Three dimensional lead inspection system
AssigneeSemiconductor Technologies & Instruments, Inc.
InventorPao Meng Lee
Life of this patent
Estimating the term…
Abstract
A semiconductor device lead inspection apparatus and method are provided for capturing images of the semiconductor edges and leads along two optical axes which have different directions in a plane perpendicular to the semiconductor device edge. A first image is reflected off an optical surface of a prism to a direction corresponding to the camera optical axis. A second image is reflected by two optical surfaces of the prism to a direction corresponding to the camera optical axis.
Claims14
Apparatus for providing first and second backlit images of a semiconductor device edge and leads extending therefrom, said images representative of first and second viewing angles corresponding to first and second different optical axes as measured in a plane perpendicular to said device edge, comprising:
- at least one illuminator providing diffuse backlight illumination of said device edge and leads along said first and second optical axes;
- a triangular prism having a first optical surface facing said device edge and intersecting said first and second optical axes, a second optical surface forming an acute angle with said first optical axes, and a third optical surface, said first and second surfaces being at selected angles to said first and second optical axes to cause a first image of said device edge and leads along said first optical axis to be reflected by said second optical surface and emerge from said third optical surface in direction corresponding to a third optical axis and to cause a second image of said device edge and said leads along said second optical axis to be reflected by said second optical surface and said first optical surface and emerge from said third optical surface in a direction corresponding to said third optical axis;
- and
- a camera arranged to capture said first and second images along said third optical axis.
A method for providing first and second backlit images of a semiconductor device edge and leads extending therefrom, said images representing first and second viewing angles corresponding to first and second optical axes as measured in a plane perpendicular to said device edge, comprising:
- illuminating said device edge and leads with backlight diffuse illumination radiating in the directions of said first and second optical axes;
- providing a triangular prism having a first optical surface facing said device edge, a second optical surface forming an acute angle with said first optical surface and a third optical surface;
- a first image of said device edge and leads by said second optical surface in a direction emerging from said third optical surface corresponding to a third optical axis;
- reflecting a second image of said device edge and leads by said second and first optical surfaces in a direction emerging from said third optical surface corresponding to said third optical axes;
- and
- capturing said first and second images along said third optical axis.
Dependencies are inferred from the claim text.