Robotic Ultrasonic Welding vs Robotic Laser Welding

FANUC R2000ib 125L R30ia Motoman MA1400 FANUC M710ic 50 Motoman HP6 NX100 FANUC Arcmate 120ic
Today’s industrial robots are capable of automating just about any production related task. Despite the growing list of robotic applications, there is one application type that remains the most common for robotic automation and that is welding. Robotic welding dates back to the first industrial robots used in manufacturing and today 50% of all active robots are used for welding automation. Most welding robots are used to automate spot or arc welding applications, but non-conventional methods are gaining traction. Laser welding and ultrasonic welding are two of the fastest growing non-conventional robotic welding methods. Below is a comparison of these two processes along with their advantages and disadvantages.

Weld Process

Ultrasonic welding melts and joins workpieces through heat created by ultrasonic vibrations which are generated with electrical voltage. Industrial robots are integrated with an ultrasonic head or actuator for the EOAT. Six-axis robots are best for automating ultrasonic welding. The FANUC Arcmate 120ic and the Yaskawa Motoman MA2010 would both be ideal for ultrasonic welding automation.

Laser welding utilizes a concentrated laser beam to weld workpieces together. Industrial robots are integrated with a laser cutting head for the end-effector. Unlike other welding applications, laser welding robots do not need to make contact with workpieces, allowing welding to take place from a distance. The ABB 2400 and FANUC Arcmate 100ic are both popular for automating laser welding.


Ultrasonic welding robots can weld not only metals, but plastics as well. Manufacturers in both the electronics and automotive industries have adopted ultrasonic welding robots to their production lines for their plastic welding capabilities. Battery packs, vehicle interior trim, headlights, and sensors are some of the items welded with ultrasonic welding robots.

Laser welding robots can weld a variety of metal types. They can even weld dissimilar metals together. Thin metals are best for robotic laser welding since this method produces a narrow, but strong weld.


The main advantages of robotic ultrasonic welding include fast cycle times and material flexibility. Ultrasonic welding robots can complete welds in as little as 200 to 500 milliseconds allowing up to 80 cycles per minute. In addition to incredibly fast welding speeds, tooling warmup and part cooling are eliminated saving significant time. The ability to weld both plastics and metals gives manufacturers greater flexibility when it comes to workpiece materials.

The main advantages of laser welding include its no contact method and its cost-effectiveness. Since there is no contact in laser welding, articulated robots can weld hard to reach or delicate workpieces. With the laser welding method, the FANUC M-710ic/20L can weld from up to a foot away from parts. The ability to weld dissimilar metals together makes laser welding more cost-effective. Manufacturers can save on material costs by welding an expensive metal to an inexpensive metal.


The main disadvantage of ultrasonic welding is that lack of familiarity may make it a challenge to implement. Most robot users are familiar with the more traditional methods of spot and robotic arc welding. The unfamiliarity of ultrasonic welding means more time may be needed for integration and training.

The main drawback of robotic laser welding is it is limited when it comes to materials. Thick or reflective metals cannot be welded with laser welding robots.

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