Patent ID: 11929334
Assignee: STATS CHIPPAC PTE. LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 0:
1. A method of making a semiconductor device, comprising:
disposing a first semiconductor die and second semiconductor die over a substrate;
disposing a beam homogenizer over the first semiconductor die by using a first camera to position the beam homogenizer over the first semiconductor die in a first position, wherein a beam from the beam homogenizer impacts the first semiconductor die and an entire footprint of the first semiconductor die is completely within the beam after the beam homogenizer is positioned over the first semiconductor die;
generating a first calibration equation by,
capturing a first image of the first semiconductor die and beam using a second camera with the beam homogenizer in the first position over the first semiconductor die, wherein the second camera is a different type of camera from the first camera,
calculating a first positional offset of the beam relative to the first semiconductor die in a first number of pixels by using image processing on the first image,
moving the beam homogenizer a known distance to a second position over the first semiconductor die,
capturing a second image of the first semiconductor die and beam using the second camera with the beam homogenizer in the second position over the first semiconductor die,
calculating a second positional offset of the beam relative to the first semiconductor die in a second number of pixels by using image processing on the second image, and
performing a linear regression with the known distance, first number of pixels, and second number of pixels;

returning the beam homogenizer to the first position over the first semiconductor die after generating the first calibration equation;
calculating a third positional offset of the beam relative to the first semiconductor die in a third number of pixels and a first rotational offset of the beam relative to the first semiconductor die in an angular unit by,
using the second camera to capture a third image of the beam and first semiconductor die,
performing image processing on the third image to determine a first boundary of the first semiconductor die and a second boundary of the beam, and
comparing the first boundary and second boundary,
wherein the entire footprint of the first semiconductor die remains completely within the beam;

using the first calibration equation to convert the third number of pixels into a first distance in millimeters;
moving the beam homogenizer the first distance in millimeters to align the beam and first semiconductor die, wherein the entire footprint of the first semiconductor die remains completely within the beam;
using a second calibration equation to convert the first rotational offset in the angular unit to a second distance in millimeters;
rotating the beam homogenizer by the second distance in millimeters to rotationally align the beam to the first semiconductor die, wherein the entire footprint of the first semiconductor die remains completely within the beam;
using the beam to melt a first solder bump of the first semiconductor die after moving the beam homogenizer the first distance in millimeters and rotating the beam homogenizer by the second distance in millimeters;
disposing the beam homogenizer over the second semiconductor die by using the first camera to position the beam homogenizer over the second semiconductor die in a third position, wherein the beam from the beam homogenizer impacts the second semiconductor die and an entire footprint of the second semiconductor die is completely within the beam after the beam homogenizer is positioned over the second semiconductor die;
calculating a fourth positional offset of the beam relative to the second semiconductor die in a fourth number of pixels and a second rotational offset of the beam relative to the second semiconductor die in the angular unit by,
using the second camera to capture a fourth image of the beam and second semiconductor die,
performing image processing on the fourth image to determine a third boundary of the second semiconductor die and a fourth boundary of the beam, and
comparing the third boundary and fourth boundary,
wherein the entire footprint of the second semiconductor die remains completely within the beam;

using the first calibration equation to convert the fourth number of pixels into a third distance in millimeters;
moving the beam homogenizer the third distance in millimeters to align the beam and second semiconductor die, wherein the entire footprint of the second semiconductor die remains completely within the beam;
using the second calibration equation to convert the second rotational offset in the angular unit to a fourth distance in millimeters;
rotating the beam homogenizer by the fourth distance in millimeters to rotationally align the beam to the second semiconductor die, wherein the entire footprint of the second semiconductor die remains completely within the beam; and
using the beam to melt a second solder bump of the second semiconductor die after moving the beam homogenizer the third distance in millimeters and rotating the beam homogenizer by the fourth distance in millimeters.