A high-universality three-layer modular PCBA full-automatic burning test device

Abstract

This application relates to a highly versatile, three-layer modular, fully automated PCBA programming and testing device, belonging to the technical field of PCBA testing equipment. The device includes a universal substrate, a fixed adapter module 2, a detachable adapter module 1, and a pressure module. Adapter module 2 includes an adapter board 2 with signal collection test points and external terminals. Adapter module 1 includes an adapter board 1 with contact test points. Probes are provided between the PCBA under test and adapter board 1, and between adapter board 1 and adapter board 2. During testing, the pressure module is the only component that reciprocates vertically, while adapter module 1 and adapter module 2 remain stationary, thus achieving separation of motion and static components and rapid model changeover. The programming signal is directly conducted to the PCBA under test via adapter board 1 to ensure signal integrity. Furthermore, the device improves testing safety and reliability through test point zoning, hardware power-on interlocking, pneumatic bidirectional interlocking, and probe dual-loop self-testing.

Description

Technical Field

[0001] This application relates to the field of PCBA testing equipment technology, and in particular to a highly versatile three-layer modular PCBA fully automatic programming and testing device. Background Technology

[0002] Printed circuit board assemblies (PCBAs) typically require programming and functional testing during mass production. Testing equipment generally uses probes to contact the test points on the PCBA under test to establish programming and testing signal channels. With the rapid iteration of PCBA models and the increasing demands for testing efficiency, signal integrity, and operational safety, testing equipment faces numerous challenges in terms of versatility, signal quality, and safety protection.

[0003] CN116794489A discloses a flip-top type testing device that presses the PCBA under test together using a flip-top structure; CN108982932A discloses an overall floating testing structure; CN106293858A discloses a software-controlled testing scheme; US6281694 discloses a scheme based on probe resistance detection. However, the above schemes still have the following problems in practical applications: First, many components need to be replaced during model changeover, resulting in poor versatility and difficulty in quickly adapting to different PCBA models under test. Second, there are many moving parts during testing, leading to high coupling and making it difficult to guarantee positioning accuracy and reliability. Third, the programmed signals undergo multiple routing and layer changes during the transfer process, which can easily cause impedance discontinuities and affect signal integrity. Fourth, the test point layout does not coordinate safety electrical spacing and signal integrity spacing, making it easy for high-voltage and low-voltage signals to interfere with each other. Fifth, power-on safety mainly relies on software control and lacks independent hardware interlocks, posing a risk of accidental power-on. Sixth, there is a lack of reliable mechanical or pneumatic interlocks between the pressing and locking actions, creating a safety hazard of conflicting actions. Seventh, the probe contact status is difficult to determine online, and failures such as probe wear, poor connection, or stuck pins are not easily detected in a timely manner. Summary of the Invention

[0004] Based on this, it is necessary to provide a highly versatile, fully automated three-layer modular PCBA programming and testing device that is highly versatile, has good signal integrity, and is safe and reliable, in order to address the above-mentioned technical problems.

[0005] This application provides a highly versatile three-layer modular fully automatic PCBA programming and testing device, including a general-purpose substrate, an adapter module 2, an adapter module 1, and a pressing module. The adapter module 2 is fixedly installed on the general-purpose substrate and includes an adapter plate 2, which is provided with signal collection test points and external terminals. The adapter module 1 is detachably installed above the adapter module 2 and includes an adapter plate 1, which is provided with contact test points corresponding to the test points of the PCBA under test. The pressing module is located above the adapter module 1 and is connected to a vertical drive mechanism to reciprocate vertically under the drive of the vertical drive mechanism. Probes are provided between the PCBA under test and the adapter plate 1, and between the adapter plate 1 and the adapter plate 2. During the test, the pressing module is the only component that reciprocates vertically, while the adapter module 1 and the adapter module 2 remain stationary.

[0006] In one embodiment, the adapter board 1 is provided with a through-conduction structure and internal wiring; the programming signal is directly transmitted to the PCBA under test via the adapter board 2, the probe, the through-conduction structure of the adapter board 1 and the probe in sequence; the test signal is transmitted to the external terminal of the adapter board 2 via the PCBA under test, the probe, the internal wiring of the adapter board 1, the probe and the adapter board 2.

[0007] In one embodiment, the adapter module 1 is a replacement part corresponding to the model of the PCBA under test, and the adapter module 1 is provided with an asymmetric positioning interface.

[0008] In one embodiment, the pressing module includes an upper plate, a positioning plate, a drawer-type guide rail, a foolproof limit block, and a positioning post. The pressing module achieves hierarchical positioning through the drawer-type guide rail and the positioning post.

[0009] In one embodiment, the adapter module 1 is provided with a limiting sleeve corresponding to the positioning post. The positioning post and the limiting sleeve cooperate to form a hard limit on the downward stroke of the pressing module.

[0010] In one embodiment, the adapter board 2 integrates a contact switch and a safety relay. The normally open contacts of the contact switch and the safety relay are connected in series and connected to the power supply circuit of the PCBA under test. The coil of the safety relay is controlled by the digital output terminal of the programmable logic controller.

[0011] In one embodiment, a locking cylinder and a pneumatically controlled directional valve are also included, the pneumatically controlled directional valve being configured to open the air path for pressing down the pressing module only after locking is in place, and to open the unlocking air path only after lifting is in place.

[0012] In one embodiment, multiple probes are connected in series to form a first circuit, and a precision resistor forms a second circuit. A programmable logic controller synchronously samples the voltage drop of the first circuit and the second circuit through two analog-to-digital conversion channels.

[0013] In one embodiment, the contact test points of the adapter plate 1 are divided into a PE zone, a high voltage zone, and a low voltage zone. The low voltage zone is further divided into a high-frequency digital zone, a low-voltage analog zone, a medium-low frequency digital zone, and a programming zone. Each zone is equipped with an independent grounding enclosure.

[0014] In one embodiment, the adapter module 2 is provided with an optical positioning reference point for alignment by the vision system of an external automated production line.

[0015] The aforementioned highly versatile, three-layer modular, fully automated PCBA programming and testing device divides the device into a fixed adapter module 2, a detachable adapter module 1, and a vertically reciprocating pressing module. During testing, only the pressing module moves while the adapter module 1 and adapter module 2 remain stationary, achieving separation of motion and statics, reducing the number of moving parts, and improving positioning accuracy and reliability. By setting the adapter module 1 as a replacement part corresponding to the PCBA model under test, only the top two layers need to be replaced during model change, improving the device's versatility for different PCBA models under test. The recorded signal is directly conducted to the PCBA under test via the direct conduction structure of adapter board 1, avoiding multiple traces and layer changes of the recorded signal in the conversion stage, thus ensuring signal integrity. By dividing the test points into zones and ensuring that the spacing between the zones meets both safety electrical clearance and signal integrity clearance requirements, both safety regulations and anti-interference requirements are taken into account. The safety of power-on and operation processes is improved by hardware interlocking consisting of contact switches and safety relays connected in series and pneumatic bidirectional interlocking consisting of pneumatically controlled reversing valves. The probe's contact status can be determined online through dual-circuit square wave self-test, which facilitates the timely detection of probe failure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of a three-layer modular PCBA fully automated programming and testing device in one embodiment; Figure 2 This is a schematic diagram of a three-layer dynamic-static separation and dual-signal path transmission in one embodiment; Figure 3 This is a cross-sectional view of the hierarchical positioning structure of the pressure module in one embodiment; Figure 4 This is a schematic diagram of the layout of the measuring points on the adapter board in one embodiment; Figure 5This is a graph showing the variation of near-end crosstalk with the center distance of the measurement points and the signal frequency in one embodiment. Figure 6 This is a schematic diagram of a load power-on hardware interlock circuit in one embodiment; Figure 7 This is a schematic diagram of a pneumatic two-way safety interlock in one embodiment; Figure 8 This is a schematic diagram of a probe dual-loop self-test architecture in one embodiment; Figure 9 This is a waveform diagram of probe self-test square wave signal sampling and fault determination in one embodiment. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] In one exemplary embodiment, such as Figure 1 As shown, a highly versatile three-layer modular PCBA fully automated programming and testing device is provided. The device, from bottom to top, comprises a general-purpose base (10), a converter module 2 (20), a converter module 1 (30), and a pressing module (40). The general-purpose base (10) is mounted on the main frame (50), which is externally equipped with a protective shell (100) and a touch screen display (110). A programmable logic controller (120) is installed inside the device. A main pressing cylinder (60) serving as a vertical drive mechanism is connected above the pressing module (40), and a locking cylinder (70) is also provided on the main frame (50). The converter module 2 (20) is fixedly mounted on the general-purpose base (10) and remains fixed during device use. The converter module 1 (30) is detachably mounted above the converter module 2 (20).

[0020] The adapter module 2 (20) includes an adapter board 2 (21), which has signal collection test points and horn-shaped terminals (22) as external terminals. The adapter module 1 (30) includes an adapter board 1 (31), which has contact test points corresponding to the test points of the PCBA (90) under test. The PCBA (90) under test is placed on top of the adapter module 1 (30), and probes (80) are provided between the PCBA (90) under test and the adapter board 1 (31), and between the adapter board 1 (31) and the adapter board 2 (21).

[0021] like Figure 2As shown, the device adopts a three-layer dynamic-static separation architecture. During the test, the pressing module (40) moves vertically downward under the drive of the main pressing cylinder (60), pressing the PCBA (90) under test onto the adapter module 1 (30). The adapter module 1 (30) and the adapter module 2 (20) remain stationary. That is, the pressing module (40) is the only component in the device that reciprocates vertically. Therefore, when changing models, only the adapter module 1 (30) and the positioning components related to the PCBA (90) under test in the pressing module (40) need to be replaced. The adapter module 2 (20) does not need to be replaced. The adapter module 1 (30) is a replacement component corresponding to the model of the PCBA (90) under test, thereby realizing a replacement method where one model of the PCBA (90) under test corresponds to one set of adapter modules 1 (30).

[0022] See also Figure 2 The adapter board 1 (31) is equipped with a direct-through structure and internal wiring. The programming signal is transmitted from the horn terminal (22) through the adapter board 2 (21), the probe (80) located between the adapter board 1 (31) and the adapter board 2 (21), the direct-through structure of the adapter board 1 (31), and the probe (80) located between the PCBA under test (90) and the adapter board 1 (31), and is directly transmitted to the PCBA under test (90) in sequence. The programming signal does not pass through additional wiring and layer change at the adapter board 1 (31), thereby avoiding impedance discontinuity and ensuring the signal integrity of the programming signal. The test signal enters the adapter board 1 (31) from the PCBA under test (90) through the probe (80), is gathered by the internal wiring of the adapter board 1 (31), and is transmitted to the adapter board 2 (21) through the probe (80), and is finally output outward from the horn terminal (22).

[0023] The adapter module 2 (20) adopts a dual positioning structure with internal 3-pin precision positioning and external 4-pin asymmetric foolproof positioning. In this application, the large end diameter of all positioning pins is φ10mm and the small end diameter is φ7.86mm. The cone length of the guide cone at the front end of the positioning pin is 4mm and the cone angle is 15°. The inner diameter of the positioning hole bushing that mates with the positioning pin is φ10.1mm. The bearing plate inside the adapter module 2 (20) is provided with 3 positioning pins arranged asymmetrically in a triangle. The corresponding position of the positioning plate is provided with 3 positioning holes. After the positioning pins mate with the positioning holes, the degrees of freedom in the X direction, Y direction and rotation direction are constrained and locked by 6 M4 screws. The positioning plate of the adapter module 2 (20) is provided with 4 asymmetrically arranged positioning pins. The corresponding position of the main frame (50) is provided with 4 positioning holes. After the positioning pins mate with the positioning holes, the adapter module 2 (20) is fixedly installed on the main frame (50) by 6 M4 screws.

[0024] After the adapter module 2 (20) is pre-aligned by the external 4 pins, the pneumatic mechanism is controlled by the touch screen (110) to lock it with one key. Installation can be completed without the aid of tools. When disassembling, it is unlocked with one key and the cylinder automatically resets to avoid the impact. As a fixed and non-replaceable component, the adapter module 2 (20) is positioned by the above-mentioned positioning pins and locked by M4 screws. Once installed, it is fixed for a long time and does not need to be disassembled when changing models. The device is equipped with a transparent acrylic protective shell (100). The protective shell (100) encloses the probe (80) and the adapter plate 2 (21) and adapter plate 1 (31) inside to isolate workshop dust, solder balls and flux volatiles, prevent the probe (80) from being damaged by foreign objects, and prevent personnel from accidentally touching the live probe (80). During the test, the contact force between the PCBA (90) under test and the adapter board 1 (31) is provided by the main pressing cylinder (60) at a constant value, so that the contact impedance of the probe (80) fluctuates less and the stability and repeatability of the test signal are high.

[0025] The adapter module 1 (30) adopts a positioning structure with inner and outer double limiting sleeves. The adapter module 1 (30) is internally fitted with a precision limiting sleeve to constrain the interlayer relative position of the adapter plate 1 (31), so that the contact measurement points of the adapter plate 1 (31) are aligned with the signal collection measurement points of the adapter plate 2 (21). The back of the adapter module 1 (30) is provided with 4 positioning pins arranged asymmetrically, and the main frame (50) is fitted with corresponding limiting sleeves. The positioning pins and limiting sleeves cooperate to realize the external installation positioning of the adapter module 1 (30). Since the 4 positioning pins are arranged asymmetrically, the adapter module 1 (30) can only be installed in a single orientation, thus forming an asymmetrical positioning interface.

[0026] The installation and removal of the adapter module 1 (30) are achieved through a pneumatic locking mechanism: after the operator pushes the back positioning pin of the adapter module 1 (30) into the main frame (50) in place, the touch screen (110) controls the corner clamping cylinders on both sides to rotate 90° to press the adapter module 1 (30) to lock it; when removing, the corner clamping cylinders on both sides rotate outward 90° simultaneously and lift to avoid, so that the operator can pull out the adapter module 1 (30). The entire replacement process does not require the use of tools. After locking, the corner clamping cylinders on both sides continuously provide clamping force to eliminate residual fitting gaps, so that the alignment relationship between the probe (80) and the measuring point of the adapter plate 1 (31) remains stable for a long time.

[0027] like Figure 3As shown, the pressing module (40) includes an upper plate (41), a positioning plate (42), a drawer-type guide rail (44), a foolproof limit block (45), and a positioning post (43). It adopts a graded positioning method that combines drawer-type pre-positioning with four-post precision positioning. In the pre-positioning stage, the foolproof notch of the positioning plate (42) faces forward and is inserted along the drawer-type guide rail (44). The fit clearance between each contact surface of the drawer-type guide rail (44) and the positioning plate (42) is 0.1mm. The foolproof notch of the positioning plate (42) cooperates with the foolproof limit block (45) to realize the rapid pre-positioning of the pressing module (40) and prevent reverse insertion. In the precision positioning stage, the main pressing cylinder (60) drives the pressing module (40) to move downward. The positioning post (43) is inserted into the adapter module 1 (30) to complete the final precision alignment. Then, the pressing module (40) is locked by 6 manual bolts.

[0028] The adapter module 1 (30) is fitted with a limiting sleeve (32) that cooperates with the positioning post (43). When the pressing module (40) moves downward, the positioning post (43) is gradually inserted into the limiting sleeve (32). The inner hole of the limiting sleeve (32) guides and centers the positioning post (43), ensuring that the pressing module (40) moves downward smoothly in the correct posture. When the shoulder end face of the positioning post (43) contacts the upper end face of the limiting sleeve (32), it forms a mechanical hard limit on the downward stroke of the pressing module (40), which physically restricts the downward stroke of the pressing module (40) and prevents the probe (80) from being over-compressed and damaged or the pads of the PCBA (90) under test from breaking due to over-pressing. Thus, the pressing module (40) achieves pre-positioning through the drawer-type guide rail (44) and fine positioning through the positioning post (43) and the limiting sleeve (32), forming a graded positioning from coarse to fine.

[0029] like Figure 4As shown, the contact measurement points of the adapter board 1 (31) are divided into multiple zones according to the signal type. These zones include a PE zone, a high-voltage zone, and a low-voltage zone. The low-voltage zone is further divided into a high-frequency digital zone, a low-voltage analog zone, a medium-low frequency digital zone, and a programming zone. The spacing between each zone simultaneously meets the safety electrical spacing and signal integrity spacing requirements: the spacing between the PE zone and the high-voltage zone is 8 mm, the spacing within the high-voltage zone is 4 mm, and the spacing between the high-voltage zone and the low-voltage zone is 8 mm. The safety design parameters of this device are: pollution level 2, substrate FR-4, relative tracking index CTI ≥ 175, overvoltage category IIIa, applicable altitude ≤ 2000m, and operating voltage 400V AC. Different zones are equipped with differentiated probes corresponding to their signal types: the high-voltage zone, high-frequency digital zone, and programming zone use 100mil probes, while the low-voltage analog zone and medium-low frequency digital zone use 75mil probes. Each zone is equipped with an independent grounding enclosure. The grounding enclosure of the analog zone is connected to the analog ground, and the grounding enclosure of the digital zone is connected to the digital ground to achieve physical isolation of the zone grounding network. The non-functional measurement point area on the adapter board 1 (31) is copper-free to avoid short circuit caused by probe (80) piercing. The functional measurement point area is formed by tinning of a steel mesh with a thickness of 120μm.

[0030] To illustrate the design basis of the partition spacing, this application uses signal integrity theory and near-end crosstalk to quantitatively evaluate the coupling between adjacent measurement points. The parasitic mutual capacitance between two adjacent probes is approximately Cm = (2πε0L) / ln(2S / d), the ratio of the coupling interference voltage to the original excitation voltage is Vn / Vs = 2πfZ0Cm, and the near-end crosstalk is NEXT = 20lg(Vn / Vs), where ε0 is the vacuum permittivity and ε0 = 8.854 × 10⁻¹² F / m, L is the effective exposed coupling length of the probe and L = 0.002m, S is the center-to-center distance between the two probes, d is the diameter of the probe metal rod (d = 0.5 × 10⁻³m for a 100mil probe and 0.45 × 10⁻³m for a 75mil probe), f is the signal frequency, and Z0 is the system matching impedance and Z0 = 50Ω. Figure 5As shown, near-end crosstalk decreases with increasing center-to-center distance of measurement points and increases with increasing signal frequency. In one example, the near-end crosstalk in the high-voltage area is approximately -100.92dB when the center-to-center distance of the measurement points is 5.6mm and the signal frequency is 800kHz; in the low-voltage analog area, the near-end crosstalk is approximately -58.66dB when the center-to-center distance of the measurement points is 4.5mm and the signal frequency is 100MHz, meeting the requirement of not exceeding -40dB; in the mid-to-low frequency digital area, the near-end crosstalk is approximately -56.82dB when the center-to-center distance of the measurement points is 2.54mm and the signal frequency is 100MHz, meeting the requirement of not exceeding -35dB; in the programming area, the near-end crosstalk is approximately -63.06dB when the center-to-center distance of the measurement points is 3.0mm and the signal frequency is 50MHz, meeting the requirement of not exceeding -35dB; and in the high-frequency digital area, the near-end crosstalk is approximately -40.08dB when the center-to-center distance of the measurement points is 8.5mm and the signal frequency is 1GHz, meeting the requirement of not exceeding -40dB. For isolation between different zones, the spacing between the low-voltage analog zone and the mid-to-low frequency digital zone is 8.0 mm, with a corresponding near-end crosstalk of approximately -60.19 dB; the spacing between the high-frequency digital zone and the mid-to-low frequency digital zone is 9.0 mm, with a corresponding near-end crosstalk of approximately -40.22 dB; and the spacing between the mid-to-low frequency digital zone and the programming zone is 6.0 mm, with a corresponding near-end crosstalk of approximately -65.48 dB. Inter-zone interference is further suppressed by setting up double-layer grounding barriers and isolation pins around each zone.

[0031] like Figure 6 As shown, the adapter board 2 (21) integrates a contact switch (24) and a safety relay (23). The 220V AC mains power is converted to 24V DC power by an AC / DC power supply after passing through a circuit breaker and a filter. The coil of the safety relay (23) is connected to the digital output terminal of the programmable logic controller (120), and a freewheeling diode is connected in parallel across the coil to absorb the induced electromotive force generated when the coil is de-energized. The normally open contacts of the contact switch (24) and the safety relay (23) are connected in series and connected in series to the power supply circuit of the PCBA (90) under test. A contact rod (46) of a customized length is fixed on the pressure module (40). When the pressure module (40) moves down to the position, the contact rod (46) triggers the contact switch (24) to close. The power supply circuit of the PCBA (90) under test is only turned on when the contact switch (24) is closed and the coil of the safety relay (23) is energized by the programmable logic controller (120) through the digital output terminal, thereby providing an independent hardware power-on interlock in addition to software control.

[0032] Based on the aforementioned hardware power-on interlock, the device also includes a software-level power-on verification: the coil of the safety relay (23) is independently controlled by the digital output terminal of the programmable logic controller (120). The programmable logic controller (120) outputs a digital signal to energize the coil of the safety relay (23) only after completing the matching verification between the model of the PCBA (90) under test and the adapter module 1 (30), the position status verification of each cylinder, the action timing verification, and the external safety condition verification. Thus, the hardware-level contact switch (24) and the software-level programmable logic controller (120) verification together constitute a double interlock for powering on the PCBA (90) under test. The two are redundant to each other, further reducing the risk of accidental power-on.

[0033] like Figure 7 As shown, the device also includes a locking cylinder (70) and a pneumatic reversing valve, which is connected to the air path of the main pressing cylinder (60) and the air path of the locking cylinder (70), respectively. In the forward direction, the pneumatic reversing valve only opens the air path of the main pressing cylinder (60) to press down the pressing module (40) after the locking cylinder (70) moves to the locking position; that is, it is not allowed to press down when it is not locked. In the reverse direction, the pneumatic reversing valve only opens the unlocking air path of the locking cylinder (70) after the pressing module (40) moves up to the lifting position; that is, it is not allowed to unlock when it is not lifted. The above-mentioned pneumatic bidirectional interlock is realized by the pneumatic reversing valve through the pneumatic control pipeline, which is redundant with the electrical control of the programmable logic controller (120), thereby improving the safety of the operation process.

[0034] Specifically, in the positive interlock, the air pressure in the rodless chamber of the locking cylinder (70) is used as a control signal to be connected to the control terminal of the main cylinder pneumatic directional valve. The air supply path of the main pressing cylinder (60) is connected to the rodless chamber of the main pressing cylinder (60) after passing through the main cylinder solenoid valve and the main cylinder pneumatic directional valve in sequence. When the locking cylinder (70) has not moved to the locking position, the pressure in the locking air path has not been established. The main cylinder pneumatic directional valve remains closed under the action of the spring, and the air supply path of the main pressing cylinder (60) is cut off. Therefore, even if the main cylinder solenoid valve is accidentally opened due to a malfunction, the pressing module (40) still cannot be pressed down. In the reverse interlock, the air pressure in the rod chamber of the main pressing cylinder (60) is used as a control signal to connect to the control terminal of the locking pneumatic directional valve. The unlocking air path of the locking cylinder (70) passes through the locking solenoid valve and the locking pneumatic directional valve in sequence before connecting to the rod chamber of the locking cylinder (70). When the main pressing cylinder (60) has not retracted to the raised position, the pressure in the rod chamber air path has not yet been established, the locking pneumatic directional valve remains closed, and the unlocking air path of the locking cylinder (70) is cut off. Therefore, even if the locking solenoid valve is accidentally opened due to a malfunction, the locking cylinder (70) still cannot be unlocked. The above interlock logic is realized by the cylinder's own air pressure directly driving the valve core of the pneumatic directional valve to switch directions. It does not rely on electronic devices, so it can still maintain a safe state when the programmable logic controller (120) fails or the whole machine is powered off.

[0035] like Figure 8As shown, the device is configured to perform self-testing on the probes (80). Multiple probes (80) are connected in series according to the test point groups to form the first loop. In one example, 20 probes (80) are divided into 5 test point groups, each test point group contains 4 probes (80); the detection signal of each test point group starts from the adapter board 2 (21), and is transmitted upward to the PCBA (90) under test through the probes (80), adapter board 1 (31), and probes (80) in sequence, and then returns downward to the adapter board 2 (21) through the probes (80), adapter board 1 (31), and probes (80) in sequence, thereby forming a longitudinal contact path. Each longitudinal contact path contains 4 probes (80) and corresponds to 8 contact points; the longitudinal contact paths of the 5 test point groups are connected in series in sequence under the action of the internal wiring of the adapter board 2 (21), forming a total of 40 contact points in the first loop, so that the contact voltage drop of the 40 contact points is added together, and the small contact voltage drop can be amplified by about 40 times without the need for an external amplifier circuit. The body resistance of a single probe (80) is approximately 30 mΩ, and the total body resistance of 20 probes (80) connected in series is approximately 600 mΩ. The device is also equipped with a precision resistor as a reference. The precision resistor has a resistance of 600 mΩ and an accuracy of ±1%. The precision resistor is connected to the square wave excitation signal to form a second circuit. The resistance of the precision resistor is equal to the total body resistance of the 20 probes (80), so that after differential operation, the voltage drop of the first circuit and the second circuit cancels out the influence of the probe (80) body resistance and the common mode error of the two circuits, leaving only the total contact voltage drop of the 40 contact points. A digital output terminal of the programmable logic controller (120) outputs a square wave excitation signal with a frequency of 1 kHz, an amplitude of 5 V, a duty cycle of 50%, and a current of 100 mA. The voltage drop of the first circuit is amplified by 40 times and then connected to one analog-to-digital conversion channel of the programmable logic controller (120). The voltage drop of the second circuit is connected to another analog-to-digital conversion channel of the programmable logic controller (120). The two analog-to-digital conversion channels are sampled synchronously under the condition that the channel deviation is less than 1μs.

[0036] like Figure 9As shown, sampling is started after a 300μs delay following the rising edge of the square wave excitation signal. The sampling window is 100μs, that is, sampling is performed within the high-level stable segment from 300μs to 400μs. 100 sets of data are collected in each cycle, and 10 cycles are collected continuously. The noise is reduced by about 10 times by the moving average filtering process. The programmable logic controller (120) determines the contact status of the probe (80) based on the voltage drop comparison between the first and second circuits: when the single-point contact resistance is 20mΩ to 50mΩ and the corresponding voltage drop is 80mV to 200mV, it is determined to be a good contact; when the single-point contact resistance is 50mΩ to 100mΩ and the corresponding voltage drop is 200mV to 400mV, it is determined to be a spring force decay and an alarm is issued; when the single-point contact resistance is greater than 100mΩ and the corresponding voltage drop is greater than 400mV, it is determined to be a broken wire or a stuck pin and is determined to be unqualified; when the voltage drop fluctuation is greater than 20mV, it is determined to be a loose connection or carbon buildup and an alarm is issued.

[0037] The adapter module 2 (20) is also equipped with optical positioning reference points; in one example, the adapter module 2 (20) integrates 3 optical positioning reference points. In the fully automatic programming and testing process, the PCBA (90) to be tested is automatically discharged by the loading machine and transported to the gripping station by the conveyor belt. The robot reads the optical features of the PCBA (90) to be tested through the vision system to complete the gripping, and then identifies the optical positioning reference points on the adapter module 2 (20) through the vision system to complete the alignment calibration, and then places the PCBA (90) to be tested stably on the adapter module 1 (30); then the device scans the code to identify the model of the PCBA (90) to be tested and automatically matches the corresponding test program, and completes the program programming and electrical testing in one stop at the same station; after the test is completed, the robot grabs the PCBA (90) to be tested again and puts it back on the conveyor belt, which is then transported to the unloading machine to complete the material collection, thereby realizing the unmanned operation of the entire process from loading, alignment, board placement, programming, testing to unloading.

[0038] Furthermore, this application can have various modified embodiments. In one modified embodiment, the manual bolt used for locking the pressing module (40) can be replaced by an added locking structure to further reduce manual operation and improve changeover efficiency. In another modified embodiment, the adapter module 1 (30) is provided with multiple adapter plates 1 (31) to achieve automated programming and testing of the entire machine for models containing multiple boards. In yet another modified embodiment, a robotic arm can correspond to one or multiple automated production lines to improve production efficiency. In yet another modified embodiment, the device can also interface with upstream surface mount production lines and downstream conformal coating production lines to further improve the automation level of the production line.

[0039] 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.

[0040] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A highly versatile, three-layer modular PCBA fully automated programming and testing device, characterized in that, Includes a general-purpose base, adapter module 2, adapter module 1, and a pressure-down module; The adapter module 2 is fixedly installed on a general-purpose base. The adapter module 2 includes an adapter plate 2, which is provided with signal collection points and external terminals. The adapter module 1 is detachably mounted on top of the adapter module 2. The adapter module 1 includes an adapter plate 1, which is provided with contact test points corresponding to the test points of the PCBA under test. The pressing module is located above the adapter module 1 and is connected to the vertical drive mechanism so that it can reciprocate in the vertical direction under the drive of the vertical drive mechanism. Probes are installed between the PCBA under test and adapter board 1, and between adapter board 1 and adapter board 2; During the test, the pressure module was the only component that reciprocated in the vertical direction, while adapter module 1 and adapter module 2 remained stationary.

2. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, Adapter board 1 is equipped with a straight-through conductive structure and internal wiring; The programming signal is transmitted directly to the PCBA under test via the adapter board 2, the probe located between the adapter board 1 and the adapter board 2, the direct conduction structure of the adapter board 1, and the probe located between the PCBA under test and the adapter board 1. The test signal is transmitted to the external terminal of the adapter board 2 via the PCBA under test, the probe located between the PCBA under test and the adapter board 1, the internal wiring of the adapter board 1, the probe located between the adapter board 1 and the adapter board 2, and the signal collection point of the adapter board 2.

3. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, The adapter module 1 is a replacement part corresponding to the model of the PCBA under test. Different models of PCBA under test correspond to different adapter modules 1. The adapter module 1 is equipped with an asymmetric positioning interface, which limits the installation orientation of the adapter module 1.

4. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, The pressing module includes an upper plate, a positioning plate, a drawer-type guide rail, a foolproof limit block, and a positioning post; The positioning plate is assembled onto the upper plate via a drawer-type guide rail, and the foolproof limit block limits the assembly position between the positioning plate and the upper plate. The positioning post is located on the side of the positioning plate away from the upper plate, and it cooperates with the adapter module 1 for positioning when the pressing module moves down to its position.

5. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 4, characterized in that, The adapter module 1 is equipped with a limit sleeve corresponding to the positioning post; The positioning post and the limiting sleeve work together to guide and center the downward movement of the pressing module, and form a hard limit on the downward stroke of the pressing module.

6. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, Adapter board 2 integrates contact switches and safety relays; The normally open contacts of the contact switch and the safety relay are connected in series and connected in series to the power supply circuit of the PCBA under test. The coil of the safety relay is connected to the digital output terminal of the programmable logic controller, and the contact switch closes when the pressing module moves to the lower position. The power supply circuit of the PCBA under test is turned on only when the contact switch is closed and the coil of the safety relay is energized by the programmable logic controller via the digital output terminal.

7. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, It also includes a lock-up cylinder and a pneumatically controlled directional valve; The locking cylinder is used to lock and unlock the pressing module. The pneumatic reversing valve is connected to the air circuit of the vertical drive mechanism and the air circuit of the locking cylinder, respectively. The pneumatic reversing valve is configured to: only after the locking cylinder moves to the locking position, open the air path of the vertical drive mechanism to press down the pressing module; only after the pressing module moves up to the lifting position, open the unlocking air path of the locking cylinder.

8. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, Multiple probes are connected in series to form a first circuit, and the first circuit is connected to a square wave excitation signal; A precision resistor is also provided as a reference, and the precision resistor is connected to the square wave excitation signal to form a second circuit. The programmable logic controller synchronously samples the voltage drop of the first circuit and the second circuit through two analog-to-digital conversion channels, and determines the contact state of the probe based on the comparison results of the voltage drop of the first circuit and the second circuit.

9. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, The contact measurement points of the adapter board 1 are divided into multiple zones, including the PE zone, the high voltage zone and the low voltage zone. The low voltage zone is further divided into the high frequency digital zone, the low voltage analog zone, the medium and low frequency digital zone and the programming zone. The spacing between each zone simultaneously meets both electrical safety clearance and signal integrity clearance requirements. Different zones are equipped with differentiated probes corresponding to their signal types, and each zone is equipped with an independent grounding enclosure.

10. The highly versatile three-layer modular PCBA fully automated programming and testing device according to claim 1, characterized in that, The adapter module 2 is equipped with an optical positioning reference point, which is used for alignment by the vision system of the external automated production line, so that the external automated production line can complete the loading, placement, programming and testing, and unloading of the PCBA under test.

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