OL1.DEC–Quality Semiconductor–SC
The small-outline package gets more space-efficient
First there was the small-outline (SO) package. That led, three years
ago, to the quarter-small-outline package (QSOP). Now, the
quarter-very-small-outline package (QVSOP) has emerged. Developed by
Quality Semiconductor (Santa Clara, CA), the QVSOP is the densest
surface-mount package available. The QVSOP is among the smallest of a
plethora of tiny packages developed in recent years. (The best known of
these is the plastic quad flatpack). Developed for high-density logic
functions, the JEDEC-recognized QVSOP measures just 390 (L) x 150 (W)
mils. Despite its small size, the QVSOP packs in 48 leads on a 15.7-mil
pitch. It is designed to integrate two or three 16- or 32-bit logic
functions in a single package and thus further expedite miniaturization of
electronic circuits. By comparison, the smallest industry-standard SO
package has the same 150-mil width as the QVSOP and is slightly shorter at
340 mil–but it has only 14 leads on a 0.050-in.lead pitch. The QSOP,
developed by Quality Semiconductor three years ago, has identical body
dimensions to the 14-pin SO package and has 24 leads spaced on a 25-mil
pitch. To achieve its high-density, efficient design, the QVSOP uses very
short package bonding wire. Moreover, its low-inductance leadframe reduces
ground bounce compared to other packages. Despite the higher lead count
and finer lead pitch, the QVSOP is designed to maintain a coplanarity of 3
mils. Thus, it can be reliably assembled on the pc board using conventional
pick-and-place equipment and soldering. The company will offer several of
its double- and triple-width FCT-T and QuickSwitch logic functions in the
new package. Other parts will be available in the package on a custom
basis. Quality Semiconductor will not charge NRE costs for the custom
parts initially. The price of a typical logic function starts at $4.05
each in 1,000-piece quantities. For more information, contact Mike Davis
of Quality Semiconductor at 408-450-8019, or . –Spencer Chin
CAPTION:
The quarter-very-small-outline package combines two or three die in the
smallest surface-mount package in the industry.
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