A Dual Leadless Chip Carrier (DLCC) is a surface mount component that contains no leads or pins, but has terminals as part of the body. Related to a LCC package.
So, a DLCC refers to an LCC package with terminals on two sides [dual] of the component body, while the more general term LCC refers to a component with terminals on all four sides of the components body; However, because LCC is the general term, the phrase LCC could also refer to a DLCC, which would be a sub-class.
Some people consider this package as a Chip Carrier, even though the government defines a Chip Carrier as having leads or terminals on all four sides of the component body.
In most cases the terms leads and terminals are used interchangeably; however, in some cases the term Lead is used to refer to a physical pin which protrudes off the component body, while the phrase terminal refers to an electrical connection to the component body. So, the phrase terminal might be used to refer to either a solder pad or physical lead on a component, while a lead most often relates to a pin.
Because this package could be almost any size, no physical dimensions are provided. Although example sizes are provided on other pages for other parts. The point here is to show the basic component body and pad layout for the DLCC package. The physical dimensions are provided for a 6 terminal DLCC Resistor Array.
There is no real reason to use this package style over some other package style. Although a surface mount package should be used before a through-hole pages, because of the reduction in physical size and other factors. It will be more common that this package is used because it’s the better choice of the other options offered by a manufacturer for whatever function is being implemented.