Micron Memory Japan, K.K.
Native name
Company typeSubsidiary
IndustrySemiconductor industry
PredecessorElpida Memory, Inc.
FateAcquired by Micron Technology
Number of employees
ParentMicron Technology

Micron Memory Japan, K.K. (Japanese: マイクロンメモリジャパン株式会社, Micron Memory Japan Kabushiki-gaisha (MMJ)) is a Japanese subsidiary of Micron Technology.[1] It was formerly known as Elpida Memory, Inc. (エルピーダメモリ株式会社, Erupīda Memori Kabushiki-gaisha) established in 1999 that developed, designed, manufactured and sold dynamic random-access memory (DRAM) products. It was also a semiconductor foundry. With headquarters in Yaesu, Chūō, Tokyo, Japan, it was initially formed under the name NEC Hitachi Memory in 1999 by the merger of the Hitachi and NEC DRAM businesses. In the following year it took on the name Elpida. In 2003, Elpida took over the Mitsubishi DRAM business. In 2004, it listed its shares in the first section of the Tokyo Stock Exchange. In 2012, those shares were delisted as a result of its bankruptcy. In 2013, Elpida was acquired by Micron Technology.[2] On February 28, 2014, Elpida changed its name to Micron Memory Japan and Elpida Akita changed its name to Micron Akita, Inc.[3]


Elpida Memory was founded in 1999 as a merger of NEC's and Hitachi's DRAM operations and began development operations for DRAM products in 2000. Both companies also spun off their other semiconductor operations into Renesas.

In 2001, the company began construction of its 300mm wafer fabrication plant. Later that year, it began sales operations in domestic markets.

In 2002, armed with the Sherman Antitrust Act, the United States Department of Justice began a probe into the activities of dynamic random access memory (DRAM) manufacturers. US computer makers, including Dell and Gateway, claimed that inflated DRAM pricing was causing lost profits and hindering their effectiveness in the marketplace. To date, five manufacturers have pleaded guilty to their involvement in an international price-fixing conspiracy including Hynix, Infineon, Micron Technology, Samsung, and Elpida. Micron Technology was not fined for its involvement due to co-operation with investigators.

In 2003, the company took over Mitsubishi Electric Corporation's DRAM operations and employed Mitsubishi development engineers.

In 2004, Elpida Memory went public and was listed on the Tokyo Stock Exchange.

In 2006, the company established Akita Elpida to take on the development of advanced back-end technology processes.

In March 2006, Elpida reported consolidated sales of 241,500,000,000 Japanese yen. It employed 3196 people.

The company received 140 billion yen in financial aid and loans from the Japanese government and banks during the financial crisis in 2009.[4]

On April 3, 2010, Elpida Memory sold ¥18.5billion worth of shares to Kingston Technology[5]

On April 22, 2010, Elpida announced it had developed the world's first four-gigabit DDR3 SDRAM. Based on a 40 nm process, this DRAM was said to use about thirty percent less power compared to two 40 nm process two-gigabit DDR3 SDRAMs. It was to operate at both standard DDR3 1.5 V and 1.35 V to further reduce power consumption.[6]

In July 2011, Elpida announced that it planned to raise $987 million by selling shares and bonds.[7] In August 2011, Elpida claimed to be the first memory maker to begin sampling 25 nm DRAMs.[8]

On February 27, 2012, Elpida filed for bankruptcy.[9][10] With liabilities of 448 billion yen (US$5.5 billion), the company's bankruptcy was Japan's largest since Japan Airlines bankrupted in January 2010.[4] The company suffered from both strong yen and a sharp drop of DRAM prices as a result of stagnant demand of personal computers and disruption of computer production caused by flooding of HDD factories in Thailand.[4] DRAM prices plunged to a record low in 2011 as the price of the benchmark DDR3 2-gigabit DRAM declined 85%.[4] Elpida was the third largest DRAM maker, held 18 percent of the market by revenue in 2011.[4]

On March 28, 2012, Elpida was delisted from the Tokyo Stock Exchange.[11] At the time, Elpida was one of the suppliers of SDRAM components for the A6 processor in the Apple iPhone 5.[12]

In February 2013, Tokyo court and Elpida creditors approved an acquisition by Micron Technology.[13]

The company became a fully owned subsidiary of Micron Technology on July 31, 2013.[14]

Effective February 28, 2014, Elpida changed its name to Micron Memory Japan and Elpida Akita changed its name to Micron Akita, Inc.[3]



Micron has two design centers, one manufacturing plant/technology development site, and two sales offices in Japan:[15]

Micron's offices in Japan
Companies Roles Name Train station Municipality
Micron Memory Japan, K.K. (MMJ) Design (DRAM)[16] Hashimoto Engineering Center Minami-Hashimoto Sagamihara, Kanagawa
Design (NAND flash memory)[16] Kamata Office Kamata Ōta, Tokyo

Technology Development

Hiroshima Plant
Hiroshima Development Center
Higashi-Hiroshima Higashihiroshima, Hiroshima
Micron Memory Japan, K.K. (MMJ)

Micron Japan, Ltd. (MJP)

Sales Tokyo Office Shinagawa Minato, Tokyo
Micron Japan, Ltd. (MJP) Sales Osaka Office Osaka Business Park
The Hiroshima Plant is Micron Memory Japan's main manufacturing fab and technology development site, which was acquired from Elpida.

The Hiroshima Plant is key to Micron's efforts to develop low-power DRAM products essential to smartphones and other mobile devices.[17] Once these products achieve yield and performance targets (optimal cost structure, quality and lower end-to-end product cycle time) in Hiroshima, the manufacturing process can then be transferred to other sites.[17]

Micron's realignment of the Japanese operations included the following:[17]

With these changes, Micron's DRAM test and assembly capabilities would be based in Hiroshima and Taiwan.[17]

See also


  1. ^ "マイクロン日本法人会社案内 | Micron Technology, Inc". jp.micron.com (in Japanese). Retrieved 2022-07-14.
  2. ^ Dylan McGrath, EETimes. "Micron Closes Elpida Acquisition." July 31, 2013. Retrieved June 30, 2017.
  3. ^ a b "エルピーダ、2月28日から社名を「マイクロンメモリ ジャパン」に変更". マイナビニュース (in Japanese). 2014-01-23. Retrieved 2022-07-14.
  4. ^ a b c d e Naoko Fujimura and Jun Yang (Feb 28, 2012). "Elpida Falls as Lack of Smartphone Strategy Spurs Japan Bankruptcy Filing". Bloomberg.
  5. ^ Elpida to raise Y18.5 billion via share sale to U.S. partner
  6. ^ Phys.org. "Elpida Completes Development of 4-Gigabit DDR3 SDRAM, Industry's Highest Density DDR3." Apr 23, 2010. Retrieved May 30, 2018.
  7. ^ "Elpida to Sell 79.7 Billion Yen in Shares, Convertible Bonds - Bloomberg". bloomberg.com. 2011. Retrieved 2 August 2011.
  8. ^ EE Times. "Elpida says its sampling first 25-nm DRAMs Archived." August 4, 2011. Retrieved August 5, 2011.
  9. ^ "Chip manufacturer Elpida is bankrupt - Heise". heise.de. 2012. Retrieved 27 February 2012.
  10. ^ Elpida press release, dated 27 February 2012. Retrieved 28 February 2012.
  11. ^ Laskoski, Madeline (March 29, 2012). "Elpida Collapse to Boost Micron, Samsung: Pro". CNBC. Retrieved March 31, 2012.
  12. ^ The Next Web. "[1]."September 21, 2012. Retrieved July 6, 2016
  13. ^ Sacramento Bee. "[2]. "February 28th, 2013. Retrieved April 16, 2013
  14. ^ Elpida Press Release. "[3]. "July 31, 2013. Retrieved October 22, 2013
  15. ^ "Locations". Retrieved 2023-01-22.
  16. ^ a b "意外と知られていない? 巨大半導体会社マイクロンの日本とのつながり". ASCII.jp (in Japanese). 8 April 2021. Retrieved 2023-01-22.
  17. ^ a b c d "Realignment of Japan Facilities Key to Micron's Asia Operations". www.micron.com. Retrieved 2022-07-14.