On July 1st, Toshiba Corporation's Semiconductor Company and Storage Products Company consolidated to form Semiconductor & Storage Products Company.This page describes reliability information of semiconductor products.

General Usage Considerations

[As of April, 2011]

Operating Environment

Temperature

Semiconductor devices are generally more sensitive to temperature than other electromechanical parts. The various electrical characteristics of a semiconductor device are restricted by the operating temperature. It is therefore necessary to understand the temperature characteristics of a device and incorporate derating into the device design in advance. When a device is used at a temperature outside the specified operating range, electrical characteristics will not be realized and device deterioration will occur more rapidly.

Humidity

Plastic package devices are sometimes not completely sealed.
When these devices are used for an extended period of time under high humidity, moisture can seep into the device and cause semiconductor chip deterioration or failure. Additionally, care shall be taken for using devices under conditions of dew condensation, because leads of device may oxidize, or ion migration may be occurred between leads. Furthermore, when devices are mounted on a regular printed circuit board, the impedance between wiring can decrease under high humidity. In systems with a high signal-source impedance, circuit board leakage or leakage between device leads can cause malfunction. In such a case, moisture-proof treatment to the device surface should be considered. On the other hand, operation under low humidity can damage a device due to the occurrence of electrostatic discharge.

Corrosive Gases

Devices react to corrosive gases may cause deteriorating device characteristics. For example, consideration must be given to lead corrosion and leakage between leads caused by the chemical reaction that occurs when a device is placed near a rubber product. The reason is that the rubber product will not only produce dew condensation but also generate sulfur-bearing corrosive gases under high-humidity conditions.

Radioactive and Cosmic Rays

Standard devices are not designed with protection against radioactive and cosmic rays. Devices must therefore be shielded if the device will be used in environments that may result in exposure to radioactive or cosmic rays above the levels that exist in the natural environment.

Strong Electrical and Magnetic Fields

Devices exposed to magnetic fields can undergo a polarization phenomenon in the plastic material or within the IC chip, which gives rise to abnormal conditions such as impedance changes or leak current increases. Malfunctions have been reported in LSIs mounted near television deflection yokes. In such cases, the LSI mounted locations must be changed or the device must be shielded against the electrical or magnetic field. Shielding against magnetism is especially required in an alternating magnetic field due to the electromotive forces generated.

Interference from Light (such as Ultraviolet Rays, Sunlight, Fluorescent Lamps, Incandescent Lamps)

Light striking a semiconductor device generates electromotive force due to photoelectric effects, sometimes causing malfunction. Devices in which the chip is visible through the package are especially affected by such light. When designing the circuits, make sure that the devices are protected against light interference. Not just optical semiconductor devices, but all types of devices are affected by light.

Dust and Oil

Similar to corrosive gases, dust and oil cause chemical reactions in semiconductor products, sometimes adversely affecting product characteristics. Be sure to use semiconductor products in an environment that will not result in dust or oil adhesion. Solvent and oil contained in heat release sheets similarly may result in semiconductor product quality deterioration, characteristic deterioration or disconnection. Be sure to use such products with care.

Smoke and Ignition

Semiconductor devices and modularized devices are not noncombustible; they can emit smoke or ignite when excessive current or failure occurs. When this happens, poisonous gases may be produced.
Be sure to develop a safe design that protects the device from excessive current so as to ensure excessive current does not flow within the device during operation or at the time of failure.
To prevent the propagation of fire caused by a smoking or ignited Toshiba product and to ensure that Toshiba products do not emit smoke or ignite due to surrounding conditions, do not use Toshiba products in close proximity to combustible thing, heat-generating thing, igniting materials or flammable materials.