TDK Corporation begins volume production of the industry’s first* 0603 type (0.6 mm x 0.3 mm) multilayer chip varistor this August. The new chip varistor is about one-fifth the volume and weight of previous products. In order to respond to the demand for smaller, lighter, and lower power consuming mobile devices including cell phones, PDAs, laptop computers, and digital cameras, semiconductor elements are being made with higher degrees of integration and to operate on lower voltages.
At the same time, however, there is also a tendency for the elements to become more susceptible to noise, and surges caused by static electricity (a large flow of a current caused by a momentary abnormal voltage) are a particular problem.
When the voltage impressed on multilayer chip varistors reaches a certain degree, current, which previously could not pass through, is suddenly able to pass, and they exhibit excellent inhibitive power against surges. Devices that are being made ever smaller but that are in frequent contact with users’ hands such as cell phones absolutely require surge protection, and as a result demand for multilayer chip varistors is increasing.
In response to smaller circuit boards, the new 0603 type multilayer chip varistors were downsized to have approximately 78% less volume (approximately one-fifth) and 64% less area (approximately one-third) than the earlier 1005 types (1.0 mm x 0.5 mm). This makes it possible to install the necessary number of varistors even on small boards.
When multilayer chip varistors are made smaller, the electrode area also becomes smaller, resulting in lower capacity to withstand surges, and as a result, it is necessary to make the varistor elements thinner to achieve the properties suitable for low voltage circuits, presenting a significant technological hurdle. TDK used minute structure control technology to create fine, uniform crystal particles as well as multilayering technology that achieves the highest possible levels of precision to develop unique rare earth zinc oxide varistors. In addition to achieving the small 0603 size, they also provide stability with extremely small deterioration of properties even after impression by static electricity.
The new varistors will be used in IC circuit power supplies, reset circuits, and input and output terminals to prevent malfunctions of mobile devices as well as damage from static electricity. In addition, these products are completely lead-free. The terminal electrodes are plated with nickel and tin, while the ground terminal has a coating of silver. The new varistors feature excellent solder-wettability and outstanding solder heat resistance. In the future, TDK will create series with special properties while closely monitoring market developments.
*As of July 28, 2003, based on TDK investigations.
Type Product Name Varistor VoltageV1mA (V) Maximum Rated Circuit
VoltageEdc (V) Electric Capacitance(reference value)(pF) [1kHz,Erms:1V]
0603 AVR-M0603 12(9.6-14.4) 7.5 35
-Shipments began in August, 2003
-Production base: Akita region
-Production Capacity: 50 million pcs. per month
-Sample price: Y15 each
Main applications: Static electricity countermeasures in cell phones, PDAs, laptop computers, digital still cameras, digital video cameras, portable audio devices, and so on.