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In the first two parts of this series, we discussed the basics of hybrid design from the PCB designer’s perspective, and this month we will conclude that discussion.
We are seeing more and more of our customers exploring the world of hybrid design, and we are getting new customers for whom hybrid design is their sole focus. The world of hybrid design is growing, and we have lots of hybrid-specific functionality built into our software that helps designers meet and conquer the unique hybrid design requirements that they are faced with.
And yet many designers out there (and I used to be one of them) have no idea what is meant when people start talking about hybrid design. It is therefore not uncommon for designers to avoid the subject directly while hoping to pick up little cues and pointers from others indirectly so that they are no longer in the dark. If that description sounds uncomfortably close to where you are at, then read on. My hope is that this three-part series will help you by serving as a basic introduction into the world of hybrid design.
If you haven’t had a chance to read the first two parts in this series, please go back to the last two months and take a look at them if you can. To summarize, however, we discussed in the first column the basic structure of hybrid designs and the benefits they offer over standard PCBs. In the second column we discussed some of the similarities and differences in CAD applications for the design of hybrids and how hybrid designs and their layer stackups are setup. We also discussed the routing of conductors (wires), and the creation of area fills and power planes. We continued from there talking about the creation of dielectric layers and their similarities and differences to fills and planes. Next we introduced the concept of cross-over dielectric layers, which is unique to hybrid designs, and how they are used. Finally we finished up with an explanation of how vias are created and managed in hybrids. Now, let’s talk about components.
The selection of components in a hybrid design is influenced by the operating temperature of the working design. Higher operating temperatures will require components that can withstand those extremes while at the same time necessitating a different amalgamation of soldering elements for manufacturing.
Passive components will use packaged parts while active components will use bare dies (no packaging). This is something different for the PCB designer who would rarely see a bare die used on a board design. Packaged active components can be used on a hybrid, but this is dependent upon the operating temperature of the design. And by using bare dies, a hybrid design realizes the benefits of shorter circuit paths, smaller size, and better thermal conditions for the device as it is glued directly to the substrate making for a better heat sink.
To read this entire article, which appeared in the May 2016 issue of The PCB Design Magazine, click here.