Quality detection system for coating protective layer on surface of PCB (Printed Circuit Board)

Abstract

A quality detection system for coating a protective layer on the surface of a PCB comprises a conveying device, a detection device and a tray, the conveying device comprises two conveying rails, the tray is arranged on the two conveying rails, and the bottom of the tray is arranged in an overhead mode; a front detection position, a middle detection position and a rear detection position are sequentially arranged on the conveying device in the detection device, the detection device comprises a shell and two detection assemblies arranged in the shell, and the two detection assemblies are arranged on the upper side and the lower side of the conveying device respectively; the detection assembly comprises a light source and a camera; the light source and the camera are arranged right above or right below the middle detection position; the light source is a double-color light source, and emitted light is white light and ultraviolet light; the light source and the camera are both of a rotating structure and can rotate to face the front detection position, the middle detection position and the rear detection position respectively. The detection system provided by the utility model improves the detection efficiency and accuracy of the protective layer coated on the surface of the PCB, is high in practicability, and has relatively high popularization significance.

Description

Technical Field

[0001] The utility model relates to a circuit board detection system, in particular to a quality detection system for a PCB surface coating protection layer. Background Art

[0002] PCB stands for printed circuit board. It is a substrate used to support and connect electronic components. Made of insulating material and covered with a conductive pattern, PCBs provide reliable electrical connections and mechanical support by creating circuit paths on the conductive layer, enabling electronic components to be mounted and interconnected. When conformal coating is applied to PCBs, quality issues such as uneven thickness, bubbles, and impurities can occur. However, quality inspection of PCB conformal coating relies primarily on manual inspection under ultraviolet light. This method is susceptible to subjective factors and cannot guarantee efficiency and accuracy. Furthermore, the long-term exposure of inspectors to ultraviolet light poses a health risk.

[0003] To this end, specialized quality inspection systems have emerged in the industry. For example, Chinese Patent 201810776733.2 discloses a system and method for inspecting the quality of double-sided conformal coating on PCBs. This prior art quality inspection system first places the PCB carrier on a carrier flip module. After inspecting the top surface, the bottom surface is rotated upward to inspect the other side, resulting in low inspection efficiency. Furthermore, this inspection device lacks accuracy in detecting bubbles and foreign matter. Utility Model Content

[0004] Based on this, it is necessary to provide a quality inspection system for the PCB surface coating protective layer in response to the shortcomings of the existing technology.

[0005] A quality inspection system for a PCB surface coating protective layer comprises a conveying device, an inspection device and a tray, wherein the inspection device is arranged on the conveying device, the PCB is mounted on the tray, and the tray is placed on the conveying device, the conveying device drives the tray and moves it forward into the inspection device for inspection; the conveying device comprises two conveying rails, the tray is placed on the two conveying rails, and the bottom is arranged overhead; a front inspection position, a middle inspection position and a rear inspection position are sequentially provided on the conveying device within the inspection device, the inspection device comprises a housing and two inspection components arranged within the housing, and the two inspection components are respectively arranged on the upper and lower sides of the conveying device; the inspection component comprises a light source and a camera, and the light source and the camera are both arranged directly above or directly below the middle inspection position; the light source is a two-color light source, emitting white light and ultraviolet light respectively; the light source and the camera are both rotating structures, which can be rotated to face the front inspection position, the middle inspection position and the rear inspection position respectively.

[0006] Furthermore, a position to be measured is provided on the conveying device on the front side of the detection device, and the position to be measured is provided with a position sensor.

[0007] Furthermore, position sensors are also provided at corresponding positions of the front detection position, the middle detection position and the rear detection position.

[0008] Furthermore, a control center is included, and the plurality of position sensors are all connected to the control center via signals.

[0009] Furthermore, the tray is a frame structure, and the tray includes two oppositely arranged side frames and a cross-shaped inner limiting frame connected to the two side frames.

[0010] Furthermore, the inner side surfaces of the side frame and the inner limit frame are both provided with card slots, and adjacent card slots on the same side are connected.

[0011] Furthermore, the inner limit frame and the side frame have corresponding inner side surfaces provided with card slots, and the inner surface facing the opening has no card slots.

[0012] In summary, the present invention improves inspection efficiency by providing a conveyor device to continuously transport the tray to the inspection device for inspection, and then providing upper and lower inspection components to simultaneously inspect the PCB without turning it over. Furthermore, the rotatable design of the inspection components allows the camera to inspect the upper and lower surfaces and sides of the PCB from the front and both sides. The images from multiple angles are then combined and compared to achieve more accurate detection of bubbles, foreign matter, and thickness uniformity. This utility model is highly practical and has strong promotional significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of a quality inspection system for a PCB surface coating protective layer according to the present invention;

[0014] Figure 2 for Figure 1 Schematic diagram of the structure of the detection device;

[0015] Figure 3 for Figure 2 Schematic diagram of the rotation method of the top camera in the middle. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] like Figures 1 to 3As shown, the present invention provides a quality inspection system for a PCB surface coating protective layer, which is used to inspect the quality of the coating protective layer on the surface of a PCB 100. The system comprises a control center (not shown), a conveyor device 10, an inspection device 20, and a tray 30. The inspection device 20 is disposed on the conveyor device 10, and the PCB is mounted on the tray 30. The tray 30 is placed on the conveyor device 10. The conveyor device 10 drives the tray 30 and the PCB forward to the inspection device 20 for inspection.

[0018] The conveying device 10 includes two conveying rails 11, and the tray 30 is placed on the two conveying rails 11, with the bottom overhead. In this embodiment, the conveying method of the conveying rail 11 is a conventional conveyor belt or roller conveying. The tray 30 is a frame structure, and the tray 30 includes two oppositely arranged side frames and a cross-shaped inner limit frame connected to the two side frames. The inner surfaces of the side frames and the inner limit frame are provided with card slots, and the PCB100 is inserted from the outside, and there is no gear structure at its outer end. The two sides of the tray 30 are mounted on the two conveying rails 11. The PCB100 is provided with a side test area and a non-detection area on the edge. In this embodiment, the non-detection area on the edge is embedded in the card slot of the tray 30, and the detection area is displayed on the outside for easy detection.

[0019] A position to be measured is also provided on the conveying device 10 on the front side of the detection device 20, and a position sensor is provided on the position to be measured. A front detection position 12, a middle detection position 13 and a rear detection position 14 are provided on the conveying device 10 in the detection device 20. The front detection position 12, the middle detection position 13 and the rear detection position 14 are arranged along the conveying direction of the conveying device 10, and each detection position is provided with a position sensor so that the pallet 30 can accurately stop at the set position. Furthermore, in this embodiment, the position sensors of the position to be measured, the front detection position 12, the middle detection position 13 and the rear detection position 14 are all connected to the control center by signal. Under the premise that there are products at the above detection positions, all position sensors should sense the pallet at the same time and send signals. When the signal transmission of one or more sensors is inconsistent with the others, or the signal is sent in advance or no signal is sent, an alarm is issued to facilitate timely detection of abnormal points.

[0020] The detection device 20 includes a housing 21 and two detection assemblies 22 disposed within the housing 21. The two detection assemblies 22 are disposed on the upper and lower sides of the conveyor 10, respectively. The detection assembly includes a light source 221 and a camera 222. The light source 221 and the camera 222 are both disposed directly above or below the central detection position 13. The light source 221 is a two-color light source that can switch between emitting white light and ultraviolet light. In addition, the light source 221 and the camera 222 are both rotatable and can be rotated to face the front detection position 12, the central detection position 13, and the rear detection position 14, respectively.

[0021] During operation, when the frontmost tray 30 enters the front inspection position 12 and the next tray 30 enters the waiting position, the conveyor pauses, and the inspection device 20 first uses white light and then ultraviolet light to take photos. The upper and lower inspection assemblies 22 respectively take photos of the upper and lower surfaces and right side of the PCB on the tray 30. The conveyor 10 then restarts and transports the previous tray 30 to the middle inspection position 13, where photos of the upper and lower front surfaces are taken. The tray then enters the rear inspection position 14, where photos of the left side and upper and lower surfaces of the PCB are taken.

[0022] Specifically, when in the front inspection position 12, the light source 221 and camera 222 of the upper inspection assembly 22 rotate toward the front inspection position to take photos of the top and right sides of the PCB. The lower inspection assembly 22 rotates toward the front inspection position to take photos of the bottom and right sides of the PCB. After inspection, the conveyor 10 operates to move the inspection tray 30 to the middle inspection position 13. The light source 221 and camera 222 of the upper inspection assembly 22 rotate toward the middle inspection position 13 to take photos of the top side of the PCB. The lower inspection assembly 22 rotates toward the middle inspection position 13 to take photos of the bottom side of the PCB. When moving to the rear inspection position 14, the light source 221 and camera 222 of the upper inspection assembly 22 rotate toward the rear inspection position 14 to take photos of the top and left sides of the PCB. The lower inspection assembly 22 rotates toward the rear inspection position 14 to take photos of the bottom and left sides of the PCB. The captured photos are then transmitted to the control center's database for comparison and analysis.

[0023] In summary, the present invention improves inspection efficiency by providing a conveyor device 10 to continuously transport a tray 30 to the inspection device 20 for inspection, and then providing upper and lower inspection assemblies 22 to simultaneously inspect the PCB without turning it over. Furthermore, the rotatable design of the inspection assembly 22 enables the camera to inspect the upper and lower surfaces and sides of the PCB from the front and both sides. By combining and comparing images from multiple angles, more accurate detection of bubbles, foreign matter, and thickness uniformity can be achieved. This utility model is highly practical and has strong promotional significance.

[0024] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A quality inspection system for a PCB surface coating protective layer, characterized by: It includes a conveying device, a detection device and a tray, the detection device is arranged on the conveying device, the PCB is installed on the tray, and the tray is placed on the conveying device, the conveying device drives the tray and moves forward to the detection device for detection; the conveying device includes two conveying rails, the tray is placed on the two conveying rails, and the bottom is overhead; the conveying device in the detection device is provided with a front detection position, a middle detection position and a rear detection position in sequence, the detection device includes an outer shell and two detection components arranged in the outer shell, and the two detection components are respectively arranged on the upper and lower sides of the conveying device; the detection component includes a light source and a camera, and the light source and the camera are both arranged directly above or directly below the middle detection position; the light source is a two-color light source, and the light output is white light and ultraviolet light respectively; the light source and the camera are both rotating structures, which can be rotated to face the front detection position, the middle detection position and the rear detection position respectively.

2. A quality inspection system for a PCB surface coating protective layer as claimed in claim 1, characterized in that: A position to be measured is also provided on the conveying device at the front side of the detection device, and the position to be measured is provided with a position sensor.

3. A quality inspection system for a PCB surface coating protective layer as claimed in claim 2, characterized in that: Position sensors are also provided at corresponding positions of the front detection position, the middle detection position and the rear detection position.

4. A quality inspection system for a PCB surface coating protective layer as claimed in claim 3, characterized in that: It also includes a control center, and the plurality of position sensors are all connected to the control center by signals.

5. The quality inspection system for a PCB surface coating protective layer according to claim 1, characterized in that: The tray is a frame structure, comprising two oppositely arranged side frames and a cross-shaped inner limiting frame connected to the two side frames.

6. A quality inspection system for a PCB surface coating protective layer as claimed in claim 5, characterized in that: The inner side surfaces of the side frame and the inner limiting frame are both provided with card slots, and adjacent card slots on the same side are connected.

7. The quality inspection system for a PCB surface coating protective layer according to claim 5, characterized in that: The inner side surfaces of the inner limit frame and the side frame corresponding to each other are provided with card slots, and the inner surface facing the opening is not provided with a card slot.

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