UV Laser Marking

Discover how UV laser markers work, when you should use one, and why their wavelength is so special.

Applications

UV lasers use a highly absorptive wavelength (355 nm) to mark parts. This high absorption rate allows UV lasers to perform "cold marking," ensuring that no extra heat stress is applied to materials, including those with high reflectance such as gold, silver, and copper. This minimizes soot and burrs caused from typical marking and processing.

Light wavelength distribution map
Applications
A
Ultraviolet range
B
Visible range
C
Infrared range
Multicolor automotive relays
Multicolor automotive relays
Earbuds
Earbuds
Chemical bottles
Chemical bottles
Copper lead frames
Copper lead frames
Steel tools (scissors, etc.)
Steel tools (scissors, etc.)
Food packaging film
Food packaging film

Mechanism and Characteristics of UV Lasers

By passing a standard wavelength laser (1064 nm) through a non-linear crystal, the wavelength is reduced to 532 nm. This light is further passed through another crystal, effectively reducing its wavelength to 355 nm. As a result, UV lasers are commonly called third-harmonic generation (THG) lasers.

Mechanism and Characteristics of UV Lasers
A
1064 nm standard wavelength
B
532 nm green wavelength
C
355 nm UV wavelength

Feature: High-contrast marking

Compared with standard laser light (1064 nm) and green laser light (532 nm), UV laser light has a remarkably higher material absorption rate. This means the power does not need to be increased to create highly visible marks.

Absorption rates for various resin materials
Absorption rates for various resin materials
* The values are for reference only and do not account for surface reflectivity.

Marking comparison

In-vehicle plastic part
[Material: Natural Polyamide]
Conventional model
Conventional model
MD-U
MD-U
Plastic Tube
[Material: Silicon]
Conventional model
Conventional model
MD-U
MD-U
Power switch cover
[Material: Urea formaldehyde white]
Conventional model
Conventional model
MD-U
MD-U
Gas meter casing
(with red marking surface)
Conventional model
Conventional model
MD-U
MD-U

Feature: Damage-free marking

UV lasers can mark highly reflective materials like gold, silver and copper with minimal heat damage thanks to the high absorption rate of UV light. This minimizes soot and burrs, prevents surface damage and enables corrosion-resistant marking.

Light absorption rate for metal
Light absorption rate for metal

Electronic parts are becoming smaller and their sealing resins are becoming thinner. Typical laser markers risk transmitting energy through sealing resins and damaging the internal components. However, UV laser markers have an incredibly high material absorption rate and can mark sealing resins without affecting the internal components.

Marking on IC package
Standard wavelength laser
Standard wavelength laser
UV laser
MD-U
A
Sealing resin
B
Chip

Marking comparison

Marking with reduced thermal damage
(silver-plated surface)
Conventional model
Conventional model
MD-U
MD-U
Cutting with reduced thermal damage
(PCB)
Conventional model
Conventional model
MD-U
MD-U
Marking with reduced rear surface damage
(transfusion bag film)
Convention model (Left: Front, Right: Back)
Convention model
(Left: Front, Right: Back)
MD-U (Left: Front, Right: Back)
MD-U
(Left: Front, Right: Back)
Marking with reduced engraving
(IC package)
Conventional model
Conventional model
MD-U
MD-U

Product Introduction

High-contrast and damage-free 3-Axis UV Laser Marker MD-U Series

High-contrast and damage-free
3-Axis UV Laser Marker
MD-U Series

High-contrast and damage-free
The UV wavelength (355 nm) enables high-contrast, damage-free “cold marking.” The MD-U series suppresses heat effects, burrs and yellow tinting to achieve nearly perfect part finishes.
High-speed digital scanner
KEYENCE's proprietary digital scanners and optimized controls enable accurate, fast marking.
Multi-function built-in camera
A built-in camera enables autofocus, 2D code reading and easy program adjustments.

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