World-Class Semiconductor Test Handlers: A Decades-Long Motion Control Partnership

Cohu is a global leader in the semiconductor industry, providing critical back-end equipment including high-performance test handlers, thermal subsystems, and semiconductor automated test equipment (ATE). For over 15 years, Greg Wagner, a Mechanical Design Engineer with 25 years of experience, has worked with Teknic to solve the complex motion control challenges inherent in high-speed semiconductor handling.

Semiconductor test handlers require extreme precision and high throughput within a limited footprint. As these machines evolve to handle smaller, more complex electronic components, the demand for space-efficient, high-performance motion control becomes a primary design driver.

In the early stages of machine development, motion control was often viewed through a purely mechanical lens. "From a mechanical guy like me, I'm looking at just basics," says Wagner. "Does it have the torque I need? Is it going to move the assembly I need? Does it have the form-fit-function? Is it going to fit in space? That's what I worry about."

However, as Cohu's machine designs grew more sophisticated, the focus shifted from basic torque requirements to total system optimization. The team needed to reduce the volume of control hardware and cabling to make room for other critical test components.

The transition to Teknic's ClearPath-SC integrated servos allowed Cohu to eliminate separate drive cards and the bulky cabling associated with traditional servo systems. By integrating the motor, encoder, drive, and controller into a single package, Cohu reclaimed valuable real estate within their test handlers.

"We were really looking to Teknic to help us optimize the space in the machine and simplify our cabling and our control hardware," explains Wagner. "The ClearPath motors in particular were really helpful for us to simplify. We got the high performance that we needed without having to devote a lot of space to it, and we simplified our cable assemblies by not having to find space for a separate servo drive."

This simplification also extended to the machine's reliability and serviceability. By reducing the number of interconnects and components, the overall system architecture became more robust.

Beyond the hardware, the success of Cohu's motion systems relied on deep technical collaboration. Wagner highlights that Teknic's involvement began early in the design cycle, providing engineering insight that was integrated directly into their development process.

"Teknic has always been more than a partner to us. It's like having in-house servo motor support—like our own in-house team," says Wagner. "That's been critical for us…I can't imagine what it would have been like with some other company."

This collaborative approach allowed Cohu to anticipate challenges during the design phase rather than reacting to them on the manufacturing floor. By involving Teknic's application expertise early in the project, Cohu ensured that the motion systems were fully vetted for real-world production environments long before the machines left the factory.

"In several different applications, Teknic was a partner in the design and development phase… offering us insight into how to configure stuff and what to expect. So, we could build that into our design and prepare for it from a manufacturing and implementation point of view, long before these machines were on the floor at customer sites."

Ultimately, this level of engineering support was a primary factor in Cohu's ability to meet critical production timelines.

"I don't think we could have ever expected another, especially a US-based supplier, to provide us with that level of support," Wagner notes. "We wouldn't have been able to really ship the machines had that not been available. So, it's been a great relationship."