CO2 Laser Marking
On this page, we explain marking examples and characteristics of CO2 laser markers, which are perfect for applications such as marking resin and paper or processing films.
Applications
CO2 lasers have the longest wavelength of all commonly used lasers, more than ten times longer than that of standard wavelength lasers.
In addition to paper and resin, it is also possible to mark wood, rubber, and transparent materials such as glass and PET plastic thanks to its heat-based marking method. On the other hand, it is hard to mark metal because the laser light has almost no reaction (is not absorbed).
- A
- Ultraviolet range
- B
- Visible range
- C
- Infrared range
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Cartons 
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Bottles 
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Design marking 
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Glass wafers 
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Weatherstripping 
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Electronic PCBs 
Mechanism and Characteristics of CO2 Lasers
CO2 lasers are gas lasers that use CO2 gas as their medium. CO2 gas is filled and enclosed in the discharge tube where the electrodes used for electrical discharge are arranged. Plasma is generated within the gas by an electrical discharge, and the generated light is amplified as it travels back and forth between the total reflective mirror and the output coupler and is output as the laser.
- A
- Total reflective mirror
- B
- Electrode
- C
- CO2 gas
- D
- Laser
- E
- Output coupler
Feature: CO2 lasers can also be used for cutting applications
CO2 lasers use heat on the target, which allows use for cutting applications such as cutting holds, gate cutting, and sticker half cutting in addition to marking. Compared to mechanical cutting using cutting tools, CO2 laser cutting has the advantage of preventing quality deterioration based on tool wear and being maintenance free.
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Film cutting and hole cutouts 
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Gate cutting 
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Sheathing cutting 
Column
Improving quality with short-wavelength and thin laser types
KEYENCE offers a product lineup including short-wavelength and thin laser types for improved quality of CO2 laser marking. Each type offers the following advantages.
Conventional methods
Damage is excessive and engravings are deep and rough
- A
- Edge
- B
- Depth
ML-Z
Damage is minimal and engravings are shallow and sharp
- A
- Edge
- B
- Depth
- 9.3 μm short wavelength model
- The wavelength of the ML-Z Series’ laser is available at 10.6 μm as well as a shortened 9.3 μm to better suit the heat absorption characteristics of resin. With a higher absorptivity in resin, this shorter wavelength allows for more precise marking with shallower engraving and less surface swelling.
Marking on PET bottles
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Standard model 
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Thin laser model 
- A
- Power density
- Thin laser type
- Compared to standard models, the laser spot diameter is smaller, enabling even finer marking. In addition, the smaller spot diameter allows for greater power density, which in turn allows for more efficient processing such as cutting and drilling.
Marking on IC chips
Product Introduction
World’s first 3-axis control3-Axis CO2 Laser MarkerML-Z Series
- 3-axis control
- The focal distance can be varied over a 42 mm range, reducing installation costs and enabling precise marking and processing that fits the product shape exactly.
- 30 W high power
- This reduces the marking processing time and enables clear and stable marking even when products move at high speed.
- 300 mm wide area
- A wide area of 300 x 300 mm is fully covered by a single unit, simplifying installations and reducing processing time.
