Special Issue

Laser processing for copper〉〉New Products

Blue-IR Hybrid Laser “BRACE”
INTRODUCTION
1.1. INTRODUCTION
The development of Electrified vehicle (xEV), which are
effective against climate change as no NOx (nitrogenoxide), PM (particulate matter) or CO2 are emitted whiledriving, has been promoted around the world in recent
years aimed toward the realization of a sustainable society. Most recently, a momentum to regulate gasoline
engine vehicles by the 2030s has risen rapidly under thepolicies of various governments. In such circumstances,the manufacturing volumes of key components such asbatteries, motors and inverters essential to xEV areexpected to grow exponentially.
Various welding methods including resistance, ultrasonic and arc weldings are used to join copper parts as aconductor at plants manufacturing main components ofxEV (Figure 1). The introduction of a laser welding using afiber laser and a semiconductor laser with a stable output
through their continuous waves as the processing heatsource is started to be considered with the aim of further
efficiency improvement, including the reduction of CO2emitted from plants and the process automation. In sucha situation, there is a growing need to replace the conventional laser light source using a fiber laser of nearinfrared light (hereinafter IR) (1070 nm wavelength band),
which is difficult to process with a high quality because of
its extremely high optical reflectivity against copper, witha blue laser (450 nm wavelength band), which has a good
optical absorption with copper and a high-power output.
We have commercialized a Blue-IR hybrid laser oscillator“BRACE”, which is the integration of a blue laser oscillaMultiple-use of copper processingin the manufacturing processes ofmajor components2.

tor with a short wavelength and an IR fiber laser, andhave started accepting orders in January 2021 (Figure 2).
The high-power and high-reliability blue laser oscillator
that can also be used as an industrial laser processing isequipped with a blue laser diode module jointly developed with Nichia Corporation, which has the world’s top
share in blue semiconductor lasers.

FEATURESOF
OFTHE
THE “BRACE”“BRACE”
2.2. FEATURES
We named the Blue-IR hybrid laser product group“BRACE” with the aim of becoming the world’s number
one in the laser processing of copper using blue lasers.
Each alphabet means: B: “Blue”, R: “InfraRed”, ACE:
“leader, best”. In addition, BRACE that connects each ofthem has the meaning of “pair, one set, giving vitality”.
Therefore, we have the meaning in the name that byusing the “BRACE” in the manufacturing process, it willconnect our company, our customers and the world, andgive vitality to the world.
The Blue-IR hybrid laser is achieved with an IR fiberlaser (wavelength 1070 nm band) that can perform a deepand high-speed processing for copper, and a blue laser(wavelength 450 nm band) that gives a preheating effectto copper. The light absorption rates of copper at room
temperature are 4% and 65% for wavelengths of1070 nm and 450 nm, respectively. Laser processing ofcopper using an IR fiber laser is difficult due to its low

Electric axle
(Motor and inverter)■Motor magnet wirewelding■Bus bar welding

FEATURES OF THE “BRACE”

Lithium ion battery module■Battery foil cutting and welding■Bus bar welding
Figure 1 Main components of an xEV and the examples ofcopper processing.

Figure 2 Picture and logo of the “BRACE”,
Blue-IR hybrid laser (The device isthe BRACE-I of the specificationsof IR: 1 kW, Blue: 150 W).

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Blue-IR Hybrid Laser “BRACE”

light absorption rate, and even if keyholes are formed andcopper melts, the molten pool is unstable. As a result, alarge amount of spatter is scattered and welding defects
are formed (Figure 3). In particular, when vertical lightenters, an IR fiber laser oscillator may be damaged by thereturn light due to its high light reflectance.
On the other hand, a blue laser has a high light absorption rate of 65% at room temperature for copper.
However, a blue laser is a laser achieved by spatially coupling multiple blue semiconductor laser beams with an
optical system. Compared to fiber lasers, the brightness
is lower by an order of magnitude or more, and thenumerical aperture (NA) of the laser beam is large. Whena single visible light laser including a blue laser is highpowered and irradiated to copper, it provides a welding
form called a heat conduction type because of the low
brightness of the light. In this case, since a melting phenomenon occurs due to the heat conduction to copper,
the depth becomes shallow and the speed cannot be

increased, so that the work is easily affected by the heat,and it generates a demerit that welding of copper materials with a thickness of 1 mm order cannot be performed
well (Figure 4).
The Blue-IR hybrid laser “BRACE” was developed tomake up for this disadvantage. The blue laser is used asa preheat source for copper. The light absorption rate ofcopper in the 1070 nm wavelength band tends toincrease as the temperature rises. By performing this preheating with a blue laser, a thermal conductivity type cavity is created on the copper surface. And the IR fiber laser
achieves keyhole-type high-aspect melting. The heat
conduction type cavity by the blue laser is a technologythat stabilizes the copper molten pool even for the keyhole formation and is also effective in reducing the welding defects such as spatters and blowholes (Figure 4). As
shown in Figure 3, increasing the light output of the bluelaser can significantly improve the molten state andobtain extremely good molten bead marks.

GoodGoodLow

Light output

Light output

Blue laser:Contribution to the processing quality

Infrared laser: Contribution to the productivity

Only infrared ﬁber laser: Even if the output is increased, the light absorption rate is low
and the processing is unstable.

High2 mm

HighHybrid: Processing is stable by adding a blue laser with a constant output.

Figure 3 Changes in the surface and the cross section of copper plates (thickness 2 mm) when the light outputsof an IR fiber laser and a Blue laser are increased, respectively.

Laser type

Molten poolformation

Quality(reduction of spatter)
Ambient
Processing Processingability
Low speed High speed heat eﬀect
stability(depth, speed)(Overheat)

Keyhole + Heat conduction cavity type
Blue/InfraredHybrid
Heat conduction typeThe inﬂuence of heaton the periphery ofthe processed partis large.

Visible light
Molten poolcross section

Due to the inﬂuence of heat, concerns about the processing capacity
and the quality (overheat at low speed) are likely to materialize.

Figure 4 Comparison between a Blue-IR hybrid laser and a visible light laser of single color.

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Blue-IR Hybrid Laser “BRACE”

PRODUCTSPECIFICATIONSSPECIFICATIONS
3.3. PRODUCTFUTUREROADMAPROADMAP4.4. FUTURE

Table 1 shows the product specifications of the BRACE-I.
The BRACE-I is equipped with a blue laser oscillator
with an optical output of 150 W and an IR fiber laser
oscillator with an optical output of 1 kW operating in asingle mode. This laser is optimal for the laser processingof copper approximately up to 1 mm thickness. Due tothe good quality of the beam of the blue laser, laser processing using a hybrid type galvanometer scanner is alsopossible.

Figure 5 shows the commercialization roadmap for the“BRACE”, a Blue-IR hybrid laser. We plan to commercialize the new BRACE-II and the BRACE-X in January 2022.
With the BRACE-X, the processing of copper materials
approximately up to 3 mm in thickness can be performed
with the development of a blue laser oscillator with an
optical output of 1 kW and the installation of a multimodeIR fiber laser with an optical output of 3 kW. As a result,for example, in motor magnet wire welding, it will be possible to achieve a welding time in the 0.1 sec/point range,
which is equal to or less than one-third of the conventional method. In battery foil welding and bus bar welding,the BRACE-II application achieves twice the processing
performance of the BRACE-I. From the above, we willcontribute in improving our customers' production efficiency of key components for xEV.

Table 1 Specifications of the BRACE-I (FBHY150/1000S-5 model).

Model

FBHY150/1000S-5
Blue laser

Fiber laser (IR)Rated output (W)

150

1000

Beam mode

MultimodeSingle mode

Construction

Oscillator /power supply integrated type

Wavelength (nm)465

Output adjustable range (%)

10 to 100 each

Modulation frequency (kHz)Up to 5

Cooling method /Oscillator, power supply, cable

Water cooling

Cooling water temperature (℃)

25

Optical output cable endconnector

QBH

We have introduced our new Blue-IR hybrid laser, the“BRACE”.
We have built application laboratories at our Chiba
Works and Nichia’s Yokohama Research Center, and canperform demo welding using the BRACE-I and a hybrid
galvanometer scanner. Please contact us for details.

Standard cable length (m)55Fiber core diameter (µm)

110

14

Beam quality M2 (typical value)―＜ 1.1

Beam quality BPP (typical value)(mm･mrad)12―

Three-phase AC 200-240

Frequency (Hz)50/60 ± 5 %Body size (mm)

W 700 × D 1000 × H 800

Body weight (kg)

About 300

Technical evolution

Power supply (V)Examples of market
target expansion

CONCLUSION
5.5. CONCLUSION

1070

For more information, please contact
Communication and Industrial Equipment Sales Department
Industrial Laser Promotion Section
TEL: +81-80-1006-6821
Person in charge: Ojima
WEB: https://www.furukawa.co.jp/fiber-laser/en/●2021● 2022● From 2023

Hybrid laser oscillator debut

Higher power output

Further evolution

BRACE-Ⅰ

Light output■Blue: 0.15 kWx
Blue:Infrared: 3 x■Infrared: 1.0 kW

6.7

BRACE-X● From 2025

Sales target
10 billion yen■ Blue: 1.0 kW■ Infrared: 3.0 kW

BRACE-Ⅱ■ Blue: 0.5 kW■ Infrared: 1.3 kW

Customerfeedback
Nichia and Furukawa Electric willpropose optimal solutions andMotor magnet wire

Processing time
Equal to or lessthan one-third

Increased production
eﬃciency

Battery foil welding

Number of weldings
At least doubles

Increased battery capacity

Copper bus bar

Sheet thickness
At least doubles

Improvement of design freedom

realize de facto standardizationin copper processing.

＊Compared to our company’sproducts, Target

Figure 5 Roadmap for the commercialization of the BRACE, Blue-IR hybrid laser.

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