Issue link: https://iconnect007.uberflip.com/i/1213413
FEBRUARY 2020 I PCB007 MAGAZINE 87 embedded actives have been used in high-vol- ume products for quite some time in the right applications. The design gets stabilized, and then they're going to keep the board assembly unchanged for a long time. Ryder: There are so many things to contend with, including design, manufacturing, ther- mal management, warpage, etc. Consider you have fundamentally different CTEs of compo- nents versus the PCB or substrate you're em- bedding it into; there's also the interconnect integrity, reliability, testing, etc. This is likely the reason such technologies remain on the shelf of most manufacturers before becoming a volume product. Happy is absolutely correct. Johnson: Let's talk a little bit about thermal management once you have embedded that active. How do they do that? Ryder: That's a very good question. There are experimental ways and given ways. The most common and directly addressable way would be to use your surrounding copper planes for conductivity. You can do that by having ther- mal vias. In other words, stacked vias that lead down to a copper plane that help to fan out and distribute some of the thermal energy caused by the component's operation. Then, you have a host of special dielectrics that claim to be highly thermally conductive. There are some very promising materials for such a task, such as graphene, which is highly thermally conduc- tive but also brings new manufacturing risks. Johnson: Graphene has promise for a lot of things, so that becomes very situationally de- pendent. Ryder: It does. Such considerations would go into your decision-making process when you're modeling that final product. You can calculate what the thermal load is going to be for a given component during activity, and you can calculate that thermal distribution within a PCB stackup. All these things can be modeled and simulated, which would be an important part of that process. Johnson: This has been great. Thank you very much, Chris. Ryder: It's my pleasure. PCB007 Dan Feinberg and Dr. John Mitchell, IPC president and CEO, discuss IPC APEX EXPO 2020, how the show is evolving to be a mini CES—including ideas and prototypes—new IPC initiatives, and IPC Design. Click the image to view video. IPC APEX EXPO 2020 and IPC Design