# US 10,307,862 B2 · Laser micromachining with tailored bursts of short laser pulses

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,307,862 B2
- Document ID: US10307862B2
- Status: Granted
- Kind: B2
- Application number: 12/413,350
- Filed: 2009-03-27
- Published: 2010-09-30
- Granted: 2019-06-04
- Earliest claimed: 2009-03-27
- Assignees: Electro Scientific Industries, Inc.
- Applicants: Yunlong Sun
- Inventors: Yunlong Sun
- Web page: https://patentgrep.com/patent/US10307862B2

## CPC

- B23K 26/0624: {using ultrashort pulses, i.e. pulses of 1 ns or less}
- B23K 26/0622: by shaping pulses
- B23K 26/40: taking account of the properties of the material involved
- B23K 2103/10: Aluminium or alloys thereof
- B23K 2103/12: Copper or alloys thereof
- B23K 2103/172: {wherein at least one of the layers is non-metallic}
- B23K 2103/30: {Organic materials}
- B23K 2103/42: {Plastics other than composite materials}
- B23K 2103/50: {Inorganic materials other than metals or composite materials}
- B23K 2103/52: {Ceramics}
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

## Abstract

A series of laser pulse bundles or bursts are used for micromachining target structures. Each burst includes short laser pulses with temporal pulse widths that are less than approximately 1 nanosecond. A laser micromachining method includes generating a burst of laser pulses and adjusting an envelope of the burst of laser pulses for processing target locations. The method includes adjusting the burst envelope by selectively adjusting one or more first laser pulses within the burst to a first amplitude based on processing characteristics of a first feature at a target location, and selectively adjusting one or more second laser pulses within the burst to a second amplitude based on processing characteristics of a second feature at the target location. The method further includes directing the amplitude adjusted burst of laser pulses to the target location.

## Claims

### Claim 1

A laser micromachining method comprising:
generating, using an ultrafast laser source, a burst of laser pulses;
adjusting respective amplitudes of individual laser pulses within the burst of laser pulses, using a high-speed optical modulator, to produce a selectively shaped single burst envelope for processing a target location of a workpiece, the target location including a first layer overlying a second layer, wherein the first layer and the second layer comprise different materials with different laser processing characteristics, the adjusting comprising:
selectively adjusting one or more first laser pulses within the single burst envelope to a first amplitude based on processing characteristics of a first layer at a target location; and
selectively adjusting one or more second laser pulses within the single burst envelope to a second amplitude based on processing characteristics of a second layer at the target location; and
directing the amplitude adjusted burst of laser pulses to the target location, the single burst envelope of laser pulses processing both the first layer and the second layer at the same target location.

### Claim 2 (depends on 1)

The method of claim 1, wherein generating the burst of laser pulses comprises:
generating mode-locked laser pulses comprising respective temporal pulse widths that are less than or equal to approximately 1 nanosecond.

### Claim 3 (depends on 2)

The method of claim 2, wherein the respective temporal pulse widths are in a range between approximately 1 nanosecond and approximately 100 femtoseconds.

### Claim 4 (depends on 2)

The method of claim 2, further comprising:
generating the laser pulses at a repetition rate in a range between approximately 100 kHz and approximately 500 MHz.

### Claim 5 (depends on 1)

The method of claim 1, wherein generating the burst of laser pulses comprises:
generating the burst within a temporal width in a range between approximately 1 nanosecond and approximately 1 microsecond.

### Claim 6 (depends on 5)

The method of claim 5, wherein the target location is selected from a group of target types comprising: an electrically conductive link severing target, a material trimming target, a via forming target, a scribing target, and a dicing target.