Same Tools, New Markets
By John Blyler
Tools developed in one market are finding success in new and sometimes unrelated markets as the same problems for which they were originally developed show up in new areas.
Consider the thermal issues in high-density SoC designs at advanced process nodes, for example. While these have been relatively minor nuisances in the past, they have become critical issues as chip packages, printed circuit boards and subsystem enclosures continue to shrink. And they will become even more pronounced as chipmakers begin to stack die over the next couple years.
So just how big is this opportunity? The IPC Trade Association recently quoted an industry study that said thermal management technologies are expected to grow by $10.2 billion in 2015.
Managing heat generation and dissipation in today’s compact and complex electronic world requires the attention of designers and manufacturers alike. It is also a system-wide problem, because optimizing a thermal problem in one area—whether it’s package, board or enclosure—rarely ensures the entire system will be optimized.
Past techniques to determine heat-related problem spots in electronic systems have relied on a physical, instrumented prototype of the design. This is both time consuming and expensive. Further, it is not conducive to meet ever narrowing time-to-market windows. So what can be done? The obvious answer is software modeling. Inexpensive, high-performance desktop and server farms have enabled the development of more accurate and sophisticated thermal modeling systems similar to the ones used by mechanical engineers. That helps explain why Mentor Graphics purchased U.K.-based Flomerics Group in 2008, which was best known for its expertise in fluid dynamics.
“Our latest version adds design guidance that shows the root causes of thermal issues and then suggests the best ways to address them,” explains Erich Buergel, general manager of Mentor’s Mechanical Analysis Division. “We can calculate thermal bottlenecks to identify thermal path restrictions as well as determine thermal shortcuts to identify which paths will be fastest and easiest in cooling the design.”
That same type of approach is being applied to other tools, as well, which are in search of new market opportunities to spur growth. What’s surprising is where these tools are finding traction. Through a serpentine path of acquisitions Synopsys acquired Saber, a mechatronics tool that has been popular in the automotive, industrial and military/aerospace markets. That same technology is now starting to find its way into SoC designs for thermal modeling, as well.
“This is a new class of verification tools,” said David Park, director of marketing for the System-to-Silicon Verification Solution at Synopsys. “It’s taking what we know from the physical world and understanding how it will impact the electrical world. The question now is how this will morph into 3D TV and 5G cell phones.”
And moving into the opposite direction, Cadence is using some of its DFM tools in the MEMS space as companies such as Freescale begin experimenting with bulk CMOS-based technology. The goal is to greatly speed up the manufacturing and design of MEMS structures, which have seen most of their success in markets where the design cycle is much longer. Being able to create a single process for a single product could open up markets even in consumer electronics for MEMS chips.
Bottlenecks and shortcuts
To understand these concepts, consider the example of a wedge-locked PCB in a sealed enclosure. Wedge-locking is used to securely mount a plug-in PCB into an enclosure for high vibration applications. Component heat can be easily trapped by the closeness of other boards and by the nearness of the enclosure. A common way to reroute the heat or provide a shortcut for heat dissipation is with a gap pad. Such a pad replaces the existing air gap with a more conductive material, thus offering a low resistance path for the heat to flow out of the system. Such a gap pad might be placed between the hot spot—typically centered at a heat generating source or package—and the bottom of the enclosure.
Running the simulation with the gap pad in place should significantly reduce the thermal temperature of the hotspot. Still, it may not yet be enough to remove the heat bottleneck. A better alternative would be to replace the gap pad with an extrusion from the chassis, in other words, changing the heat conductive material to steel. Then the frame becomes a giant heat sink.
Manufacturing Impacted
There is a growing need in thermal simulation and analysis to complement or even replace physical hardware-based prototypes with virtual software prototypes. Equally important is the need to guide designers to solution options based on these simulations.
John Isaac, director of marketing development for Mentor’s System Design Division, puts it this way: “Simulation with solutions helps the designer reduce trial and error passes at a design by providing guidance to potential solutions. In turn, this greatly improves the productivity of the designer while reducing the time-to-market window for the product.”
This is all well and good for the package, board and module designer. But how can this simulation system help the manufacturing engineer? After all, a design fix for a thermal bottleneck or shortcut might not be manufacturable, due to space constraints or material issues.
For example, designers might identify a thermal paste as a potential solution to a heat bottleneck. But the paste material with the correct thermal characteristics may not be approved for that manufacturing process. Conversely, the placement of the paste may interfere with other design components.
Designers and manufacturers are feeling the “heat” from an increase in thermal management issues. Fast and accurate simulation tools with solution guidance options offer a shortcut to cool these heated issues.
Tags: Cadence, mechatronics, MEMS, Mentor Graphics, Synopsys, thermal management