Pacmar Technologies (United States)

The U.S. Navy is considering medium voltage DC (MVDC) power systems as opposed to traditional AC power systems in order to accommodate modern shipboard systems: high power sensors, electronic warfare, and weapons systems. A digital twin of an MVDC naval power system is useful so that its operation can be better understood. In this work, a scaled-down demonstration model of a modern MVDC naval power system is studied through a series of experiments showing the operational benefits of the system when implemented with digital twin technologies. Two portable hybrid unified models of the scaled demonstration system were developed with incorporated machine learning techniques to show improved autonomous control. Because the unified models are portable, they may be developed in one tool, but then used with another tool on another platform. In a field setting, for example, a unified model may be simulated alongside an actual Navy ship to better understand its operation and vice versa.

With growing interest for human space tourism in the twenty-first century, much attention has been directed to the robust engineering of Environmental Control and Life Support Systems in space habitats. The stable, reliable operation of such a habitat is partly achieved with an ability to recognize and predict faults. For these two purposes, a reinforcement learning adversarial agent (ReLAA) is utilized in this work. A ReLAA is trained with experimental data to actively recognize and predict faults. These capabilities are achieved by proposing actions that activate known faults in a system. Instead of issuing these harmful actions to the actual hardware, a digital twin of the mock space habitat is simulated to discover vulnerabilities that would lead to faulted operation. The methods developed in this work will allow for the discovery of damaging latent behavior, and the reduction of false positive and negative fault identification.

Whether the need is due to poorly bondable materials, non-flat bonding surfaces, odd packaging situations, or just the need for high reliability; the integrity of a wire bond interconnect can usually be greatly improved through the proper use of Auxiliary Wires. Auxiliary Wires are defined as Security Wires, Security Bumps, or Stand-Off Stitch (aka Stitch on Bump). The old stand-by Security Wire has been an asset for several decades, however, this is being replaced by Security Bumps which require a smaller second bond termination area. Further, Stand-Off Stitch (SOS) has many more applications and also has many side benefits that could be incorporated into a circuit design for better wire strength properties, fewer interconnects (die to die bonding), and lower loops. Stand-Off Stitch bonding involves the placement of a ball bump at one end of the wire interconnect, then placing a wire with another ball at the other end of the interconnect and stitching off the wire on the previous placed ball bump. This results in a near homogeneous stitch bond interconnect to the bump with an inherent improvement in stitch bond pull strength. Another use for SOS is Reverse Bonding (Stitch bond on bump on die bond pad) often resulting in a lower loop profile than standard forward wire loop and the loop is stronger because the wire hasn't been work annealed above the ball (in the Heat Affected Zone). A major impediment to the implementation of SOS is the retraining of visual inspectors and the approval of quality departments.

ABSTRACT Ball bumping can provide an engineer several advantages over plated-up bumps for several reasons: ball bumps can be more cost effective than plated bumps; ball bumps can support multiple substrate attach technologies; single pass ball bump shapes are available without the planarization requirement; and ball bumping offers a technique for manufacturing unique thin flat pancake shaped bumps and other shapes.

ABSTRACT Until recently, the assembly of optoelectronic components has been almost exclusively a manual process due to package complexity and relatively low production volumes. As the demand for photonics components grows, increasing emphasis is being placed on automating this assembly process to drive down component costs and increase volume. Currently, optoelectronic component manufacturers are utilizing automated equipment to conduct multichip epoxy and eutectic die attachments and to wire bond. In the future, other processes requiring sub-micron resolution and involving complex sets of iterative alignment steps, such as active fiber alignment and active subcomponent alignment, will be performed by fully automated systems. This equipment will incorporate several technological advances that will reduce assembly time and increase yield. Since the packaging process accounts for 60 to 80% of the cost of optoelectronic components today [1], advances in automation will be essential for controlling component costs and meeting demand. This paper analyzes some of the challenges to automation in the field of optoelectronics, the current state of the art for optoelectronic automated die attach and wire bonding, and presents an example of some of the cost advantages associated with automation.