Large-size PCB size detection equipment

Abstract

The utility model discloses size detection equipment for a large-size PCB (Printed Circuit Board). The size detection equipment comprises a base, a control terminal, and a bearing mechanism, a driving mechanism and an optical imaging mechanism which are arranged on the base, the driving mechanism is composed of double sliding platforms which are perpendicular to each other and is provided with a linear driving motor and a grating ruler assembly, and precise synchronous movement is achieved. The optical imaging mechanism comprises a TDI camera and telecentric lens coaxial module, distortion-free continuous line scanning imaging can be achieved, and splicing errors are avoided; the bearing mechanism is provided with a light-transmitting table top and a built-in lighting cavity, and a side lighting module can be selectively installed to provide stable lighting. The equipment realizes the full-width seamless high-precision detection of the large-size PCB, accurately verifies the appearance, the hole site and the relative position, and meets the first detection requirements of high-end products.

Description

TECHNICAL FIELD

[0001] The utility model relates to PCB detection equipment technical field, especially a large size PCB size detection equipment. BACKGROUND

[0002] In the field of printed circuit board (PCB) manufacturing, with the development of electronic equipment towards large-scale and high-precision, the application scenarios of large size PCB (such as single block size >= 600mm*800mm) are increasingly widespread, covering key fields such as communication base station equipment, industrial control mainboard, and large display panel driving board. As the core link that determines the final size precision of PCB, the first piece detection is directly related to the product qualification rate of subsequent batch production, and it is necessary to accurately verify whether the outline, hole coordinate and relative position relationship of holes and outline of large size PCB meet the design requirements.

[0003] Currently, the core technical bottleneck of large size PCB size detection is the difficulty in balancing the width and precision. In existing detection equipment, the mainstream scheme takes a fixed area array camera as the core imaging unit, and its single imaging field of view is limited. For large size PCB, multiple camera movements and image splicing are required to complete full-width detection. Due to the accumulation of platform motion errors, image distortion errors and other system errors in the splicing process, the precision of the final measurement result is significantly reduced, especially in the edge area of PCB and the dense area of holes, the error often exceeds the industry allowed precision standard of ±0.01mm, which cannot meet the detection needs of high-end large size PCB. UTILITY MODEL CONTENTS

[0004] The main purpose of the utility model is to provide a large size PCB size detection equipment, which aims to set a camera module with a TDI camera and a telecentric lens coaxially assembled, cooperate with a double sliding platform driving mechanism and a grating ruler position feedback structure that are synchronously linked with the imaging action, and realize seamless high-precision scanning imaging of large size PCB.

[0005] To achieve the above purpose, the utility model provides a large size PCB size detection equipment, which comprises a base, a control terminal, a bearing mechanism, a driving mechanism and an optical imaging mechanism connected with the control terminal and arranged on the base, the driving mechanism is arranged on the base, the bearing mechanism is assembled on the driving mechanism, and the driving mechanism is used to drive the bearing mechanism to move the large size PCB in the horizontal plane of the base and realize synchronous linkage with the scanning action of the optical imaging mechanism.

[0006] The optical imaging mechanism is arranged above the bearing mechanism, and comprises a mounting frame fixed to the base, a connecting seat slidingly assembled to the mounting frame, an adjusting mechanism for driving the connecting seat to move up and down relative to the bearing mechanism to adjust the imaging distance, and a camera module arranged on the connecting seat; the camera module comprises a TDI camera and a telecentric lens coaxially arranged below the TDI camera, and the telecentric lens is used to make the chief ray of the imaging light incident to the surface of the large-size PCB parallel to the optical axis and suppress perspective distortion; the TDI camera is used to complete continuous line scanning imaging of the large-size PCB in a motion state through the telecentric lens and output imaging data carrying the profile and hole features of the large-size PCB.

[0007] In a possible implementation, the driving mechanism comprises a first sliding platform and a second sliding platform arranged perpendicularly to each other, the first sliding platform is slidingly connected to the base through a sliding block guide rail structure, the second sliding platform is arranged on the first sliding platform through a sliding block guide rail structure, the moving directions of the first sliding platform and the second sliding platform are perpendicular to each other, and the bearing mechanism is fixed to the second sliding platform; the driving mechanism further comprises driving motors for driving the first sliding platform and the second sliding platform to move linearly in the horizontal direction, and the driving motors are linear driving motors.

[0008] In a possible implementation, the driving mechanism further comprises grating scale assemblies arranged between the first sliding platform and the base and between the second sliding platform and the first sliding platform, respectively; the grating scale assembly comprises a grating scale body and a reading head matched with the grating scale body, the reading head is fixed to the sliding platform and is signal-connected to the control terminal, and the grating scale body is arranged parallel to the moving direction of the corresponding first sliding platform or second sliding platform.

[0009] In a possible implementation, the bearing mechanism comprises a bearing table fixedly arranged on the second sliding platform, the second sliding platform is provided with an illumination cavity with an opening above, the bearing table is made of a light-transmitting material and is embedded in the opening of the illumination cavity, and the illumination cavity is provided with an illumination light source electrically connected to the control terminal.

[0010] In a possible implementation, the adjusting mechanism comprises an adjusting screw rod rotatably arranged on the mounting frame and an adjusting screw hole arranged on the connecting seat, one end of the adjusting screw rod is fixed with a knob, and the other end is threadedly connected with the adjusting screw hole.

[0011] In a possible implementation, the driving mechanism further comprises a limiting and buffering assembly arranged between the first sliding platform and the base and between the second sliding platform and the first sliding platform respectively; the limiting and buffering assembly comprises two groups of buffering members and a limiting seat; the limiting seat is fixed to the bottom of the first sliding platform towards the base and the bottom of the second sliding platform towards the first sliding platform, and the limiting seat is located at the middle of the corresponding sliding platform; the two groups of buffering members are arranged at the two ends of the limiting seat along the movement direction of the corresponding sliding platform.

[0012] In a possible implementation, the limiting and buffering assembly further comprises a Hall sensor arranged on the base and the first sliding platform, and the first sliding platform and the second sliding platform are provided with an induction sheet matched with the corresponding Hall sensor; the Hall sensor is connected to a control terminal, and is used to trigger a signal to make the corresponding driving motor decelerate until stop when the corresponding sliding platform moves to the position close to the stroke limit.

[0013] In a possible implementation, the bearing mechanism further comprises a side lighting module detachably arranged above the bearing table top; the side lighting module is higher than the bearing table top to illuminate above the PCB board arranged on the bearing table top.

[0014] In a possible implementation, the side of the bearing table top is provided with a mounting groove; the side lighting module comprises a lighting pipe embedded in the mounting groove; the lighting pipe has a frame-shaped structure surrounding the bearing table top, and one side of the lighting pipe relative to the center of the bearing table top is provided with a light-transmitting part made of transparent material; the bottom of the lighting pipe is provided with a light source; a plurality of reflecting mirrors are rotatably arranged in the lighting pipe; the plurality of reflecting mirrors are arranged corresponding to the light-transmitting part, and are used to reflect the light of the light source at the bottom to illuminate the center of the bearing table top through the light-transmitting part; a rotating assembly is further included, and the rotating assembly is used to adjust the reflection angle of the light by the reflecting mirrors.

[0015] In a possible implementation, the lighting pipe has a hollow rectangular structure in cross section, which comprises the light-transmitting part on one side relative to the center of the bearing table top, a light inlet part made of transparent material arranged on the bottom of the bearing table top, and an L-shaped connecting part; the connecting part, the light-transmitting part and the light inlet part are connected to form a closed structure; the light-transmitting part is arranged obliquely relative to the bottom of the bearing table top.

[0016] The rotating assembly comprises a rotating shaft fixedly arranged on the side of the reflecting mirror away from the light-transmitting part; one side of the lighting pipe corresponding to the rotating shaft is rotatably provided with a driving shaft perpendicular to the rotating shaft; the driving shaft and the rotating shaft are connected through a bevel gear set.

[0017] Compared with the prior art, the application has the following advantages:

[0018] 1. Through the coaxial assembly of the TDI camera and the telecentric lens, the telecentric lens can suppress the perspective distortion of the image. Combined with the TDI camera, it can continuously scan the PCB in motion without the need for image stitching, avoiding the systematic errors accumulated during the stitching process, and achieving high-precision inspection of the entire range of large-size PCBs.

[0019] 2. The drive mechanism adopts a double sliding platform with mutual perpendicularity and a linear drive motor, combined with the real-time position feedback structure of the grating ruler assembly, which can accurately calibrate the movement position of the sliding platform, ensure the synchronous matching of PCB movement speed and camera scanning speed, and further improve imaging and measurement accuracy.

[0020] 3. The integrated structure of the light-transmitting support platform and the built-in lighting cavity of the support mechanism can provide uniform backlighting, providing stable lighting conditions for clear imaging of the TDI camera and telecentric lens, and helping to accurately identify PCB outline and hole features. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional structural diagram of Example 1;

[0023] Figure 2 This is a schematic diagram of the structure of Example 1;

[0024] Figure 3 for Figure 1 Enlarged view at point A;

[0025] Figure 4 This is a structural diagram of the drive mechanism in Example 1;

[0026] Figure 5 This is a structural diagram of the first sliding platform of this utility model;

[0027] Figure 6 for Figure 5 Enlarged view at point B;

[0028] Figure 7 for Figure 5 Enlarged view at point C;

[0029] Figure 8 This is a schematic diagram of the structure of Example 2;

[0030] Figure 9 This is an exploded structural diagram of Example 2;

[0031] Figure 10 is a bottom structure diagram of a side light-emitting module;

[0032] Figure 11 is a partial cross-sectional view of a lighting pipe;

[0033] Figure 12 is a top partial cross-sectional view of a lighting pipe;

[0034] Figure 13 is a structural schematic diagram of embodiment 3;

[0035] Explanation of reference numerals:

[0036] 1, base; 2, control terminal; 3, bearing mechanism; 30, bearing table top; 31, lighting cavity; 32, lighting light source; 33, diffuse reflection plate; 4, driving mechanism; 40, first sliding platform; 41, second sliding platform; 42, driving motor; 43, sliding block guide rail structure; 44, grating ruler body; 45, reading head; 5, optical imaging mechanism; 50, mounting frame; 51, connecting seat; 52, adjusting mechanism; 520, adjusting screw; 521, knob; 53, camera module; 530, TDI camera; 531, telecentric lens; 6, limiting buffer assembly; 60, limiting seat; 61, buffer piece; 610, buffer sleeve; 620, limiting rod; 62, hall sensor; 63, induction sheet; 7, side lighting module; 70, lighting pipe; 71, light transmission part; 72, reflector; 73, rotating shaft; 74, light inlet part; 75, connecting part; 76, driving shaft; 77, bevel gear set; 8, mounting groove; 9, clamping groove; 10, bolt head; 11, strip light source.

[0037] The realization, functional features and advantages of the utility model will be further described with reference to the drawings in combination with embodiments. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0039] Embodiment 1

[0040] Reference Figures 1 to 7 The present embodiment proposes a large-size PCB size detection device, which comprises a base 1, a control terminal 2, a bearing mechanism 3, a driving mechanism 4 and an optical imaging mechanism 5.

[0041] The base 1 is used to support the bearing mechanism 3, the driving mechanism 4 and the optical imaging mechanism 5, and the control terminal 2 comprises an electric control box connected with the bearing mechanism 3, the driving mechanism 4 and the optical imaging mechanism 5 through an electric wire and a computer device connected with the electric control box.

[0042] The electric control box is fixedly installed on the base 1, and an industrial control host is arranged in the electric control box, wherein the industrial control host is pre-installed with a motion control algorithm and a synchronous trigger algorithm, and an operation panel is integrated with function keys such as start, stop, parameter setting and light source adjustment, so as to facilitate on-site rapid operation of an operator.

[0043] Meanwhile, the electric control box is bidirectionally connected with a linear driving motor 42 of the driving mechanism 4, a grating ruler assembly and a Hall sensor 62, an illumination light source 32 of the bearing mechanism 3 and a TDI camera 530 of the optical imaging mechanism 5 through an industrial bus, so as to not only issue instructions such as motion control, light source start-stop and camera scanning, but also receive various feedback data in real time and transmit the feedback data to the computer.

[0044] As shown in Figures 1-2 , the driving mechanism 4 is assembled on the upper end surface of the base 1 through bolt fastening, and is composed of a first sliding platform 40 and a second sliding platform 41 arranged perpendicularly to each other, forming a high-precision cross linear motion structure. The first sliding platform 40 is slidably connected with the base 1 through a sliding block guide rail structure 43, the guide rail is fixed in parallel along the length direction of the base 1, and the sliding block is bolted to the bottom of the first sliding platform 40; the second sliding platform 41 is assembled on the upper end surface of the first sliding platform 40 through another set of sliding block guide rail structures 43, and the guide rails of the set are perpendicular to the guide rails of the first sliding platform 40, and the sliding block is fixed to the bottom of the second sliding platform 41.

[0045] As shown in Figure 3 , the optical imaging mechanism 5 is arranged above the bearing mechanism 3, and a mounting frame 50 is fixedly connected to the upper end surface of the base 1 through a bolt set, and the height of the mounting frame 50 is higher than the maximum movement height of the bearing mechanism 3, so as to avoid movement interference with the bearing mechanism 3.

[0046] The connecting seat 51 is slidably assembled to the inner side wall of the mounting frame 50 through a sliding block structure. The mounting frame 50 is further provided with an adjusting mechanism 52, which is composed of an adjusting lead screw 520 and an adjusting screw hole. One end of the adjusting lead screw 520 is rotatably connected to the top crossbeam of the mounting frame 50 through a bearing, and the other end penetrates through the crossbeam and is threadedly connected with the adjusting screw hole provided on the connecting seat 51. The top end of the adjusting lead screw 520 is further fixed with a knob 521. By rotating the knob 521, an operator can drive the adjusting lead screw 520 to rotate, thereby driving the connecting seat 51 to slide up and down along the inner side wall of the mounting frame 50, accurately adjusting the imaging distance between the camera module 53 and the PCB, adapting to the detection of large-size PCBs of different thickness specifications, and improving the versatility of the equipment.

[0047] The lower end surface of the connecting seat 51 is fixedly provided with the camera module 53 through a special flange plate. The module is coaxially assembled by a high-speed line scan TDI camera 530 and a line array telecentric lens 531, and the two are fastened by flange bolts. The optical axis of the telecentric lens 531 is perpendicular to the upper end surface of the bearing table 30, ensuring the perpendicularity of the imaging light path.

[0048] The telecentric lens 531 adopts object-side telecentric optical design and is composed of multiple groups of optical lenses with different curvatures. The core working principle is to control the light path of the lens group so that the chief ray of the imaging light incident to the PCB surface is always parallel to the lens optical axis, thereby eliminating the imaging distortion caused by the perspective effect of traditional lenses and ensuring that the magnification of the features on the PCB surface, whether in the central region or the edge region, remains consistent when imaging, providing accurate image basis for subsequent size measurement.

[0049] The TDI camera 530 belongs to a special type of line array camera, and its photosensitive surface is composed of multiple arrays of photosensitive elements arranged in the motion direction of the PCB. During operation, relying on the time delay integration technology, when the driving mechanism 4 drives the PCB to pass through the field of view of the lens at a constant speed, the same feature on the PCB will pass through different photosensitive elements in turn. The camera controls each photosensitive element to expose and accumulate electric charge in a preset time sequence, and finally integrates and outputs the integrated electric charge signal. This working method can effectively improve the sensitivity and signal-to-noise ratio of imaging. Even if the PCB is in motion, a clear and non-blurred line scan image can be obtained, avoiding the error accumulation caused by multiple splicing of traditional area array cameras. During equipment operation, the TDI camera 530 is connected to the computer through a data line, continuously collects line image data of the PCB surface at a preset frequency, and transmits the imaging data carrying the PCB profile, hole feature and defect information to the computer in real time.

[0050] Compared with the prior art, the device first solves the core bottleneck that the traditional fixed area array camera cannot detect large size PCB with both high accuracy and large field of view. In the prior art, the fixed area array camera has a limited field of view in single imaging, and the full field detection needs to be completed by multiple movements and splicing. The platform movement error and image distortion error will be accumulated, resulting in a decrease in the final measurement accuracy. Especially in the edge area and the hole dense area of the PCB, the error often exceeds the industry standard. At the same time, the traditional lens is affected by the perspective effect, and the magnification of the center and the edge area of the PCB is inconsistent during imaging, which further aggravates the size measurement deviation.

[0051] The telecentric lens 531 is designed by telecentric optical design on the object side. The light path of multiple groups of optical lenses with different curvatures is controlled, so that the chief ray of the imaging light incident to the PCB surface is always parallel to the optical axis. The perspective distortion of the traditional lens is completely eliminated, and the feature imaging magnification of the center and the edge area of the PCB remains highly consistent. The uniformity of the size measurement reference of different areas is ensured from the optical source. The high-speed line scanning TDI camera 530 relies on the time delay integration technology. During the process of driving the PCB to move at a constant speed by the driving mechanism 4, the multiple photosensitive element arrays arranged along the movement direction are exposed and charge is accumulated successively. Unlike the traditional area array camera, the line scanning TDI camera 530 does not need to perform multiple image splicing. The accumulation of various errors in the splicing process is fundamentally avoided, and the sensitivity and signal-to-noise ratio of the imaging are greatly improved. Even if the PCB is in a continuous motion state, a clear and non-fuzzy line scanning image can still be obtained.

[0052] The high-precision light path control of the telecentric lens 531 and the continuous integration imaging technology of the TDI camera 530 support each other, so that the full field imaging of the large size PCB has both the accuracy of no distortion and the integrity of no splicing. The fine profile of the PCB edge and the adjacent hole boundary in the hole dense area, which are difficult to be accurately captured by the traditional device, can form clear and sharp imaging features in the device, providing an image quality basis far beyond the expectation for subsequent sub-pixel level profile extraction. This change directly covers the accuracy of the size measurement over the full field, and the edge area accuracy does not decay. At the same time, the appearance defects such as small gaps and fine burrs, as well as the fine displacement deviation between the hole layer and the appearance layer, can be accurately identified, effectively solving the problems of single detection function and insufficient defect and layer deviation detection capability of the existing device. In addition, the continuous scanning mode without multiple splicing, combined with high-precision motion control, greatly shortens the time of full field detection, solves the low efficiency of the existing line scanning splicing scheme, realizes the dual requirements of high-precision detection and high-efficiency first detection of large size PCB, and fully adapts to the actual application scenario of quickly verifying the product qualification rate in the PCB production site.

[0053] As shown in FIG. 1, the device comprises a driving mechanism 4, a telecentric lens 531, a high-speed line scanning TDI camera 530, and a data processing system 5. Figures 4-7As shown, specifically, the driving mechanism 4 is equipped with two groups of linear drive motors 42, which are connected with the first sliding platform 40 and the second sliding platform 41 respectively, and directly drive the platforms to move linearly along the guide rails. Compared with the traditional screw transmission, the error of the intermediate transmission link is reduced, and the motion stability and response speed are improved.

[0054] In order to further ensure the motion accuracy, the driving mechanism 4 is equipped with a grating ruler assembly between the first sliding platform 40 and the base 1, and between the second sliding platform 41 and the first sliding platform 40. The grating ruler body 44 is fixed in parallel on the upper end face of the base 1 or the first sliding platform 40 along the motion direction of the corresponding platform. The reading head 45 is fixed on the bottom of the corresponding sliding platform through a support and is signal connected with the electric control box, so as to collect position data in real time and feed back to the electric control box.

[0055] During the system calibration stage, the device corrects the platform motion accuracy by the laser interferometer, establishes a system error model, compensates and calibrates the interpolation error of the grating ruler on this basis, realizes high-precision closed-loop control of the motion position by combining with the software algorithm, and ensures that the PCB motion trajectory is completely consistent with the preset path.

[0056] As shown, Figure 6 Meanwhile, the driving mechanism 4 is provided with a limiting and buffering assembly 6. The limiting seat 60 is fixed on the bottom of the first sliding platform 40 towards the base 1 and the bottom of the second sliding platform 41 towards the first sliding platform 40 through bolts, and the limiting seat 60 is located at the middle part of the corresponding sliding platform. The two groups of buffering pieces 61 each include a buffering sleeve 610 and a limiting rod 620 slidingly arranged on the buffering sleeve 610. A spring abutting against the limiting rod 620 is arranged in the buffering sleeve 610. The buffering piece 61 can be fixed on the corresponding position of the base 1 or the first sliding platform 40 through a support and is arranged at both ends of the limiting seat 60 along the motion direction of the sliding platform. The impact force at the stroke limit can be absorbed by the elastic deformation of the buffering piece 61, so as to avoid rigid collision.

[0057] As shown, Figure 7 In addition, the Hall sensors 62 are respectively installed in the middle parts of the base 1 and the first sliding platform 40. The corresponding sensing sheets 63 are fixed on the side ends of the first sliding platform 40 and the second sliding platform 41 through supports. When the platforms approach the stroke limit, the sensing sheets 63 trigger the Hall sensors 62. The Hall sensors 62 send signals to the electric control box. The electric control box immediately instructs the linear drive motor 42 to slow down until it stops, forming double protection and improving the operation safety and stability of the device.

[0058] As shown, Figure 2 The bearing mechanism 3 is fixedly assembled on the upper end face of the second sliding platform 41 through bolts. The core includes a bearing table 30 and an illumination cavity 31. The illumination cavity 31 is a cavity structure with an opening at the top and is directly machined on the upper end face of the second sliding platform 41.

[0059] The bearing table 30 is made of high-transmittance PC (polycarbonate) plate material, which has excellent light transmittance and structural strength, can ensure effective penetration of backlight light, and can stably bear large-size PCB to avoid deformation of the table during detection. The edges of the bearing table 30 are uniformly provided with a plurality of mounting holes, and the edges of the opening of the illumination cavity 31 are provided with matching threaded holes. The bearing table 30 is fastened and connected through the mounting holes and the threaded holes by cross countersunk head bolts, and is detachably fixed with the illumination cavity 31.

[0060] Among them, since the bearing table moves slowly during detection, the large-size PCB on the bearing table will not slide relatively on the bearing table due to the movement during detection, which will affect the detection. Therefore, no clamping component is provided on the bearing table 30 in the present application, and the PCB does not need to be clamped and fixed.

[0061] The illumination cavity 31 is provided with an illumination light source 32 electrically connected with the electric control box. The illumination light source 32 takes high-brightness LED surface light source as the core light-emitting unit. The LED surface light source is arranged in an array, and has uniform lamp bead density, stable brightness, low energy consumption, long service life, and is suitable for long-time continuous work requirement of industrial detection scene. The luminous brightness can be steplessly adjusted through the operation panel of the electric control box, and the best illumination intensity can be adapted according to PCBs with different thicknesses and different colors. Between the bearing table 30 and the LED surface light source, a diffuse reflection plate 33 is horizontally arranged. The diffuse reflection plate 33 is made of white high-transmittance acrylic material, and its edge is fixed through the annular support shoulder and buckle structure inside the illumination cavity 31, to ensure that the LED surface light source and the bearing table 30 are parallel after installation. The core function of the diffuse reflection plate 33 is to convert the direct light emitted by the LED surface light source into uniform diffuse light, effectively eliminating the light spot and uneven brightness phenomenon caused by the lamp bead array, so that the light forms a global uniform backlight effect when it penetrates through the bearing table 30, and finally the outline, hole boundary and appearance defects (such as notches, edge collapse and burrs) of the PCB form clear and sharp high-contrast imaging, which provides a stable and reliable image basis for subsequent sub-pixel level outline extraction.

[0062] In the actual detection process, the operator first places the large-size PCB to be detected on the bearing table 30, imports the corresponding PCB design data into the computer, and the system automatically generates the detection target and the detection area; then the equipment is started through the electric control box and the computer, and the lighting light source 32 is started immediately. The operator adjusts the camera module 53 to the best imaging distance by rotating the knob 521 adjustment mechanism 52. Then the electric control box issues a motion command to drive the mechanism 4 to drive the bearing mechanism 3 to move at a preset speed. The grating ruler assembly feedbacks the platform position information in real time, and the electric control box dynamically adjusts the motor speed according to the position data to ensure that the PCB movement speed is strictly synchronized with the scanning frequency of the TDI camera 530. The TDI camera 530 continuously collects image data and transmits it to the computer. After the computer completes image stitching, size measurement, defect identification and interlayer deviation comparison, the detection results are output on the computer, and finally the full-width seamless high-precision comprehensive detection of large-size PCB is realized, meeting the accuracy and efficiency requirements of high-end large-size PCB after forming Rapid first inspection.

[0063] Example 2

[0064] On the basis of example 1, the bearing mechanism 3 is further optimized and improved in this embodiment.

[0065] As shown in Figures 8-12 , in this embodiment, the bearing table 30 is still made of high-transmittance PC (polycarbonate) plate material, which is detachably connected with the threaded holes on the opening edge of the lighting cavity 31 through bolts, and the upper end surface is flush with the upper end surface of the second sliding platform 41 to ensure the flatness of the PCB placement.

[0066] As shown in Figures 8-10 , a circular mounting groove 8 adapted to the side lighting module 7 is provided around the side edge of the bearing table 30. The depth and width of the mounting groove 8 are accurately designed according to the cross-sectional size of the lighting pipe 70, and the threaded holes are arranged in the mounting groove 8. After the bolt is installed in the threaded hole, the bolt head 10 will protrude from the bottom of the mounting groove 8. A clamping groove 9 corresponding to the position of the bolt head 10 is provided at the bottom of the side lighting module 7, and a magnet is arranged in the clamping groove 9. The side lighting module 7 can be embedded in the mounting groove 8 and positioned by the clamping groove 9 and the bolt. The magnet can adsorb the bolt head 10, thereby improving the connection stability of the side lighting module 7 and facilitating the operator to quickly disassemble and assemble.

[0067] The structure of the illumination cavity 31 and the design and implementation of the internal illumination light source 32 and the diffuse reflection plate 33 are consistent with Embodiment 1: the illumination cavity 31 is an open cavity processed on the end face of the second sliding platform 41, the internal high-brightness LED surface light source is arranged in an array, and the brightness can be steplessly adjusted through the electric control box; the diffuse reflection plate 33 is made of white high-transmittance acrylic material, is used for converting direct light into uniform diffuse light, provides stable bottom backlight for the PCB, and ensures the basic imaging contrast of the outline and the hole position.

[0068] As shown in Figures 11-12 , the side illumination module 7 can be detachably embedded in the annular mounting groove 8 of the bearing table 30, is arranged higher than the bearing table 30, performs directional illumination on the upper side of the PCB through the frame-shaped surrounding structure, and forms a synergistic illumination effect with the bottom backlight. The side illumination module 7 includes an illumination pipeline 70, a side light source, a reflector 72 and a rotating assembly.

[0069] The illumination pipeline 70 is in a rectangular frame-shaped structure matched with the bearing table 30, is a hollow rectangular closed structure, and is fixedly connected by a connecting portion 75, a light-transmitting portion 71 and a light-incident portion 74 through glue or welding. The connecting portion 75 is in an “L” shape, is made of plastic or metal material, and plays a frame supporting role; the light-incident portion 74 is arranged at the bottom of the illumination pipeline 70 and is parallel to the PC plate of the bearing table 30, is made of high-transmittance PC material, and is used for receiving light of the side light source; the light-transmitting portion 71 is located at the side of the illumination pipeline 70 opposite to the center of the bearing table 30, is arranged obliquely relative to the bottom of the bearing table 30, is also made of high-transmittance PC material, and the oblique angle is designed through optical simulation to ensure that the reflected light can be accurately focused on the detection area on the surface of the PCB.

[0070] Since the bearing table 30 is made of high-transmittance PC material, part of the light emitted by the LED surface light source in the illumination cavity 31 is converted into uniform diffuse light by the diffuse reflection plate 33, penetrates the bearing table 30 to form bottom backlight, and the other part of the light directly penetrates the light-incident portion 74 through the edge area of the bearing table 30 to enter the inside of the illumination pipeline 70, without additional light path guidance, thereby realizing efficient reuse of the light source.

[0071] The light-transmitting portion 71 is located at the side of the illumination pipeline 70 opposite to the center of the bearing table 30, is arranged obliquely relative to the bottom of the bearing table 30, is also made of high-transmittance PC material, and the oblique angle is designed through optical simulation to ensure that the light reflected by the reflector 72 can be accurately focused on the detection area on the surface of the PCB, and the light coverage range is complementary to the bottom backlight, and just fills the shadow area of the thick-specification PCB hole wall and the surface concave-convex defects.

[0072] The plurality of reflectors 72 are arranged in a direction that is fully adapted to the frame-shaped structure of the illumination pipeline 70, and the mirror surfaces are treated to have high reflection efficiency. Each reflector 72 is fixed with a rotating shaft 73 on a side away from the light-transmitting part 71. The two ends of the rotating shaft 73 are rotatably connected to the inner side wall of the illumination pipeline 70 through micro bearings, so that the reflector 72 can rotate flexibly.

[0073] The rotating assembly is used to adjust the reflection angle of the reflector 72, and thus change the illumination direction and focusing range of the light. The rotating assembly includes a driving shaft 76 and a bevel gear set 77. The driving shaft 76 is arranged along the length direction of the illumination pipeline 70, and is rotatably arranged on a side of the illumination pipeline 70 corresponding to the rotating shaft 73 and perpendicular to the rotating shaft 73. The two ends of the driving shaft 76 are rotatably connected to the side wall of the illumination pipeline 70 through bearings, and one end extends to the outside of the illumination pipeline 70 and is fixed with an adjusting hand wheel, so as to facilitate manual adjustment by an operator.

[0074] The bevel gear set 77 includes a driven bevel gear fixed to the end of the rotating shaft 73 and a driving bevel gear fixed to a corresponding position of the driving shaft 76. The driving bevel gear and the driven bevel gear are meshed with each other to realize power transmission. When the operator rotates the adjusting hand wheel, the driving shaft 76 drives the driving bevel gear to rotate, and the driven rotating shaft 73 and the reflector 72 are synchronously rotated through the meshing transmission of the bevel gear set 77, so as to accurately adjust the reflection angle of the reflector 72 and realize flexible adaptation of the illumination range and intensity of the illumination light.

[0075] The detachable design of the side illumination module 7 improves the versatility of the equipment. For a conventional thin-specification PCB, the side illumination module 7 can be removed, and only the bottom backlight can be used to meet the detection requirements. For a complex structure PCB, the side illumination module 7 is installed, and the reflection angle and light source brightness of the reflector 72 are adjusted to adapt to different sizes and different hole distribution detection scenes. The illumination angle can be increased for the hole-intensive area to strengthen the hole wall illumination. The angle can be finely adjusted for the edge defect area to highlight the defect profile. The brightness of the side light source and the bottom backlight is independently adjusted, and the best brightness parameter can be selected according to the color (such as a dark solder mask) and material characteristics of the PCB surface, so as to further improve the imaging contrast.

[0076] Meanwhile, compared with the existing light supplement lamp fixed with a lens, the side illumination module 7 can ensure uniform illumination of the PCB, and avoid the movement of the light source to affect the display of the features on the PCB.

[0077] In the actual testing process, the operator first places the large-size PCB to be tested stably on the support platform 30. Based on the PCB's thickness, hole depth, and surface defects, the side lighting module 7 is embedded in the mounting groove 8 of the support platform 30, and positioned and fixed using the elastic clips on the groove wall. Then, the corresponding PCB design data is imported into the computer, and the system automatically generates the testing target and testing area. The equipment is started via the control panel, and the operator can choose to simultaneously turn on the bottom lighting source 32 and the side lighting source, or turn on the bottom backlight alone, depending on the testing requirements. The operator observes the imaging preview on the computer and rotates the adjustment handwheel of the side lighting module 7, which, via the bevel gear set 77, adjusts the reflection of the reflector 72. The angle is adjusted, and the brightness of the bottom light source and the side light source are adjusted separately through the electrical control box until the outline, hole position, hole wall and surface defects of the PCB are clearly imaged without shadows; then the adjustment knob 521 of the optical imaging mechanism 5 is rotated to adjust the camera module 53 to the optimal imaging distance; the electrical control box issues a motion command, the drive mechanism 4 drives the bearing mechanism 3 to move at a preset speed, and the grating ruler assembly provides real-time feedback of the platform position information to ensure that the PCB movement speed is strictly synchronized with the scanning frequency of the TDI camera 530; the TDI camera 530 continuously acquires image data and transmits it to the computer. After the computer completes image stitching, size measurement, defect identification and interlayer deviation comparison, the detection results are output on the display module.

[0078] Example 3

[0079] like Figure 13 As shown in Embodiment 2, the light source within the lighting conduit 70 can be an independent light source, fixed below the light inlet 74 and detachably connected to the lighting conduit 70 via bolts. It employs low-power, high-brightness LED strip light sources 11, evenly arranged along the frame structure of the lighting conduit 70. Its brightness can be independently adjusted via the electrical control box to adapt to the PCB inspection needs of different surface characteristics. The light source and the electrical control box are connected via wires and are uniformly controlled by the control box. Depending on the inspection scenario, it can be turned on independently or synchronously with the bottom backlight.

[0080] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0081] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, and improvement made in the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A large-size PCB size detection device, comprising a base (1), a control terminal (2), a bearing mechanism (3), a driving mechanism (4) and an optical imaging mechanism (5) which are signal connected with the control terminal (2) and arranged on the base (1), characterized in that: The driving mechanism (4) is arranged on the base (1), and the bearing mechanism (3) is assembled on the driving mechanism (4), and the driving mechanism (4) is used for driving the bearing mechanism (3) to drive the large-size PCB to move in the horizontal plane of the base (1) and realize synchronous linkage with the scanning action of the optical imaging mechanism (5); The optical imaging mechanism (5) is arranged above the bearing mechanism (3) and comprises a mounting frame (50) fixed to the base (1), a connecting seat (51) slidingly assembled on the mounting frame (50), an adjusting mechanism (52) for driving the connecting seat (51) to move up and down relative to the bearing mechanism (3) to adjust the imaging distance, and a camera module (53) arranged on the connecting seat (51); the camera module (53) comprises a TDI camera (530) and a telecentric lens (531) coaxially assembled below the TDI camera (530), the telecentric lens (531) is used for making the chief ray of the imaging light incident to the surface of the large-size PCB parallel to the optical axis and suppressing perspective distortion, and the TDI camera (530) is used for completing continuous line scanning imaging of the large-size PCB in a moving state through the telecentric lens (531) and outputting imaging data carrying the profile and hole features of the large-size PCB.

2. The large size PCB dimension detecting apparatus according to claim 1, wherein The driving mechanism (4) comprises a first sliding platform (40) and a second sliding platform (41) arranged perpendicular to each other, the first sliding platform (40) is slidingly connected with the base (1) through a sliding block guide rail structure (43), the second sliding platform (41) is arranged on the first sliding platform (40) through the sliding block guide rail structure (43), the moving directions of the first sliding platform (40) and the second sliding platform (41) are perpendicular to each other, and the bearing mechanism (3) is fixed on the second sliding platform (41); the driving mechanism (4) further comprises a driving motor (42) for driving the first sliding platform (40) and the second sliding platform (41) to move linearly in the horizontal direction, and the driving motor (42) is a linear driving motor (42).

3. The large size PCB dimension detecting apparatus according to claim 2, wherein The driving mechanism (4) further comprises a grating ruler assembly arranged between the first sliding platform (40) and the base (1) and between the second sliding platform (41) and the first sliding platform (40), respectively; the grating ruler assembly comprises a grating ruler body (44) and a reading head (45) matched with the grating ruler body (44), the reading head (45) is fixed to the sliding platform and is signal-connected with the control terminal (2), and the grating ruler body (44) is arranged parallel to the moving direction of the corresponding first sliding platform (40) or second sliding platform (41).

4. The apparatus according to claim 2, wherein The bearing mechanism (3) comprises a bearing table (30) fixedly arranged on the second sliding platform (41), the second sliding platform (41) is provided with an illumination cavity (31) with an opening above, the bearing table (30) is made of a light-transmitting material and is embedded in the opening of the illumination cavity (31), and the illumination cavity (31) is provided with an illumination light source (32) electrically connected with the control terminal (2).

5. The apparatus according to claim 1, wherein The adjusting mechanism (52) comprises an adjusting screw rod (520) rotatably arranged on the mounting frame (50), and an adjusting screw hole arranged on the connecting seat (51), one end of the adjusting screw rod (520) is fixed with a knob (521), and the other end is threadedly connected with the adjusting screw hole.

6. The apparatus according to claim 3, wherein The driving mechanism (4) further comprises a limiting and buffering assembly (6) arranged between the first sliding platform (40) and the base (1) and between the second sliding platform (41) and the first sliding platform (40) respectively; the limiting and buffering assembly (6) comprises two groups of buffering members (61) and a limiting seat (60); the limiting seat (60) is correspondingly fixed to the bottom of the first sliding platform (40) towards the base (1) and the bottom of the second sliding platform (41) towards the first sliding platform (40), and the limiting seat (60) is located at the middle of the corresponding sliding platform; the two groups of buffering members (61) are correspondingly arranged at the two ends of the limiting seat (60) along the movement direction of the corresponding sliding platform.

7. The apparatus according to claim 6, wherein The limiting and buffering assembly (6) further comprises a Hall sensor (62) arranged on the base (1) and the first sliding platform (40), the first sliding platform (40) and the second sliding platform (41) are provided with an induction sheet (63) matched with the corresponding Hall sensor (62); the Hall sensor (62) is connected with the control terminal (2) and is used for triggering a signal to make the corresponding driving motor (42) slow down and stop when the corresponding sliding platform moves to the position close to the stroke limit.

8. The apparatus according to claim 4, wherein The bearing mechanism (3) further comprises a side lighting module (7) detachably arranged above the bearing table (30), the side lighting module (7) is higher than the bearing table (30) to illuminate above the PCB placed on the bearing table (30).

9. The apparatus according to claim 8, wherein The bearing table (30) is provided with a mounting groove (8) on the side edge; the side lighting module (7) comprises a lighting pipe (70) embedded in the mounting groove (8), the lighting pipe (70) is in a frame structure surrounding the bearing table (30), and one side of the lighting pipe (70) relative to the center of the bearing table (30) is provided with a light transmission part (71) made of transparent material; the bottom of the lighting pipe (70) is provided with a light source; further comprising a plurality of reflecting mirrors (72) rotatably arranged in the lighting pipe (70), the plurality of reflecting mirrors (72) are arranged corresponding to the light transmission part (71), and the reflecting mirrors (72) are used for reflecting the light of the bottom light source to illuminate the center of the bearing table (30) through the light transmission part (71); further comprising a rotating assembly, the rotating assembly is used for adjusting the reflection angle of the reflecting mirrors (72) to the light.

10. The apparatus for detecting the size of a large-sized PCB according to claim 9, wherein, The lighting pipe (70) is in a hollow rectangular structure, which comprises the light transmission part (71) on one side relative to the center of the bearing table (30), the light inlet part (74) arranged on the bottom of the bearing table (30) and made of transparent material, and the connecting part (75) in "L" shape, the connecting part (75), the light transmission part (71) and the light inlet part (74) are connected to form a closed structure; the light transmission part (71) is arranged obliquely relative to the bottom of the bearing table (30); The rotating assembly comprises a rotating shaft (73) fixedly arranged on the side of the reflector (72) away from the light-transmitting part (71), and the lighting pipeline (70) is rotatably arranged on the side corresponding to the rotating shaft (73) and is provided with a driving shaft (76) perpendicular to the rotating shaft (73), and the driving shaft (76) and the rotating shaft (73) are in transmission connection through a bevel gear set (77).

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