US 2010/0315655 A1 · Method And Device For Measuring A Height Difference

Abstract

Determination of the height difference between a first reference point and a second reference point, at least one of the two reference points lying on a semiconductor chip, which is mounted on a substrate, comprises the steps A) recording a first image from a first direction, which runs diagonally to the surface of the substrate at a predetermined angle α2, the substrate and the semiconductor chip being illuminated from a second direction which runs diagonally to the surface of the substrate at a predetermined angle α3, a telecentric optics being located in the beam path, B) recording a second image from the second direction, the substrate and the semiconductor chip being illuminated from the first direction, either the cited telecentric optics or a further telecentric optics being located in the beam path, C) ascertaining a first coordinate of the position of the first reference point and a first coordinate of the position of the second reference point in the first image and determining a first difference between these two coordinates, D) ascertaining a first coordinate of the position of the first reference point and a first coordinate of the position of the second reference point in the second image and determining a second difference between these two coordinates, and E) calculating the height difference from the first difference and the second difference.

Claims6

Dependent claims

A method for measuring a height difference between a first reference point and a second reference point, at least one of the first and second reference points lying on a semiconductor chip, the chip mounted on a surface of a substrate, the method comprising:

recording a first image from a first direction, which runs diagonally to the surface of the substrate at a predetermined angle α2, the substrate and the semiconductor chip being illuminated by a beam of light along a first beam path from a second direction which runs diagonally to the surface of the substrate at a predetermined angle α3, a first telecentric optics located in the first beam path;
recording a second image from the second direction, the substrate and the semiconductor chip being illuminated by a beam of light along a second beam path from the first direction, either the first telecentric optics or a second telecentric optics located in the second beam path;
ascertaining a first coordinate of a position of the first reference point and a first coordinate of a position of the second reference point in the first image and determining a first difference between these two coordinates;
ascertaining a first coordinate of the position of the first reference point and a first coordinate of the position of the second reference point in the second image and determining a second difference between these two coordinates;
and
calculating the height difference from the first difference and the second difference.

3 more elements

A device for measuring a height difference between a first reference point and a second reference point, at least one of the first and second reference points lying on a semiconductor chip mounted on a substrate, the device comprising:

a single camera;
a telecentric optics situated in front of the camera;
a first, second and third semitransparent mirror arranged parallel to one another;
and
two light sources, the three mirrors and the two light sources configured (1) to permit the camera to record images of the substrate and the semiconductor chip from both a first direction and a second direction;
(2) to permit the substrate and the semiconductor chip to be illuminated from the second direction to record an image from the first direction;
and (3) to permit the substrate and the semiconductor chip to be illuminated from the first direction to record an image from the second direction.

4 more elements

Dependencies are inferred from the claim text.

Method And Device For Measuring A Height Difference

Life of this patent

Method And Device For Measuring A Height Difference

Life of this patent

Abstract

Claims6