Renesas reveals Naka fab status to press, test run underway
Renesas moved to satisfy the hunger for information on how work to restore its Naka fab is progressing by inviting journalists to see for themselves. The company revealed that restoration of facilities for both 200mm and 300mm lines has been completed and test runs are underway for both lines.
View from the gate. N3 (300mm line) is at the center. The junction of the connecting corridor and the N3 building were damaged and are now being repaired.
At the Naka plant, Renesas has a 200mm wafer line with a monthly capacity of 34,000 wafers and a 300mm line whose monthly capacity is 14,000 wafers. The 200mm line started a test run on April 23 with the first lot named Kizuna (bond or ties) to express appreciation for the support received. The 300mm line followed on April 25.
The lots in the test runs at the lines are not for product manufacturing. As reported earlier, Renesas set June 15 as the target date for resumption of production on the 200mm line. The volume of the test run is 100 wafers a day, which translates into 3,000 wafers a month, about 10% of capacity.
Tetsuya Tsurumaru, senior vice president in charge of the Production and Technology Unit said that Renesas will announce a more detailed production plan, including a plan for the 300mm line, in mid-May,
Renesas' framework for restoring the LSI supply chain centering on microcontrollers consists of three measures:
1. Restoration of the lines at Naka as early as possible.
2. Shifting fabrication to Renesas' other fabs
3. Outsourcing to TSMC and Global Foundries
"We are doing our utmost to restore the supply chain in the shortest possible period by making full use of these three measures," said Tsurumaru. Renesas is receiving support from various sectors—plant constructors, equipment vendors, material suppliers and customers. On the busiest days, as many as 2500 engineers and workers have been toiling at the Naka fab in a concerted effort to put it back on its feet. With this support, Renesas estimates that the prospects for restoration as of March 31 have been brought forward by about one month. Completion of restoration of the 200mm production facilities by mid- May means everything should be ready for the resumption of production in mid-June.
For automotive microcontrollers, Renesas' Tsugaru fab in Yamagata Prefecture and Global Foundries are shouldering additional fabrication. The company's Saijo fab in western Japan will increase general-purpose microcontroller fabrication and the Tsuruoka 300mm wafer fab in Yamaga Prefecture will fabricate more system-on-chip LSIs to help the Naka fab.
Renesas has been trumpeting that it has over 30% of the worldwide microcontroller market. Indeed, for automotive-use microcontrollers, the company's market share was 44% in 2010, according to iSuppli. The Naka fab had been fabricating about 25% of the microcontrollers made by Renesas.
Teams of engineers adjusting systems at the CVD process bay but only one green lamp is on, indicating a system is operating. (At the 200mm line in the Naka clean room)
The Naka fab is designed to withstand a 400 gal tremor, but a seismic meter at the site recorded 950 gals at the peak, according to Tsurumaru. Renesas conducted emergency drills assuming a seismic intensity level of 6, but 950 gals is equivalent to the highest level, 7.
On March 11, the first quake struck off the coast of Miyazaki Prefecture, which was the M9.0 Great East Japan Earthquake, followed about 30 minutes later by an M7.7 aftershock off the coast of Ibaraki Prefecture, where the Naka fab is located.
"The impact of the aftershock seemed greater to us than that of the monster quake," said Takashi Aoyagi, general manager of the Production and Technology Unit at Naka Factory. "About 150 engineers and operators were in the clean rooms when the quake struck. All were safely evacuated, but then the aftershock occurred and seemed to cause heavier damage to the facilities," he said.
To the press, Renesas reported typical earthquake damage suffered by buildings, clean rooms and other facilities—cables adrift, collapsed walls in clean rooms and breakage of the brackets that secure production systems.
Sanyo Electric's Niigata fab was severely damaged in 2004 by the M6.8 Mid-Niigata Prefecture Earthquake whose epicenter was directly below the fab. That calamity served as a wakeup call for other semiconductor manufacturers in Japan. Renesas learned from it. Improved measures to prevent fire and leakage of gas or chemical liquids worked as intended and no fire or leakage occurred, according to Aoyagi. Improvement in the securing of production equipment in light of Sanyo's experience helped mitigate the damage to facilities, he said.
Following the mega-quake, disrupted supply chains are a source of grave concern for industry. Renesas, however, does not expect to have any trouble securing wafers and other materials until September thanks to close support from various sectors, according to Tsurumaru.