Integrated X-ray and visual inspection systems

• US 6,272,204 B1
• Filed: 02/23/1999
• Issued: 08/07/2001
• Est. Priority Date: 02/23/1999
• Status: Expired due to Fees

• Current Assignee: Photon Dynamics Incorporated (KLA Corporation)
• Original Assignee: CR Technology, Inc. (KLA Corporation)
• Inventors: Amtower, Richard E., Chen, Shih-Liang, McGaffey, Jason T.
• Primary Examiner(s): Bruce, David V.
• Assistant Examiner(s): Dunn, Drew A.
• Application Number:
  US09/255,975
• Time in Patent Office: 896 Days
• Field of Search: 378/63, 378/62, 378/58, 378/98, 378/98.3, 382/145, 382/147, 382/150
• US Class Current: 378/63
• CPC Class Codes: G01N 23/04 and forming images of the material

Abstract

An integrated X-ray and visual inspection system having an inspection subsystem with a holder holding an object to be inspected, an X-ray source, a camera receiving an X-ray image of an object to be inspected and a camera receiving a visible image of an object to be inspected, the X-ray source and camera receiving the X-ray image being positioned on opposite sides of the holder. A display may also be provided for displaying the images. The system is well suited to the inspection of printed circuit boards having electronic components mounted thereon, in which case the holder may be a conveyor for the printed circuit boards. Independent positioning of the X-ray source and camera receiving the X-ray image allows offset images of the printed circuit board topside and bottomside features of the board. Various other features of the system and methods are disclosed.

Claims

1. An apparatus for inspecting an object, the apparatus comprising:

an inspection subsystem having therein, a holder holding an object to be inspected, an X-ray source, a first camera receiving an X-ray image of an object to be inspected and a second camera receiving a visible image of an object to be inspected, the X-ray source and first camera being positioned on opposite sides of the holder;

an X-ray image processor coupled to the first camera receiving the X-ray image of the object to be inspected and processing the X-ray image data;

a visual image processor coupled to the second camera receiving the visual image of the object to be inspected and processing the visual image data;

a processing unit coupled to the visual image processor and X-ray image processor combining the results of the processing of the first and second images to generate a decision; and

,

a display for displaying the X-ray image and the visible image.

2. The apparatus of claim 1 wherein the first and second cameras are on the same side of the holder.

3. The apparatus of claim 1 wherein the X-ray source and the first camera are separately positionable relative to an object to be inspected to provide offset views of the features of the object to be inspected.

4. The apparatus of claim 1 wherein the first camera includes an X-ray camera.

5. The apparatus of claim 1 wherein the X-ray source and the first camera are positionable by translational movements.

6. The apparatus of claim 1 wherein the second camera is positionable by translational movements.

7. The apparatus of claim 1 wherein the object to be inspected is a printed circuit board containing electronic components, and the holder is a conveyor controlling the movement of the printed circuit board through the inspection area.

8. The apparatus of claim 7 wherein the X-ray source and the first camera are separately positionable relative to the printed circuit board to provide offset views of the printed circuit board to allow separation of the topside and the bottomside features of the printed circuit board.

9. The apparatus of claim 8 wherein the X-ray source and the first camera are positionable by X-Y movements.

10. The apparatus of claim 1 wherein the first and second cameras are moveable within the subsystem to controllably view different parts of the object to be inspected.

11. The apparatus of claim 1 wherein the visual image processor detects component presence and position, component identification, orientation and polarity, and/or solder defects.

12. The apparatus of claim 1 wherein the X-ray image processor detects voids, solder joint quality, and/or wire sweep measurement.

13. An apparatus for inspecting a printed circuit board with components thereon, the apparatus comprising:

within a single inspection subsystem, a holder for holding a printed circuit board having first and second sides, an X-ray source on a first side of a printed circuit board in the holder, a first camera on the second side of a printed circuit board in the holder providing X-ray image data for a printed circuit board resulting from X-rays from the X-ray source passing through a printed circuit board and components thereon, and a second camera providing visible image data for one of the first and second sides of a printed circuit board in the holder;

an X-ray image processor coupled to the first camera receiving the X-ray image data for the printed circuit board to be inspected and processing the X-ray image data;

a visual image processor coupled to the second camera receiving the visual image data for the printed circuit board to be inspected and processing the visual image data;

a processing unit coupled to the visual image processor and X-ray image processor combining the results of the processing of the visual image data and the X-ray image data to generate a decision.

14. The apparatus of claim 13 further comprised of a display for displaying the X-ray image data and the visible image data.

15. The apparatus of claim 13 wherein the first and second cameras are on the same side of the holder.

16. The apparatus of claim 13 wherein the X-ray source and the first camera are separately positionable relative to a printed circuit board in the holder to provide offset views of the features of the printed circuit board.

17. The apparatus of claim 13 wherein the first camera includes an X-ray camera.

18. The apparatus of claim 17 wherein the holder is a conveyor controlling the movement of a printed circuit board through the inspection area.

19. The apparatus of claim 18 wherein the X-ray source and the first camera are separately positionable relative to the printed circuit board to provide offset views of the printed circuit board to allow separation of the topside and the bottomside features of the printed circuit board.

20. The apparatus of claim 19 wherein the X-ray source and the first camera are positionable by X-Y movements.

21. The apparatus of claim 13 wherein the first and second cameras are moveable within the subsystem to controllably view different parts of the printed circuit board to be inspected.

22. The apparatus of claim 13 wherein the visual image processor detects component presence and position, component identification, orientation and polarity, and/or solder defects.

23. The apparatus of claim 13 wherein the X-ray image processor detects voids, solder joint quality, and/or wire sweep measurement.

24. A method for inspecting an object comprising:

placing an object to be inspected into an inspection subsystem;

passing X-ray radiation through the object to be inspected within the inspection subsystem;

providing in electronic form X-ray image data of an object to be inspected within the inspection subsystem;

providing in electronic form visual image data of an object to be inspected within the inspection subsystem;

processing the visual image data to detect features in the visual image;

processing the X-ray image data to detect features in the X-ray image; and

,

combining the results of the processing of the visual image data and the X-ray image data to generate a decision.

25. The method of claim 24 wherein the X-ray image data may include X-ray image data for X-ray radiation passing through the object to be inspected at different angles to provide offset views of the features of the object to be inspected.

26. The method of claim 24 wherein the object to be inspected is a printed circuit board containing electronic components, and the printed circuit board is placed in the inspection subsystem by a conveyor.

27. The method of claim 24 wherein providing in electronic form X-ray image data of an object to be inspected within the inspection subsystem is achieved by movement of a first camera to different positions within the inspection subsystem, and providing in electronic form visual image data of an object to be inspected within the inspection subsystem is achieved by movement of a second camera to different positions within the inspection subsystem.

28. The method of claim 26 wherein the visual image data is processed to detect component presence and position, component identification, orientation and polarity, and/or solder defects.

29. The method of claim 26 wherein the X-ray image data is processed to detect voids, solder joint quality, and/or wire sweep measurement.

30. The method of claim 24 wherein the X-ray image data may include X-ray image data for X-ray radiation passing through the printed circuit board and electronic components thereon at different angles to provide offset views of the topside and the bottomside features of the printed circuit board.