Circuit board detection device and detection method

Abstract

The invention belongs to the technical field of circuit board manufacturing and detecting, and particularly relates to a circuit board detecting device and method.The device comprises a workbench, two visual detecting heads arranged on the workbench, a feeding rotary table, a lifting table and a rotary table, the feeding rotary disc is rotationally installed on the upper surface of the workbench, at least six material carrying holes are distributed in the feeding rotary disc in a circumferential array mode, the inner walls of the material carrying holes are in a step shape, material carrying molds are inserted into the steps, and clamping channels are formed in the two sides of each material carrying mold. The upper surface of the workbench is sequentially divided into a lower surface detection area, an upper surface detection area, an X-ray detection area and a live detection area around the feeding turntable; the method comprises steps 1-6. Detection can be carried out in four areas through the same material carrying die, particularly, horizontal clamping and transferring of the circuit board are kept, the deviation correction performance is good in the double-face continuous rapid detection process, and surface electronic elements are not damaged in the whole process.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit board manufacturing detection, and in particular relates to a circuit board detection device and a detection method. Background Art

[0002] With the increase in the number of new energy vehicles, the demand for automotive chips has been rising year by year, ranging from dozens to hundreds, and even thousands. With the development of automotive intelligence, the number of chip types has also increased from 40 to more than 150. These chips are integrated into circuit boards and completed, and need to be tested in time before being put into use.

[0003] During the manufacturing process of automotive circuit boards, various components are integrated onto the substrate and welded. Before power-on testing, appearance testing, dimension measurement, welding quality testing, and short circuit testing are still required. In particular, multiple welding points are required during the manufacturing process, and the solder joints are relatively small, which may lead to defects such as cold soldering and desoldering. The welding of components such as capacitors and CPUs on the front of the automotive circuit board requires visual inspection, and the pins on the back also require visual inspection.

[0004] Existing manufacturers use a pair of rollers to clamp and transport circuit boards, and send them between two CCD industrial cameras, while taking images of the front and back sides for inspection. However, there are protrusions such as lead corners on both sides of the circuit board, which are easily skewed when placed on the pair of rollers. During the double-sided continuous and rapid inspection process, skew, deviation, and misalignment occur. Summary of the invention

[0005] The purpose of the present invention is to provide a circuit board detection device and detection method, which can detect in four areas through the same loading mold, especially keep the circuit board horizontally clamped and transferred, have good correction performance during the double-sided continuous and rapid detection process, and the entire process does not damage the surface electronic components.

[0006] The technical solution adopted by the present invention is as follows: A circuit board detection device and detection method, comprising a workbench and two visual detection heads arranged on the workbench, a loading and unloading manipulator is arranged outside the workbench, and further comprising: The upper surface of the workbench is divided into a lower surface detection area, an upper surface detection area, an X-ray detection area and a charged detection area in sequence around the feeding turntable; A feeding turntable, the feeding turntable is rotatably mounted on the upper surface of the workbench, at least six loading molds are distributed in a circumferential array on the upper surface of the feeding turntable, clamping channels are opened on both sides of the loading molds, memory alloy sheets are installed on both sides of the inner wall of the loading mold, and a silicone layer is fixed on the surface of the memory alloy sheet; A lifting platform, the lifting platform is arranged in the lower surface detection area directly facing the loading mold, and a detection end of the visual detection head passes through the lifting platform from the middle upward; The three turntables are rotatably installed in the upper surface detection area, the X-ray detection area and the live detection area respectively. Two symmetrical electric clamps are arranged above the three turntables. The electric clamps pass through the clamping channels to grab the circuit boards in the loading mold and transport them to the upper surface detection area, the X-ray detection area and the live detection area respectively.

[0007] After the automotive circuit boards are welded, they are stacked one by one on a pallet, picked up by a double-claw gripper driven by a loading and unloading robot, and placed one by one on the loading holes of the feeding turntable in the loading area. They are carried by the loading mold and the feeding turntable rotates intermittently so that all the loading holes are loaded with circuit boards.

[0008] The circuit board first enters the lower surface inspection area, where the lifting platform is raised and drives the bottom flange plate and two columns to rise, driving the bearing block upward through the clamping channel, lifting the circuit board upward and away from the loading mold, exposing the lower surface of the circuit to the outside world, and the circuit on the lower surface is staggered from the bearing block. At this time, two fill lights are turned on to provide a bright environment, and a visual inspection head is started to take a picture of the lower surface of the circuit board, which is transmitted to the industrial computer for comparison of the lower surface solder joints. Then it is lowered and the circuit board is grabbed and put back into the loading mold.

[0009] The circuit board then enters the upper surface inspection area, where the turntable descends, driving an electric gripper to insert into the gripping channel to grip the circuit board, rotate half a circle forward and place it directly under another visual inspection head, take a picture of the upper surface of the circuit board, and transmit it to the industrial computer for upper surface solder joint comparison. Then it reverses half a circle and descends, grabs the circuit board and puts it back into the loading mold.

[0010] The circuit board then enters the X-ray inspection area, where it is grabbed by a turntable and an electric gripper and placed in the X-ray shooting area to obtain an X-ray image of the entire circuit board, which is then transmitted to an industrial computer for internal solder joint comparison. The circuit board is then grabbed and placed back into the loading mold.

[0011] During the unloading stage, the circuit board enters the driven detection area again, and is still grabbed by the turntable and electric gripper, electrically connected to the detection circuit, combined with the DC block of the oscilloscope, through the DC coupling method, the AC and DC components of the measured signal are observed at the same time, and drawn into a line graph on the industrial computer for comparison.

[0012] The circuit boards then enter the unloading area, where they are picked up by a double-claw gripper driven by a loading and unloading robot. After comparison, they are classified into Grade I, Grade II, and Grade III products and placed in different trays.

[0013] The four areas are divided in this way, and various tests are carried out separately during short stops. The circuit board only needs to move up and down along the loading hole of the feeding turntable to complete the upper and lower surface solder joints, internal solder joints and power-on tests. Double-sided continuous testing can be completed through the same loading mold. During double-sided testing, lifting the circuit board along the loading hole can also prevent the circuit board from turning over and bumping into electronic components. Only the loading mold is needed to support the lower surface of the circuit board, which will not damage the electronic components carried, facilitating continuous and rapid testing.

[0014] As a preferred solution, a loading hole for accommodating the loading mold is further provided on the upper surface of the feeding turntable, and limit pins are vertically inserted into the four corners inside the loading mold, and the lower ends of the limit pins extend to the lower surface of the feeding turntable and are bonded with rubber sleeves. Two symmetrical alignment sensors are respectively arranged on both sides of two adjacent limit pins, and the alignment sensors are fixed on the upper surface of the workbench. After the circuit board is placed in the loading mold, the limit pins will be pressed down, and the lower ends of the limit pins will extend to the bottom of the feeding turntable while stretching the rubber sleeve for deformation, which can play a shock-absorbing role for the circuit board and enter the four detection areas until they are detected by both groups of alignment sensors. The industrial computer displays an in-place signal, and starts the upper and lower surface solder joints, internal solder joints and power-on detection. After the detection is completed, the four circuit boards fall back so that all the limit pins are detected by the alignment sensors, and then a reset signal is displayed. At this time, the feeding turntable is controlled to rotate a certain angle to realize the reset detection of the circuit board and elastic buffering and shock absorption.

[0015] As a preferred solution, vertical holes that are connected to the limit pins are opened inside the loading mold, and ball heads are bonded to the upper ends of the limit pins. When the ball heads carry the circuit board, they are immersed in the vertical holes, provide fixed-point support, and provide buffering through deformation. The ball heads reduce the area of ​​friction with the circuit board, avoid the circuit board's lower surface and its solder joints as much as possible, and reduce the mechanical damage to the circuit board when it is passed through the four detection areas.

[0016] As a preferred solution, the four corners of the lifting platform are fixed with bottom flange plates, two columns and two fill lights are fixed at intervals on the lower surface of the lifting platform, and the four bottom flange plates are fixed with bearing blocks on one side close to the middle of the lifting platform. The bearing blocks pass through the clamping channel when the bottom flange plates are lifted, and the lower ends of the two columns are sleeved with arc-shaped alloy plates. The lower surface detection area is also fixed with a vertical movement module, and the output end of the vertical movement module is fixedly connected to one side of the two alloy plates. The columns and the vertical movement module are vertically staggered with the alignment sensor, and the vertical movement module moves the columns and the alloy plates upward to lift the bearing blocks to lift the circuit board upward and suspend it above the feeding turntable. After the detection of the solder joints on the lower surface of the circuit board is completed, the vertical movement module moves the columns and the alloy plates downward to drive the bottom flange plates and the bearing blocks to be lower than the limit pins to prevent them from hitting the limit pins.

[0017] As a preferred solution, a vertical shaft is fixed axially in the middle of the lower surface of the feeding turntable, and a brake motor is fixed on the lower surface of the workbench. The output end of the brake motor passes through the workbench upward and a belt is arranged between the output end and the outer side of the vertical shaft. The brake motor rotates unidirectionally and drives the vertical shaft through the belt with a smaller transmission ratio, so that the feeding turntable rotates at a low speed to avoid excessive rotation and flying off the circuit board.

[0018] As a preferred solution, three feeding motors are fixed to the lower surface of the workbench, and the output ends of the three feeding motors pass through the workbench and are fixedly connected to the lower surface of the turntable. Hydraulic cylinders are vertically fixed to the upper surfaces of the three turntables, and the three hydraulic cylinder rods are fixed with main steel rods. The two ends of the main steel rods are respectively fixedly connected to the roots of two electric clamps. The upper surface detection area is fixed with a detection mold facing the electric clamps. The hydraulic cylinder lifts the main steel rod to raise the electric clamps, or lowers the main steel rod to lower the electric clamps. At the same time, the feeding motor rotates forward half a circle to drive the circuit board away from the feeding turntable, or reverses half a circle to drive the circuit board close to the feeding turntable.

[0019] As a preferred solution, the X-ray detection area is fixed with an X-ray detection table which is staggered with the main steel rod, the upper end of the X-ray detection table is fixed with a transmitter facing the electric clamp, and the lower end of the X-ray detection table is fixed with a detector facing the transmitter. After the circuit board is placed in the X-ray detection area, it falls on the detector, and the transmitter emits X-rays downward, passing through the circuit board. These X-rays are received by the detector, drawn into a perspective image on the X-ray detection table, and transmitted to the industrial computer for comparison with the preset image.

[0020] As a preferred solution, the live detection area is fixed with an insulating mold facing the electric clamp, and an insertion notch is provided at one end of the insulating mold away from the feeding turntable. The insulating mold separates the circuit board from the X-ray detection area.

[0021] As a preferred solution, the charged detection area is provided with a charged probe, an elastic part and a transverse movement module along a straight line, the elastic part is fixed at the output end of the transverse movement module, the root of the charged probe is slidably connected to the output end of the transverse movement module, and the sliding charged probe of the transverse movement module is electrically connected to the circuit board through the plug-in notch.

[0022] A circuit board detection method comprises the following steps: Step 1: Use the loading and unloading manipulator to drive the double-claw gripper to pick up the materials one by one and place them in the loading holes of the feeding turntable in the loading area, and then carry them through the loading mold; Step 2: The feeding turntable rotates intermittently, first feeding the circuit board into the lower surface inspection area, starting a visual inspection head there to take a picture of the lower surface of the circuit board, and then putting it back into the loading mold; Step 3: The feeding turntable rotates intermittently, the circuit board enters the upper surface inspection area, takes a picture of the upper surface of the circuit board, and then puts it back into the loading mold; Step 4: The feeding turntable rotates intermittently, the circuit board enters the X-ray inspection area, takes an X-ray image, and then is put back into the loading mold; Step 5: The feeding turntable rotates intermittently, and the circuit board enters the charged detection area, is electrically connected to the detection circuit, and the AC and DC components of the measured signal are observed. A line graph is drawn on the industrial computer for comparison, and then the circuit board is put back into the loading mold; Step 6: The feeding turntable rotates intermittently, and the circuit board enters the unloading area again. The loading and unloading robot drives the double-claw gripper to grab it. After the circuit board is compared by the industrial computer, it is classified into Grade I, Grade II, and Grade III and placed in different trays.

[0023] The technical effects achieved by the present invention are: The present invention is divided into four areas, and various tests are carried out in the four areas respectively during a short stop. The circuit board only needs to move up and down along the loading hole of the feeding turntable to complete the upper and lower surface solder joints, internal solder joints and power-on tests. Double-sided testing can be completed through the same loading mold. During the double-sided testing, the circuit board does not need to be turned over when it is lifted along the loading hole. Only the loading mold is needed to support the lower surface of the circuit board, so that no damage is caused to the mounted electronic components, which is convenient for continuous and rapid testing.

[0024] The circuit board of the present invention presses down the limit pin and stretches the rubber sleeve to deform, which can play a shock-absorbing role on the circuit board. The circuit board enters the four detection areas and cannot start detection until it is detected by two groups of alignment sensors. The four circuit boards fall back so that all the limit pins are detected by the alignment sensors, and then a reset signal is displayed, thereby realizing the reset detection of the circuit board and elastic buffering and shock absorption at the same time, so that the transmission accuracy of the circuit board between the four detection areas is higher, and the limit pin lifts the circuit board to align it horizontally on both sides at the memory alloy sheet, and an alarm is triggered in time if the material is stuck or skewed, thereby reducing the bad sheet rate during detection.

[0025] The vertical movement module of the present invention lifts or lowers the circuit board, so as to expose the solder joints on the lower surface of the circuit board for detection. At the same time, the bottom flange plate and the bearing block are driven below the limit pins to perform evasive actions during the detection process to prevent collision with the limit pins, thereby ensuring that the various actions carried out inside the detection device are highly safe, and the lifting and lowering of the circuit board and the in-place detection do not interfere with each other.

[0026] The present invention goes through steps one to six. During the whole process, the detection device is enclosed in a metal cabinet, the electric door is opened, and an external loading and unloading robot is used to pick up and place the circuit board. The time taken for picking up and placing is short, and the detection efficiency is not significantly reduced. After the electric door is closed, the detection in the four areas is carried out, and the upper and lower surface solder joints, internal solder joints and power-on detection are isolated from the external environment. On the one hand, it can reduce the interference of the external environment on the circuit board, and on the other hand, it can block the internal current and X-rays, thereby improving the safety of the detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a perspective view of a circuit board detection device in embodiment 1 of the present invention; Figure 2 It is a three-dimensional internal structure diagram of a circuit board detection device in Embodiment 1 of the present invention; Figure 3 It is a front view of the feeding turntable in the first embodiment of the present invention; Figure 4 is a bottom view of the feeding turntable in the first embodiment of the present invention; Figure 5 is a front view of the vertical movement module in the first embodiment of the present invention; Figure 6 In the first embodiment of the present invention Figure 5 A magnified view of point A; Figure 7 is a front view of the turntable in the first embodiment of the present invention; Figure 8 is a front view of the loading mold in the first embodiment of the present invention; Fig. 9 is a front view of the limit pin in the first embodiment of the present invention; Fig.10 is a front view of two alignment sensors in the first embodiment of the present invention; Fig.11 is a front view of the lateral movement module toward the insulating mold in the first embodiment of the present invention; Fig.12 It is a flow chart of a circuit board detection method in Embodiment 2 of the present invention.

[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Workbench; 2. Loading and unloading manipulator; 3. Visual inspection head; 4. Feeding turntable; 401. Loading hole; 402. Loading mold; 4021. Memory alloy sheet; 4022. Silicone layer; 403. Clamping channel; 404. Limiting needle; 405. Rubber sleeve; 406. Alignment sensor; 407. Vertical hole; 408. Ball head; 5. Lifting platform; 501. Bottom flange plate; 502. Column; 503. Bearing block; 504. Fill light; 505, vertical movement module; 506, alloy plate; 6, turntable; 601, main steel rod; 602, electric gripper; 603, X-ray inspection table; 604, detector; 605, transmitter; 7, vertical axis; 8, brake motor; 9, belt; 10, feeding motor; 11, hydraulic cylinder; 12, inspection mold; 13, insulating mold; 14, plug-in notch; 15, charged probe; 16, elastic part; 17, horizontal movement module. DETAILED DESCRIPTION

[0029] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0030] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

[0031] According to Embodiment 1 and Embodiment 2 of the present invention, a circuit board detection device and a detection method are provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system containing at least one set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0032] Embodiment 2 associated therewith may also be executed in an electronic device including a memory and a processor, a similar control device or a cloud. Taking an electronic device as an example, the electronic device may include one or more processors and a memory for storing data. Optionally, the electronic device may also include a communication device and a display device for communication functions. A person of ordinary skill in the art may understand and know that the above structural description is only illustrative and does not limit the structure of the above electronic device. For example, the X-ray detection station 603 may also include more or fewer components than the above structural description, or have a configuration different from the above structural description.

[0033] In this specific solution, an industrial computer is generally used for control, and the processor CPU that can be installed can include one or more processing units. For example, the processor can include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microprocessor (MCU), a programmable logic device (field-programmable gate array, FPGA), a neural network processor (neural-network processing unit, NPU), a tensor processor (tensor processing unit, TPU), an artificial intelligence (artificial intelligence, AI) type processor, and other processing devices.

[0034] At the same time, the storage module can be used to store computer programs, such as storing the computer program corresponding to the control system in the embodiment of the present invention, and the processor implements the above-mentioned detection method and the application results of the circuit board detection method by running the computer program stored in the memory. The memory may include a high-speed random access memory and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory.

[0035] The photos taken during the whole process, comparison parameters, comparison results, test data, etc. are constructed into a dynamic model according to the test function partition, and the floating data is displayed in real time to mark the bad points and fault causes for each circuit board. The circuit boards can be graded according to the number and location of the bad points. For example: no bad circuit boards are grade I products, single-sided bad circuit boards are grade II products, and double-sided bad circuit boards are grade III products. Among them, grade II products have a certain repair value, and grade III products have a low repair value.

[0036] Especially as my country vigorously develops new energy vehicles, and users have higher requirements for vehicle intelligence, such as sentry mode, automatic retractable rearview mirror, electric heated car glass defogger, etc., the use of automotive circuit boards can reach tens of thousands, and various software are configured to improve user experience. The quality of automotive circuit boards manufactured indirectly determines the continuity and reliability of these vehicles to maintain intelligent performance. Therefore, before the automotive circuit boards leave the factory, we should do our best to inspect them, and conduct continuous and rapid inspections during the two-sided inspection process.

[0037] Embodiment 1: like Figure 1-Figure 11 As shown, a circuit board inspection device includes a workbench 1 and two visual inspection heads 3 arranged on the workbench 1. Both visual inspection heads 3 use STC-A33A CCD industrial cameras. A loading and unloading manipulator 2 is arranged outside the workbench 1. The loading and unloading manipulator 2 is controlled by a preset program. A double-claw gripper is rotatably installed at the output end of the loading and unloading manipulator 2 for picking up and placing circuit boards. The device also includes: A feeding turntable 4 is rotatably mounted on the upper surface of the workbench 1. At least six loading holes 401 are distributed in a circular array on the feeding turntable 4. The inner walls of the loading holes 401 are step-shaped and loading molds 402 are inserted at the steps. Clamping channels 403 are opened on both sides of the loading mold 402. Memory alloy sheets 4021 are installed on both sides of the inner wall of the loading mold 402. Silicone layers 4022 are fixed on the surfaces of the memory alloy sheets 4021. The silicone layers 4022 are used to reduce the friction between the memory alloy sheets 4021 and the circuit board, so that the circuit board can enter and exit the memory alloy sheets 4021 more smoothly. The upper surface of the workbench 1 is equally divided into six areas around the feeding turntable 4. The six areas are divided into a loading area, a lower surface (i.e., the back of the circuit board) detection area, an upper surface (i.e., the front of the circuit board) detection area, an X-ray detection area, a charged detection area, and a unloading area.

[0038] Furthermore, the number of the loading holes 401 is set to six, so as to maintain the structural strength of the feeding turntable 4 and feed six circuit boards at the same time.

[0039] Furthermore, the number of the loading holes 401 is set to eight, which reduces the structural strength to a certain extent and enables online transportation of more than six circuit boards.

[0040] The lifting platform 5 is arranged in the lower surface detection area facing the loading hole 401, and the four corners of the lifting platform 5 are fixed with bottom flange plates 501. Two columns 502 and two fill lights 504 are fixed at intervals on the lower surface of the lifting platform 5. A supporting block 503 is fixed on one side of the four bottom flange plates 501 close to the middle of the lifting platform 5. The supporting block 503 passes through the clamping channel 403 when the bottom flange plate 501 is lifted, and a visual inspection head 3 detection end passes through the lifting platform 5 from the middle of the two fill lights 504 upward.

[0041] The turntable 6, three turntables 6 are rotatably installed in the upper surface detection area, the X-ray detection area and the live detection area respectively. A main steel rod 601 is horizontally arranged above the three turntables 6. Electric clamps 602 are fixed downward at both ends of the main steel rod 601. The electric clamps 602 pass through the clamping channel 403 to grab the circuit board in the loading mold 402, and transport them to the upper surface detection area, the X-ray detection area and the live detection area respectively.

[0042] Through the above structure, the inspection of the circuit board is divided into the following stages: In the loading stage, after the automotive circuit boards are welded, they are stacked one by one on a pallet, picked up by a double-claw gripper driven by the loading and unloading robot 2, and placed one by one on the loading holes 401 of the feeding turntable 4 located in the loading area. They are carried by the loading mold 402, and the feeding turntable 4 rotates intermittently so that the loading holes 401 are all loaded with circuit boards.

[0043] Among them, the shape of the memory alloy sheet 4021 and the silicone layer 4022 can be set to an inverted "M" shape, and the circuit board can be clamped from both sides by using the middle recess. In particular, the curved shape of the memory alloy sheet 4021 and the silicone layer 4022 can be slightly deformed under pressure, and can adapt well to circuit boards of different sizes.

[0044] The circuit board first enters the lower surface inspection area, where it is raised by the lifting platform 5 and drives the bottom flange plate 501 and two columns 502 to rise, driving the bearing block 503 to pass through the clamping channel 403 upward, lifting the circuit board upward and away from the loading mold 402, exposing the lower surface of the circuit to the outside world, and the circuit on the lower surface is offset from the bearing block 503. At this time, two fill lights 504 are turned on to provide a bright environment, and a visual inspection head 3 is started to take a picture of the lower surface of the circuit board, which is transmitted to the industrial computer for comparison of the lower surface solder joints. Then it is lowered and the circuit board is grabbed and put back into the loading mold 402.

[0045] The circuit board then enters the upper surface inspection area, where the turntable 6 descends, driving an electric gripper 602 to insert into the gripping channel 403 to grip the circuit board, rotate half a circle forward and place it directly under another visual inspection head 3, take a picture of the upper surface of the circuit board, and transmit it to the industrial computer for upper surface solder joint comparison. Then it reverses half a circle and descends, grabs the circuit board and puts it back into the loading mold 402.

[0046] The circuit board enters the X-ray inspection area again, and is still grabbed by the turntable 6 in cooperation with the electric gripper 602 and placed in the X-ray shooting area to obtain the X-ray image of the entire circuit board, which is transmitted to the industrial computer for internal solder joint comparison, and then the circuit board is grabbed and placed back into the loading mold 402.

[0047] During the unloading stage, the circuit board enters the live detection area again, and is still grabbed by the turntable 6 in cooperation with the electric gripper 602, and electrically connected to the detection circuit. Combined with the DC block of the oscilloscope, the AC and DC components of the measured signal are observed simultaneously through DC coupling, and drawn into a line graph on the industrial computer for comparison.

[0048] The circuit board then enters the unloading area and is picked up by a double-claw gripper driven by the unloading and loading robot 2. After being compared by an industrial computer, the circuit board is classified into Grade I, Grade II, and Grade III and placed in different trays.

[0049] The four areas are divided in this way, and various tests are carried out separately during short stops. The circuit board only needs to move up and down along the loading hole 401 of the feeding turntable 4 to complete the upper and lower surface solder joints, internal solder joints and power-on tests. The double-sided continuous test can be completed through the same loading mold 402, especially the horizontal clamping and transfer of the circuit board is maintained. The deviation correction performance is good during the double-sided continuous and rapid test. The circuit board is lifted and lowered along the loading hole 401 to prevent the circuit board from turning over and colliding with electronic components. Only the loading mold 402 is needed to support the lower surface of the circuit board, and no damage is caused to the electronic components carried.

[0050] Among them, the detection in the four areas can be carried out simultaneously or separately without interfering with each other and with good independence.

[0051] The shape of the memory alloy sheet 4021 and the silicone layer 4022 can also be set to a "U" shape, using the opening to clamp the circuit board from both sides, and cooperate with the loading mold 402 to straighten the circuit board to a horizontal state to prevent the circuit board from tilting.

[0052] See attached Figure 2 , Fig. 9 and Fig.10, the four corners inside the loading mold 402 are vertically inserted with limit pins 404, the lower ends of the limit pins 404 extend to the lower surface of the feeding turntable 4 and are bonded with rubber sleeves 405, the rubber sleeves 405 can be made of silicone material with good insulation, two adjacent limit pins 404 are respectively provided with two symmetrical alignment sensors 406, the alignment sensors 406 are controlled by single-chip microcomputers as lower computers, and these single-chip microcomputers are connected to industrial computers by signal, and the alignment sensors 406 are fixed on the upper surface of the workbench 1. After the circuit board is placed in the loading mold 402, it is clamped by the memory alloy sheet 4021, and the limit pins 404 are pressed down. The lower ends of the limit pins 404 extend to the bottom of the feeding turntable 4 and the rubber sleeves are stretched at the same time. 405 is deformed to reduce shock to the circuit board, and the four limit pins 404 lift the circuit board to close to the upper wall of the memory alloy sheet 4021 to achieve bilateral horizontal alignment and enter the four detection areas until they are detected by the two sets of alignment sensors 406. The industrial computer displays an in-place signal and starts the upper and lower surface solder joints, internal solder joints and power-on detection. After the detection is completed, the four circuit boards fall back so that all the limit pins 404 are detected by the alignment sensors 406, and then a reset signal is displayed. At this time, the feeding turntable 4 is controlled to rotate a certain angle to realize the reset detection of the circuit board and elastic buffering and shock reduction at the same time, so that the transmission accuracy of the circuit board between the four detection areas is higher, and timely alarms are given for stuck materials or skewness, thereby reducing the bad chip rate during detection.

[0053] Refer to the attached Figure 2 , Figure 8 and Fig. 9 The loading mold 402 is provided with a vertical hole 407 which is sleeved with the limit pin 404. The upper end of the limit pin 404 is bonded with a ball head 408. The ball head 408 can be made of silicone material. When the ball head 408 carries the circuit board, it is immersed in the vertical hole 407 to provide fixed-point support and buffer through deformation. The ball head 408 reduces the area of ​​friction with the circuit board and avoids the circuit board's lower surface and its solder joints as much as possible, minimizing the mechanical damage to the circuit board when it is transferred in the four detection areas.

[0054] Refer to the attached Figure 2 , Figure 5 and Figure 6, the lower ends of the two columns 502 are both sleeved with an arc-shaped alloy plate 506, and the lower surface detection area is also fixed with a vertical movement module 505 by bolts. The vertical movement module 505 is controlled by a single-chip microcomputer as a lower computer, and these single-chip microcomputers are connected to the industrial computer by signal. The signal transmission between the single-chip microcomputer and the vertical movement module 505 is carried out through a relay, and the output end of the vertical movement module 505 is fixedly connected to one side of the two alloy plates 506 by screws. The columns 502 and the vertical movement module 505 are vertically staggered from the alignment sensor 406, and the vertical movement module 505 moves the columns 502 and the alloy plate 506 upward, which can lift the bearing block 503 to lift the circuit board upward and suspend it above the feeding turntable 4. After the detection of the solder joints on the lower surface of the circuit board is completed, the vertical movement module 505 moves the columns 502 and the alloy plate 506 downward, driving the bottom flange plate 501 and the bearing block 503 below the limit pin 404 to prevent the limit pin 404 from being hit.

[0055] See attached Figure 1 , Figure 3 and Figure 4 A vertical shaft 7 is axially fixed in the middle of the lower surface of the feeding turntable 4, and a brake motor 8 is fixed on the lower surface of the workbench 1. The brake motor 8 can select a YEJ three-phase asynchronous motor. The brake motor 8 is controlled by a single-chip microcomputer as a lower computer. The single-chip microcomputer is connected to the industrial computer by signal. The signal is transmitted between the single-chip microcomputer and the brake motor 8 through a relay. The output end of the brake motor 8 runs upward through the workbench 1 and a belt 9 is arranged between the output end and the outer side of the vertical shaft 7. The brake motor 8 rotates in one direction and drives the vertical shaft 7 through the belt 9 with a smaller transmission ratio, so that the feeding turntable 4 rotates at a low speed to avoid excessive rotation and throwing off the circuit board.

[0056] See attached Figure 2 , Figure 7 and Fig.10 Three feeding motors 10 are also fixed on the lower surface of the workbench 1. The feeding motor 10 can also be a YEJ three-phase asynchronous motor. The output ends of the three feeding motors 10 run through the workbench 1 and are fixedly connected to the lower surface of the turntable 6. Hydraulic cylinders 11 are vertically fixed on the upper surfaces of the three turntables 6. The feeding motors 10 and the hydraulic cylinders 11 are controlled by a single-chip microcomputer as a lower computer. The single-chip microcomputer is connected to the industrial computer by signal. The single-chip microcomputer transmits signals to the feeding motors 10 and the hydraulic cylinders 11 through relays. The cylinder rods of the three hydraulic cylinders 11 are fixedly connected to the middle of the main steel rod 601. A detection mold 12 facing the electric clamp 602 is fixed in the upper surface detection area. The hydraulic cylinder 11 lifts the main steel rod 601 to raise the electric clamp 602, or lowers the main steel rod 601 to lower the electric clamp 602. At the same time, the feeding motor 10 rotates half a circle forward to drive the circuit board away from the feeding turntable 4, or reverses half a circle to drive the circuit board close to the feeding turntable 4.

[0057] See attached Figure 1 , Figure 2 and Fig.10 An X-ray inspection table 603 offset from the main steel rod 601 is fixed in the X-ray inspection area. An emitter 605 facing the electric clamp 602 is fixed on the upper end of the X-ray inspection table 603. A detector 604 facing the emitter 605 is fixed on the lower end of the X-ray inspection table 603. After the circuit board is placed in the X-ray inspection area, it falls on the detector 604. The emitter 605 emits X-rays downward, passing through the circuit board. The X-rays are received by the detector 604 and drawn into a perspective image on the X-ray inspection table 603 and transmitted to the industrial computer for comparison with the preset image.

[0058] See attached Figure 1 , Figure 2 and Fig.11 An insulating mold 13 facing the electric clamp 602 is fixed in the live detection area. A plug-in notch 14 is provided at one end of the insulating mold 13 away from the feeding turntable 4. The insulating mold 13 separates the circuit board from the X-ray detection area. After the circuit board is placed in the live detection area, it falls into the insulating mold 13. The power pin of the circuit board is exposed in the plug-in notch 14. The detection circuit is connected from the plug-in notch 14. Combined with the DC block of the oscilloscope, the AC and DC components of the measured signal are observed simultaneously through DC coupling, and a line graph is drawn on the industrial computer for comparison.

[0059] See attached Figure 1 , Figure 2 and Fig.11 A charged probe 15, an elastic member 16 and a transverse movement module 17 are arranged along a straight line in the charged detection area. The charged probe 15 and the transverse movement module 17 are controlled by a single-chip microcomputer as a lower computer. The single-chip microcomputer is connected to the industrial computer by signal. The single-chip microcomputer transmits signals to the transverse movement module 17 through a relay. The elastic member 16 is fixed at the output end of the transverse movement module 17. The root of the charged probe 15 is slidably connected to the output end of the transverse movement module 17. The transverse movement module 17 slides the charged probe 15 through the plug-in notch 14 to be electrically connected to the circuit board.

[0060] Furthermore, the charged probe 15 is electrically connected to an oscilloscope and an industrial computer in sequence. After contacting the circuit board, it can perform charged online detection to observe the AC and DC components of the measured signal, and draw a line graph on the industrial computer for comparison.

[0061] The different graphic comparisons in the above process can be performed synchronously in partitions on industrial computers. LabVIEW software can be used to directly connect to the CCD camera to obtain image data and perform image processing and analysis, such as image preprocessing, feature extraction, defect detection, etc., as well as HALCON software. HALCON software supports the rapid development of machine vision solutions for quality inspection, area measurement, object recognition and other fields through a large number of built-in visual operators. For images of captured circuit boards, local features can be refined to save analysis time.

[0062] Embodiment 2: In order to ensure smooth transmission of circuit boards and minimize the jams between inspection areas, we have improved the inspection steps before the circuit boards leave the factory, so that both sides of the circuit boards can be inspected continuously and quickly without changing lines.

[0063] like Fig.12 As shown, a circuit board detection method includes the following steps: Step 1: Use the loading and unloading robot 2 to drive the double-claw gripper to pick up and place them one by one on the loading holes 401 of the feeding turntable 4 located in the loading area, and carry them through the loading mold 402; Step 2: The feeding turntable 4 rotates intermittently, first feeding the circuit board into the lower surface detection area, and the lifting platform 5 is raised and drives the bottom flange plate 501 and the two columns 502 to rise, driving the bearing block 503 to pass through the clamping channel 403 upward, and lift the circuit board upward to separate from the loading mold 402, so that the lower surface of the circuit is exposed to the outside world, and the circuit on the lower surface is staggered from the bearing block 503; At this time, two fill lights 504 are turned on to provide a bright environment, and a visual inspection head 3 is started to take a picture of the lower surface of the circuit board, which is transmitted to the industrial computer for comparison of the lower surface solder joints, and then the circuit board is lowered and grabbed and put back into the loading mold 402; Step 3: The feeding turntable 4 rotates intermittently, and the circuit board enters the upper surface inspection area. The turntable 6 in this area descends, driving an electric clamp 602 to insert into the clamping channel 403 to clamp the circuit board. The turntable 6 rotates half a circle forward and is placed directly under another visual inspection head 3. The upper surface image of the circuit board is taken and transmitted to the industrial computer for upper surface solder joint comparison. The turntable 6 is then reversed half a circle and descended to grab the circuit board and put it back into the loading mold 402. Step 4: The feeding turntable 4 rotates intermittently, and the circuit board enters the X-ray inspection area. The turntable 6 cooperates with the electric gripper 602 to clamp the circuit board and put it on the detector 604. The emitter 605 emits X-rays downward, passing through the circuit board. The detector 604 receives these X-rays and draws them into a perspective image on the X-ray inspection table 603. The image is transmitted to the industrial computer and compared with the preset image. The turntable 6 is then reversed half a circle and lowered to grab the circuit board and put it back into the loading mold 402. Step 5: The feeding turntable 4 rotates intermittently, and the circuit board enters the charged detection area. The turntable 6 cooperates with the electric gripper 602 to grab the circuit board and put it on the insulating mold 13. Then the lateral movement module 17 is started to slide the charged probe 15 through the plug-in notch 14 to be electrically connected to the circuit board. The circuit is electrically connected to the detection circuit. Combined with the DC block of the oscilloscope, the AC and DC components of the measured signal are observed simultaneously through the DC coupling method, and a line graph is drawn on the industrial computer for comparison; Then, the turntable 6 is reversed half a turn and lowered to grab the circuit board and put it back into the loading mold 402; Step 6: The feeding turntable 4 rotates intermittently, and the circuit board enters the unloading area again. The unloading and loading robot 2 drives the double-claw gripper to grab it. After the circuit board is compared by the industrial computer, it is classified into grade I, grade II, and grade III and placed in different trays.

[0064] During the whole process, the detection device is enclosed in a metal cabinet, the electric door is opened, and the external loading and unloading robot 2 is used to pick up and place the circuit board. The picking and placing time is short, and the detection efficiency is not significantly reduced. After the electric door is closed, the detection in the four areas is carried out, and the upper and lower surface solder joints, internal solder joints and power-on detection are isolated from the external environment. On the one hand, it can reduce the interference of the external environment on the circuit board, and on the other hand, it can block the internal current and X-rays, thereby improving the safety of the detection process.

[0065] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A circuit board inspection device, comprising a workbench (1) and two visual inspection heads (3) arranged on the workbench (1), wherein a loading and unloading manipulator (2) is arranged outside the workbench (1), characterized in that: Also includes: The upper surface of the workbench (1) is divided into a lower surface detection area, an upper surface detection area, an X-ray detection area and a charged detection area in sequence around the feeding turntable (4); A feeding turntable (4), the feeding turntable (4) being rotatably mounted on the upper surface of the workbench (1), at least six loading molds (402) being arranged in a circular array on the upper surface of the feeding turntable (4), clamping channels (403) being provided on both sides of the loading mold (402), memory alloy sheets (4021) being installed on both sides of the inner wall of the loading mold (402), and silicone layers (4022) being fixed on the surfaces of the memory alloy sheets (4021); A lifting platform (5), the lifting platform (5) being arranged in the lower surface detection area directly facing the loading mold (402), and a detection end of the visual detection head (3) passing through the lifting platform (5) from the middle upward; A turntable (6), wherein the three turntables (6) are rotatably mounted on the upper surface detection area, the X-ray detection area and the live detection area, respectively; two symmetrical electric clamps (602) are arranged above the three turntables (6); the electric clamps (602) pass through the clamping channel (403) to grab the circuit board in the loading mold (402), and transport them to the upper surface detection area, the X-ray detection area and the live detection area, respectively; During inspection, the feeding turntable (4) drives the circuit board through the loading mold (402), passing through the lower surface inspection area, the upper surface inspection area, the X-ray inspection area and the live inspection area in sequence, and horizontal transfer and clamping are maintained throughout the entire process, and the circuit board is prevented from turning over and bumping against electronic components.

2. A circuit board detection device according to claim 1, characterized in that: The upper surface of the feeding turntable (4) is also provided with a loading hole (401) for accommodating a loading mold (402); four corners inside the loading mold (402) are vertically inserted with limit pins (404); the lower ends of the limit pins (404) extend to the lower surface of the feeding turntable (4) and are bonded with rubber sleeves (405); two symmetrical alignment sensors (406) are respectively arranged on both sides of two adjacent limit pins (404); the alignment sensors (406) are fixed on the upper surface of the workbench (1).

3. A circuit board detection device according to claim 2, characterized in that: The loading mold (402) is provided with a vertical hole (407) sleeved with the limiting pin (404), and the upper end of the limiting pin (404) is bonded with a ball head (408). When the ball head (408) carries the circuit board, it sinks into the vertical hole (407) and performs buffering through deformation.

4. A circuit board detection device according to claim 2, characterized in that: The four corners of the lifting platform (5) are fixed with bottom flange plates (501), and two columns (502) and two fill lights (504) are fixed at intervals on the lower surface of the lifting platform (5). The four bottom flange plates (501) are fixed with a bearing block (503) on one side close to the middle of the lifting platform (5). When the bottom flange plate (501) is lifted, the bearing block (503) passes through the clamping channel (403). The lower ends of the two columns (502) are sleeved with an arc-shaped alloy plate (506). The lower surface detection area is also fixed with a vertical movement module (505), and the output end of the vertical movement module (505) is fixedly connected to one side of the two alloy plates (506). The columns (502) and the vertical movement module (505) are vertically offset from the alignment sensor (406).

5. A circuit board detection device according to claim 1, characterized in that: A vertical shaft (7) is fixed axially in the middle of the lower surface of the feeding turntable (4), and a brake motor (8) is fixed on the lower surface of the workbench (1). The output end of the brake motor (8) passes through the workbench (1) upward, and a belt (9) is arranged between the output end and the outer side of the vertical shaft (7).

6. A circuit board detection device according to claim 1, characterized in that: Three feeding motors (10) are also fixed on the lower surface of the workbench (1). The output ends of the three feeding motors (10) pass through the workbench (1) and are fixedly connected to the lower surface of the turntable (6). The upper surfaces of the three turntables (6) are vertically fixed with hydraulic cylinders (11). The cylinder rods of the three hydraulic cylinders (11) are fixed with main steel rods (601). The two ends of the main steel rods (601) are respectively fixedly connected to the roots of two electric clamps (602). The upper surface detection area is fixed with a detection mold (12) that is opposite to the electric clamps (602).

7. A circuit board detection device according to claim 6, characterized in that: The X-ray detection area is fixed with an X-ray detection table (603) staggered from the main steel rod (601), the upper end of the X-ray detection table (603) is fixed with an emitter (605) facing the electric clamp (602), and the lower end of the X-ray detection table (603) is fixed with a detector (604) facing the emitter (605).

8. A circuit board detection device according to claim 1, characterized in that: An insulating mold (13) facing the electric clamp (602) is fixed to the live detection area, and an insertion notch (14) is provided at one end of the insulating mold (13) away from the feeding turntable (4). The insulating mold (13) separates the circuit board from the X-ray detection area.

9. A circuit board detection device according to claim 8, characterized in that: The charged detection area is provided with a charged probe (15), an elastic member (16) and a transverse movement module (17) along a straight line; the elastic member (16) is fixed to an output end of the transverse movement module (17); the root of the charged probe (15) is slidably connected to the output end of the transverse movement module (17); the sliding charged probe (15) of the transverse movement module (17) passes through the plug-in notch (14) to be electrically connected to the circuit board.

10. A circuit board detection method, characterized in that: A circuit board detection device applied to any one of claims 1-9, comprising the following steps: Step 1: Use the loading and unloading manipulator (2) to drive the double-claw gripper to pick up the materials one by one and place them in the loading holes (401) located in the loading area of ​​the feeding turntable (4) and carry them through the loading mold (402); Step 2: The feeding turntable (4) rotates intermittently, first feeding the circuit board into the lower surface inspection area, starting a visual inspection head (3) there to take a picture of the lower surface of the circuit board, and then putting it back into the loading mold (402); Step 3: The feeding turntable (4) rotates intermittently, the circuit board enters the upper surface inspection area, a picture of the upper surface of the circuit board is taken, and then the circuit board is put back into the loading mold (402); Step 4: The feeding turntable (4) rotates intermittently, and the circuit board enters the X-ray detection area, takes an X-ray image, and then is put back into the loading mold (402); Step 5: The feeding turntable (4) rotates intermittently, and the circuit board enters the charged detection area, is electrically connected to the detection circuit, and the AC and DC components of the measured signal are observed. A line graph is drawn on an industrial computer for comparison, and then the circuit board is put back into the loading mold (402); Step 6: The feeding turntable (4) rotates intermittently, and the circuit board enters the unloading area again. The unloading and loading robot (2) drives the double-claw gripper to pick up the circuit board. After the industrial computer compares the circuit board, it is classified into Grade I, Grade II, and Grade III and placed in different trays.

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