Toshiba Semiconductor User Manual

[ 6 ] Handling Guide

1. Using Toshiba Semiconductors Safely

TOSHIBA is continually working to improve the quality and reliability of its products. Nevertheless, semiconductor devices in general can malfunction or fail due to their inherent electrical sensitivity and vulnerability to physical stress. It is the responsibility of the buyer, when utilizing TOSHIBA products, to comply with the standards of safety in making a safe design for the entire system, and to avoid situations in which a malfunction or failure of such TOSHIBA products could cause loss of human life, bodily injury or damage to property. In developing your designs, please ensure that TOSHIBA products are used within specified operating ranges as set forth in the most recent TOSHIBA products specifications. Also, please keep in mind the precautions and conditions set forth in the “Handli ng Guide for Semiconductor Devices,” or “TOSHIBA Semiconductor Reliability Han d book” etc..

The TOSHIBA products listed in this document are intended for usage in general electronics applications (computer, personal equipment, office equipment, measuring equipment, industrial robotics, domestic appliances, etc.). These TOSHIBA products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury (“Unintended Usage”). Unintended Usage include atomi c energy control instrum ents, airplane or spa ceship instruments, transportation instruments, traffic signal instruments, combustion control instruments, medical instruments, all types of safety devices, etc.. Unintended Usage of TOSHIBA products listed in this document shall be made at the customer’s own risk.

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2. Safety Precautions

This section lists important precautions which users of semiconductor devices (and anyone else) should observe in order to avoid injury and damage to property, and to ensure safe and correct use of devices.

Please be sure that you understand the meanings of the labels and the graphic symbol described below before you move on to the detailed descriptions of the precautions.

[Explanation of labels]

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Indicates an imminently hazardous situation which will result in death or serious injury if you do not follow instructions

Indicates a potentially hazardous situation which coul d result i n death or serious i njury if you do not follow instructions.

Indicates a potentially hazardous situati on which if not avoided, may result in minor injury or moderate injury.

[Explanation of graphic symbol ]

Graphic symbol Meaning

Indicates that caution is required (laser beam is dangerous to eyes).

2.1 General Precautions regarding Semiconductor Devices

Do not use devices under conditions exceeding their absolute maximum ratings (e.g. current, volt age, power dissipation or temperature).

This may cause the device to break down, degrade its performance, or cause it to catch fire or explode resulting in injury.

Do not insert devices in the wrong orientation. Make sure that the positive and negative terminals of power supplies are connected correctly. Otherwise the rat e d

maximum current or power dissipation may be exceeded and the device may break down or undergo performance degradation, causing it to catch fire or explode and resulting in injury.

When power to a device is on, do not touch the device’s heat sink. Heat sinks become hot, so you may burn your hand.

Do not touch the tips of device leads. Because some types of device have leads with pointed tips, you may prick your fi nger.

When conducting any kind of evaluation, inspection or testing, be sure to connect the testing equipm ent’s el ect rodes or probes to the pins of the device under test before powering it on.

Otherwise, you may receive an electric shock causing injury.

Before grounding an item of measuring equipment or a soldering iron, check that there is no electrical leakage from it. Electrical leakage may cause the device which you are testing or soldering to break down, or could give you an electric

shock.

Always wear protective glasses when cutting the leads of a device with clippers or a similar tool. If you do not, small bits of metal flying off the cut ends may damage your eyes.

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3. General Safety Precautions and Usage Considerations

This section is designed to help you gain a better understanding of semiconductor devices, so as to ensure the safety, quality and reliability of the devices which you incorporate into your designs.

3.1 From Incoming to Shipping

3.1.1 Electrostatic Discharge (ESD)

When handling individual devices (which are not yet mounted on a printed circuit board), be sure that the environment is protected against electrostatic electricity. Operators should wear anti-static clothing, and containers and other objects which come into direct contact with devices should be made of anti-static materials and should be grounded to earth via an 0.5 to 1.0-MΩ protective resistor.

Please follow the precautions described below; this is particularly important for devices which are marked “Be careful of static.”.

(1) Work environment

• When humidity in the wo rking environment decreases, the human body and other insulators can easily become charged with static electricity due to friction. Maintain the recommended humidity of 40% to 60% in the work environment, while also taking into account the fact that moisture-proof-packed products may absorb moisture after unpacking.

• Be sure that all equipmen t, jigs and tools in the working area are grounded to earth.

• Place a conductive mat over the floor of the work area, or take other appropriate measures,

so that the floor surface is protected against static electricity and is grounded to earth. The surface resistivity should be 10

7.5 × 10

• Cover the workbench surface also with a conductive mat (with a surface resistivity of 10 10 this is to disperse static electricity on the surface (through resistive components) and ground it to earth. Workbench surfaces must no t be constructed of low-resista nce metallic materials that allow rapid static discharge when a charged device touches the m directly.

• Pay attention to the following points when using automatic equipment in your workplace:

(a) When picking up ICs with a vacuum unit, use a conductive rubber fitting on the end of the

pick-up wand to protect against electrostati c charge.

(b) Minimize friction on IC package surfaces. If some rubbing is unavoidable due to the device’s

mechanical structure, minimize the friction plane or use material with a small friction coefficient and low electrical resistance. Also, consider the use of an ionizer.

dissipates static electricity

(d) Ensure that no statically charged bodies (such as work clothes or the human body) touch the

devices

to 108 Ω

Ω/sq, for a resistance between surface and ground of 7.5 × 105 to 10

to 108 Ω/sq and the resistance between surface and ground,

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Ω) . The purpose of

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(e) M ake sure that section s of the tape carrier which come into contact with ins t allation devices

or other electrical machinery are made of a low-resistance material. (f) Make sure that jigs and tools used in the assembly process do not touch devices. (g) In processes in which packages may retain an electrostatic charge, use an ionizer to

neutralize the ions.

• Make sure that CRT displays in the working area are protected against static charge, for example by a VDT filter. As much as possible, avoid turning displays on and off. Doing so can cause electrostatic induction in devices.

• Keep track of charged potential in the working area by taking periodic measurements.

• Ensure that work chairs are protected by an anti-stati c textile cover and are grounded to

the floor surface by a grounding chain. (Suggested resistance between the seat surface and

grounding chain is 7.5 × 10

• Install anti-static mats on storage shelf surfaces. (Suggested surface resistivity is 10 Ω/sq; suggested resistance between surface and ground is 7.5 × 10

• For transport and temporary storage of devices, use containers (boxes, jigs or bags) that are

made of anti-static materials or materials which dissipate electrostatic charge.

• Make sure that cart surfaces which come into con t act with device packaging are m ade of materials which will conduct static electricity, and verify that they are grounded to the floor surface via a grounding chain.

• In any location where the level of static electricity is to be closely controlled, the ground resistance level should be Class 3 or above. Use different ground wires for all items of equipment which may co me into physical contact with devices.

(2) Operating environment

• Operators must wear anti-static clothing and conductive shoes (or a leg or heel strap).

• Operators must wear a wrist strap grounded to earth via a resistor of about 1 MΩ.

• Soldering irons must be grounded from iron tip to earth, and must be used only at low voltages (6 V to 24 V).

• If the tweezers you use are likely to touch the device terminals, use anti-static tweezers and in particular avoid metallic tweezers. If a charged device touches a low-resistance tool, rapid discharge can occur. When using vacuum tweezers, attach a conductive chucking pa t to the tip, and connect it to a dedicated ground used especially for anti-static purposes (suggested resistance value: 10

• Do not place devices or their containers near sources of strong electrical fields (such as above a CRT).

to 10

to 108 Ω).

Ω.)

to 108 Ω.)

to 108

• When storing printed circuit boards which have devices mounted on them, use a board container or bag that is protected against static charge. To avoid the occurrence of static charge or discharge due to friction, keep the boards separate from one other and do not stack them directly on top of one another.

• Ensure, if possible, that any articles (such as clipboards) which are brought to any location where the level of static electricity must be closely controlled are constructed of anti-static materials.

• In cases where the human body comes into direct contact with a device, be sure to wear anti-static finger cove rs or gloves (suggested resistance value: 10

• Equipment safety covers installed near devices should have resistance ratings of 10 less.

• If a wrist strap cannot be used for some reason, and there is a possibility of imparting friction to devices, use an ionizer.

3.1.2 Vibration, Impact and Stress

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Ω or less).

Ω or

Handle devices and packagi ng materials with care. To avoid damage to devices, do not toss or drop packages. Ensure that devices are not subjected to mechanical vibration or shock during transportation. Ceramic package devices and devices in canister-type packages which have empty space inside them are subject to damage from vibration and shock because the bonding wires are secured only at their ends.

Plastic molded devices, on the other hand, have a relatively high level of resistance to vibration and mechanical shock because their bonding wires are enveloped and fixed in resin. However, when any device or package type is installed in target equipment, it is to some extent susceptible to wiring disconnections and other damage from vibration, shock and stressed solder junctions. Therefore when devices are incorporated into the design of equipment which will be subject to vibration, the structural design of the equipment must be thought out carefully.

If a device is subjected to especially strong vibration, mechanical shock or stress, the package or the chip itself may crack. In products such as CCDs whi ch incorporate window glass, thi s could cause surface flaws in the glass or cause the connection between the glass and the ceramic to separate.

Furthermore, it is known that st ress applied to a semiconductor device through the package changes the resistance characteristics of the ch ip because of piezoelectri c effects. In analog circuit design attention must be paid to the problem of package stress as well as to the dangers of vibration and shock as described above.

Vibration

3.2 Storage

3.2.1 General Storage

• Avoid storage locations where devices will be exposed to moisture or direct sunlight

• Follow the instructions printed on the device cartons regarding

transportation and storage.

• The storage area temperature should be kept within a temperature range of 5°C to 35°C, and relative humidity should be maintained at between 45% and 75%.

• Do not store devices in the presence of harmful (especially corrosive) gases, or i n dusty conditions.

• Use storage areas where there is minimal temperature fluctuation. Rapid temperature changes can cause moisture to form on stored devices, resulting in lead oxidation or corrosion. As a result, the solderability of the leads will be degraded.

• When repacking devices, use anti-static containers.

• Do not allow external forces or loads to be applied to devices while they are in storage.

• If devices have been stored for more than two years, their electrical characteristics should be

tested and their leads should be tested for ease of soldering before they are used.

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Humidity:

Temperature:

3.3 Design

Care must be exercised in the design of electronic equipment to achieve the desired reliability. It is important not only to adhere to specifications concerning absolute maximum ratings and recommended operating conditions, it is also important to consider the overall environment in which equipment will be used, including factors such as the ambient temperature, transient noise and voltage and current surges, as well as mounting conditions which affect device reliability. This sectio n describes some general precautions which you should observe when designing ci rcuits and when mounting devices on printed circuit boards.

For more detailed information about each product family, refer to the relevant individual technical datasheets available from Toshiba

3.3.1 Absolute Maximum Ratings

The absolute maximum ratings are rated values which must not be exceeded during operation, even for an instant. Although absolute maximum ratings differ from product to product, they essentially concern the voltage and current at each pin, the allowable power dissipation, and the junction and storage temperatures.

If the voltage or current on any pin exceeds the absolute maximum rating, the device’s internal circuitry can become degraded. In the worst case, heat generated in internal circuitry can fuse wiring or cause the semiconductor chip to break down.

If storage or operating temperatures exceed rated values, the package seal can deteriorate or the wires can become disconnected due to the differences between the thermal expansion coefficients of the materials from which the device is constructed.

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Do not use devices under conditions in which their absolute maximum

ratings (e.g. current, voltage, power dissipation or temperature) will be exceeded. A device may break down or its performance may be degraded, causing it to catch fire or explode resulting in injury to th e user.

3.3.2 Recommended Operating Conditions

The recommended ope r ating conditions for each device are those necessary to guarantee that the device will operate as specified in the datasheet. If greater reliability is required, derate th e device’s absolute maximum ratings for voltage, current, power and temperature before using it.

3.3.3 Derating

When incorporating a device into your design, reduce its rated absolute maximum vo ltage, current, power dissipation and operating temperature in order to ensure high reliability. Since derating differs from application to application, refer to the technical datasheets available for the various devices use d in your design.

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