(November 24, 2008) SINGAPORE — STATS ChipPAC Ltd. has expanded its quad flat no-lead (QFN) packaging portfolio with a strip-etch version for applications requiring increased design flexibility and higher input/output (I/O) performance in a small, thin package profile. The new QFN package family, referred to as QFNs-se, reportedly features a higher number of very thin I/O terminal pads than conventional single or dual-row QFN or leadframe-based quad flat packages (QFPs). Additionally, it is also said to be a cost-effective alternative to lower ball count fine pitch ball grid array (FBGA) packages.
According to Han Byung Joon, Ph.D., executive V.P. and CTO, STATS ChipPAC, QFNs-se handles more pin count than previous QFN generations, and when combined with die shrinks enabled by the advancement of wafer fab technology, offers a smaller footprint and lower cost alternative. Additionally, it offers more options such as singulated unit test process or strip test process. Testing multiple devices simultaneously in a strip format offers a reduction in production cycle time and a lower cost of test.
The QFNs-se is reportedly available in a lead pitch as low as 0.40mm with a nominal package profile height of 0.55mm. The key to the increased performance and design flexibility of the QFNs-se is the strip etch process used to make this QFN type. The leadframe is completely removed during the strip etch process, achieving more space within the mold cap to allow for thicker die or stacked die configurations. The terminal pads are plated on the leadframe before it is removed, allowing increased flexibility in terminal pitch, combining terminals and connecting terminals to the exposed die paddle. The QFNs-se can accommodate a range of die sizes and die stacking without increasing the final body size.