Apparatus for optically inspecting electronic circuits

• US 9,036,024 B2
• Filed: 07/25/2011
• Issued: 05/19/2015
• Est. Priority Date: 07/26/2010
• Status: Active Grant

• Current Assignee: VIT SA (Mycronic AB)
• Original Assignee: VIT SA (Mycronic AB)
• Inventors: Perriollat, Mathieu
• Primary Examiner(s): Torrente, Richard
• Assistant Examiner(s): SUH, JOSEPH JINWOO
• Application Number:
  US13/190,149
• Publication Number:
  US 20120019650A1
• Time in Patent Office: 1,394 Days
• Field of Search: 348/87, 348/92, 348/46, 340/935, 356/239.1, 356/606, 382/154
• US Class Current: 348/87
• CPC Class Codes: G01B 11/2545 with one projection direction and several detection directions, e.g. stereo
• CPC Class Codes: G01N 2021/95638 for PCB's
• CPC Class Codes: G01N 21/8851 Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 2201/0635 Structured illumination, e.g. with grating
• CPC Class Codes: G01R 31/308 using non-ionising electromagnetic radiation, e.g. optical radiation investigating or analysing materials by the use of optical means G01N21/00; image analysis G06T7/00
• CPC Class Codes: G06T 1/0007 Image acquisition

Abstract

An installation of optical inspection of integrated circuits or the like, comprising: a planar conveyor along a first direction of the objects to be analyzed and a photographic system placed above an area of the conveyor and in a fixed position with respect thereto, the photographic system comprising at least one first set of digital cameras each comprising an orthogonal array of pixels, said cameras being aligned in a second direction different from the first one, the cameras being all oriented so that one of the orthogonal directions of their pixel array forms a first angle with the first direction.

Claims

1. An apparatus for optical inspection of objects, comprising:

a planar conveyor (1) along a first direction (X) of objects to be analyzed;

a photographic system (2) placed above an area of the conveyor and in a fixed position with respect thereto, the photographic system comprising at least one first set (2) of digital cameras (22) each comprising an orthogonal array of pixels, said cameras being aligned in a second direction (Y, Y′

) different from the first direction, the cameras being all oriented so that the orthogonal array of pixels is parallel to a plane (X, Y) of the planar conveyor and one of the orthogonal directions of their pixel array forms a first, non-zero angle (α

) less than 90 degrees with the first direction and the other direction of the orthogonal directions of their pixel array forms the first, non-zero angle (α

) less than 90 degrees with another direction perpendicular to the first direction.

2. The apparatus of claim 1, wherein the second direction is perpendicular to the first direction.

3. The apparatus of claim 1, wherein the pixels of the cameras are aligned with the second direction.

4. The apparatus of claim 1, wherein an image processing system is capable of applying a super-resolution processing to a succession of images provided by the photographic system.

5. The apparatus of claim 1, wherein the first angle (a) ranges between 3 and 20 degrees.

6. The apparatus of claim 1, comprising a second set of cameras (22), parallel to the first one in the second direction (Y).

7. The apparatus of claim 6, further comprising two projectors (24) of determined patterns, these patterns being such that two straight lines projected by the projectors are aligned in a plane defined by the first direction (X) and the second direction (Y) and are coplanar to a straight line (242) interconnecting the optical centers of the two projectors, the two straight lines forming one contiguous line.

8. An apparatus for optical inspection of objects, comprising:

a planar conveyor (1) along a first direction (X) of objects to be analyzed;

a photographic system (2) placed above an area of the conveyor and in a fixed position with respect thereto, the photographic system comprising at least one first set (2) of digital cameras (22) each comprising an orthogonal array of pixels, said cameras being aligned in a second direction (Y, Y′

) different from the first direction, the cameras being all oriented so that the orthogonal array of pixels is parallel to a plane (X, Y) of the planar the conveyor and one of the orthogonal directions of their pixel array forms a first, non-zero angle (α

) with the first direction and the other direction of the orthogonal directions of their pixel array is not perpendicular with the first direction.