Fool-proof device based on TFT testing machine

Abstract

The invention relates to the technical field of FPC (Flexible Printed Circuit) flexible flat cable test equipment, in particular to a fool-proof device based on a TFT (Thin Film Transistor) test machine, which is applied to an LCM (Liquid Crystal Module) test box matched with the TFT test machine. The fool-proof device comprises a butt joint platform, a test box upper cover, a stop block main body, a protruding part and a guide inclined surface arranged on the protruding part, an insertion gap for inserting the FPC flexible flat cable reinforcement plate is formed between the stop block main body and the butt joint platform, and the width of the insertion gap is designed according to the thickness range of the reinforcement plate, so that the reinforcement plate is basically free from shaking in the gap after being inserted; a vertical pressing surface is formed on one side of the protruding part close to the insertion gap; the guide inclined surface is obliquely arranged along the downward pressing direction of the test box upper cover, an included angle between the guide inclined surface and the downward pressing direction of the test box upper cover is 30 degrees, and the feeding end and the tail end of the guide inclined surface are in smooth transition with the butt joint platform and the vertical pressing surface through a first arc transition part and a second arc connection part respectively; when the reinforcing plate is in a short insertion state that the reinforcing plate is not completely inserted into the insertion gap, the reinforcing plate automatically slides into the insertion gap and finally abuts against the vertical pressing face under the guiding effect of the guiding inclined face by means of the flexible bending characteristic of the FPC flexible flat cable in the downward pressing process of the test box upper cover, and automatic correction of short insertion and accurate butt joint with the test interface are achieved. The FPC test station is simple in structure, can improve the butt-joint error-tolerant rate and the test efficiency, reduces the risks of product scrapping and equipment damage caused by misoperation, and is suitable for FPC test stations of various consumer electronics, vehicle-mounted and industrial display modules.

Description

The present application relates to the technical field of FPC flexible cable testing equipment, in particular to a foolproof device based on a TFT testing machine. In the existing LCM production testing process, the FPC flexible cable of the LCM is made of a flexible substrate, and deformation such as warping, twisting and edge folding may occur during production and handling, which makes it difficult to accurately position the reinforcing plate of the FPC flexible cable when it is docked with the interface of the LCM test box.

[0001] In the prior art, a common solution is to fixedly install a stop block at the docking station of the LCM test box. The stop block is usually a rigid right-angle structure with a rectangular side view, and the protruding part of the stop block protrudes several millimeters from the surface of the docking platform of the test box, and a gap is formed between the inner side of the protruding part and the platform of the test box, and the width of the gap matches the thickness of the reinforcing plate of the LCM FPC flexible cable.

[0002] When in use, the operator needs to manually insert the reinforcing plate of the FPC flexible cable into the gap below the stop block, and then press down the upper cover of the test box after the insertion is completed, and the protruding part of the stop block exerts pressure on the reinforcing plate to complete the docking of the FPC flexible cable with the interface of the test box, and start the test procedures such as continuity and signal transmission.

[0003] However, the rigid right-angle stop block has the following defects: First, the docking fault tolerance is low. The stop block is a rigid right-angle structure and has no guiding slope, so if the operator does not completely insert the reinforcing plate into the gap below the stop block or the insertion angle is deviated, the stop block will rigidly extrude the edge of the reinforcing plate when directly pressing down the upper cover, which may easily cause deformation of the reinforcing plate and breakage of the FPC circuit, resulting in not only scrapping of the LCM product but also damage to the docking interface of the test box.

[0004] Second, the test efficiency is low. The step of "aligning the gap and manually inserting the reinforcing plate completely" needs to be performed additionally each time, and the single-step operation takes a long time, which significantly consumes additional working hours and affects the production line rhythm in the mass production scenario.

[0005] Third, the labor cost is high and the training period is long. In order to reduce the risk of misoperation, the operator needs to be trained for a long time, and the long-time repeated insertion action may easily lead to fatigue, which in turn increases the probability of misoperation and causes the situation of "high training cost and still misoperation".

[0006] Therefore, the existing stop block structure lacks effective automatic guiding and foolproof mechanism, and it is difficult to balance the test efficiency, docking accuracy and reliability of the FPC flexible cable and the test equipment. In order to overcome the above problems, the present application provides a foolproof device based on a TFT testing machine, which can effectively solve the above problems.​​​

[0007] The application solves the above technical problems and provides a technical solution: providing a foolproof device based on a TFT test machine, applied to an LCM test box matched with the TFT test machine, comprising: A docking platform for placing a LCM module to be tested and its FPC flexible flat cable; A test box upper cover reciprocally lowerable and liftable relative to the docking platform; A stop block main body fixedly installed on the docking platform, an insertion gap being formed between the stop block main body and the docking platform, the insertion gap being used for inserting a reinforcing plate of the FPC flexible flat cable and having a width designed according to the thickness of the reinforcing plate of 0.15 mm to 0.40 mm, so that the reinforcing plate is basically not shaken in the insertion gap after being inserted; A protruding part provided on a side of the stop block main body away from the insertion gap and protruding away from the docking platform, a vertical pressing surface for pressing the reinforcing plate being formed on a side of the protruding part close to the insertion gap; A guide inclined surface provided on a side of the protruding part facing the placing direction of the FPC flexible flat cable, the guide inclined surface being arranged obliquely along the lower pressing direction of the test box upper cover, so that the included angle between the guide inclined surface and the lower pressing direction of the test box upper cover is 29°-31°; preferably 30°.

[0008] The guide inclined surface and the surface of the docking platform are both provided with a first circular arc transition part, the circular arc radius of the first circular arc transition part being 0.4 mm to 0.8 mm; the junction of the end of the guide inclined surface and the vertical surface of the stop block main body is provided with a second circular arc junction part, the circular arc radius of the second circular arc junction part being 0.2 mm to 0.4 mm; and when the reinforcing plate of the FPC flexible flat cable is not completely inserted into the insertion gap but only rests on the guide inclined surface at the front end in a short insertion state, in the process of the test box upper cover being pressed down from the initial position to the terminal position, under the flexible bending cooperation of the reinforcing plate, the reinforcing plate is pushed and slid into the insertion gap under the guidance of the guide inclined surface and finally abuts against the vertical pressing surface, so that the short insertion is automatically corrected and the precise docking of the FPC flexible flat cable and the LCM test box interface is realized without increasing the risk of scratching the reinforcing plate. Preferably, the effective length of the insertion gap along the length direction of the docking platform is greater than the effective length of the reinforcing plate of the FPC flexible flat cable in the insertion direction, so as to ensure that both ends of the reinforcing plate are in the support range between the stop block main body and the docking platform after being completely inserted.

[0009] Preferably, the length of the guide slope in the direction of the butt joint platform plane projection is 4-8 mm, wherein when the thickness of the reinforcing plate is 0.15-0.25 mm, the length of the guide slope is 4-5 mm, and when the thickness of the reinforcing plate is 0.25-0.40 mm, the length of the guide slope is 6-8 mm.

[0010] Preferably, the protruding part is a detachable structure, detachably connected to the stop block body through threaded fasteners and / or positioning pins, and the protruding part has multiple specifications, and the length of the guide slope of each specification of the protruding part corresponds to match a FPC flexible flat cable reinforcing plate of a preset thickness range, so as to adapt to different specifications of LCM by replacing the protruding part.

[0011] Preferably, the stop block body and the protruding part are integrally made of POM engineering plastic, and the tensile strength of the POM engineering plastic is not less than 60 MPa, and the friction coefficient is not higher than 0.15.

[0012] Preferably, the stop block body and / or the protruding part are made of PA66 glass fiber engineering plastic, the glass fiber content is about 25%, and the surface of the guide slope, the vertical pressing surface and the butt joint platform is sprayed with a PTFE coating with a thickness of 5-8 μm.

[0013] Preferably, the stop block body and the butt joint platform are integrally processed and formed, so that there is no assembly gap between the guide slope and the butt joint platform.

[0014] Preferably, the stop block body is fixedly connected to the butt joint platform through at least two M4 screws, and the distance between the screws is 12-18 mm.

[0015] The FPC flexible flat cable testing method based on the fool-proof device is applied to an LCM testing box matched with a TFT testing machine, and includes the following steps: Step S1, placing a to-be-tested LCM module on the butt joint platform, so that the FPC flexible flat cable of the LCM module is unfolded in a preset direction and arranged towards the fool-proof device; Step S2, pushing the front end of the reinforcing plate of the FPC flexible flat cable to the vicinity of the guide slope by an operator, so that the reinforcing plate is at least partially rested on the guide slope, without having to ensure that the reinforcing plate is completely inserted into the insertion gap; Step S3, start TFT tester test process, make the test box upper cover from the initial position to the docking platform direction down, under the pressure of the test box upper cover to the reinforcing plate, using the flexible bending characteristics of FPC flexible cable, the reinforcing plate slides along the guide slope and is guided into the insertion gap, until the front end of the reinforcing plate abuts against the vertical pressing surface, realizing the accurate butt joint of FPC flexible cable and LCM test box interface; Step S4, test the conduction and or signal transmission of LCM; Step S5, after the test, release the pressure of the test box upper cover, make the FPC flexible cable drive the reinforcing plate along the guide slope and exit the insertion gap under the action of the elastic restoring force.

[0016] Preferably, the test method is carried out under high and low temperature and or vibration environment, for simulating the use condition of vehicle-mounted LCM or industrial LCM, to verify the butt joint stability of FPC flexible cable based on the foolproof device under simulated working condition.

[0017] Compared with the prior art, the foolproof device based on TFT tester has the following beneficial effects: One, the fault tolerance of butt joint is improved. In the prior art, if the operator does not insert the reinforcing plate into the gap below the retaining wall and directly presses the upper cover, the rigid right-angle retaining wall will generate local concentrated stress on the edge of the reinforcing plate, which is easy to cause the deformation of the reinforcing plate and the fracture of the FPC line. In the application, the protruding part of the stop block is changed into a guide slope arranged in the direction of the upper cover pressing down, and a circular arc transition part with a specific radius is arranged at the inlet end and the end, so that the reinforcing plate that is not completely inserted can automatically slide into the insertion gap along the slope under the flexible bending cooperation of FPC, avoiding hard pressure, thereby obviously reducing the scrap and test box interface abnormity caused by short insertion.

[0018] Two, the test efficiency is improved and the operation steps are simplified. The application uses the pressing action of the test box upper cover to complete the automatic compensation of the insertion depth of the reinforcing plate, without the need to perform an independent accurate insertion action. In actual production line application, the single LCM test cycle can be shortened, and the artificial operation time can be significantly saved in batch production, thereby improving the test capacity.

[0019] Three, the labor and training cost is reduced. Since the foolproof device of the application allows the reinforcing plate to automatically correct within a certain short insertion range, the operator no longer needs to accurately align and completely insert the reinforcing plate, new employees can master the operation process after a short training period, the training period and training cost are reduced, and the reduction of operation steps and alignment accuracy requirements is also conducive to reducing misoperation.

[0020] Four, good adaptability and durability. By coordinating the length of the guide slope with the thickness range of the reinforcing plate 0.15mm to 0.40mm, and by realizing the switching of different slope length specifications through replaceable protrusions, one set of stop block structure of the application can adapt to LCM FPC reinforcing plates of various specifications. At the same time, engineering plastic materials with high strength and low friction coefficient are used, and PTFE coating can be selected for the structure, so that the foolproof device still has good wear resistance and low friction characteristics under various working conditions such as normal temperature, high temperature and vibration, has a long service life and low maintenance cost.

[0021] Five, conducive to clean environment and high reliability testing. The stop block body and the LCM test box docking platform are integrally processed and formed, there is no assembly gap between the guide slope and the docking platform, which can reduce the risk of dust and impurities accumulating in the gap, reduce the pollution of the LCM FPC flexible flat cable and the test box interface, and is suitable for medical display, industrial control display and other application scenarios with high requirements for environmental cleanliness and docking reliability. BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a top view of the foolproof device based on the TFT tester of the application; Figure 2 is a side view of the foolproof device based on the TFT tester of the application; Figure 3 is Figure 2 is an enlarged view of A in FIG. 6. DETAILED DESCRIPTION In order to make the purpose, technical scheme and advantages of the application more clear, the application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the application are only relative positions on the specified view, not absolute positions.

[0023] In addition, the description of "first", "second" and the like in the application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0024] Please refer to Figures 1 to 3 The foolproof device based on the TFT tester of the application is applied to the LCM test box matched with the TFT tester, which comprises: The docking platform is used for placing the LCM module and the FPC soft cable; The test box upper cover can be reciprocally pressed down and lifted relative to the docking platform; The stop block body is fixedly installed on the docking platform, and an insertion gap is formed between the stop block body and the docking platform. The insertion gap is used for inserting the reinforcing plate of the FPC soft cable. The width of the insertion gap is designed according to the thickness of the reinforcing plate of 0.15 mm to 0.40 mm, so that the reinforcing plate is basically not shaken in the insertion gap after being inserted. The protruding portion is arranged on the side of the stop block body away from the insertion gap and protrudes away from the docking platform. A vertical pressing surface for pressing the reinforcing plate is formed on the side of the protruding portion close to the insertion gap. The guide inclined surface is arranged on the side of the protruding portion facing the placing direction of the FPC soft cable. The guide inclined surface is arranged to be inclined along the pressing direction of the test box upper cover, so that the included angle between the guide inclined surface and the docking platform is 29°-31°; preferably 30°. The guide inclined surface and the surface of the docking platform are both provided with a first circular arc transition portion. The circular arc radius of the first circular arc transition portion is 0.4 mm to 0.8 mm. The end of the guide inclined surface and the vertical surface of the stop block body are provided with a second circular arc joint portion. The circular arc radius of the second circular arc joint portion is 0.2 mm to 0.4 mm.

[0025] When the reinforcing plate of the FPC soft cable is not completely inserted into the insertion gap but only rests on the guide inclined surface at the front end in a short insertion state, during the process of the test box upper cover being pressed from the initial position to the terminal position, under the flexible bending cooperation of the reinforcing plate, the reinforcing plate is pushed and slides into the insertion gap under the guidance of the guide inclined surface and finally abuts against the vertical pressing surface, thereby automatically correcting the short insertion and realizing the precise docking of the FPC soft cable and the LCM test box interface without increasing the risk of scratching the reinforcing plate.

[0026] Preferably, the effective length of the insertion gap along the length direction of the docking platform is greater than the effective length of the reinforcing plate of the FPC soft cable in the insertion direction, so as to ensure that both ends of the reinforcing plate are within the supporting range between the stop block body and the docking platform after being completely inserted.

[0027] Preferably, the length of the guide inclined surface in the projection direction of the docking platform plane is 4 mm to 8 mm. When the thickness of the reinforcing plate is 0.15 mm to 0.25 mm, the length of the guide inclined surface is 4 mm to 5 mm. When the thickness of the reinforcing plate is 0.25 mm to 0.40 mm, the length of the guide inclined surface is 6 mm to 8 mm. The length of the guide inclined surface is matched with the thickness of the reinforcing plate, so as to ensure that the reinforcing plate can slide into the insertion gap along the guide inclined surface in the short insertion state, while avoiding excessive bending of the FPC soft cable caused by too long guide stroke.

[0028] Preferably, the protruding part is detachable, detachably connected to the block body by a threaded fastener and / or a positioning pin, and has multiple specifications, each of which has a length of the guide slope corresponding to a preset thickness range of the FPC flexible flat cable reinforcing plate, so as to adapt to different specifications of the LCM by replacing the protruding part.

[0029] Preferably, the block body and the protruding part are integrally made of POM engineering plastic, the tensile strength of which is not less than 60 MPa and the friction coefficient of which is not higher than 0.15, so as to reduce the friction damage between the guide slope and the FPC flexible flat cable reinforcing plate and improve the wear resistance of the fool-proof device.

[0030] Preferably, the block body and / or the protruding part are made of PA66 glass fiber engineering plastic, the content of which is about 25%, and the surface of the guide slope and / or the vertical pressing surface and the surface of the docking platform are sprayed with a PTFE coating with a thickness of 5-8 microns, so as to improve the dimensional stability in high-temperature scenarios and further reduce the friction coefficient.

[0031] Preferably, the block body and the docking platform are integrally processed and formed, so that there is no assembly gap between the guide slope and the docking platform, thereby reducing the retention of dust and impurities and reducing the pollution risk of the LCM FPC flexible flat cable and the test box interface.

[0032] Preferably, the block body is fixedly connected to the docking platform by at least two M4 screws, and the distance between the screws is 12-18 mm, so as to ensure the connection stability in the repeated test process and avoid the position deviation of the block, which leads to the decrease of the docking accuracy of the FPC flexible flat cable and the LCM test box interface.

[0033] The application also provides an FPC flexible flat cable test method based on the above-mentioned fool-proof device, which is applied to an LCM test box matched with a TFT test machine and includes the following steps: Step one: place the LCM module to be tested on the docking platform, so that the FPC flexible flat cable is unfolded in a preset direction and arranged towards the fool-proof device; Step two: the operator only needs to push the front end of the reinforcing plate of the FPC flexible flat cable to the vicinity of the guide slope, so that the reinforcing plate is at least partially placed on the guide slope, without having to ensure that the reinforcing plate is completely inserted into the insertion gap; Step three: start the test process of the TFT test machine, so that the upper cover of the test box is pressed downward from the initial position towards the docking platform, under the pressing force of the upper cover of the test box on the reinforcing plate, the reinforcing plate is guided to slide along the guide slope and enter the insertion gap, until the front end of the reinforcing plate abuts against the vertical pressing surface, thereby automatically correcting the insertion depth deviation caused by the short insertion, and realizing the precise docking of the FPC flexible flat cable and the LCM test box interface. Step four, the LCM is tested for conduction and or signal transmission; Step five, after the test is completed, the pressure of the test box cover is released, and the FPC flexible flat cable drives the reinforcing plate to exit the insertion gap along the guide slope in the reverse direction under the action of its own elastic restoring force, thereby preparing for the next test process.

[0034] Preferably, the above test method is carried out under high and low temperature and or vibration environment, which is used to simulate the working condition of vehicle-mounted LCM or industrial LCM, so as to verify the stability of FPC flexible flat cable docking based on the foolproof device under simulated working condition.

[0035] The foolproof device of the application is not simply relying on the slope structure on the stop block to improve the insertion smoothness of the FPC reinforcing plate, but the pressing stroke of the LCM test box cover, the flexible bending ability of the FPC flexible flat cable, the insertion gap size between the stop block and the docking platform, and the geometric parameters of the guide slope are designed as a whole, so as to realize automatic deviation correction and stable compression under short insertion condition.

[0036] Specifically, on the one hand, the FPC flexible flat cable body has a certain flexibility, and the front end of the reinforcing plate can produce controllable elastic bending around the FPC body under the pressing force of the test box cover when it is not completely inserted into the gap below the stop block; on the other hand, the guide slope is arranged inclined along the downward pressing direction of the test box cover, and the included angle between the guide slope and the downward pressing direction of the test box cover is limited to 29°-31°; preferably 30°, and the sharp corner edges at the inlet end and the terminal end are eliminated through the first circular arc transition part and the second circular arc connection part, so that the reinforcing plate always moves along the guide slope during bending without being hung or scratched.

[0037] Under the above conditions, when the operator only rests the front end of the reinforcing plate on the guide slope without completely inserting it into the insertion gap, as the test box cover is pressed downward from the initial position, the reinforcing plate is driven to slide into the insertion gap between the stop block and the docking platform along the slope direction under the tangential thrust component at the guide slope contact point, and is moderately bent under the vertical pressing component, thereby completing the dynamic conversion from short insertion state to complete insertion and compression before the cover reaches the terminal position. The insertion gap width is designed according to the thickness of the reinforcing plate 0.15mm to 0.40mm, so that the reinforcing plate can be reliably clamped without shaking after being completely inserted, and the test interface is stably compressed in combination with the vertical compression surface.

[0038] The above-mentioned synergistic mechanism shows that the application is not simply adding a slope to the stop block, but by comprehensively matching the slope angle, the circular arc transition radius, the effective length of the slope, the thickness range of the reinforcing plate, the flexible characteristics of the FPC, and the pressing stroke of the upper cover, the necessary action of pressing the upper cover of the test box naturally bears the functions of automatic deviation correction and compensation of insertion depth, thereby significantly improving the fault tolerance and docking reliability of the FPC reinforcing plate insertion without increasing additional operation steps.

[0039] Specifically, the foolproof device based on a TFT test machine comprises a docking platform 1, a stop block body 2, and a protruding part 21. The docking platform 1 is a docking table for LCM test boxes, used for placing LCM modules to be tested and their FPC flexible flat cables 4; the stop block body 2 is fixedly connected with the docking platform 1 through at least two M4 specification fastening screws, and the screw spacing is 12-18 mm, so as to ensure that the stop block body 2 does not loosen or displace during multiple tests.

[0040] An insertion gap 22 for inserting the FPC reinforcing plate 41 is formed between the stop block body 2 and the docking platform 1, and the width of the insertion gap 22 is designed according to the thickness of the reinforcing plate 41, preferably in the range of 0.15-0.40 mm, so that the reinforcing plate 41 does not shake in the insertion gap after being inserted.

[0041] A guide slope 211 is arranged on the side of the protruding part 21 facing the placement direction of the FPC flexible flat cable 4, and the guide slope 211 is arranged obliquely along the downward pressing direction of the upper cover 3 of the TFT test machine. The included angle between the guide slope 211 and the downward pressing direction of the upper cover 3 of the test box is 30°. The feed end 211a of the guide slope 211 and the surface of the docking platform 1 are both provided with a first circular arc transition part, and the circular arc radius of the first circular arc transition part is 0.4-0.8 mm, so as to eliminate sharp angles and reduce the risk of scratching the FPC flexible flat cable 4; and the junction of the discharge end 211b of the guide slope 211 and the vertical surface of the stop block body 2 is provided with a second circular arc junction part, and the circular arc radius of the second circular arc junction part is 0.2-0.4 mm, so as to ensure that the reinforcing plate 41 smoothly transitions to the vertical pressing surface 23 after sliding into the insertion gap 22 and is reliably positioned. The fixed 30° slope can simplify the processing technology of the retaining wall, reduce the processing precision requirement, and reduce the processing cost by 18%-22%; ensure the consistency of different batches of retaining walls, avoid the influence of angle deviation on the docking accuracy of the LCM FPC and the test box interface, and be suitable for batch testing scenarios of a single specification LCM (such as a mobile phone LCM production line).

[0042] The length of the guide slope 211 in the direction of the planar projection of the docking platform 1 is 4-5 mm, which is suitable for FPC reinforcing plates 41 with a thickness of 0.15-0.25 mm. The protruding part 21 can be integrally formed with the stopper body 2 or connected by screws to achieve a detachable structure. Without replacing the stopper body 2, only by replacing the protruding part with different slope lengths, the testing requirements of LCMs of different specifications can be met, and the component replacement time is ≤40 seconds.

[0043] The stopper body 2 and the protruding part 21 can be integrally formed by injection molding with POM engineering plastic. The tensile strength of POM engineering plastic is not less than 60 MPa, and the friction coefficient is not higher than 0.15, which is beneficial to reduce the friction damage between the guide slope 211 and the FPC reinforcing plate 41 during frequent plugging and sliding, and at the same time avoids scratching the docking interface of the LCM test box. The service life of the stopper can reach more than 120,000 times of LCM test.

[0044] In use, the operator places the LCM to be tested on the docking platform 1, and only needs to roughly push the front end of the FPC reinforcing plate 41 to the vicinity of the guide slope 211 so that it is partially rested on the guide slope 211, without the need to ensure that the reinforcing plate 41 completely enters the insertion gap 22. Then, the TFT tester test process is started, the upper cover 3 is moved downward and applies a pressing force to the FPC reinforcing plate 41. Under the guidance of the guide slope 211 and the flexible deformation of the FPC flexible flat cable 4, the reinforcing plate 41 slides along the guide slope 211 to the direction of the insertion gap 22. When the front edge of the reinforcing plate 41 enters the insertion gap 22, the reinforcing plate 41 completely slides into the insertion gap 22 and finally abuts against the vertical pressing surface 23 under the continued downward pressure, realizing automatic deviation correction and precise docking.

[0045] After the test is completed, the pressing force of the upper cover 3 is released, and the FPC flexible flat cable 4 drives the reinforcing plate 41 to slide reversely along the guide slope 211 and exit the insertion gap 22 under the action of its elastic restoring force, preparing for the next test. The foolproof device can still maintain good guiding performance and docking accuracy after multiple uses.

[0046] The stopper body 2 and the protruding part 21 can also be made of PA66+glass fiber engineering plastic with a glass fiber content of about 25%. The surface of the guide slope 211 and the vertical pressing surface 23 is sprayed with a PTFE coating with a thickness of 5-8 μm to further reduce the friction coefficient and improve wear resistance. PA66+glass fiber material has high temperature resistance (heat distortion temperature ≥120℃), which can adapt to the 85℃ high temperature test scene of vehicle-mounted LCM. After spraying the PTFE coating, the friction coefficient is reduced to 0.12-0.14, ensuring smooth guidance of the LCM FPC along the slope and perfect adaptation to the testing requirements of vehicle-mounted LCM.

[0047] The application is suitable for the test working condition of vehicle-mounted LCM such as vehicle-mounted central control screen and instrument panel in high-temperature environment. The TFT tester and LCM test box are arranged in the high-temperature environment box, and the butt joint test of FPC flexible flat cable is performed by using the foolproof device. Since the PA66 glass fiber material has good heat resistance and dimensional stability, the geometric accuracy of the guide slope 211 and the insertion gap 22 can be ensured in the high-temperature environment, so that the automatic sliding and stable compression of the reinforcing plate 41 under the high-temperature condition are ensured.

[0048] The butt joint platform 1 and the block body 2 can also be integrally machined, which can be integrally machined by metal CNC or integrally molded by engineering plastic. There is no assembly gap between the butt joint platform 1 and the block body 2, and the guide slope 211 and the arc transition of the butt joint platform 1 are integrally machined.

[0049] The integrated structure can significantly reduce the accumulation of dust and impurities between the block and the butt joint platform, reduce the risk of polluting the LCM and the test interface, and be suitable for the application of LCM products such as medical monitoring display screen and industrial control display screen in the test process. At the same time, the size deviation caused by assembly error is reduced, and the butt joint accuracy between the FPC reinforcing plate 41 and the test box interface is further improved. Reducing assembly error, improving the butt joint accuracy of LCM FPC and test box interface, and improving the test qualified rate by 3%~5%.

[0050] Compared with the prior art, the foolproof device based on the TFT tester has the following beneficial effects: First, the fault tolerance of butt joint is improved. In the prior art, if the operator does not completely insert the reinforcing plate into the gap below the retaining wall and directly presses the upper cover, the rigid right-angle retaining wall will generate local concentrated stress on the edge of the reinforcing plate, which is easy to cause deformation of the reinforcing plate and rupture of the FPC line. In the application, the protruding part of the block is changed to a guide slope arranged along the pressing direction of the upper cover, and a circular arc transition part with a specific radius is arranged at the inlet end and the end, so that the reinforcing plate that is not completely inserted can automatically slide into the insertion gap along the slope under the flexible bending cooperation of the FPC, avoiding hard pressure, thereby obviously reducing the scrap and test box interface abnormity caused by short insertion, avoiding FPC damage caused by rigid extrusion, reducing the LCM product scrap rate to below 0.1%, and protecting the LCM test box interface, thereby reducing the annual maintenance cost by more than 80%.

[0051] Second, the test efficiency is improved and the operation steps are simplified. The present application uses the pressing action of the test box cover to complete the automatic compensation of the reinforcing plate insertion depth, without the need to perform an independent precise insertion action. In actual production line applications, the single LCM test cycle can be shortened, and the labor operation time can be significantly saved in batch production, thereby improving the test capacity. Tests show that the single LCM test time is shortened by 2-4 seconds, 4.4-8.9 hours of labor time is saved per day when 8000 pieces are tested per day, and the LCM test capacity is improved by 10%-15%.

[0052] Third, the labor and training costs are reduced. Since the foolproof device of the present application allows the reinforcing plate to still be automatically corrected within a certain short insertion range, the operator no longer needs to accurately align and completely insert the reinforcing plate, and new employees can master the operation process after a short training period, thereby reducing the training period and training costs. At the same time, the reduction in operation steps and the reduction in alignment accuracy requirements also help to reduce misoperations. New employees do not need special training and can operate skillfully within 30 minutes, thereby reducing training costs by 90%. The reduction in operation steps reduces personnel fatigue, and one LCM test station can reduce one operator, which saves labor costs of 60,000 yuan per year according to the monthly salary of 5,000 yuan per person.

[0053] Fourth, good adaptability and durability. By coordinating the length of the guide slope with the thickness range of the reinforcing plate of 0.15-0.40 mm, and by switching different slope length specifications through replaceable protrusions, one set of stop block structure of the present application can adapt to LCM FPC reinforcing plates of various specifications. At the same time, an engineering plastic material with high strength and low friction coefficient is used, and a PTFE coating can be sprayed on the structure, so that the foolproof device still has good wear resistance and low friction characteristics under various working conditions such as normal temperature, high temperature and vibration, has a long service life, and has low maintenance costs. The 30° slope can cover more than 95% of mainstream LCM FPC reinforcing plate specifications, without the need to customize a special test box retaining wall; the POM material is suitable for all working conditions of LCM testing, and the service life is more than 120,000 times, and the stop block replacement frequency is reduced by 75%.

[0054] Fifth, it is conducive to clean environment and high reliability testing. The stop block body and the LCM test box docking platform are integrally formed, there is no assembly gap between the guide slope and the docking platform, which can reduce the risk of dust and impurities accumulating in the gap, reduce the pollution to the LCM FPC flexible flat cable and the test box interface, and is suitable for medical display, industrial control display and other application scenarios with high requirements for environmental cleanliness and docking reliability.

[0055] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any modification, equivalent replacement and improvement within the concept of the present application shall be included in the patent protection scope of the present application.

Claims

1. A foolproof device based on a TFT tester, which is applied to an LCM test box supporting the TFT tester, and is characterized in that include: The docking platform is used to hold the LCM module under test and its FPC flexible flat cable; The test box cover can be repeatedly pressed down and lifted relative to the docking platform; The main body of the stop block is fixedly installed on the docking platform, and an insertion gap is formed between the main body of the stop block and the docking platform. The insertion gap is used to insert the reinforcing plate of the FPC flexible flat cable. A protrusion is provided on the side of the stop body away from the insertion gap and protrudes in a direction away from the docking platform. The side of the protrusion near the insertion gap forms a vertical pressing surface for pressing the reinforcing plate. A guide slope is provided on the side of the protrusion facing the placement direction of the FPC flexible flat cable. The guide slope is arranged obliquely along the downward pressing direction of the test box cover, so that the angle between the guide slope and the downward pressing direction of the test box cover is 29°-31°. The feed end of the guide ramp and the surface of the docking platform are both provided with a first arc transition portion, the arc radius of the first arc transition portion being 0.4mm to 0.8mm; a second arc connection portion is provided at the junction of the end of the guide ramp and the vertical surface of the stop block body, the arc radius of the second arc connection portion being 0.2mm to 0.4mm; and when the reinforcing plate of the FPC flexible flat cable is not fully inserted into the insertion gap but only rests on the guide ramp in a short-insertion state, during the process of the test box cover pressing down from the initial position to the termination position, under the flexible bending cooperation of the reinforcing plate, the reinforcing plate is pushed and slid into the insertion gap under the guidance of the guide ramp and finally abuts against the vertical pressing surface.

2. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The effective length of the insertion gap along the length direction of the docking platform is greater than the effective length of the FPC flexible flat cable reinforcement plate in the insertion direction.

3. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The length of the guide ramp in the direction of projection on the docking platform plane is 4mm to 8mm. When the thickness of the reinforcing plate is 0.15mm to 0.25mm, the length of the guide ramp is 4mm to 5mm. When the thickness of the reinforcing plate is 0.25mm to 0.40mm, the length of the guide ramp is 6mm to 8mm.

4. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The protrusion is a detachable structure and is detachably connected to the block body by threaded fasteners and / or positioning pins. The protrusion has various specifications, and the length of the guide slope of each specification of the protrusion corresponds to a FPC flexible flat cable reinforcement plate with a preset thickness range.

5. The error-proofing device based on a TFT testing machine as described in claim 1, characterized in that, The main body of the stop block and the protrusion are made of POM engineering plastic, and the tensile strength of the POM engineering plastic is not less than 60MPa and the coefficient of friction is not higher than 0.

15.

6. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The main body of the stop and the protrusion are made of PA66 glass fiber reinforced engineering plastic with a glass fiber content of 25%, and a PTFE coating with a thickness of 5μm to 8μm is sprayed on the surfaces of the guide slope, the vertical pressing surface and the docking platform.

7. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The main body of the stop block is integrally formed with the docking platform.

8. The error-proof device based on a TFT testing machine as described in claim 1, characterized in that, The block body is fixedly connected to the docking platform by at least two M4 screws, with the spacing between the screws being 12mm to 18mm.

9. The FPC flexible cable testing method for the anti-fooling device according to any one of claims 1 to 8, which is applied to the LCM test box supporting the TFT tester, is characterized in that Includes the following steps: Step S1: Place the LCM module to be tested on the docking platform, and unfold its FPC flexible flat cable along a preset direction and arrange it toward the foolproof device. Step S2: The operator pushes the front end of the reinforcing plate of the FPC flexible cable to the vicinity of the guide slope, so that the reinforcing plate at least partially rests on the guide slope, without ensuring that the reinforcing plate is fully inserted into the insertion gap. Step S3: Start the TFT tester test process, press the test box cover down from the initial position toward the docking platform. Under the pressing force applied by the test box cover to the reinforcing plate, the reinforcing plate slides along the guide slope and is guided into the insertion gap by utilizing the flexible bending characteristics of the FPC cable, until the front end of the reinforcing plate abuts against the vertical pressing surface, thus achieving precise docking between the FPC cable and the LCM test box interface. Step S4: Perform continuity and / or signal transmission tests on the LCM; Step S5: After the test is completed, release the pressure of the test box cover, so that the FPC flexible cable can drive the reinforcing plate to exit the insertion gap in the opposite direction along the guide slope under its own elastic restoring force.

10. The error-proof device based on a TFT testing machine as described in claim 9, characterized in that, The test method is conducted in high and low temperature and / or vibration environments to simulate the operating conditions of vehicle-mounted LCMs or industrial LCMs.

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