Electrolytic capacitors in an SMT package are not as often used as leaded radial or axial capacitors are. However they offer many advantages, which make the assembly easier and save a PCB space.
Electrolytic capacitors in an SMT package offer the same properties as their leaded familes (THT version), but they are much easier to assemble on a PCB. If you have a device, where most of components are in an SMT version, you probably proceed the way that SMT components are machine-assembled to PCB with a following reflow soldering. Leaded THT components (through hole technology) are then soldered in the 2-nd technological step – by a solder wave or manually. In a device containing many various THT components this 2-nd technological step is inavoidable. But in devices where only few THT components are, it is often possible to minimize their count or totally eliminate. This makes a production of the device significantly cheaper and quicker. Moreover in comparison to manual soldering, reflow soldering is much more consistent, ensuring a stable quality of soldering in various production batches.
Saving of a space is the second essential advantage. SMT electrolytic capacitors are available even with a very low profile. Thanks to the fact, that pads of SMT capacitors don´t require holes drilling into a PCB, like it is at THT technology, in many applications they can significantly simplify design of multilayer PCBs. Another advantage at HF circuits can be the fact, that integrity of the ground layer on the PCB won´t be corrupted by their usage. Continue reading Get familiar with SMD electrolytic capacitors advantages