Electronic component products and method of manufacturing electronic component products
A calibration and part inspection method for the inspection of ball grid array, BGA, devices. Two cameras image a precision pattern mask with dot patterns deposited on a transparent reticle. The precision pattern mask is used for calibration of the system. A light source and overhead light reflective diffuser provide illumination. A first camera images the reticle precision pattern mask from directly below. An additional mirror or prism located below the bottom plane of the reticle reflects the reticle pattern mask from a side view, through prisms or reflective surfaces, into a second camera and a second additional mirror or prism located below the bottom plane of the reticle reflects the opposite side view of the reticle pattern mask through prisms or mirrors into a second camera. By imaging more than one dot pattern the missing state values of the system can be resolved using a trigonometric solution. The reticle with the pattern mask is removed after calibration and the BGA to be inspected is placed with the balls facing downward, in such a manner as to be imaged by the two cameras. The scene of the part can thus be triangulated and the dimensions of the BGA are determined.
1. A method of manufacturing a ball array device, the method comprising:
making a three dimensional inspection of a lead on the ball array device with the ball array device being positioned in a fixed optical system; and
selecting the ball array device as a produced ball array device based upon the results of the three dimensional inspection;
wherein the three dimensional inspection comprises:
illuminating the ball array device;
taking a first image of the ball array device with a first camera disposed in a fixed focus position relative to the ball array device to obtain a characteristic circular doughnut shape image from at least one ball;
taking a second image of the ball array device with a second camera disposed in a fixed focus position relative to the ball array device to obtain a side view image of the at least one ball; and
processing the first image and the second image using a triangulation method to calculate a three dimensional position of the at least one ball with reference to a pre-calculated calibration plane.
2. The method of manufacturing of claim 1 , wherein the second image comprises a segment having a crescent shape.
3. The method of manufacturing of claim 1 , wherein the calibration plane comprises a coordinate system having X, Y and Z axes and wherein an X measurement value is proportional to a Z measurement value.
4. The method of manufacturing of claim 1 , wherein the triangulation method to calculate a three dimensional position of the at least one ball is based on determining a center of the ball in the first image and determining a ball top location in the second image.
5. The method of manufacturing of claim 1 , wherein the pre-calculated calibration plane is defined through measuring a calibration pattern.
6. The method of manufacturing of claim 1 , wherein the taking a second image further comprises interposing a mirror between the ball array device and the second camera.
7. The method of manufacturing of claim 1 , wherein the second image is obtained at a low angle of view.
8. The method of manufacturing of claim 1 , wherein the first camera and the second camera are fixed at different angles relative to the calibration plane.
9. The method of manufacturing of claim 1 , wherein the processing measurements from the first image and the second image comprises employing grayscale edge detection to locate ball positions.
10. The method of manufacturing of claim 1 , wherein the illuminating the ball array device comprises employing diffuse illumination.
11. The method of manufacturing of claim 1 , wherein the ball array device comprises a ball grid array device.
12. The method of manufacturing of claim 1 , wherein the ball array device comprises a bump on wafer device.
13. The method of manufacturing of claim 1 , wherein illuminating is achieved using a single light source.
14. The method of manufacturing of claim 1 , wherein illuminating is achieved using more than one light source.
15. The method of manufacturing of claim 14 , wherein the more than one light sources used are spectrally diverse from one another.
16. A method of manufacturing a ball array device, the method comprising:
making a three dimensional inspection of a lead on the ball array device with the ball array device being positioned in an optical system; and
selecting the ball array device as a produced ball array device based upon the results of the three dimensional inspection;
wherein the three dimensional inspection comprises:
illuminating the ball array device to produce reflections;
taking a first image of the reflections with a first camera disposed in a first fixed position to obtain a circular doughnut shape image of the ball array device;
taking a second image of the reflections with a second camera disposed in a second fixed position non-parallel to the first fixed position to obtain a side view of the ball array device; and
processing measurements from the first image and the second image to calculate a three dimensional position of at least one ball using a triangulation method with reference to a pre-calculated calibration plane.
17. The method of manufacturing of claim 16 , wherein the second image comprises a segment having a crescent shape.
18. The method of manufacturing of claim 16 , wherein the calibration plane comprises a coordinate system having X, Y and Z axes and wherein an X measurement value is proportional to a Z measurement value.
19. The method of manufacturing of claim 16 , wherein the pre-calculated calibration plane is defined through measuring a calibration pattern.
20. The method of manufacturing of claim 16 , wherein the taking a second image further comprises interposing a mirror between the ball array device and the second camera.
21. The method of manufacturing of claim 16 , wherein the processing measurements from the first image and the second image comprises employing grayscale edge detection to locate ball positions.
22. The method of manufacturing of claim 16 , wherein the processing measurements from the first image and the second image comprises employing grayscale edge detection to locate ball positions.
23. The method of manufacturing of claim 16 , wherein the illuminating the ball array device comprises employing diffuse illumination.
24. The method of manufacturing of claim 16 , wherein the ball array device comprises a ball grid array device.
25. The method of manufacturing of claim 16 , wherein the ball array device comprises a bump on wafer device.
26. The method of manufacturing of claim 16 , wherein illuminating is achieved using a single light source.
27. The method of manufacturing of claim 16 , wherein illuminating is achieved using more than one light source.
28. The method of manufacturing of claim 27 , wherein the more than one light sources used are spectrally diverse from one another.
29. A method of manufacturing a ball array device, the method comprising:
making a three dimensional inspection of a lead on the ball array device with the ball array device being positioned in an optical system; and
selecting the ball array device as a produced ball array device based upon the results of the three dimensional inspection;
wherein the three dimensional inspection comprises:
illuminating the ball array device;
taking a first image of the ball array device with a first camera disposed in a first fixed position relative to the ball array device to obtain a circular doughnut shape view of the ball array device, wherein the first camera includes a charged coupled device array;
taking a second image of the ball array device with a second camera disposed in a second fixed position non-parallel to the first fixed position to obtain a side view of the ball array device, wherein a fixed mirror is interposed to reflect light between the ball array device and the second camera, and wherein the second camera includes a charged coupled device array; and
processing measurements from the first image and the second image to calculate a three dimensional position of at least one ball using a triangulation method with reference to a pre-calculated calibration plane, wherein the calibration plane comprises a coordinate system having X, Y and Z axes, and wherein an X measurement value is proportional to a Z measurement value.
30. The method of manufacturing of claim 29 , wherein the second image comprises a segment having a crescent shape.
31. The method of manufacturing of claim 29 , wherein the pre-calculated calibration plane is defined through measuring a calibration pattern.
32. The method of manufacturing of claim 29 , wherein the processing measurements from the first image and the second image comprises employing grayscale edge detection to locate ball positions.
33. The method of manufacturing of claim 29 , wherein the illuminating the ball array device comprises employing diffuse illumination.
34. The method of manufacturing of claim 29 , wherein the ball array device comprises a ball grid array device.
35. The method of manufacturing of claim 29 , wherein the ball array device comprises a bump on wafer device.