The 2nd smallest chip style in the modern day is the VQFN package (very thin quad flat no-lead package). It offers significant benefits in practice: size, cost, and minimial parasitics. Just by being smaller package, your inductance and resistances are cut down significantly, because there's fewer leads "in the way" of the chip.
Alas, VQFN packages traditionally require X-Ray inspection to see if they bound to the PCB correctly. An intriguing modern technological advancement is solving this expensive problem. As it turns out, creating a dimple (in this article), or a ledge (other chip-manufacturers) will allow the solder to climb up the side of the VQFN package.
This "climb" allows for us to visually inspect chip solder once again (like in the slightly bigger TQFP package).
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This seems like a big technological advancement, allowing for VQFN packages to be used in more situations. Today it still seems niche, but more-and-more chips (especially those designed for automotive use) are being designed as VQFN-wettable flank packages.
Alas, VQFN packages traditionally require X-Ray inspection to see if they bound to the PCB correctly. An intriguing modern technological advancement is solving this expensive problem. As it turns out, creating a dimple (in this article), or a ledge (other chip-manufacturers) will allow the solder to climb up the side of the VQFN package.
This "climb" allows for us to visually inspect chip solder once again (like in the slightly bigger TQFP package).
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This seems like a big technological advancement, allowing for VQFN packages to be used in more situations. Today it still seems niche, but more-and-more chips (especially those designed for automotive use) are being designed as VQFN-wettable flank packages.