Beam shaping and projection imaging with solid state UV gaussian beam to form vias

A laser system, comprising:

• a diode-pumped, solid-state laser for generating ultraviolet Gaussian laser output having a Gaussian energy along an optical path;
• a beam-shaping element positioned along the optical path for converting the Gaussian laser output to shaped output having a central irradiance profile of high and uniform intensity and an outer irradiance profile of low intensity;
• an aperture positioned along the optical path for clipping a major portion of the outer irradiance profile of the shaped output and passing a major portion of the Gaussian energy through the aperture to produce apertured shaped output having apertured shaped energy;
• a zoom lens assembly positioned along the optical path between the aperture and a target location on a work piece;
• one or more imaging lens components for converting the apertured shaped output into imaged shaped output;
• and
• a positioning system for directing the imaged shaped output toward the target location to form a via.

A laser system, comprising:

• a diode-pumped, solid-state laser for generating Gaussian laser output having a Gaussian energy along an optical path;
• a first removable imaging optics rail positioned along the optical path, the first imaging optics rail housing a first beam shaping component and a first aperture, the first beam shaping component being positioned along a first rail path collinear with the optical path to convert the Gaussian laser output to first shaped output having a first central irradiance profile of high and uniform intensity and a first outer irradiance profile of low intensity, the first aperture being positioned along the optical path to clip a first portion of the first outer irradiance profile of the first shaped output and pass at least 50% of the Gaussian energy through the first aperture to produce first apertured shaped output having first apertured shaped energy, the first imaging optics rail being replaceable with a second imaging optics rail housing a second beam shaping component and a second aperture, the second beam shaping component being positioned along a second rail path designed to be collinear with the optical path to convert the Gaussian laser output to second shaped output having a second central irradiance profile of high and uniform intensity and a second outer irradiance profile of low intensity, the second aperture being positioned along the optical path to clip a second portion of the second outer irradiance profile of the second shaped output and pass at least 50% of the Gaussian energy through the second aperture to produce second apertured shaped output having second apertured shaped energy, wherein the second apertured shaped energy is of an amount different from that of the first apertured shaped energy;
• one or more imaging lens components for converting the first or second apertured shaped output into respective first or second image shaped output, wherein the first image shaped output has a first irradiance on a work piece and the second imaged shaped output has a second irradiance on the work piece different from the that of the first irradiance profile;
• and
• a positioning system for directing the imaged shaped output toward a target location on the work piece.

A method for substantially matching the performance of substantially similar first and second laser systems, the first laser system having a first diode-pumped, solid-state laser for generating first ultraviolet Gaussian laser output having a first Gaussian energy along a first optical path;

• a first diffractive optical element positioned along the first optical path for converting the first Gaussian laser output to first shaped output having a first central irradiance profile of high and uniform intensity and a first outer irradiance profile of low intensity, a first variable beam expansion assembly positioned along the first optical path between the first laser and the first diffractive optical element, a first aperture positioned along the first optical path for clipping a major portion of the first outer irradiance profile of the first shaped output and passing at least 50% of the first Gaussian energy through the first aperture to produce first apertured shaped output having first apertured shaped energy, one or more first imaging lens components for converting the first apertured shaped output into first image shaped output;
• and a first positioning system for directing the first imaged shaped output toward a first target location on a first work piece, the second laser system having a second diode-pumped, solid-state laser for generating second ultraviolet Gaussian laser output having a second Gaussian energy along a second optical path;
• a second diffractive optical element positioned along the second optical path for converting the second Gaussian laser output to second shaped output having a second central irradiance profile of high and uniform intensity and a second outer irradiance profile of low intensity, a second variable beam expansion assembly positioned along the second optical path between the second laser and the second diffractive optical element, a second aperture positioned along the second optical path for clipping a major portion of the second outer irradiance profile of the second shaped output and passing at least 50% of the second Gaussian energy through the second aperture to produce second apertured shaped output having second apertured shaped energy, one or more second imaging lens components for converting the second apertured shaped output into second image shaped output;
• and a second positioning system for directing the second imaged shaped output toward a second target location on a second work piece, the first and second lasers or the first and second diffractive optical elements have unintentional performance differences, comprising:
• impinging the first target with the first imaged shaped output of the first laser system;
• impinging the second target with the second imaged shaped output of the second laser system;
• comparing first results of impingement with the first imaged shaped output to second results of impingement with the second imaged shaped output;
• and
• employing the first and/or second variable beam expansion assemblies to compensate for performance differences between the first and second results such that the first and second laser systems exhibit substantially the same performance for a given laser application.

A method for substantially matching a second performance of a laser system on a second target of a second material to a first performance of the laser system on a first target of a first material, the laser system including a diode-pumped, solid-state laser for generating ultraviolet Gaussian laser output having a Gaussian energy along an optical path, a beam-shaping element positioned along the optical path for converting the Gaussian laser output to shaped output having a central irradiance profile of high and uniform intensity and an outer irradiance profile of low intensity, an aperture positioned along the optical path for clipping a major portion of the outer irradiance profile of the shaped output and passing a major portion of the Gaussian energy through the aperture to produce apertured shaped output having apertured shaped energy, a zoom lens assembly positioned along the optical path between the aperture and a target location on a work piece, one or more imaging lens components for converting the apertured shaped output into image shaped output, and a positioning system for directing the imaged shaped output toward the target location to form a via, the first and second target materials having different laser ablation characteristics such that a given set of laser parameters would form with a first imaged shaped output a first via of a first major spatial dimension in the first target material and the same set of laser parameters would form with a second imaged shaped output a second via of second major spatial dimension in the second target material, comprising:

• impinging the first target material with the first imaged shaped output of the first spot size to form the first via of the first major spatial dimension;
• impinging the second target with the second imaged shaped output of the second spot size to form the second via of the second major spatial dimension;
• comparing the first and second spatial dimensions;
• and
• employing the zoom lens assembly to compensate for differences between the first and second major spatial dimensions such that vias formed in the first and second target materials exhibit substantially similar major spatial dimensions with substantially similar laser parameters.