COSTA MESA, Calif. -- Irvine Sensors Corp. is using packaging to develop a stacked memory product, the company said Wednesday (March 31, 2004).
Initially Costa Mesa-based company is creating 1-Gbit and 2-Gbit double data rate synchronous DRAMs with a clock frequency of 333-MHz. These products consist of stacks of up to four 512-Mbit DDR SDRAM 333-MHz parts made by Micron Technology Inc. of Boise, Idaho.
Packaging the stacks involves the modification of industry-standard Thin Small Outline Packages (TSOPs) to permit them to be stacked and mounted using Ball Grid Array (BGA) attachment technology, with a height nearly half that of a comparable stack of standard BGA packages.
A two-chip-high version of this stack, such as the 1-Gbit DRAM, is expected to be only 1.7-millimeters high, compared to a height of 3.2-mm for Irvine Sensors' stack of two comparable standard BGA parts. A four-chip-high version, the 2-Gbit DRAM, is expected to be only 3.0-mm in height. Future products are also expected to include stacked SDRAM and DDR memory chips not presently available in BGA packages.
"Given the ever-present pressure to reduce the size of electronic products, we believe that there will be increasing demand for memory parts packaged in low-profile BGA forms," said John Carson, president of Irvine Sensors, in a statement. "In fact, we have already received an order for limited production deliveries of such a part later this year. By starting with TSOPs and essentially shaving them down to size and then adding BGA attachments, we can meet that demand while taking advantage of the better economics of the more mature TSOP products."
Carson said Irvine Sensors had received a first United States patent on the conversion of TSOPs to allow them to be stacked in alternate forms.
Carson did not indicate whether the conversion carried any engineering or contractual implications for the parts originally supplied and packaged by Micron.
The company said it expects to have stacked low-profile BGA parts available in the third quarter of 2004.