TDK Develops, Begins Mass Production of Magnetic Sheets
with Ultra-High Magnetic Permeability

Information contained in the news releases are current as of the date of the press announcement, but may be subject to change without prior notice.

Achieving Highest Magnetic Permeability (μ' = 180) for Noise Suppression

Mar. 18, 2009

TDK Corporation announced today that it recently developed a new magnetic sheet for noise suppressing applications (product name: IRJ17) that achieves both magnetic permeability¹ at the industry's highest levels and excellent fire resistance. Mass production is scheduled to begin in March. The new magnetic sheets make use of TDK's strengths in materials technology, combine original soft magnetic materials² with polymer materials, and employ a magnetic powder created through the use of innovative powder composition and formation methods.

In recent years, numerous types of electronic devices such as digital cameras and mobile phones have become more compact and slimmer even as they adopt more functions. In conjunction with these changes, their internal circuit boards have become increasingly integrated and noise countermeasures must exhibit excellent control effects over a wide range of frequencies from low to high. Noise countermeasures are implemented through board circuit designs and various electronic components mounted on the boards, but it is also necessary to control unexpected and unwanted radiated noise. The use of magnetic sheets made of soft magnetic materials that are capable of absorbing noise and converting it to thermal energy can prevent noise from leaking outside devices and prevent harmful effects on other boards and components from internal reflection.

The new IRJ17 magnetic sheets meet these market needs by exhibiting outstanding attenuation effects on noise reflected from ICs and flexible printed circuit boards over a wide frequency range from low frequencies above 5 MHz to high frequencies. The noise control effects of IRJ17 magnetic sheets include the industry's highest magnetic permeability (μ' = 180) and magnetic characteristics that are approximately 1.7 times better than those of earlier TDK products. With regard to the fire resistance requirements of electronic components, IRJ17 magnetic sheets have obtained certification under the American UL94V-0 standard.³

The launch of these new magnetic sheets will make possible noise countermeasures finely tailored to customer needs over a broad range of frequencies from high to low in combination with TDK magnetic sheets that are currently available (product names: IRJ09, IRJ04).

Glossary

1. Magnetic permeability: The rate of increase in magnetization when a magnetic field is applied to a magnetic object; an indication of the ease of absorption of magnetic force lines by a magnetic object. Magnetic permeability is expressed by μ (mu).
2. Soft magnetic materials: Magnetic materials with low coercive force and high magnetic permeability.
3. ULV94V-0: A fire resistance (UL-94) standard adopted by Underwriters Laboratories Inc. of the United States.

Main Features

1. A compound magnetic sheet that uses a new and original magnetic powder developed by TDK to achieve the outstanding noise suppressing effects at the industry's best levels at low frequencies (μ' = 180) while maintaining fire resistance (UL94V-0).
2. RoHS Directive compliant.

Main Characteristics

Recommended frequency range	5 MHz - 3 GHz
Operating temperature range	-40°C - +85°C
Magnetic permeability(μ')1MHz	180
Fire resistance	UL94V-0
Thickness (mm)	0.1, 0.2, 0.3, and 0.4

Main Applications

Mobile phones, PC, digital still cameras, digital video cameras, and other electronic devices.

Production and Sales Plan

• Production location: Japan
• Production capacity: 50,000 sheets/month
• Start of production: March 2009

For further information, contact the Corporate Communications Dept.
Tel.: 81-3-6778-1055
E-mail: TDK.PR@tdk.com