Laser bonding is a marking technique that uses
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
s to bond an additive marking substance to a
substrate.
First invented in the mid 1990s by Paul W. Harrison, the founder of TherMark, LLC, this patent protected and patent pending technology produces permanent marks on metal, glass, ceramic and plastic parts for a diverse range of industrial and artistic applications, ranging from aerospace and medical to the awards and engraving industries. It differs from the more widely known techniques of
laser engraving
Laser engraving is the practice of using lasers to engrave an object. Laser marking, on the other hand, is a broader category of methods to leave marks on an object, which in some cases, also includes color change due to chemical/molecular alte ...
and
laser ablation
Laser ablation or photoablation (also called laser blasting) is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser ...
in that it is an additive process, adding material to the substrate surface instead of removing it.
Laser bonding has been achieved by
Nd:YAG,
CO2 laser,
Fiber laser
A fiber laser (or fibre laser in British English) is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium and holmium. They are related t ...
and
Diode-pumped solid-state laser
A diode-pumped solid-state laser (DPSSL) is a solid-state laser made by pumping a solid gain medium, for example, a ruby or a neodymium-doped YAG crystal, with a laser diode.
DPSSLs have advantages in compactness and efficiency over other types, ...
and can be accomplished using other forms of
radiant energy
Radiant may refer to:
Computers, software, and video games
* Radiant (software), a content management system
* GtkRadiant, a level editor created by id Software for their games
* Radiant AI, a technology developed by Bethesda Softworks for ''The ...
.
The laser bonding process
Mark quality depends on a variety of factors, including the substrate used, marking speed, laser spot size, beam overlap, materials thickness, and laser parameters. Laser bonding materials may be applied by various methods, including a brush on technique, spraying, pad printing, screen printing, roll coating, tape, and others.
The marking process generally comprises three steps:
1. Application of the marking material.
2. Irradiating the marking material with a laser in the form of the desired mark.
3. Removal of excess, unbonded material.
The resulting marking is permanently bonded to the substrate, and in most cases it is as durable as the substrate itself.
The durability of laser bonded markings
Markings placed on stainless steel are extremely durable and have survived such testing as abrasion resistance, chemical resistance, outdoor exposure, extreme heat, extreme cold, acids, bases and various organic solvents.
Marks on glass have been tested for resistance to acids, bases and scratching.
NASA's International Space Station, or ISS, was home to aluminum squares laser marked with CerMarkĀ® marking material for almost four years. These squares were part of the Material International Space Station Experiment, or MISSE.
In this experiment test markings were applied to coupons made of materials commonly used in the construction of the external components used on space transportation vehicles, satellites and space stations. Markings applied using a wide range of different methods and techniques, including laser bonding. The material test coupons were then affixed to spaces provided on test panels, which were then installed onto trays which were attached to the ISS during a space walk conducted during the STS-105 Mission flown on August 10, 2001. The trays were positioned on the ISS so that they could expect to receive the maximum amount of impact damage and exposure to a high degree of atomic oxygen and UV radiation.
The experiment was recovered on July 30, 2005 during STS-114 and returned to earth on August 9, 2005. The markings,
DataMatrix
A Data Matrix is a two-dimensional code consisting of black and white "cells" or dots arranged in either a square (geometry), square or rectangle, rectangular pattern, also known as a matrix (mathematics), matrix. The information to be encoded ...
two dimensional bar codes, were evaluated and found to be readable and visually looked as good as the day they were placed in orbit.
The laser bonding process is outlined and specified in both military and NASA
[NASA HDBK-6003 NASA Marking Handbook, Laser Bonding Section 5.1.5, p.15] marking specifications and standards. Laser bonding is also a preferred technique for use in the United States Department of Defense "Item Unique Identification" system (IUID).
See also
*
Laser engraving
Laser engraving is the practice of using lasers to engrave an object. Laser marking, on the other hand, is a broader category of methods to leave marks on an object, which in some cases, also includes color change due to chemical/molecular alte ...
*
Laser ablation
Laser ablation or photoablation (also called laser blasting) is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser ...
*
Laser applications
Many scientific, military, medical and commercial laser applications have been developed since the invention of the laser in 1958. The coherency, high monochromaticity, and ability to reach extremely high powers are all properties which allow f ...
References
{{Lasers
Bonding
Laser applications