019] According to another aspect of the present invention, a non-contact electrostatic discharge (ESD) warning method for a memory testing environment is provided, the non-contact ESD warning method comprising the following steps:

[0020] S201: System initialization and self-test, reading parameter configuration data;

[0021] S202: When the system is available and the workstation is not in operation, continuously collect electrostatic induction signals to generate background baseline data;

[0022] S203: Synchronously acquire distance signals and electrostatic induction signals;

[0023] S204: Using the distance signal as a gating condition, determine whether to allow updating the background baseline data based on the distance signal and the electrostatic induction signal. If allowed, update the background baseline data; otherwise, freeze the background baseline data.

[0024] S205: Generate risk data based on electrostatic induction signals and updated or frozen background baseline data;

[0025] S206: Compare the risk data with the preset threshold and output the judgment result;

[0026] S207: Drive alarm and / or interlock control actions based on the judgment result;

[0027] S208: When the recovery conditions are met, the alarm or interlock status is cleared and the process returns to step S203.

[0028] The non-contact electrostatic discharge (ESD) warning system and method for memory testing environments provided by embodiments of the present invention have at least one or a portion of the following advantages:

[0029] (1) The distance signal output by the proximity recognition module is used as the gate condition. When the charged target does not enter the preset monitoring area, the standby monitoring state is maintained. When the charged target enters the preset monitoring area and the electrostatic induction signal meets the preset condition, the judgment result is output. This can effectively reduce the interference from the background electric field and non-risk objects at a distance, improve the reliability of the early warning and reduce the false alarm rate.

[0030] (2) The electrostatic induction signal is protected, buffered, amplified, filtered and feature extracted by the front-end conditioning unit and the electrostatic judgment signal H is output. The background baseline data J is generated or frozen by the baseline management unit of the core control unit, the risk data K is generated by the risk mapping unit, and the judgment result is generated by the threshold judgment unit. This realizes the high signal-to-noise ratio extraction and multi-level comprehensive judgment of the electrostatic signal.

[0031] (3) By generating distance weight W based on distance signal, generating background correction electrostatic increment ΔH based on electrostatic induction signal and background baseline data J, and generating risk data K based on ΔH and W as a comprehensive judgment basis, quantitative compensation of distance factor for electrostatic risk judgment is realized, so that near-distance weak electric objects and far-distance strong electric objects can be effectively distinguished.

[0032] (4) By setting dynamic update and freeze conditions for the background baseline: when the distance signal is greater than the preset monitoring distance threshold, the deviation of the electrostatic induction signal relative to the background baseline data is lower than the preset baseline update threshold, and the rate of change of the electrostatic induction signal is lower than the preset rate of change threshold, the baseline is allowed to be updated; otherwise, the baseline is frozen. This can prevent the system from mistakenly identifying live personnel approaching, real discharge events, or high-risk workstation actions as normal background, thereby improving the robustness of baseline management.

[0033] (5) Through background correction electrostatic increment calculation, distance weight calculation and risk data calculation, quantitative compensation of the physical law that electrostatic field strength is inversely proportional to the square of distance and dynamic adjustment of risk level by work position status are realized.

[0034] (6) By setting a first-level threshold T1 and a second-level threshold T2 (T2>T1), when the risk data K reaches T1 but is lower than T2 and continues to reach the preset de-shaking time, the first-level judgment result is output to trigger the prompt. When K reaches T2 and continues to reach the de-shaking time, the second-level judgment result is output to trigger the interlock control, thus realizing graded early warning and graded control, and avoiding the test station from frequently entering the alarm or interlock state due to short-term interference.

[0035] (7) By continuously collecting distance signal and electrostatic induction signal after outputting the judgment result, when the distance signal is greater than the preset monitoring distance threshold, the risk data K is lower than the preset recovery threshold and the duration of the state reaches the preset recovery time, the alarm or interlock state is released and monitoring is restored. The recovery threshold is lower than the first-level threshold T1, forming a hysteresis interval, which avoids the system from prematurely releasing protection due to the short distance of the charged object or the short-term drop of the electrostatic signal.

[0036] (8) The sensing electrode is set facing the direction of approach of the charged target to couple the change of the spatial electrostatic field. The guard ring electrode is set around the sensing electrode to limit the effective sensing area and reduce the electric field interference of the surrounding environment. The guard ring electrode is driven by the in-phase buffer output of the high-impedance buffer unit of the signal processing and control module, which can reduce the influence of leakage current and parasitic capacitance on the original electrostatic induction signal and improve the sensitivity and anti-interference ability of electrostatic detection.

[0037] (9) The ESD event detection module captures the radio frequency transient signal generated by electrostatic discharge and outputs the event pulse signal. When the event pulse signal is confirmed to be valid, the event judgment result is directly output and the timestamp, work station number and current risk data are latched. The dual mode of early warning and traceability is realized, providing data support for subsequent failure analysis, work station statistics and protection strategy optimization.

[0038] (10) The Time-of-Flight (ToF) sensor is used for proximity detection within a range of 15-100cm, the infrared sensor is used for proximity judgment in a fixed direction, and the millimeter-wave sensor is used for human presence and movement detection in dusty, low-light or obstructed environments, thus achieving flexible adaptation to various application scenarios.

[0039] (11) The environmental acquisition module collects environmental temperature, humidity and air pressure data and outputs environmental compensation data. The workstation status module collects the current working status (idle, plug-in, crimp, power on, test run) of the memory test workstation and outputs workstation status data, so that the system can dynamically adjust the risk judgment logic according to environmental parameters and workstation status, and improve the accuracy and pertinence of the judgment.

[0040] (12) Through the closed-loop workflow of system initialization and self-test, background baseline establishment, real-time input acquisition, gating control and background baseline update, risk mapping, threshold determination, execution output and event recording, and recovery monitoring, a complete protection closed loop of "detecting proximity - identifying risks - hierarchical alarm - control blocking - recording events - recovery monitoring" is realized. Attached Figure Description

[0041] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0042] Figure 1 This is a diagram illustrating the architecture of a non-contact electrostatic early warning system according to an embodiment of the present invention.

[0043] Figure 2 In order to be in Figure 1 The schematic diagram of the hardware circuit block diagram of the early warning system based on the system architecture shown is a schematic diagram of the principle.

[0044] Figure 3 A flowchart of a non-contact electrostatic discharge early warning method according to an embodiment of the present invention;

[0045] Figure 4 This is a complete workflow diagram of the early warning system of the present invention from power-on to resumption of monitoring. Detailed Implementation

[0046] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0047] See Figure 1 The diagram shows an architecture of a non-contact electrostatic warning system 100 according to one embodiment.

[0048] The present invention first provides a non-contact electrostatic discharge early warning system 100 for memory testing environment. Figure 1 The overall structure, signal flow direction, interaction between functional modules, and connection relationship between each functional module and the final application station (e.g., memory test fixture / motherboard) of the non-contact electrostatic early warning system (hereinafter referred to as the early warning system) 100 of the present invention are shown at the macro system level.

[0049] The early warning system 100 includes a proximity recognition module 111, an electrostatic induction module 112, a signal processing and control module 120, an alarm module 131, an interlock control module 132, and a log and host computer interface module 133. In an optional embodiment, an electrostatic discharge event (ESD event) detection module can be added to record the actual discharge transient.

[0050] The early warning system 100 is designed with a layered architecture of "perception input layer - control layer - execution output layer":

[0051] Perceptual input layer ( Figure 1 The leftmost module mainly includes three core functional modules: a proximity recognition module 111, which can be exemplarily a time-of-flight (ToF) sensor, an infrared sensor, a millimeter-wave sensor, or an ultrasonic sensor, for outputting a distance signal P; an electrostatic induction module 112, which uses a "sensing electrode + guard ring electrode + high input impedance front end", for outputting a raw electrostatic induction signal A; and an ESD event detection module 113 (optional), which uses an antenna or radio frequency transient detection to capture real discharge transients and output an event pulse signal X.

[0052] The signal processing and control module 120 of the control layer is the central hub of the early warning system 100, connecting all input and output modules, including an analog front end (AFE), an analog-to-digital converter (ADC) for sampling, and a microcontroller unit (MCU) or field-programmable gate array (FPGA) control chip. The core function of the signal processing and control module 120 is to process various signals input from the aforementioned functional modules, perform fusion decision-making, debouncing, threshold control, and finally output the decision result Q.

[0053] Execute output layer ( Figure 1The rightmost section includes: an alarm module 131, such as an integrated audible and visual alarm, which drives a buzzer and / or indicator light upon receiving a command; an interlocking control module 132, which, upon receiving a command, implements physical interlocking actions such as "pause testing / prohibit plugging / unplugging" through relay output or optocoupler isolation output; and a log and host computer interface module 133, which, upon receiving a command, uploads event logs and status to a host computer (such as an industrial control computer or central control system) through interfaces such as a Universal Asynchronous Receiver / Transmitter (UART), General Purpose Input / Output (GPIO), or Inter-Integrated Circuit (I2C). Ultimately, the targets of electrostatic discharge (ESD) protection are memory test fixtures, motherboards, FPGA test platforms, etc.

[0054] The early warning system 100 operates through a closed-loop logic of "proximity gate control + electrostatic induction + fusion judgment + hierarchical alarm + interlock recovery". The distance signal P is output by the proximity recognition module 111; the original electrostatic induction signal A is output by the electrostatic induction module 112; the electrostatic judgment signal H is output by the front-end conditioning unit in the signal processing and control module 120; the background baseline data J is generated and stored by the signal processing and control module 120; the distance weight W is generated by the signal processing and control module 120 based on the distance signal P; the risk data K is generated by the signal processing and control module 120 based on the electrostatic judgment signal H, the background baseline data J, and the distance weight W; and the judgment result Q is generated by the signal processing and control module 120 based on the risk data K, the event pulse signal X, and the workstation status data G. Furthermore, the above parameters are continuously transmitted throughout the process and are not used as isolated parameters.

[0055] The core concept of the early warning system 100 lies in its dual-channel fusion decision-making: the early warning system 100 does not rely solely on the electrostatic induction signal, but instead inputs both the distance signal P and the electrostatic induction signal A into the signal processing and control module 120. Simultaneously, the early warning system 100 can only trigger an early warning or interlock when a charged target enters a preset distance area (proximity gating) and the electrostatic induction signal meets the corresponding threshold. This solves the false alarm problem mentioned in the background art, which concerns whether it is a person with a strong charge at a distance or a person with a weak charge very close by.

[0056] In one specific embodiment, the proximity recognition module 111 is configured to recognize whether a human body, hand, tool or charged target has entered a preset monitoring area and output a distance signal P.

[0057] The proximity recognition module 111 is positioned near the personnel approach side, fixture side, or test socket of, for example, a memory testing station, to acquire the distance between the charged target and the memory testing station and output a distance signal P. The proximity recognition module 111 may include one or more of a Time-of-Flight (ToF) sensor, an infrared sensor, or a millimeter-wave sensor. Specifically, a ToF sensor is suitable for detecting hand or upper body proximity within a range of 15-100cm; an infrared sensor is suitable for low-cost, fixed-direction proximity detection; and a millimeter-wave sensor is suitable for detecting human presence and movement in dusty, low-light, or obstructed environments. The output of the proximity recognition module 111 is connected to the distance input of the signal processing and control module 120, which defines the distance data output by the proximity recognition module 111 as the distance signal P.

[0058] The proximity recognition module 111 can employ a single-sensor or multi-sensor fusion scheme, without limitation. For example, Time-of-Flight (ToF) is suitable for applications requiring precise distance measurement, such as manual testing stations or embedded modules in fixtures, where the target is a hand or small tool. It can stably output distance values ​​within a range of 10-100cm, with a response time typically of 10-30ms. Infrared is suitable for bypass modules on motherboard / FPGA platforms, offering slower response but lower power consumption.

[0059] In one specific embodiment, the electrostatic induction module 112 is configured to sense changes in the spatial electrostatic field and output an electrical signal suitable for front-end sampling, namely the original electrostatic induction signal A.

[0060] The electrostatic induction module 112 is positioned near the proximity recognition module 111 or at the edge of the sensitive workstation to sense changes in the spatial electrostatic field and output a raw electrostatic induction signal A. The electrostatic induction module 112 includes a sensing electrode and a guard ring electrode. The sensing electrode faces the approach direction of the target object and is used to couple the changes in the spatial electrostatic field caused by the approach of a charged target. The guard ring electrode surrounds the sensing electrode and is used to limit the effective sensing area and reduce interference from the surrounding environmental electric field. The sensing electrode is connected to the input protection unit of the signal processing and control module 120, and the guard ring electrode is connected to the high-impedance buffer unit or guard ring drive end of the signal processing and control module 120. This spatial arrangement makes the electrostatic induction module 112 more sensitive to charged targets approaching the workstation and less sensitive to lateral background electric fields and internal interference from fixtures / workstations / platforms.

[0061] Among them, the high-impedance buffer unit is a buffer amplifier with ultra-high input impedance and low output impedance, and its input impedance is not less than 10. 12 Ω is used to perform impedance transformation on electrostatic induction signals to reduce the influence of source impedance on signal acquisition and ensure that even weak electrostatic signals can be effectively sampled and processed by subsequent circuits.

[0062] In one specific embodiment, the signal processing and control module 120 is configured to communicate with the proximity recognition module 111 and the electrostatic induction module 112. It receives a distance signal P and an electrostatic induction signal A, which are then conditioned by the front end to form an electrostatic determination signal H. Based on the distance signal P and the electrostatic determination signal H, the module performs a comprehensive judgment and outputs a judgment result Q. The signal processing and control module 120 uses the distance signal P as a gating condition. When the distance signal P indicates that the charged target has not entered the preset monitoring area, it maintains a standby monitoring state; when the distance signal P indicates that the charged target has entered the preset monitoring area and the electrostatic determination signal H meets the preset condition, it outputs the judgment result Q.

[0063] Furthermore, the signal processing and control module 120 includes a front-end conditioning unit and a core control unit. The front-end conditioning unit is communicatively connected between the electrostatic induction module 112 and the core control unit, and is configured to protect, buffer, amplify, filter, and extract features from the original electrostatic induction signal A, and output an electrostatic determination signal H. The front-end conditioning unit includes an input protection unit, a high-impedance buffer unit, a filtering and amplification unit, and a feature extraction unit; the input protection unit is used to limit the amplitude of electrostatic transients entering the subsequent circuits; the high-impedance buffer unit is used to reduce the influence of the source impedance of the electrostatic induction module 112 on signal acquisition; the filtering and amplification unit is used to suppress power frequency, motor, power supply, and radio frequency interference and improve the effective signal amplitude; the feature extraction unit is used to obtain the envelope value, root mean square (RMS) value, or peak feature from the filtered signal and form the electrostatic determination signal H.

[0064] The core control unit includes a sampling unit, a baseline management unit, a risk mapping unit, a threshold determination unit, and a state machine unit. The sampling unit receives an electrostatic discharge (ESD) judgment signal H, a distance signal P, environmental compensation data M, workstation status data G, and an event pulse signal X. The baseline management unit is configured to generate or freeze background baseline data J based on safety conditions. The risk mapping unit generates risk data K based on the ESD judgment signal H, background baseline data J, and distance signal P (specifically, a distance weight W generated based on distance signal P). The threshold determination unit generates a determination result Q based on the risk data K. The state machine unit drives the alarm module 131, the interlock control module 132, and the log and host computer interface module 133 based on the determination result Q.

[0065] The signal processing and control module 120 generates distance weight W based on the distance signal P, generates background correction electrostatic increment ΔH based on the electrostatic determination signal H and background baseline data J, and generates risk data K based on ΔH and distance weight W as the basis for comprehensive judgment.

[0066] In one specific embodiment, the alarm module 131 is configured to communicate with the signal processing and control module 120, receive the judgment result Q, and execute a prompting action. The alarm module 131 includes an indicator light driving circuit and a buzzer driving circuit, used to output different color indicators and buzzer modes according to the warning level. The alarm module 131 receives the judgment result Q and executes the prompting action.

[0067] In one specific embodiment, the interlocking control module 132 is configured to communicate with the signal processing and control module 120, receive the judgment result Q, and execute interlocking actions. The interlocking control module 132 includes a relay output circuit, an optocoupler-isolated output circuit, or a digital output interface, used to output interlocking control signals to test fixtures, test hosts, FPGA boards, or central control nodes, for controlling functions such as pausing testing, prohibiting insertion / removal, prohibiting startup, or outputting external relay signals. The interlocking control module 132 receives the judgment result Q and executes the corresponding interlocking action.

[0068] In one specific embodiment, the log and host computer interface module 133 includes interfaces such as UART, I2C, GPIO, RS-485, Universal Serial Bus (USB), or Ethernet, for uploading workstation number, judgment result Q, risk data K, event pulse signal X, background baseline data J, and parameter configuration data T. The log and host computer interface module 133 receives the judgment result Q and performs a recording action.

[0069] In an optional embodiment, the early warning system 100 may also include an environmental acquisition module. This module collects environmental parameters such as temperature, humidity, air pressure, or other environmental parameters that affect electrostatic accumulation and discharge characteristics, and outputs environmental compensation data M. The environmental compensation data M is input to the signal processing and control module 120 to generate an estimated environmental noise value N, which participates in the establishment of background baseline data J and the calculation of risk data K.

[0070] In an optional embodiment, the early warning system 100 may also include a workstation status module. This workstation status module is configured to collect the current working status of the memory testing workstation, including idle, plug / unplug, crimp, power-on, and test running states, and output workstation status data G. The workstation status data G serves as the source of gating conditions and risk weighting coefficient Cg, participating in the update control of background baseline data J, the calculation of risk data K, and the generation of the judgment result Q.

[0071] The workstation status data G comes from the workstation status module or from an external interface (such as a test host or central control system). It is used to characterize the current working status of the memory test workstation. The workstation status data G includes, but is not limited to, idle, plugged in, crimped, powered on, and test running status.

[0072] In an optional embodiment, the early warning system 100 may also include an ESD event detection module 113. This ESD event detection module 113 is communicatively connected to the signal processing and control module 120 and is used to capture electromagnetic waves generated by actual electrostatic discharge and generate radio frequency spike signals.

[0073] The ESD event detection module 113 can use a PCB trace antenna, a short whip antenna, or a loop antenna. PCB trace antennas are suitable for small box-type modules, short whip antennas are suitable for column-mounted workstation early warning devices, and loop antennas are suitable for placement around the test socket or the side wall of the fixture.

[0074] The ESD event antenna is preferably installed near the insertion / removal path of the memory test fixture, the edge of the test socket, or near a sensitive test point. The RF spike signal is compared and converted into a digital pulse (i.e., event pulse signal X) that can be directly recognized by the signal processing and control module 120 via a high-speed comparator or RF detection unit. This signals the early warning system 100 or the host computer, notifying them that "an electrostatic discharge event has actually occurred," providing a basis for subsequent event recording and mandatory interlocking. The hardware trigger level of the ESD event detection module 113 can be set via parameter configuration data T, or it can be automatically generated based on the statistical value of the background RF noise at the workstation.

[0075] In a preferred embodiment, the specific implementation of the electrostatic induction signal analog front-end processing is described below:

[0076] The algorithmic steps from the acquisition of the electrostatic signal to its input to the MUX include:

[0077] Step 1: The inductive electrode outputs the original electrostatic induction signal A. This signal is then sequentially input into an input protection network consisting of a current-limiting resistor, a transient voltage suppression (TVS) transistor, and an RC network. The current-limiting resistor limits transient inrush current, the TVS transistor cuts off spikes exceeding a preset voltage, and the RC network performs integral smoothing and primary low-pass filtering on high-frequency spikes and glitches. This transforms the original electrostatic induction signal A, containing high-voltage spikes and random glitches, into a low-voltage base signal B with limited amplitude, controlled spectrum, and suitable for subsequent processing.

[0078] Step Two: The low-voltage base signal B is input to an ultra-high input impedance preamplifier. Because the electrostatic induction signal itself has extremely high source impedance and extremely low current carrying capacity, direct input to subsequent circuits would result in significant signal collapse. Therefore, the preamplifier first performs a high-impedance buffer transformation on the low-voltage base signal B, converting it into a low-impedance voltage characteristic signal C1 that can stably drive subsequent circuits. Simultaneously, the in-phase component of the preamplifier output generates a guard ring drive signal C2, which is fed back to the guard ring electrode to reduce the sensitivity of the input node to parasitic leakage current and environmental coupling noise. Subsequently, the low-impedance voltage characteristic signal C1 enters the preamplifier path, where linear amplification is performed through a preset gain coefficient, boosting the weak electrostatic changes into a recognizable primary amplified signal D. Through high-impedance buffering, guard ring feedback, and primary amplification, the signal-to-noise ratio can be significantly improved while maintaining the integrity of the original electrostatic characteristics, preventing the weak electrostatic characteristics from attenuating or being submerged during transmission and sampling.

[0079] Step 3: The primary amplified signal D is sequentially input to a bandpass filter and a low-pass filter. The bandpass filter suppresses DC drift and high-frequency noise components outside the target frequency band, while the low-pass filter further filters out high-frequency periodic interference introduced by motors, power supplies, lighting, electromagnetic equipment, and RF modules. During the filtering process, only low-frequency slowly varying signals and local abrupt changes caused by human proximity, triboelectric charging, or object movement are retained, thus converting the primary amplified signal D into a low-frequency electrostatic characteristic signal E with higher spectral purity. By performing frequency domain screening and background noise suppression on the low-frequency electrostatic characteristic signal E, the early warning system 100 can significantly reduce the interference of environmental power frequency, RF, and mechanical noise on the electrostatic determination result Q, improving the stability and accuracy of subsequent risk identification processes.

[0080] Step 4: The original electrostatic signal A can be split into a branch signal A1, which is then input to the Programmable Gain Amplifier (PGA). The PGA dynamically adjusts the amplification factor based on the real-time amplitude of the current broadband branch signal A1. When the amplitude of the broadband branch signal A1 is small, the amplification gain is increased to enhance weak transient characteristics. When the broadband branch signal A1 approaches the upper limit of the subsequent processing stage, the amplification factor is reduced or attenuation processing is performed to prevent sudden electrostatic spikes from causing saturation distortion in the subsequent stage. After dynamic gain processing, a normalized broadband characteristic signal F is output. By performing dynamic gain enhancement processing on the broadband transient signal, the early warning system 100 can improve the detectability of weak transient signals while retaining the characteristics of rapid electrostatic changes, thereby enhancing the response capability to sudden electrostatic risks.

[0081] Step 5: The electrostatic characteristic signal E and the normalized broadband characteristic signal F are jointly input to the rectification / envelope extraction unit or the root mean square (RMS) estimation unit. The rectification / envelope extraction unit performs peak tracking, rectification, and envelope smoothing on the two waveforms to extract the electrostatic change trend and transient peak characteristics. The RMS estimation unit performs root mean square statistics on the alternating energy within a preset time window to obtain the corresponding effective energy value. Subsequently, the early warning system 100 maps the two signals into a relatively smoothly changing processed electrostatic induction signal, i.e., the electrostatic determination signal H. The electrostatic determination signal H is input to the signal processing and control module 120 as the final electrostatic determination signal.

[0082] In a preferred embodiment, the present invention also provides a circuit implementation scheme.

[0083] See Figure 2 The diagram shows the hardware circuit block diagram of the early warning system 100.

[0084] Figure 2 Is Figure 1 Based on this, a disassembly diagram of the specific circuit implementation structure of the signal processing and control module 120 and its peripheral input / output functional modules is provided. This hardware circuit is mainly divided into five parts, as detailed below:

[0085] Part 1, Sensing and Input Section: Electrostatic Induction Module 112 (Sensing Electrode + Guard Ring Electrode). The sensing electrode uses a metal detection plate to capture the spatial electric field, and the guard ring electrode is set around the sensing electrode to shield and suppress leakage. At the same time, the proximity sensor (ToF / infrared / millimeter wave) and ESD event antenna (optional) are used for ranging and transient radiation detection (capturing radio frequency discharge transients), respectively.

[0086] The second part, the analog front-end (AFE), includes an input protection network comprising current-limiting resistors, TVS diodes, and RC circuits to prevent high-voltage electrostatic transients from damaging subsequent circuits. An ultra-high input impedance preamplifier (high-impedance buffer unit) addresses the extremely high impedance of electrostatic induction signal sources, buffering and amplifying weak signals; its in-phase output also drives the guard ring electrode. Bandpass / low-pass filters suppress power frequency, motor, power supply, and radio frequency interference in the environment (environmental noise suppression). A programmable gain stage (PGA) and rectification / envelope extraction and RMS estimation units dynamically amplify different signal amplitudes and process the AC electrostatic signal into a slowly varying signal (i.e., electrostatic determination signal H) recognizable by the signal processing and control module 120. Furthermore, the analog front-end (AFE) also includes a distance measurement interface (ToF / infrared / millimeter-wave signal processing) and a high-speed comparator / RF detection (over-threshold pulse extraction) for processing distance signals and event pulse signals respectively.

[0087] The third part, the data conversion and control section, uses a multiplexer (MUX) and a high-precision ADC (12 / 16 / 24-bit programmable rate) to sequentially switch multiple analog signals, including the electrostatic discharge (ESD) detection signal H, distance signal P, ESD pulse signal (event pulse signal X), and environmental compensation data M, to the high-precision ADC for sampling. These signals are then converted into digital signals and input to the signal processing and control module 120 (e.g., an MCU / FPGA control core). The signal processing and control module 120 can be implemented using an MCU, FPGA, System on Chip (SoC), or a distributed architecture. It is responsible for threshold determination, debouncing, baseline compensation, state machine management, log management, and communication protocol management. Peripherals are equipped with electrically erasable programmable read-only memory (EEPROM) / flash memory to store parameter baselines, and clock / power monitoring (e.g., watchdog / reset management) to ensure system reliability.

[0088] Part Four, Output and Execution Section: Includes buzzer driver, LED driver for red / yellow / green indicator lights, relay / optocoupler isolation driver (interlocked output / pause test), and communication interface (UART, I2C, GPIO, RS-485, USB or Ethernet, etc.).

[0089] Part 5, Power Supply Section: Includes 9-24VDC DC input, electromagnetic interference (EMI) filtering (common-mode inductor / capacitor), reverse connection protection, low dropout regulator (LDO) / DC-DC converter step-down, etc. Analog ground AGND and digital ground DGND use split copper foil and are connected through a single-point grounding / isolation design.

[0090] In the analog front-end circuit, three characteristic signals (static discharge judgment signal H, distance signal P, and event pulse signal X), along with environmental compensation data M and workstation status data G, are input to a multiplexer (MUX). The MUX selects the appropriate signal based on timing and outputs it to a high-precision ADC sampling unit (supporting 12 / 16 / 24-bit and programmable speeds). This converts the analog signal into a digital signal, which is then input to the signal processing and control module 120. The signal processing and control module 120 is responsible for threshold determination, debouncing, baseline compensation, and state machine management, and outputs the judgment command to the output and execution circuit. The signal processing and control module 120 is connected to a non-volatile memory, which stores parameter configuration data T, initial values ​​of background baseline data J, threshold parameters, workstation number, and event records. The signal processing and control module 120 is also connected to a clock and power monitoring circuit. This circuit outputs an abnormal state in case of power failure, clock anomaly, or watchdog reset. In this abnormal state, the signal processing and control module 120 keeps the interlocking control module 132 in a fail-safe state.

[0091] In the output and execution circuit section, the judgment instructions of the signal processing and control module 120 are output unidirectionally to the three execution modules: the instructions are transmitted to the buzzer via the buzzer driver circuit, and to the red / yellow / green indicator lights via the LED driver circuit (forming the alarm module 131); the instructions are transmitted to the interlock output / pause test interface via the relay or optocoupler isolation driver circuit (forming the interlock control module 132); the instructions are transmitted to the host computer interface such as UART / I2C / GPIO via the communication interface (forming the log and host computer interface module 133).

[0092] In the power supply circuit section, the power module receives 9V to 24V DC input. The DC input passes through EMI filtering, reverse connection protection, and TVS surge protection before entering the DC-DC or LDO power management circuit. The power management circuit outputs analog and digital power rails. The analog power rail supplies power to the electrostatic discharge (ESD) sensing module 112 and the analog front-end, while the digital power rail supplies power to the control module, alarm module 131, interlock control module 132, and log and host computer interface module 133. Analog ground (AGND) and digital ground (DGND) use segmented copper foil and are connected at a single point via a 0Ω resistor, ferrite bead, or narrow bridge. The interlock output is isolated from external test equipment via optocouplers or relays. This power supply circuit design reduces the coupling of digital switching noise to the ESD sensing module 112, improving the signal-to-noise ratio of the ESD detection signal H. The clear separation of analog ground (AGND) and digital ground (DGND), connected by a single-point grounding and isolation design, effectively prevents digital logic switching noise from coupling to the high-sensitivity analog ESD detection front-end through the power supply or ground wire, significantly improving the signal-to-noise ratio.

[0093] See Figure 3This paper illustrates the overall process of the non-contact electrostatic discharge (ESD) warning method for memory testing environments provided by the present invention.

[0094] Step S201: System initialization and self-test, read parameter configuration data.

[0095] The signal processing and control module 120 reads the parameter configuration data T from the memory. The parameter configuration data T includes at least: monitoring distance threshold P0, baseline update threshold B0, rate of change threshold D0, first-level threshold T1, second-level threshold T2, dejittering time t_d, and recovery time t_r.

[0096] The signal processing and control module 120 then checks the availability of the proximity recognition module 111, electrostatic induction module 112, interlock control module 132, and log and host computer interface module 133, and generates self-test status data U. The self-test status data U serves as input for subsequent steps; the signal processing and control module 120 only allows the system to proceed to step S202 when the self-test status data U indicates that the system is available. This step aims to prevent the system from mistakenly entering monitoring mode when sensors are disconnected, interlocks fail, or communication is abnormal.

[0097] Step S202: When the system is available and the workstation is in a non-working state, continuously collect electrostatic induction signals to generate background baseline data.

[0098] When the self-test status data U indicates that the system is available and the workstation status data G indicates that the memory test workstation is not in the plugging / unplugging, crimping, power-on, or test start state, the signal processing and control module 120 continuously acquires the electrostatic discharge judgment signal H and the environmental compensation data M. The signal processing and control module 120 performs a weighted average of the electrostatic discharge judgment signal H within multiple sampling periods to obtain the background baseline data J; at the same time, it generates an estimated environmental noise value N based on the environmental compensation data M.

[0099] Background baseline data J and environmental noise estimate N are written into the working buffer of signal processing and control module 120 and used as inputs for steps S204 and S205. This step serves to establish a reference for the current background electrostatic field at the workstation, preventing the fixed environmental bias from being directly used as a risk factor for human or tool proximity.

[0100] Step S203: Synchronously acquire distance signals and electrostatic induction signals.

[0101] The signal processing and control module 120 synchronously acquires distance signal P, electrostatic discharge judgment signal H, event pulse signal X, environmental compensation data M, and workstation status data G according to a preset sampling period. The distance signal P comes from the proximity recognition module 111, the electrostatic discharge judgment signal H comes from the front-end conditioning unit in the signal processing and control module 120, the event pulse signal X comes from the ESD event detection module 113, the environmental compensation data M comes from the environmental acquisition module, and the workstation status data G comes from the workstation status module or an external interface.

[0102] The above data are time-aligned within the same time window to form a real-time input data group R0, which serves as the input for step S204. This step ensures that distance, static electricity, environment, and workstation status correspond to the same workstation time.

[0103] Step S204: Using the distance signal as a gating condition, determine whether it is allowed to update the background baseline data based on the distance signal and the electrostatic induction signal. If allowed, update the background baseline data; otherwise, freeze the background baseline data.

[0104] The signal processing and control module 120 determines whether the background baseline data J can be updated based on the real-time input data group R0. When the distance signal P is greater than the monitoring distance threshold P0, the deviation of the electrostatic determination signal H from the background baseline data J is less than the baseline update threshold B0, the rate of change of the electrostatic determination signal H is less than the rate of change threshold D0, the event pulse signal X is not triggered, and the station status data G indicates that the station is in an idle state, the signal processing and control module 120 allows the background baseline data J to be updated, and records the updated background baseline data as J1.

[0105] When any of the above conditions are not met, the signal processing and control module 120 freezes the background baseline data J and records the frozen background baseline data as J1. The background baseline data J1 serves as the input for step S205. The purpose of this step is to prevent the system from mistakenly identifying the approach of a live person, a real discharge event, or a high-risk workstation action as normal background.

[0106] In other words, the background baseline data is not updated dynamically all the time, but only when safety conditions are met, in order to avoid misidentifying abnormal electrostatic states as normal background. The signal processing and control module 120 only allows the background baseline data to be updated when the proximity recognition module 111 does not detect a charged target entering the preset monitoring area, and the electrostatic induction signal is below the baseline update threshold within a preset stable time.

[0107] For example, background baseline data updates are prohibited in the following states: a charged target has entered the preset monitoring area; the system is in a level one early warning state; the system is in a level two alarm or interlock state; the rate of change of the electrostatic induction signal exceeds the preset rate of change threshold; and the ESD event detection module 113 detects a suspected discharge transient.

[0108] Step S205: Generate risk data based on the electrostatic induction signal and the updated or frozen background baseline data.

[0109] The signal processing and control module 120 first calculates the background correction electrostatic increment ΔH based on the electrostatic determination signal H and the background baseline data J1, where ΔH = max(0, |H-J1|-N), and N is the estimated environmental noise value obtained from the environmental compensation data M. Specifically, the signal processing and control module 120 generates the current environmental noise estimate N based on environmental parameters such as temperature, humidity, and air pressure collected by the environmental acquisition module, using a preset environmental noise model or mapping table, which is used to compensate for the background correction electrostatic increment. The signal processing and control module 120 then generates a distance weight W based on the distance signal P.

[0110] In a preferred example, the distance weight W = clip((Pref / max(P, Pmin)) α The distance is defined as follows: Pref is the reference distance, Pmin is the minimum effective distance, α is the weighting exponent, Wmin is the minimum weight, and Wmax is the maximum weight. The signal processing and control module 120 multiplies the background correction electrostatic increment ΔH by the distance weight W and combines it with the station coefficient Cg corresponding to the station status data G to obtain the risk data K, i.e., K = ΔH × W × Cg. The risk data K serves as the input for step S206. The purpose of this step is to incorporate the distance factor into the electrostatic risk determination, enabling the distinction between near-distance weak electrical objects and far-distance strong electrical objects.

[0111] For example, the distance-weighted mapping formula can be W=(d0 / d). 2 Where d is the measured distance and d0 is the reference distance (e.g., 10cm). The electrostatic field strength is inversely proportional to the square of the distance, and this weight can compensate for the influence of distance changes on the induced signal. When the target moves from 30cm to 15cm, the weight increases by 4 times, so that "4 times the charge at 30cm" and "1 times the charge at 15cm" are mapped to similar risk values.

[0112] Step S206: Compare the risk data with the preset threshold and output the judgment result.

[0113] The preset conditions include a primary threshold T1 and a secondary threshold T2, where the secondary threshold T2 is greater than the primary threshold T1. The signal processing and control module 120 compares the risk data K with the primary threshold T1 and the secondary threshold T2.

[0114] When the risk data K reaches the first-level threshold T1 but is lower than the second-level threshold T2, the signal processing and control module 120 starts the first-level timer; when K remains above the first-level threshold T1 for a period of time t_d, the signal processing and control module 120 outputs the first-level judgment result Q1.

[0115] When K reaches the secondary threshold T2, the signal processing and control module 120 starts the secondary timer; when K remains above the secondary threshold T2 for a continuous period of time t_d, the signal processing and control module 120 outputs the secondary judgment result Q2.

[0116] When the event pulse signal X is confirmed to be valid, the signal processing and control module 120 directly outputs the event judgment result Q3.

[0117] The judgment result Q1, judgment result Q2, or event judgment result Q3 are used as inputs for step S7. The purpose of this step is to filter transient noise and prevent the test station from frequently entering alarm or interlock states due to short-term interference.

[0118] Step S207: Drive alarm and / or interlock control actions based on the judgment result.

[0119] When the signal processing and control module 120 receives the judgment result Q1, the signal processing and control module 120 drives the alarm module 131 to output a first-level prompt, which includes a yellow indicator and an intermittent buzzer.

[0120] When the signal processing and control module 120 receives the judgment result Q2, the signal processing and control module 120 simultaneously drives the alarm module 131 and the interlocking control module 132 to output a secondary interlocking control signal. The secondary interlocking control signal is used to pause the test, prohibit plugging and unplugging, prohibit starting, or prohibit power-on.

[0121] When the signal processing and control module 120 receives the event judgment result Q3, the signal processing and control module 120 latches the timestamp, workstation number, current risk data K and current workstation status data G corresponding to the event pulse signal X, and uploads the event record data E0 through the log and host computer interface module 133.

[0122] The execution status data Y output from this step serves as the input for step S8. The purpose of this step is to transform the risk identification results into executable workstation protection actions and traceable event data.

[0123] Step S208: When the recovery conditions are met, the alarm or interlock status is cleared and the process returns to step S203.

[0124] The signal processing and control module 120 continuously collects the distance signal P, the electrostatic discharge judgment signal H, and the workstation status data G. When the distance signal P is greater than the monitoring distance threshold P0, the risk data K is lower than the recovery threshold Tr, and the duration of this state reaches the recovery time t_r, the signal processing and control module 120 releases the first-level prompt or the second-level interlock and restores the system state to the monitoring state.

[0125] After recovery, the signal processing and control module 120 returns to step S203 to continue collecting real-time input data group R0; when the recovery conditions are not met, the signal processing and control module 120 maintains the current alarm or interlock state. The purpose of this step is to prevent the system from prematurely deactivating protection due to the short-term movement of the energized object away or the brief drop in the electrostatic signal.

[0126] The recovery threshold Tr is lower than the first-level threshold T1. After outputting the first-level judgment result Q1 or the second-level judgment result Q2, the signal processing and control module 120 continuously collects the distance signal P and the electrostatic judgment signal H; when the distance signal P is greater than the preset monitoring distance threshold P0, the risk data K is lower than the preset recovery threshold Tr, and the duration of this state reaches the preset recovery time t_r, the alarm or interlock state is released and monitoring is restored.

[0127] In some specific embodiments, the primary threshold T1 and the secondary threshold T2 can be fixed and preset, or they can be adjusted online after the host computer writes the parameter configuration data T. The primary threshold T1 is used to prompt the energized target to perform a grounding or temporarily delay approach action, and the secondary threshold T2 is used to trigger interlocking control actions.

[0128] Generally, the secondary threshold T2 is greater than the primary threshold T1, and the recovery threshold Tr is lower than the primary threshold T1, to form a hysteresis interval. The background baseline data update threshold B0 can be 2-5 times the root mean square value of normal background noise, the rate of change threshold D0 can be 3-8 times the average rate of change of stable background, the de-jitter time t_d can be 50-500ms, and the recovery time t_r can be 2-10s.

[0129] See Figure 4 The diagram illustrates the complete workflow of an example of the early warning system 100 of the present invention from power-on to resumption of monitoring. The specific execution process is as follows:

[0130] System power-on / initialization and self-test parameter loading: The signal processing and control module 120 performs system power-on / initialization and performs self-test and parameter loading. The loaded parameters include thresholds, calibration coefficients, communication interfaces and relay status, etc.

[0131] Background baseline data acquisition: After the system self-test passes, the signal processing and control module 120 acquires background baseline data to form the background baseline data of the current environment.

[0132] Personnel Entry Detection and Standby Monitoring: The signal processing and control module 120 determines whether personnel have entered the monitoring area. If not, it controls the early warning system to enter standby monitoring mode and continues to detect; if yes, it proceeds to the next step.

[0133] Signal Acquisition and Fusion: The signal processing and control module 120 simultaneously performs proximity recognition and distance measurement (ToF / infrared / millimeter wave) and electrostatic induction signal acquisition (sensing electrode / front-end amplification / ADC sampling). Subsequently, signal fusion and jitter reduction processing are performed, including distance gating, background compensation, and duration determination.

[0134] Level 1 Threshold Determination and Early Warning: The signal processing and control module 120 determines whether the processed risk signal exceeds the Level 1 early warning threshold. If not, it controls the early warning system to continue monitoring / updating the background baseline data and looping; if so, it triggers a Level 1 early warning, manifested as a yellow light / intermittent buzzer / a prompt to ground first.

[0135] Secondary threshold determination and interlocking: The signal processing and control module 120 further determines whether the secondary danger threshold has been exceeded. If not, the primary warning is maintained and monitoring continues; if so, a secondary alarm is triggered, manifested as a red light / continuous buzzer / output interlocking, and a pause test or prohibition of plugging / unplugging operations is executed.

[0136] ESD Event Detection and Recovery Determination: In alarm or interlock status, optional ESD event detection (wireless / RF transient detection) can be performed, and the event time / number / workstation number is recorded. Then, it is determined whether the personnel have completed grounding / left the hazardous area. If not, the alarm status is maintained; if yes, the alarm is cleared / standby is restored.

[0137] Return to continuous monitoring: After resuming standby, the system returns to continuous monitoring and repeats the above steps.

[0138] Example 1:

[0139] Warning for manual memory testing station.

[0140] The early warning system is fixed to the side of the memory test fixture or test socket, with the electrostatic induction electrode facing the direction of the operator's hand approach. The proximity recognition module is located adjacent to the electrostatic induction electrode. The distance between the early warning system and the memory test fixture can be set to 15-40cm, and the monitoring distance threshold P0 can be set to 0.5m.

[0141] When an operator's hands or upper body enter the monitoring area, the control module freezes the background baseline data J and generates risk data K based on the distance signal P and the electrostatic determination signal H. When risk data K reaches the first-level threshold T1, the warning system outputs a yellow indicator and intermittent beeping; when risk data K reaches the second-level threshold T2, the warning system outputs a relay interlock control signal to pause the test or prohibit further insertion and removal.

[0142] Taking a manual memory testing station as an example, the monitoring distance threshold P0 is set to 0.5m, the reference distance Pref is set to 0.5m, the minimum effective distance Pmin is set to 0.1m, the weighting index α is set to 1, the minimum weight Wmin is set to 1, and the maximum weight Wmax is set to 6.

[0143] If at a certain moment the electrostatic discharge judgment signal H is 180, the background baseline data J1 is 40, and the estimated environmental noise value N is 20, then the background correction electrostatic discharge increment ΔH = max(0, |180-40|-20) = 120. When the distance signal P is 0.25m, the distance weight W = (0.5 / 0.25) = 2. If the workstation coefficient Cg is 1, then the risk data K = 120 × 2 × 1 = 240. If the first-level threshold T1 is 180 and the second-level threshold T2 is 360, then the control module outputs the judgment result Q1 and triggers the first-level prompt.

[0144] If the distance signal P further decreases to 0.15m and the electrostatic determination signal H increases to 230, then ΔH=170, W is approximately 3.33, and K is approximately 566, which is greater than the secondary threshold T2. The control module outputs the determination result Q2 and triggers the secondary interlock.

[0145] Example 2:

[0146] Bypass warning for motherboard / FPGA platform.

[0147] The early warning system is fixed as a small add-on module to the edge of the motherboard, near the memory area, or at the edge of the FPGA test board. The device connects to the host computer software via UART, GPIO, or I2C. The monitoring distance threshold P0 can be set to 0.3-0.8m. When an operator prepares to touch the memory area, probe point, or test interface, the proximity recognition module outputs a distance signal P, the electrostatic induction module 112 outputs a raw electrostatic induction signal A, the control module generates risk data K, and determines whether to issue a warning, record, or interlock based on the workstation status data G.

[0148] In motherboard or FPGA board bypass applications, the monitoring distance threshold P0 can be set to 0.3-0.8m, the reference distance Pref can be set to 0.4-0.6m, and the station coefficient Cg can be set to 1.2-2.0 when the memory area is open, the probe is in contact, or the test point is exposed, and can be set to 0.5-1.0 when the board is closed or no DUT is in place.

[0149] Example 3:

[0150] An enhanced early warning system with event logging.

[0151] Based on Embodiments 1 and 2 above, an ESD event detection module is added to the early warning system. The ESD event antenna is positioned, for example, near the edge of a test socket, near a fixture opening, or near a sensitive test point. When a real electrostatic discharge occurs, the ESD event antenna outputs a transient radio frequency signal. A high-speed comparator converts the transient radio frequency signal into an event pulse signal X. The control module latches the timestamp, workstation number, risk data K, and workstation status data G corresponding to the event pulse signal X. This event record can be used for subsequent failure analysis, workstation statistics, and protection strategy optimization.

[0152] Example 4:

[0153] An extension solution for an early warning system linked to access control / enabling.

[0154] In semi-automated or automated workstations, the early warning system can be connected to workstation access control, test start button, robot arm enable signal, or insertion / removal mechanism action permission. The monitoring distance threshold P0 can be set to 0.5-1.0m, and the robot arm enable status, fixture opening / closing status, and test start status can be included as part of the workstation status data G. When the system detects a charged target entering the monitoring area and the risk data K reaches the secondary threshold T2, the interlock control module outputs a prohibition signal; when the risk data K is lower than the recovery threshold Tr and the recovery time reaches t_r, the interlock control module releases the prohibition signal. This embodiment is applicable to semi-automated or automated memory testing workstations.

[0155] The non-contact electrostatic discharge (ESD) warning system and method for memory testing environments provided by embodiments of the present invention have at least one or a portion of the following advantages:

[0156] (1) The distance signal output by the proximity recognition module is used as the gate condition. When the charged target does not enter the preset monitoring area, the standby monitoring state is maintained. When the charged target enters the preset monitoring area and the electrostatic induction signal meets the preset condition, the judgment result is output. This can effectively reduce the interference from the background electric field and non-risk objects at a distance, improve the reliability of the early warning and reduce the false alarm rate.

[0157] (2) The electrostatic induction signal is protected, buffered, amplified, filtered and feature extracted by the front-end conditioning unit and the electrostatic judgment signal H is output. The background baseline data J is generated or frozen by the baseline management unit of the core control unit, the risk data K is generated by the risk mapping unit, and the judgment result is generated by the threshold judgment unit. This realizes the high signal-to-noise ratio extraction and multi-level comprehensive judgment of the electrostatic signal.

[0158] (3) By generating distance weight W based on distance signal, generating background correction electrostatic increment ΔH based on electrostatic induction signal and background baseline data J, and generating risk data K based on ΔH and W as a comprehensive judgment basis, quantitative compensation of distance factor for electrostatic risk judgment is realized, so that near-distance weak electric objects and far-distance strong electric objects can be effectively distinguished.

[0159] (4) By setting dynamic update and freeze conditions for the background baseline: when the distance signal is greater than the preset monitoring distance threshold, the deviation of the electrostatic induction signal relative to the background baseline data is lower than the preset baseline update threshold, and the rate of change of the electrostatic induction signal is lower than the preset rate of change threshold, the baseline is allowed to be updated; otherwise, the baseline is frozen. This can prevent the system from mistakenly identifying live personnel approaching, real discharge events, or high-risk workstation actions as normal background, thereby improving the robustness of baseline management.

[0160] (5) Through background correction electrostatic increment calculation, distance weight calculation and risk data calculation, quantitative compensation of the physical law that electrostatic field strength is inversely proportional to the square of distance and dynamic adjustment of risk level by work position status are realized.

[0161] (6) By setting a first-level threshold T1 and a second-level threshold T2 (T2>T1), when the risk data K reaches T1 but is lower than T2 and continues to reach the preset de-shaking time, the first-level judgment result is output to trigger the prompt. When K reaches T2 and continues to reach the de-shaking time, the second-level judgment result is output to trigger the interlock control, thus realizing graded early warning and graded control, and avoiding the test station from frequently entering the alarm or interlock state due to short-term interference.

[0162] (7) By continuously collecting distance signal and electrostatic induction signal after outputting the judgment result, when the distance signal is greater than the preset monitoring distance threshold, the risk data K is lower than the preset recovery threshold and the duration of the state reaches the preset recovery time, the alarm or interlock state is released and monitoring is restored. The recovery threshold is lower than the first-level threshold T1, forming a hysteresis interval, which avoids the system from prematurely releasing protection due to the short distance of the charged object or the short-term drop of the electrostatic signal.

[0163] (8) The sensing electrode is set facing the direction of approach of the charged target to couple the change of the spatial electrostatic field. The guard ring electrode is set around the sensing electrode to limit the effective sensing area and reduce the electric field interference of the surrounding environment. The guard ring electrode is driven by the in-phase buffer output of the high-impedance buffer unit of the signal processing and control module, which can reduce the influence of leakage current and parasitic capacitance on the original electrostatic induction signal and improve the sensitivity and anti-interference ability of electrostatic detection.

[0164] (9) The ESD event detection module captures the radio frequency transient signal generated by electrostatic discharge and outputs the event pulse signal. When the event pulse signal is confirmed to be valid, the event judgment result is directly output and the timestamp, work station number and current risk data are latched. The dual mode of early warning and traceability is realized, providing data support for subsequent failure analysis, work station statistics and protection strategy optimization.

[0165] (10) The Time-of-Flight (ToF) sensor is used for proximity detection within a range of 15-100cm, the infrared sensor is used for proximity judgment in a fixed direction, and the millimeter-wave sensor is used for human presence and movement detection in dusty, low-light or obstructed environments, thus achieving flexible adaptation to various application scenarios.

[0166] (11) The environmental acquisition module collects environmental temperature, humidity and air pressure data and outputs environmental compensation data. The workstation status module collects the current working status (idle, plug-in, crimp, power on, test run) of the memory test workstation and outputs workstation status data, so that the system can dynamically adjust the risk judgment logic according to environmental parameters and workstation status, and improve the accuracy and pertinence of the judgment.

[0167] (12) Through the closed-loop workflow of system initialization and self-test, background baseline establishment, real-time input acquisition, gating control and background baseline update, risk mapping, threshold determination, execution output and event recording, and recovery monitoring, a complete protection closed loop of "detecting proximity - identifying risks - hierarchical alarm - control blocking - recording events - recovery monitoring" is realized.

[0168] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A non-contact electrostatic discharge (ESD) warning system for memory testing environments, characterized in that, The non-contact electrostatic early warning system includes: The proximity detection module is configured to detect whether a charged target has entered a preset monitoring area and output a distance signal; The electrostatic induction module is configured to sense changes in the spatial electrostatic field and output an electrostatic induction signal. The signal processing and control module is configured to communicate with the proximity recognition module and the electrostatic induction module, receive the distance signal and the electrostatic induction signal, generate or freeze background baseline data, and make a comprehensive judgment based on the distance signal, the electrostatic induction signal and the background baseline data, and output the judgment result. The alarm module is configured to communicate with the signal processing and control module, receive the judgment result, and perform a prompting action. The interlocking control module is configured to communicate with the signal processing and control module, receive the determination result, and execute the interlocking action; wherein... The signal processing and control module uses the distance signal as a gating condition. When the distance signal indicates that the charged target has not entered the preset monitoring area, the signal processing and control module maintains a standby monitoring state. When the distance signal indicates that the charged target has entered the preset monitoring area and the electrostatic induction signal meets the preset conditions, the signal processing and control module outputs the determination result.

2. The non-contact electrostatic early warning system according to claim 1, characterized in that, The signal processing and control module includes a front-end conditioning unit and a core control unit; The front-end conditioning unit is communicatively connected between the electrostatic induction module and the core control unit, and is configured to protect, buffer, amplify, filter and extract features of the electrostatic induction signal, and output an electrostatic determination signal H. The core control unit includes a baseline management unit, a risk mapping unit, and a threshold determination unit; The baseline management unit is configured to generate or freeze background baseline data J according to security conditions; The risk mapping unit is used to generate risk data K based on the electrostatic determination signal H, the background baseline data J, and the distance signal; The threshold determination unit is used to generate the determination result based on the risk data K.

3. The non-contact electrostatic early warning system according to claim 2, characterized in that, The signal processing and control module generates a distance weight W based on the distance signal, generates a background correction electrostatic increment ΔH based on the electrostatic induction signal and the background baseline data J, and generates risk data K based on the background correction electrostatic increment ΔH and the distance weight W, which serves as the basis for the comprehensive judgment.

4. The non-contact electrostatic early warning system according to claim 3, characterized in that, The signal processing and control module is further configured to: When the distance signal is greater than a preset monitoring distance threshold, the deviation of the electrostatic induction signal relative to the background baseline data is less than a preset baseline update threshold, and the rate of change of the electrostatic induction signal is less than a preset rate of change threshold, the background baseline data is allowed to be updated. When any one of the following conditions is not met: the distance signal is greater than a preset monitoring distance threshold, the deviation of the electrostatic induction signal relative to the background baseline data is lower than a preset baseline update threshold, or the rate of change of the electrostatic induction signal is lower than a preset rate of change threshold, the background baseline data is frozen.

5. The non-contact electrostatic early warning system according to claim 3, characterized in that, The background correction electrostatic increment ΔH = max(0, |H-J1|-N), where H is the electrostatic judgment signal output after the electrostatic induction signal is conditioned, J1 is the updated or frozen background baseline data, and N is the environmental noise estimate generated by the signal processing and control module based on the environmental compensation data M output by the environmental acquisition module and used to characterize the current environmental noise level. The distance weight W = clip((Pref / max(P, Pmin)) α , Wmin, Wmax), where P is the distance signal, Pref is the reference distance, Pmin is the minimum effective distance, α is the weighting exponent, Wmin is the minimum weight, and Wmax is the maximum weight; The risk data K = ΔH × W × Cg, where Cg is the workstation coefficient determined based on the workstation status data.

6. The non-contact electrostatic early warning system according to claim 3, characterized in that, The preset conditions include a primary threshold T1 and a secondary threshold T2, wherein the secondary threshold T2 is greater than the primary threshold T1; The signal processing and control module is configured as follows: When the risk data K reaches the first-level threshold T1 but is lower than the second-level threshold T2, and continues to reach the preset de-jitter time, the first-level judgment result is output, and the alarm module responds to the first-level judgment result by outputting a first-level prompt. When the risk data K reaches the secondary threshold T2 and continues to reach the de-jitter time, a secondary judgment result is output. The alarm module responds to the secondary judgment result by outputting a secondary prompt, and the interlocking control module responds to the secondary judgment result by outputting an interlocking control signal.

7. The non-contact electrostatic early warning system according to claim 6, characterized in that, The signal processing and control module is further configured to: After outputting the first-level determination result or the second-level determination result, the distance signal and the electrostatic induction signal are continuously collected; When the distance signal is greater than the preset monitoring distance threshold, the risk data K is lower than the preset recovery threshold, and the duration of this state reaches the preset recovery time, the alarm or interlock state is lifted and monitoring is restored. The recovery threshold is lower than the first-level threshold T1.

8. The non-contact electrostatic early warning system according to claim 2, characterized in that, The electrostatic induction module includes a sensing electrode and a retaining ring electrode; The sensing electrode is positioned facing the approach direction of the charged target to couple the change in the spatial electrostatic field caused by the approach of the charged target and output the electrostatic induction signal. The retaining ring electrode is arranged around the sensing electrode to limit the effective sensing area and reduce the interference of the surrounding environmental electric field on the sensing electrode. The retaining ring electrode is driven by the in-phase buffer output of the high-impedance buffer unit of the signal processing and control module; The high-impedance buffer unit is a buffer amplifier with high input impedance and low output impedance, which performs impedance transformation on the electrostatic induction signal.

9. The non-contact electrostatic early warning system according to claim 1, characterized in that, The non-contact electrostatic early warning system also includes an electrostatic discharge event detection module, which is communicatively connected to the signal processing and control module to capture the radio frequency transient signal generated by the electrostatic discharge of the charged target and output the event pulse signal. The signal processing and control module is further configured to: when the event pulse signal is confirmed to be valid, directly output the event determination result, and latch the timestamp, workstation number and current risk data corresponding to the event pulse signal.

10. The non-contact electrostatic early warning system according to claim 1, characterized in that, The proximity recognition module includes at least one of a time-of-flight sensor, an infrared sensor, and a millimeter-wave sensor; The time-of-flight sensor is used for proximity detection of the charged target within a range of 15-100cm, the infrared sensor is used for proximity judgment in a fixed direction, and the millimeter-wave sensor is used for human presence and movement detection in dusty, low-light, or obscured environments.

11. The non-contact electrostatic early warning system according to claim 1, characterized in that, The non-contact electrostatic early warning system also includes an environmental data acquisition module and a workstation status module; The environmental acquisition module is configured to acquire ambient temperature, humidity and air pressure data, and output environmental compensation data to the signal processing and control module. The workstation status module is configured to collect the current working status of the memory test workstation, including idle, plug / unplug, crimp, power-on, and test running status, and output the workstation status data to the signal processing and control module.

12. A non-contact electrostatic discharge (ESD) warning method for a memory testing environment, wherein the non-contact ESD warning method is used in the non-contact ESD warning system according to any one of claims 1-11, characterized in that, The non-contact electrostatic early warning method includes the following steps: S201: System initialization and self-test, reading parameter configuration data; S202: When the system is available and the workstation is not in operation, continuously collect electrostatic induction signals to generate background baseline data; S203: Synchronously acquire distance signals and electrostatic induction signals; S204: Using the distance signal as a gating condition, determine whether updating the background baseline data is allowed based on the distance signal and the electrostatic induction signal. If allowed, update the background baseline data; otherwise, freeze the background baseline data. S205: Generate risk data based on the electrostatic induction signal and the updated or frozen background baseline data; S206: Compare the risk data with a preset threshold and output the judgment result; S207: Drive alarm and / or interlock control actions according to the determination result; S208: When the recovery conditions are met, the alarm or interlock status is cleared and the process returns to step S203.

13. The non-contact electrostatic early warning method according to claim 12, characterized in that, In step S204, when the distance signal is greater than a preset monitoring distance threshold, the deviation of the electrostatic induction signal relative to the background baseline data is lower than a preset baseline update threshold, the rate of change of the electrostatic induction signal is lower than a preset rate of change threshold, and the workstation status data indicates that the workstation is in an idle state, the background baseline data is allowed to be updated. Otherwise, freeze the background baseline data; The workstation status data comes from the data collected by the workstation status module, which represents the current working status of the memory test workstation. The workstation status data includes idle, plug / unplug, crimp, power-on, and test running status.

14. The non-contact electrostatic early warning method according to claim 12, characterized in that, In step S205, a distance weight W is generated based on the distance signal, and a background correction electrostatic increment ΔH is generated based on the electrostatic induction signal and the updated or frozen background baseline data J1. The background correction electrostatic increment ΔH = max(0, |H-J1|-N), where H is the electrostatic judgment signal output after conditioning of the electrostatic induction signal, and N is the estimated value of environmental noise. The risk data K = ΔH × W × Cg, where Cg is the workstation coefficient determined based on the workstation status data.

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