Digital Optics Corp. (Charlotte, NC) needed to expand its component production requirements for several customers in the telecommunication and data communication industries. The company manufactures photonic chips, which are optical subassemblies that integrate optics and active components at the wafer and die level.

Prior to purchasing the equipment from Palomar Technologies (Vista, CA), Digital Optics was building optical subassemblies using a semiautomatic system that required an operator. This involved manual manipulation to place and align the parts precisely. The company realized that this process would not meet its needs for increased production. The challenge was to automate production while improving the consistency and repeatability of the production processes.

The laser diode assembly (LDA) cell and process support from Palomar Technologies provided the flexibility to increase throughput across all product lines. "Our primary need was to be able to ramp up production while achieving a consistently high yield," says Jay Mathews, senior development engineer for Digital Optics. "The semiautomatic equipment we were using was operator-dependent and labor-intensive. We needed a highly flexible and fully automated tool that could be used in a variety of product applications."

The tolerances for optical component assembly are exceptionally stringent, with placement accuracies measured in microns or nanometers. Automation is further challenged by a complex, modular and highly integrated component design. Because of this, manual or semiautomatic assembly is predominant.

The LDA cell is a high-precision assembly system that fully automates complex laser diode component assembly. The LDA places and attaches microchips to their subassembly. It then performs the interconnect to attach these assemblies to their packaging. Using a Cognex Corp. (Natick, MA) pattern recognition system, the LDA has achieved a placement accuracy of 5 microns for varying applications. At the same time, the system’s patented heat process precisely controls the temperature required for die attach.

"Early on, the relationship with Palomar was beyond just selling us a tool. We were partnering for the long term," says Mathews. "Palomar worked with us, so we could be successful on multiple product lines and technologies. This included assembly process development and precision placement to ensure the highest level of performance in the assembly process across multiple platforms."

Digital Optics first worked with Palomar to determine the feasibility of the application for automation. "Working closely with Palomar application engineers, we jointly developed an integration assembly process for a current product. A program was written to address a specific application and the LDA was programmed at the Palomar factory before delivery to Digital Optics," Mathews continues.

Automating the assembly process at Digital Optics has eliminated operator error, making the process highly repeatable and consistent. Improved placement accuracy has resulted in significant improvements in both yield and throughput. The company estimates that it has achieved a fivefold improvement in throughput as result of the LDA implementation.

"Our approach was technically driven, providing the capability for continued and future expansion," states Mathews. "Flexibility, the improvement in accuracy and yield, and a wider spectrum of product capability, all of this benefits our customers."

For more information on laser diode assembly cells, call 760-931-3600 or visit www.palomartechnologies.com.

For more information on vision systems, call 508-650-3000 or visit www.cognex.com.