What is laser welding?

Laser welding is a technique that exploits the transparency of plastics to laser light. In this technique, laser light irradiating a target body (made of resin or plastic) generates heat at the interface between the body and a separate absorber layer to create welded junctions.


レーザー透過性に優れたポリアミド樹脂 leona SNシリーズ

What are LEONA™ SN series, next generation halogen & red phosphorus free flame retardant polyamide series?

旭化成のポリアミド樹脂レオナ™ は強度・剛性、耐熱性、耐薬品性に優れたエンジニアリングプラスチックです。ガラス繊維のような充填材(フィラー)によって強化することで、強度・剛性、耐久性、寸法安定性が向上します。

レオナ™ SNシリーズは、環境と安全を考慮したノンハロゲン・赤燐フリーの難燃ポリアミド樹脂です。レーザー透過性・接合強度に優れ、さらに、高強度・高剛性、UL94 V-0(0.75mm)取得、耐トラッキング性(CTI)600V(PLC 0)と、優れた性能を有します。

Laser transmission properties of LEONA™ SN-series resins

レオナ™SNシリーズの中でも、ガラス繊維25%強化品であるSN11Bのレーザー透過率 (940nm)を、LEONA™一般的なノンハロゲン難燃ポリアミド樹脂(ガラス繊維含有量はSN11Bと同じ25%)と比較したところ、ナチュラル色で約2倍、黒色で3-4倍でした。

LEONA™  SN series laser transmittance (light wavelength: 940nm)
Laser transmittance (wavelength: 940 nm)


  • 高速加工による生産性の向上が可能
  • 低出力レーザーでも加工可能
  • 表面に焦げを発生させない

Comparison of welding speeds: LEONA™ SN series (left) vs. general non-halogen flame-retardant polyamide (right)
(Caution: Please note the strong light in this video.)

Strength of laser-welded joints with LEONA™ SN-series


Laser welding output and bonding strength
Joint strength vs. power consumption for laser-welded joints

Deep-black appearance of LEONA™ SN-series (in case of specialized laser-transmitting black colorization)


Appearance of laser-welded test pieces and magnified surface views

LEONA™ laser-welding case study

  • バッテリーケースの小型化・軽量化


Conventional welding methods such as vibration or ultrasonic welding entail significant vibrations that may damage sensitive components inside the case. Also, the use of screws or other fasteners requires that some portion of the case be dedicated to bosses or other fastener housings, increasing its spatial footprint. The use of laser welding eliminates such fasteners while avoiding damage to components inside the case, reducing its size and weight.

Battery case
  • 電装部品の溶着界面の焦げ低減

One promising application made possible by the improved laser transmittance of flame-retardant resin grades is laser welding of electronic components, for which conventional welding techniques are difficult to apply. 
The ability to weld components with lower laser power reduces the emergence of unattractive “burned”-looking regions in welded surfaces.

Laser welding of electronic components with flame-retardant resin grades
Laser welding of electronic components with flame-retardant resin grades
  • その他の想定用途

Valves, pumps, electric parking brakes, ECU cases, vehicle-mounted cameras, and more

Other themes


PA樹脂 レオナ™