DO-213 SMD Package
Diode Package DO-213 Case style, Surface Mount
DO-213 Diode Package
The DO-213 package is a Surface Mount Device [SMD]. This package style is also called a Melf package; metal Electrode Leadless Face. How to Derate a DO-213 package based on temperature. The URS SMD is another style of Melf package.
For better heat conduction into the printed circuit board, use a larger copper pad. The larger the pad the lower the thermal resistance as shown in this graph; Thermal Resistance vs Pad Area. Increasing the size of the pad on another layer also helps, if there is no available board space on the top layer. It doesn't matter which layer the heat is sent to, although if the heat is dumped into an inner layer it has to be allowed to escape.
DO-213AB package [DO213]; |  PCB Mounted MELF |
Of course this package style could also be used by other two-leaded components, but it might not use the term DO which refers to a diode.
Editor note; although I make note of a URS package, the only place I ever found a URS package is contained within a DOD specification. I've never seen the term used in a data sheet, although the government document would not be using the term if industry did not, so it must exist. So the URS term could just be a suffix of a part number and not it's own package style. On the other hand DO-213 is certainly a valid package type, and the MELF phrase is also a common method of referring to DO-213 like packages.
