Boise’s Micron Technology Inc. managed to cross the 20 percent market-share threshold in the NAND flash-memory business during the second quarter, a research firm said. That’s the first time that has occurred since Micron entered the NAND flash sector seven years ago.

Micron posted the strongest sequential performance of all NAND suppliers, with second-quarter revenue totaling $897 million, up 6 percent from $846 million in the first quarter, according to an IHS iSuppli. Other top suppliers suffered revenue declines.

IHS iSuppli ranked Micron third in the market, behind No. 1 Samsung Electronics of South Korea, which has 42.5 percent; and No. 2 Toshiba, of Japan, with 24.7 percent. SK Hynix Semiconductor of South Korea was fourth with 11.8 percent.

NAND became Micron’s top-selling product this year, passing dynamic random-access memory, or DRAM, which Micron has made since its founding in 1978. DRAM is the most common form of memory in personal computers. NAND is common in cell phones and cameras. NAND is a contraction of not-and, a computer-logic term.