Limitations
The quad flat-pack has connections only around the periphery of the package. To increase the number of pins, the spacing was decreased from 50 mil (thousandths of an inch) (as found on small outline packages) to 20 and later 12 mil. However, this close lead spacing made solder bridges more likely and put higher demands on the soldering process and alignment of parts during assembly. The later pin grid array and ball grid array packages, by allowing connections to be made over the area of the package and not just around the edges, allowed for higher pin counts with similar package sizes, and reduced the problems with close lead spacing.
Read more about this topic: Quad Flat Package
Famous quotes containing the word limitations:
“The only rules comedy can tolerate are those of taste, and the only limitations those of libel.”
—James Thurber (1894–1961)
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