After the
circuit design is captured in a schematic, most EDA tools allow the design to be simulated. Schematic capture involves not only entering the circuits into the CAD system, but also generally calls for decisions that may seem more appropriate for later in the design, such as
package choice. Although you may be able to change the package later, many PCB CAD systems ask you to choose both the part and package when placing it into the schematic capture program. This also brings into play such considerations as prototyping and assembly. In a high-volume assembly environment, there will be plenty of opportunities for
DFM analysis. However, in a
rapid prototyping environment such as at assembly houses specializing in low-volume/high-mix and quick turnaround times, the
pick and place machines are programmed directly from the board layout files. Careful package selection during schematic capture will save time during the assembly and
debug process. With new parts, the CAD system may not have your chosen component in its parts library, so you may need to create the parts library yourself. Again, you may at the time not be overly concerned with the package, but careful creation of the part library will save time and risk later. == See also ==