A pin coplanarity detection device and detection method thereof

Abstract

The present invention belongs to the field of visual inspection technology, in particular to a pin coplanarity inspection device and a method thereof, the device comprising a control host system, a material conveying mechanism for horizontally conveying an inspection workpiece along a Y-axis direction, a first eccentric light source for obliquely irradiating the horizontal workpiece to be inspected downward, a first image acquisition mechanism for sequentially acquiring a plurality of upper side images of the workpiece to be inspected in the Y-axis direction, and a second eccentric light source for obliquely irradiating the horizontal workpiece to be inspected upward, and a second image acquisition mechanism for sequentially acquiring a plurality of lower side images of the workpiece to be inspected in the Y-axis direction; the first eccentric light source and the second eccentric light source both comprise at least two independently operable lighting units; the grayscale distribution is acquired along the length direction of the workpiece to be inspected by controlling the host system and judging whether there is a mismatch with a preset grayscale image according to the grayscale distribution, thereby achieving the correspondence between the grayscale, the brightness and the degree of skewness of the workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of visual inspection, and in particular to a pin coplanarity inspection device and a inspection method thereof. Background Art

[0002] Before soldering and mounting components such as terminal blocks or some data connectors, the pin coplanarity needs to be tested to ensure that the pin coplanarity meets the operating requirements. If the coplanarity is insufficient, it will cause the chip solder joints to be misaligned and the pins to be offset. If the coplanarity is too large, it will also cause scratches on the substrate.

[0003] The current inspection method is still mainly manual inspection, which is to place the inspected surface of the component to be inspected flat on the inspection table, and then display the axial projection of the terminal on the display screen through CCD, and mark the limited area in the screen area. If the worker finds that the terminal foot is outside the limited area, the product will be discarded to the NG station. However, this inspection method has the problems of inaccuracy, low efficiency and poor repeatability.

[0004] Therefore, how to accurately detect the coplanarity of the terminal pins has become an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0005] The object of the present invention is to provide a pin coplanarity detection device and a detection method thereof to solve the problems raised in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a pin coplanarity detection device, comprising:

[0007] A material conveying mechanism, used for horizontally conveying a transparent carrier plate loaded with horizontal workpieces to be inspected along the Y-axis direction;

[0008] A first eccentric light source is used to illuminate the horizontal workpiece to be inspected in an oblique downward direction; the first eccentric light source includes at least two first lighting units that can work independently, and the two first lighting units are arranged along the Y-axis direction;

[0009] A first image acquisition mechanism is disposed above the workpiece to be inspected and receives the light reflected by the first eccentric light source from the upper surface of the workpiece to be inspected to sequentially acquire a plurality of upper side images of the workpiece to be inspected in the Y-axis direction;

[0010] A second eccentric light source is used to illuminate the horizontal workpiece to be inspected in an inclined upward direction; the second eccentric light source includes at least two second lighting units that can work independently, and the two lighting units are arranged along the Y-axis direction;

[0011] A second image acquisition mechanism is disposed below the workpiece to be inspected and receives the light reflected by the second eccentric light source from the lower surface of the workpiece to be inspected to sequentially acquire multiple lower side images of the workpiece to be inspected in the Y-axis direction;

[0012] The host system is controlled to obtain the grayscale distribution of the first image and the second image along the length direction of the workpiece to be inspected, and it is determined whether there is a mismatch with a preset grayscale image according to the grayscale distribution.

[0013] The PIN coplanarity detection device of the present invention is characterized in that the first image acquisition mechanism is provided in plurality and distributed in a ring shape, and the first eccentric light source is provided in plurality corresponding to the first image acquisition mechanism.

[0014] The PIN needle coplanarity detection device described in the present invention, wherein the first image acquisition mechanisms are provided with three and arranged in a triangle, two of the three first image acquisition mechanisms are arranged along the Y-axis direction, and the plurality of first eccentric light sources are respectively located below the plurality of first image acquisition mechanisms.

[0015] The PIN coplanarity detection device described in the present invention is characterized in that the second eccentric light source is ring-shaped, the second lighting unit is arranged along the circumferential direction of the second eccentric light source, and the second image acquisition mechanism is coaxially arranged below the second eccentric light source.

[0016] The PIN coplanarity detection device of the present invention further comprises a first multi-axis driving mechanism for driving the second image acquisition mechanism to move on the ZYX axis.

[0017] The PIN coplanarity detection device of the present invention further comprises a second multi-axis driving mechanism for driving the first image acquisition mechanism to move in the XYZ axis direction.

[0018] The pin needle coplanarity detection device described in the present invention, wherein the first multi-axis drive mechanism and the second multi-axis drive mechanism both include an X-axis screw module, a Y-axis screw module and a Z-axis screw module.

[0019] The pin coplanarity detection device described in the present invention, wherein the material conveying mechanism includes two support frames arranged side by side along the X-axis direction, a transmission belt arranged on the support frames and rotating along the Y-axis direction, and a synchronous motor driving the two transmission belts to move synchronously; a movable pressure block is provided on the support frame above the transmission belt, and a pressing mechanism is also provided on the support frame to drive the movable pressure block to press down or leave the transparent carrier.

[0020] The pin needle coplanarity detection device described in the present invention, wherein the pressing mechanism includes a driving shaft arranged parallel to the top of the support frame, and a rotating unit driving the driving shaft to rotate around a fixed axis; the driving shaft is rotatably connected to the support frame, and the movable pressing block is provided with multiple and evenly arranged along the length direction of the driving shaft.

[0021] To achieve the above object, the present invention provides a method for detecting a pin coplanarity detection device, the method comprising the following steps:

[0022] The workpiece to be inspected is placed horizontally on the transparent carrier, and the two first lighting units of the first eccentric light source project light onto the upper surface of the workpiece to be inspected at an angle tilted downward and along the Y-axis direction;

[0023] The first image acquisition mechanism and the two first lighting units cooperate to sequentially acquire multiple upper side images of the upper surface of the workpiece to be inspected in the Y-axis direction, and the second image acquisition mechanism and the two second lighting units cooperate to sequentially acquire multiple lower side images of the lower surface of the workpiece to be inspected in the Y-axis direction;

[0024] Acquire grayscale images of the upper image and the lower image, and preset a plurality of grayscale distribution intervals in the grayscale images along the length direction of the workpiece to be inspected;

[0025] Whether the workpieces to be inspected are coplanar is determined according to the extent to which the grayscale values ​​of the plurality of grayscale distribution intervals exceed a threshold.

[0026] Compared with the prior art, the present invention has the following beneficial effects: during detection, the material conveying mechanism passes the horizontally placed workpiece to be detected through the first image acquisition mechanism and the second image acquisition mechanism in sequence, and the first eccentric light source and the second eccentric light source irradiate inclined light on the upper and lower surfaces of the workpiece to be detected and reflect it into the first image acquisition mechanism and the second image acquisition mechanism. If the workpiece to be detected is skewed, the intensity of the light reflected at the skewed position is different from the standard brightness of the normal workpiece, and the acquired upper and lower images are further processed by grayscale to obtain the surface grayscale distribution of the workpiece to be detected. If the detected grayscale distribution and the grayscale distribution of the normal workpiece are within the set threshold, it means that the state of the workpiece meets the standard. If the grayscale distribution is too different from the standard grayscale distribution, it means that the degree of skewness of the workpiece is extremely large, it is a defective product and cannot pass the detection. The detection method of this scheme is simple, and the speed, efficiency and accuracy can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is an overall structural diagram of the pin coplanarity detection device of the present invention.

[0029] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0030] Figure 3 This is a principle diagram of the optical path of the pin coplanarity detection device of the present invention when detecting a normal workpiece.

[0031] Figure 4 The present invention is a schematic diagram of the optical path of the pin coplanarity detection device when detecting an abnormal workpiece.

[0032] Figure 5 The present invention is a flowchart of the steps of the detection method of the pin coplanarity detection device. DETAILED DESCRIPTION

[0033] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the present invention and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] "Multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0036] Moreover, the terms "up, down, left, right, upper end, lower end, longitudinal" and the like indicating directions are all based on the posture and position of the device or equipment described in this solution during normal use.

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0038] This embodiment discloses Figures 1 to 5 The pin coplanarity detection device shown in the figure comprises a material conveying mechanism 10, which is used to horizontally transport a transparent carrier plate 20 loaded with a horizontal workpiece to be detected along the Y-axis direction, and the workpiece to be detected is horizontally placed on the transparent carrier plate 20, so that the pin 100 is also in a horizontal state;

[0039] Furthermore, the device also includes a first eccentric light source 30, which is used to illuminate the upper surface of the horizontal workpiece to be inspected at an angle downward; the first eccentric light source 30 includes at least two independently operable first lighting units 31, and the two first lighting units 31 are arranged along the Y-axis direction to provide the required lighting for the upper surface of the workpiece in the Y-axis direction.

[0040] Furthermore, the present device also includes a first image acquisition mechanism 40, which is arranged above the workpiece to be inspected and receives the light reflected by the first eccentric light source 30 through the upper surface of the workpiece to be inspected to sequentially acquire multiple upper side images of the workpiece to be inspected in the Y-axis direction. During the actual detection process, the upper side image needs to be shot at least once for each of the two first lighting units 31. In order to improve the anti-interference ability of recognition, the best way is to shoot multiple corresponding photos in the Y-axis direction and classify the multiple upper side images into the libraries corresponding to the two first lighting units 31, respectively, to facilitate separate comparison in subsequent image processing, thereby improving the refinement of recognition and ensuring the accuracy of the detection results.

[0041] Furthermore, the device also includes a second eccentric light source 50, which is used to illuminate the horizontal workpiece to be inspected at an angle upward; the second eccentric light source 50 includes at least two second lighting units 51 that can work independently, and the two lighting units are arranged along the Y-axis direction to provide the required lighting for the lower surface of the workpiece in the Y-axis direction.

[0042] Furthermore, the device also includes a second image acquisition mechanism 60, which is arranged below the workpiece to be detected and receives the light reflected by the second eccentric light source 50 through the lower surface of the workpiece to be detected to sequentially acquire multiple lower side images of the workpiece to be detected in the Y-axis direction. Similarly, in the actual detection process, the lower side images generally correspond to the two second lighting units 51 to sequentially acquire multiple images to increase the sample size of the comparison database and ensure the accuracy of the detection results. Among them, the first image acquisition mechanism 40 and the second image acquisition mechanism 60 are both high-precision cameras.

[0043] Furthermore, the device also includes a control host system 70, which obtains the grayscale distribution of the first image and the second image along the length direction of the workpiece to be inspected, and determines whether there is a mismatch with a preset grayscale image based on the grayscale distribution.

[0044] Specifically, during the inspection, the material conveying mechanism 10 sequentially passes the horizontally placed workpiece to be inspected through the first image acquisition mechanism 40 and the second image acquisition mechanism 60, and the first eccentric light source 30 and the second eccentric light source 50 irradiate the inclined light on the upper and lower surfaces of the workpiece to be inspected and reflect it into the first image acquisition mechanism 40 and the second image acquisition mechanism 60. If the workpiece to be inspected is skewed, the intensity of the light reflected from the skewed position is different from the standard brightness of the normal workpiece. The acquired upper and lower images are further processed by grayscale to obtain the surface grayscale distribution of the workpiece to be inspected. If the detected grayscale distribution is within the set threshold value with the grayscale distribution of the normal workpiece, it means that the state of the workpiece meets the standard (specifically, Figure 3 As shown, a normal pin can reflect light normally). If the grayscale distribution is too different from the standard grayscale distribution, it means that the workpiece is extremely skewed (for example, Figure 4 As shown, unqualified pins cannot reflect light normally, are defective products, and cannot pass the test; the detection method of this solution is simple, and the speed, efficiency and accuracy can be greatly improved.

[0045] In the present embodiment, a plurality of first image acquisition mechanisms 40 are provided and are distributed in a ring shape, and a plurality of first eccentric light sources 30 are provided corresponding to the first image acquisition mechanisms 40; specifically, three first image acquisition mechanisms 40 are provided and are arranged in a triangle shape; two of the three first image acquisition mechanisms 40 are arranged along the Y-axis direction, and the plurality of first eccentric light sources 30 are respectively located below the plurality of first image acquisition mechanisms 40. By providing a plurality of first image acquisition mechanisms 40, the surface reflection of the workpiece can be photographed at multiple angles, and the reflection of the surface of a skewed workpiece can be avoided from being close to that of a normal workpiece, which can effectively improve the fault tolerance of the system detection.

[0046] In this embodiment, the second eccentric light source 50 is ring-shaped, and the two second lighting units 51 are arranged along the circumferential direction of the second eccentric light source 50. The second image acquisition mechanism 60 is coaxially arranged below the second eccentric light source so that the second image acquisition mechanism 60 can continuously acquire the image of the workpiece through reciprocating motion.

[0047] Furthermore, the pin coplanarity detection device described in this embodiment also includes a first multi-axis driving mechanism 80 for driving the second image acquisition mechanism 60 to move on the ZYX axis, and a second multi-axis driving mechanism 90 for driving the first image acquisition mechanism 40 to move in the XYZ axis direction; so as to achieve image capture in a larger range and facilitate batch detection operations.

[0048] In this embodiment, the first multi-axis driving mechanism 80 and the second multi-axis driving mechanism 90 both include an X-axis screw module a1, a Y-axis screw module a2 and a Z-axis screw module a3. Of course, mechanisms such as a cylinder guide module or a linear motor module may also be used.

[0049] In this embodiment, the material conveying mechanism 10 includes two support frames 101 arranged side by side along the X-axis direction, a transmission belt 102 arranged on the support frame 101 and rotating along the Y-axis direction, and a synchronous motor 103 driving the two transmission belts 102 to move synchronously; a movable pressing block 110 is provided on the support frame 101 above the transmission belt 102, and a pressing mechanism 120 is also provided on the support frame 101 to drive the movable pressing block 110 to press down or leave the transparent carrier 20; wherein the pressing mechanism 120 includes a driving shaft 121 arranged parallel to the top of the support frame 101, and a rotating unit 122 driving the driving shaft 121 to rotate around a fixed axis; wherein the rotating unit 122 It can be a motor, a rotary cylinder, or a linear cylinder or electric cylinder connected by an eccentric rotation of a connecting rod. In this scheme, the last implementation mode is preferably used, in which the linear cylinder 221 is vertically arranged upward, one end of the connecting rod 222 is fixed to the driving shaft, and the other end is longitudinally hinged to the piston rod of the linear cylinder 221; further, the driving shaft 121 is rotatably connected to the support frame 101, and a plurality of movable pressure blocks 110 are provided and evenly arranged along the length direction of the driving shaft 121; through the cooperation of the pressing mechanism 120 and the movable pressure block 110, the stability of the transparent carrier 20 after it is in place can be guaranteed to avoid shaking that causes the workpiece to move and affect the detection.

[0050] Furthermore, the detection method of the pin coplanarity detection device described in this embodiment is as follows: Figure 5 As shown, the method comprises the following steps:

[0051] Step S10: The workpiece to be inspected is horizontally placed on the transparent carrier 20, and the two first lighting units 31 of the first eccentric light source 30 project light onto the upper surface of the workpiece to be inspected at an angle tilted downward and along the Y-axis direction;

[0052] Step S20: the first image acquisition mechanism 40 and the two first lighting units 31 cooperate to sequentially acquire multiple upper side images of the upper surface of the workpiece to be inspected in the Y-axis direction, and the second image acquisition mechanism 60 and the two second lighting units 51 cooperate to sequentially acquire multiple lower side images of the lower surface of the workpiece to be inspected in the Y-axis direction;

[0053] Step S30: obtaining grayscale images of the upper image and the lower image, and presetting a plurality of grayscale distribution intervals in the grayscale images along the length direction of the workpiece to be inspected;

[0054] Step S40: Determine whether the workpieces to be inspected are coplanar based on the degree to which the grayscale values ​​of multiple grayscale distribution intervals exceed the threshold. That is to say, if the difference between the grayscale value of each grayscale distribution interval and the preset standard value is within the allowable threshold range, it can be determined that the pin needle currently being inspected is not bent or skewed. If it exceeds the allowable threshold, it means that there are bent or skewed pin needles.

[0055] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A pin coplanarity detection device, characterized in that: include: A material conveying mechanism, used for horizontally conveying a transparent carrier plate loaded with horizontal workpieces to be inspected along the Y-axis direction; A first eccentric light source is used to illuminate the horizontal workpiece to be inspected in an oblique downward direction; the first eccentric light source includes at least two first lighting units that can work independently, and the two first lighting units are arranged along the Y-axis direction; A first image acquisition mechanism is disposed above the workpiece to be inspected and receives the light reflected by the first eccentric light source from the upper surface of the workpiece to be inspected to sequentially acquire a plurality of upper side images of the workpiece to be inspected in the Y-axis direction; A second eccentric light source is used to illuminate the horizontal workpiece to be inspected in an inclined upward direction; the second eccentric light source includes at least two second lighting units that can work independently, and the two lighting units are arranged along the Y-axis direction; A second image acquisition mechanism is disposed below the workpiece to be inspected and receives the light reflected by the second eccentric light source from the lower surface of the workpiece to be inspected to sequentially acquire multiple lower side images of the workpiece to be inspected in the Y-axis direction; Controlling the host system to obtain the grayscale distribution of the first image and the second image along the length direction of the workpiece to be inspected, and judging whether there is a mismatch with a preset grayscale image according to the grayscale distribution; The first image acquisition mechanism is provided in plurality and distributed in a ring shape, and the first eccentric light source is provided in plurality corresponding to the first image acquisition mechanism; The first image acquisition mechanisms are provided in three and arranged in a triangle, two of the three first image acquisition mechanisms are arranged along the Y-axis direction, and the first eccentric light sources are respectively located below the first image acquisition mechanisms.

2. The pin coplanarity detection device according to claim 1, characterized in that: The second eccentric light source is annular, the two second lighting units are arranged along the circumferential direction of the second eccentric light source, and the second image acquisition mechanism is coaxially arranged below the second eccentric light source.

3. The pin coplanarity detection device according to claim 2, characterized in that: The pin coplanarity detection device further comprises a first multi-axis driving mechanism for driving the second image acquisition mechanism to move on the ZYX axis.

4. The pin coplanarity detection device according to claim 3, characterized in that: The pin coplanarity detection device further comprises a second multi-axis driving mechanism for driving the first image acquisition mechanism to move in the XYZ axis direction.

5. The pin coplanarity detection device according to claim 4, characterized in that: The first multi-axis driving mechanism and the second multi-axis driving mechanism each include an X-axis screw module, a Y-axis screw module and a Z-axis screw module.

6. The pin coplanarity detection device according to claim 1, characterized in that: The material conveying mechanism includes two support frames arranged side by side along the X-axis direction, a transmission belt arranged on the support frames and rotating along the Y-axis direction, and a synchronous motor driving the two transmission belts to move synchronously; a movable pressure block is provided on the support frame above the transmission belt, and a pressing mechanism is also provided on the support frame to drive the movable pressure block to press down or leave the transparent carrier.

7. The pin coplanarity detection device according to claim 6, characterized in that: The pressing mechanism includes a driving shaft arranged parallel to the support frame and a rotating unit driving the driving shaft to rotate around a fixed axis; the driving shaft is rotatably connected to the support frame, and a plurality of movable pressing blocks are provided and are evenly arranged along the length direction of the driving shaft.

8. A pin coplanarity detection device detection method, applied to the pin coplanarity detection device according to any one of claims 1 to 7, characterized in that: The detection method comprises the following steps: The workpiece to be inspected is placed horizontally on the transparent carrier, and the two first lighting units of the first eccentric light source project light onto the upper surface of the workpiece to be inspected at an angle tilted downward and along the Y-axis direction; The first image acquisition mechanism and the two first lighting units cooperate to sequentially acquire multiple upper side images of the upper surface of the workpiece to be inspected in the Y-axis direction, and the second image acquisition mechanism and the two second lighting units cooperate to sequentially acquire multiple lower side images of the lower surface of the workpiece to be inspected in the Y-axis direction; Acquire grayscale images of the upper image and the lower image, and preset a plurality of grayscale distribution intervals in the grayscale images along the length direction of the workpiece to be inspected; Whether the workpieces to be inspected are coplanar is determined according to the extent to which the grayscale values ​​of the plurality of grayscale distribution intervals exceed a threshold.

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