Integrated circuit board visual inspection system and method

Abstract

The application discloses an integrated circuit board visual detection system, which comprises a first straight conveying belt unit and a visual detection dark box. One end of the conveying path of the first straight conveying belt unit is a circuit board feeding part, and the other end of the conveying path of the first straight conveying belt unit is provided with a circuit board turning-over mechanism. The integrated circuit board visual detection system can realize visual detection based on the one-by-one conveying of the straight conveying belt, and the integrated circuit board at the conveying end is turned over through the turning-over mechanism, so that the front and back of the conveyed integrated circuit board can be detected.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit board testing. Background Technology

[0002] Visual inspection of integrated circuit boards using a vision inspection system has been widely applied. The principle is to use an industrial vision inspection camera to scan and photograph each integrated circuit board being inspected on a conveyor belt, obtaining the surface pattern of the integrated circuit board. The vision system then analyzes and identifies visible structures on the surface of the integrated circuit board, such as dirt, spacing between components, component size, and component shape, and compares them with a standard pattern to determine whether it is qualified. Existing vision inspection methods based on linear conveyor belts can generally only inspect the front side of the conveyed integrated circuit boards and cannot inspect the back side. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a visual inspection system and method for integrated circuit boards, which can realize the inspection of both the front and back sides of integrated circuit boards.

[0004] Technical solution: To achieve the above objectives, the integrated circuit board visual inspection system of the present invention is characterized in that: it includes a first linear conveyor belt unit and a visual inspection dark box, one end of the conveying path of the first linear conveyor belt unit is a board loading part for the board to be inspected, and the other end of the conveying path of the first linear conveyor belt unit is provided with a board flipping mechanism.

[0005] The first linear conveyor belt unit passes through the conveyor belt through-hole on the side of the visual inspection dark box, which is equipped with a downward-facing visual camera. When the first linear conveyor belt unit conveys the circuit board to be inspected into the visual inspection dark box, the visual camera can completely capture the pattern on the upper surface of the circuit board to be inspected.

[0006] Furthermore, a conveyor belt end roller is tensioned on the inner side of the end of the first linear conveyor belt unit, and the active rotation of the conveyor belt end roller causes the first linear conveyor belt unit to perform linear conveying motion.

[0007] Furthermore, the section where the conveyor surface of the first linear conveyor belt unit is located is called the linear conveyor section, and the section where the conveyor belt of the first linear conveyor belt unit crosses the end roller of the conveyor belt in a semi-circular arc is called the conveyor belt arc section, and the outer arc surface of the conveyor belt arc section is tangent to the conveyor surface of the linear conveyor section.

[0008] Furthermore, the circuit board flipping mechanism includes motor a, the output shaft of motor a is a rotating shaft a, the axis of rotating shaft a coincides with the axis of the roller at the end of the conveyor belt; it also includes a wheel axle parallel to rotating shaft a, one end of the wheel axle is fixed to rotating shaft axle a via rocker arm a; a rolling roller is coaxially mounted on the outside of the wheel axle via bearings, the outer ring of the rolling roller is an elastic rolling surface.

[0009] Furthermore, when the rolling roller is parallel to the top of the end roller of the conveyor belt, the gap between the elastic rolling surface and the arc segment of the conveyor belt is just enough for the horizontal circuit board to be tested to pass through to the right.

[0010] Furthermore, the section through which the horizontal circuit board to be tested passes to the right through the gap between the elastic roller and the arc segment of the conveyor belt is denoted as the circuit board passing section. At this time, if the rotating shaft a rotates slowly clockwise, it will drive the elastic roller of the rolling roller to roll clockwise along the arc path of the arc segment of the conveyor belt, thereby causing the elastic roller of the rolling roller to gradually roll the circuit board passing section, forcing the circuit board passing section to gradually adhere to the arc segment of the conveyor belt, and causing the end of the circuit board to be tested away from the circuit board passing section to tilt upwards. When the elastic roller of the rolling roller rolls to the end of the circuit board passing section, the tilted circuit board to be tested forms an angle a° with the straight conveyor section.

[0011] Furthermore, the circuit board flipping mechanism also includes a b motor, the output shaft of which is denoted as the b rotating shaft. The b rotating shaft is parallel to the a rotating shaft and is higher than the surface of the linear conveyor section. The b rotating shaft is fixedly connected to a clamping unit via a b rocker arm. When the elastic rolling surface of the rolling roller rolls at the end of the circuit board passing section, forming an angle a° between the raised circuit board to be tested and the linear conveyor section, the b rotating shaft can drive the clamping unit to move to the lower side of the raised circuit board to be tested away from the end of the circuit board passing section via the b rocker arm. The clamping unit clamps the raised circuit board to be tested away from the end of the circuit board passing section.

[0012] Furthermore, a second linear conveyor unit is provided along the length direction at the end of the first linear conveyor unit away from the circuit board flipping mechanism, so that the circuit board conveyed on its own conveyor surface can be smoothly transferred to the second linear conveyor unit.

[0013] Furthermore, the inspection methods of the integrated circuit board vision inspection system:

[0014] Step 1: Place a circuit board on the board loading section of the circuit board to be tested;

[0015] Step 2: Transfer the circuit board to the right into the visual inspection dark box and perform visual inspection on the front of the circuit board;

[0016] Step 3: Continue to convey the circuit board to the right until the right end of the circuit board to be tested passes through the gap between the elastic roller and the arc section of the conveyor belt.

[0017] Step 4: A rotating shaft rotates clockwise, and the elastic rolling surface of the rolling roller rolls the circuit board through the section, so that the circuit board to be tested and the linear conveyor section form an angle a°.

[0018] Step 5: Rotate the b-axis counterclockwise, and the b-rocker arm drives the clamping unit to rotate counterclockwise around the axis of the b-axis until the raised circuit board to be tested is away from the lower side of one end of the circuit board passage section, and the clamping unit performs a clamping action.

[0019] Step six, the a-axis continues to rotate clockwise, and the elastic rolling surface of the rolling roller disengages from the circuit board and passes through the end of the segment;

[0020] Step 7: Rotate the b-axis counterclockwise. The clamping unit and the circuit board as a whole rotate counterclockwise around the axis of the b-axis until the circuit board is parallel to the upper side of the straight conveyor section.

[0021] Step 8: Control the clamping unit to perform a release action;

[0022] Step nine: The first linear conveyor belt unit conveys the circuit board to the left into the visual inspection dark box and performs visual inspection on the reverse side of the circuit board.

[0023] Beneficial effects: Based on visual inspection of sequential conveyor belt transport, the present invention enables the inspection of both the front and back sides of the transported integrated circuit board by flipping the board at the end of the conveyor belt using a flipping mechanism. Attached Figure Description

[0024] Appendix Figure 1 This is a schematic diagram of the overall structure of this solution;

[0025] Appendix Figure 2 A schematic diagram of the circuit board flipping mechanism;

[0026] Appendix Figure 3 This is a schematic diagram of the "Step 1" state;

[0027] Appendix Figure 4 This is a schematic diagram of the "Step Two" state;

[0028] Appendix Figure 5 This is a schematic diagram of the overall state in "Step Three";

[0029] Appendix Figure 6 This is a magnified view of a portion of the "Step 3" state;

[0030] Appendix Figure 7 This is a structural diagram of the "Step Four" state;

[0031] Appendix Figure 8 For the appendix Figure 7 The diagram showing the rocker arm has been omitted.

[0032] Appendix Figure 9 This is a structural diagram of the "Step 5" state;

[0033] Appendix Figure 10 For the appendix Figure 9 A three-dimensional schematic diagram;

[0034] Appendix Figure 11 This is a schematic diagram of the "Step Six" state;

[0035] Appendix Figure 12 This is a schematic diagram of the "Step Seven" state;

[0036] Appendix Figure 13 This is a schematic diagram of the clamping unit structure. Detailed Implementation

[0037] The invention will now be further described with reference to the accompanying drawings.

[0038] As attached Figures 1 to 13 The integrated circuit board vision inspection system shown is as follows: Figure 1 It includes a first linear conveyor belt unit 6 and a vision inspection dark box 16. One end of the conveying path of the first linear conveyor belt unit 6 is the board loading section 15 for the circuit board to be inspected, and the other end of the conveying path of the first linear conveyor belt unit 6 is provided with a circuit board flipping mechanism 17. A conveyor belt end roller 30 is tensioned on the inner side of the end of the first linear conveyor belt unit 6. The active rotation of the conveyor belt end roller 30 causes the first linear conveyor belt unit 6 to perform linear conveying motion.

[0039] The middle part of the first linear conveyor belt unit 6 passes through the conveyor belt through-hole 14 on the side of the visual inspection dark box 16. A visual camera 24 with the lens 25 facing downward is installed inside the visual inspection dark box 16. When the first linear conveyor belt unit 6 conveys the circuit board 8 to be inspected into the visual inspection dark box 16, the visual camera 24 can completely capture the pattern on the upper surface of the circuit board 8 to be inspected. Then, the existing vision system analyzes and identifies the visible structures such as dirt, spacing between components, component size, and component shape on the surface of the integrated circuit board and compares them with the standard pattern to determine whether it is qualified.

[0040] A second linear conveyor unit 5 is provided along the length of the end of the first linear conveyor unit 6 away from the circuit board flipping mechanism 17. The first linear conveyor unit 6 can smoothly transfer the circuit board 8 conveyed on its own conveying surface to the second linear conveyor unit 5. The second linear conveyor unit 5 is used to convey the circuit board that has completed the front and back visual inspection.

[0041] like Figure 2 and 7The section of the conveyor belt of the first linear conveyor belt unit 6 where the conveyor surface is located is denoted as linear conveyor section 6.1. The section of the conveyor belt of the first linear conveyor belt unit 6 that crosses the conveyor belt end roller 30 in a semi-circular arc is denoted as conveyor belt arc section 6.2. The outer arc surface of conveyor belt arc section 6.2 is tangent to the conveyor surface of linear conveyor section 6.1. The circuit board flipping mechanism 17 includes a bracket 19, on which a motor 20 is fixedly mounted. The output shaft of motor 20 is a rotating shaft 12. The axis of 2 coincides with the axis of the end roller 30 of the conveyor belt; it also includes a wheel axle 22 parallel to the a rotating shaft 12, one end of the wheel axle 22 is fixed to the a rotating shaft 12 via the a rocker arm 13; a rolling roller 7 is coaxially mounted on the wheel axle 22 via a bearing 21, the outer ring of the rolling roller 7 is an elastic rolling surface 7.1; the elastic rolling surface 7.1 can be made of elastic foam material or soft rubber material, in specific process steps, to avoid the flexible material elastic rolling surface 7.1 from crushing the integrated circuit board being tested.

[0042] like Figure 2 and 6 When the rolling roller 7 is parallel to the end roller 30 of the conveyor belt, the gap between the elastic rolling surface 7.1 and the arc segment 6.2 of the conveyor belt is just enough for the horizontal circuit board 8 to be tested to pass through to the right. The section where the horizontal circuit board 8 passes through the gap between the elastic rolling surface 7.1 and the arc segment 6.2 of the conveyor belt is denoted as the circuit board passing section 8.1. At this time, the rotating shaft 12 slowly rotates clockwise, which drives the elastic rolling surface 7.1 of the rolling roller 7 to roll clockwise along the arc path of the arc segment 6.2 of the conveyor belt. This causes the elastic rolling surface 7.1 of the rolling roller 7 to gradually roll the circuit board passing section 8.1, so that the circuit board passing section 8.1 is gradually forced to fit the arc segment 6.2 of the conveyor belt. This causes the end of the circuit board 8 to be tested away from the circuit board passing section 8.1 to be raised upward. When the elastic rolling surface 7.1 of the rolling roller 7 rolls to the end of the circuit board passing section 8.1, the raised circuit board 8 to be tested forms an angle α° with the straight conveyor segment 6.1. Figure 7 and 8 Angle a° is a preset value, which can fluctuate around 60°.

[0043] like Figure 2The circuit board flipping mechanism 17 also includes a b motor 18 fixed on a bracket 19. The output shaft of the b motor 18 is denoted as the b rotating shaft 10. The b rotating shaft 10 is parallel to the a rotating shaft 12, and the b rotating shaft 10 is higher than the plane where the linear conveyor section 6.1 is located. The b rotating shaft 10 is fixedly connected to a clamping unit 9 via a b rocker arm 11. The elastic rolling surface 7.1 of the rolling roller 7 rolls on the end of the circuit board passing section 8.1, so that when the raised circuit board 8 to be tested forms an angle α° with the linear conveyor section 6.1, the b rotating shaft 10 can drive the clamping unit 9 to move to the lower side of the raised circuit board 8 to the side away from the end of the circuit board passing section 8.1 via the b rocker arm 11. The clamping unit 9 clamps the lower side of the raised circuit board 8 to the side away from the end of the circuit board passing section 8.1. Figure 7 , 9 As shown in Figure 10.

[0044] like Figure 13 The specific structure of the clamping unit 9 includes a structural plate 1, with the end of the rocker arm 11 fixedly connected to the back side of the structural plate 1; a first clamping plate 4.1 and a second clamping plate 4.2 are respectively provided on both sides of the structural plate 1; a first set of electric telescopic devices 2.1 and a second set of electric telescopic devices 2.2 are respectively provided on the back of the structural plate 1; the first set of electric telescopic devices 2.1 and the second set of electric telescopic devices 2.2 drive the first clamping plate 4.1 and the second clamping plate 4.2 to perform a clamping action that moves closer to each other through the first telescopic rod 3.1 and the second telescopic rod 3.2 respectively.

[0045] Working method: In the initial state, the rolling roller 7 is positioned directly above the end roller 30 of the conveyor belt, parallel to it;

[0046] Step one: The robotic arm places a circuit board 8 to be inspected face up at the board loading section 15 of the first linear conveyor unit 6; as shown... Figure 3 As shown;

[0047] Step two: The first linear conveyor belt unit 6 conveys the circuit board 8, facing upwards, to the right into the visual inspection dark box 16; subsequently, the visual camera 24 inside the visual inspection dark box 16 captures the pattern on the upper surface of the circuit board 8, thus completing the frontal visual inspection of the circuit board 8; as shown... Figure 4 As shown;

[0048] Step 3: The first linear conveyor belt unit 6 continues to convey the circuit board 8, which has already undergone frontal visual inspection, to the right out of the visual inspection dark box 16. As the circuit board 8 to be inspected continues to be conveyed to the right, until the right end of the circuit board 8 passes through the gap between the elastic roller surface 7.1 and the arc segment 6.2 of the conveyor belt, the horizontal section of the circuit board 8 passing through the gap between the elastic roller surface 7.1 and the arc segment 6.2 of the conveyor belt is denoted as the circuit board passing section 8.1; Figure 5 and 6As shown;

[0049] Step four: Control motor 20 to slowly rotate shaft 12 clockwise, causing the elastic rolling surface 7.1 of the rolling roller 7 to roll clockwise along the arc path of the conveyor belt arc segment 6.2. This gradually rolls the elastic rolling surface 7.1 of the rolling roller 7 over the circuit board passing through segment 8.1, forcing the circuit board through segment 8.1 to gradually adhere to the arc segment 6.2 of the conveyor belt. Consequently, the end of the circuit board 8 to be tested away from the circuit board passing through segment 8.1 is lifted upwards until the elastic rolling surface 7.1 of the rolling roller 7 reaches the end of the circuit board passing through segment 8.1. The lifted circuit board 8 to be tested forms an angle α° with the straight conveyor segment 6.1. Figure 7 As shown;

[0050] Step 5: Control motor 18 to rotate shaft 10 counterclockwise, causing rocker arm 11 to drive clamping unit 9 to rotate counterclockwise around shaft 10 until clamping unit 9 moves to the lower side of the raised circuit board 8 away from the end of the circuit board through section 8.1. Clamping unit 9 then clamps the raised circuit board 8 away from the lower side of the end of the circuit board through section 8.1. Figure 9 As shown; (Since the elastic rolling surface 7.1 of the rolling roller 7 is a non-rigid structure, the included angle a° is not rigid. Therefore, in this step, even if the clamping unit 9 rotates counterclockwise around the axis of the b rotating shaft 10 and interferes with the movement of the circuit board 8 that has been raised, the included angle a° will change adaptively).

[0051] Step six: Control motor 20 to make shaft 12 continue to rotate slowly clockwise, thereby making the elastic rolling surface 7.1 of the rolling roller 7 continue to roll clockwise until it disengages from the end of the circuit board passage section 8.1, thus releasing the circuit board passage section 8.1;

[0052] Step 7: Control motor 18 to rotate shaft 10 counterclockwise, thereby causing rocker arm 11 to drive clamping unit 9 and the circuit board 8 to be tested clamped by clamping unit 9 to rotate counterclockwise around the axis of shaft 10 as a whole, until the circuit board 8 to be tested clamped by clamping unit 9 is parallel to the upper side of linear conveyor section 6.1. At this time, the reverse side of the circuit board 8 to be tested clamped by clamping unit 9 is facing upward.

[0053] Step 8: Control the clamping unit 9 to release the circuit board 8 to be tested, which is then released and placed parallel to the straight conveyor section 6.1 with its reverse side facing up. This completes the flipping action.

[0054] Step 9: The first linear conveyor belt unit 6 conveys the circuit board 8 to be inspected, which has completed the flipping action and is facing up, to the left into the visual inspection dark box 16; then the visual camera 24 in the visual inspection dark box 16 captures the pattern on the upper surface of the circuit board 8 to be inspected, thereby completing the visual inspection of the reverse side of the circuit board 8 to be inspected.

[0055] Step 10: The first linear conveyor belt unit 6 smoothly transfers the circuit board 8, which has completed the front and back visual inspection, to the second linear conveyor unit 5.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A visual inspection system for integrated circuit boards, characterized in that: It includes a first linear conveyor belt unit (6) and a visual inspection dark box (16). One end of the conveying path of the first linear conveyor belt unit (6) is the board loading section (15) of the circuit board to be inspected, and the other end of the conveying path of the first linear conveyor belt unit (6) is provided with a circuit board flipping mechanism (17). The first linear conveyor belt unit (6) passes through the conveyor belt throughlet (14) on the side of the visual inspection dark box (16). A visual camera (24) with its lens (25) facing downwards is installed inside the visual inspection dark box (16). When the first linear conveyor belt unit (6) conveys the circuit board (8) to be inspected into the visual inspection dark box (16), the visual camera (24) can completely capture the pattern on the upper surface of the circuit board (8) to be inspected. The inner side of the end of the first linear conveyor belt unit (6) is tensioned with a conveyor belt end roller (30), and the active rotation of the conveyor belt end roller (30) causes the first linear conveyor belt unit (6) to perform linear conveying motion. The section of the conveyor belt of the first linear conveyor belt unit (6) where the conveyor surface is located is called the linear conveyor section (6.1), and the section of the conveyor belt of the first linear conveyor belt unit (6) that crosses the conveyor belt end roller (30) in a semi-circular arc is called the conveyor belt arc section (6.2). The outer arc surface of the conveyor belt arc section (6.2) is tangent to the conveyor surface of the linear conveyor section (6.1). The circuit board flipping mechanism (17) includes a motor (20), the output shaft of the motor (20) is a rotating shaft (12), the axis of the rotating shaft (12) coincides with the axis of the conveyor belt end roller (30); it also includes a wheel axle (22) parallel to the rotating shaft (12), one end of the wheel axle (22) is fixed to the rotating shaft (12) by a rocker arm (13); a rolling wheel (7) is coaxially mounted on the wheel axle (22) through a bearing (21), and the outer ring of the rolling wheel (7) is an elastic rolling surface (7.1); When the rolling roller (7) is parallel to the top of the end roller (30) of the conveyor belt, the gap between the elastic rolling surface (7.1) and the arc section (6.2) of the conveyor belt is just enough for the horizontal circuit board (8) to be tested to pass through to the right. The horizontal circuit board (8) to be tested passes through the gap between the elastic rolling surface (7.1) and the arc section of the conveyor belt (6.2) to the right, which is called the circuit board passing section (8.1). At this time, if the a rotating shaft (12) rotates slowly clockwise, it will drive the elastic rolling surface (7.1) of the rolling roller (7) to roll clockwise along the arc path of the arc section of the conveyor belt (6.2), so that the elastic rolling surface (7.1) of the rolling roller (7) gradually rolls the circuit board passing section (8.1), so that the circuit board passing section (8.1) gradually forces the circuit board passing section (8.1) to fit the arc section of the conveyor belt (6.2), and then the end of the circuit board (8) to be tested away from the circuit board passing section (8.1) is tilted upward. When the elastic rolling surface (7.1) of the rolling roller (7) rolls to the end of the circuit board passing section (8.1), the tilted circuit board (8) to be tested forms an angle a° between it and the straight conveyor section (6.1). The circuit board flipping mechanism (17) also includes a b motor (18), the output shaft of which is called the b shaft (10). The b shaft (10) is parallel to the a shaft (12), and the b shaft (10) is higher than the plane where the linear conveyor section (6.1) is located. The b shaft (10) is fixedly connected to the clamping unit (9) through the b rocker arm (11). The elastic rolling surface (7.1) of the rolling roller (7) rolls on the end of the circuit board passing section (8.1), so that when the raised circuit board to be tested (8) forms an angle a° with the linear conveyor section (6.1), the b shaft (10) can drive the clamping unit (9) to move to the lower side of the raised circuit board to be tested (8) away from the circuit board passing section (8.1) through the b rocker arm (11). The clamping unit (9) clamps the raised circuit board to be tested (8) away from the circuit board passing section (8.1).

2. The inspection method of the integrated circuit board visual inspection system according to claim 1, characterized in that: Step 1: Place a circuit board (8) on the board loading section (15) of the circuit board to be tested; Step 2: Transfer the circuit board (8) to the right into the visual inspection dark box (16) and perform visual inspection on the front of the circuit board (8); Step 3: Continue to convey the circuit board (8) to the right until the right end of the circuit board (8) to be tested passes through the gap between the elastic roller surface (7.1) and the arc section of the conveyor belt (6.2); Step 4: the a rotating shaft (12) rotates clockwise, and the elastic rolling surface (7.1) of the rolling roller (7) rolls the circuit board through the section (8.1), so that the circuit board (8) to be tested and the linear conveying section (6.1) form an angle a°; Step 5, the b-rotor (10) rotates counterclockwise, and the b-rocker (11) drives the clamping unit (9) to rotate counterclockwise around the axis of the b-rotor (10) until the underside of the circuit board (8) that has been raised away from the circuit board through section (8.1) is away from the circuit board. The clamping unit (9) performs a clamping action. Step six, the a rotating shaft (12) continues to rotate clockwise, and the elastic rolling surface (7.1) of the rolling roller (7) disengages from the end of the circuit board passing through section (8.1); Step 7: Rotate the b-axis (10) counterclockwise, and the clamping unit (9) and the circuit board (8) rotate counterclockwise as a whole around the axis of the b-axis (10) until the circuit board (8) is parallel to the upper side of the straight conveyor section (6.1); Step 8: Control the clamping unit (9) to perform a release action; Step nine, the first linear conveyor belt unit (6) conveys the circuit board (8) to the left into the visual inspection dark box (16) and performs visual inspection on the reverse side of the circuit board (8).

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