INSTALLATION OF 3D INSPECTION OF ELECTRONIC CIRCUITS

• US 20120019651A1
• Filed: 07/25/2011
• Published: 01/26/2012
• Est. Priority Date: 07/26/2010
• Status: Active Grant

• Current Assignee: VIT SA (Mycronic AB)
• Original Assignee: VIT SA (Mycronic AB)
• Inventors: PERRIOLLAT, Mathieu
• Granted Patent: US 9,170,207 B2
• Time in Patent Office: Days
• 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 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 photographic system placed above a scene in a plane defined by a first and a second direction, the photographic system comprising several digital cameras each comprising an orthogonal array of pixels, all cameras having their respective optical axes inclined by a first angle with respect to a third direction perpendicular to the two others; and two projectors of determined patterns, these patterns being such that two straight lines projected by each of the projectors are aligned in the plane defined by the first two directions and are coplanar with a straight line interconnecting the optical centers of the two projectors.

Claims

1. An installation of optical inspection of integrated circuits or the like, comprising:

a photographic system placed above a scene in a plane defined by a first and a second direction, the photographic system comprising several digital cameras (22) each comprising an orthogonal array of pixels, all cameras having their respective optical axes inclined by a first angle (β

) with respect to a third direction (Z) perpendicular to the two others; and

two projectors (24) of determined patterns, these patterns being such that two straight lines projected by each of the projectors are aligned in the plane defined by the first two directions (X, Y) and are coplanar with a straight line (242) interconnecting the optical centers of the two projectors.

2. The installation of claim 1, wherein the first angle (β

) ranges between 15 and 25 degrees.

3. The installation of claim 1, wherein four cameras are associated with each projector and are oriented to aim at a same point on the viewing axis of this projector.

4. The installation of claim 1, wherein said patterns are such that two straight lines projected by each of the projectors are aligned in a plane defined by the first two directions (X, Y) and are coplanar with a straight line (242) interconnecting the optical centers of the two projectors.

5. The installation 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.

6. The installation of claim 1, further comprising a conveyor of the objects to be analyzed in a first direction (X) of said plane, the photographic system (2) being placed above an area of the conveyor and in a fixed position with respect thereto and said cameras being distributed in two sets (2) of cameras aligned in a second direction (Y, Y′

) different from the first one, the cameras being all oriented so that one of the orthogonal directions of their pixel array forms a second angle (α

) with the first direction.

7. The installation of claim 6, wherein the second direction is perpendicular to the first one.

8. The installation of claim 6, wherein the pixels of the different cameras are aligned with the second direction.

9. The installation of claim 5, wherein the second angle (α

) ranges between 3 and 20 degrees.