Surface Mount Resistors Safety precautions

Surface Mount Resistors Safety precautions
Safety Precautions (Common precautions for Surface Mount Resistors)
The following are precautions for individual products. Please also refer to the common precautions for Fixed Resistors
in this catalog.
1. Take measures against mechanical stress during and after mounting of Surface Mount Resistors (hereafter called the
resistors) so as not to damage their electrodes and protective coatings.
Be careful not to misplace the resistors on the land patterns. Otherwise, solder bridging may occur.
2. Keep the rated power and ambient temperature within the specified derating curve.
Some circuit boards, wiring patterns, temperatures of heat generated by adjacent components, or ambient
temperatures can become factors in the rise of the temperature of the resistors, regardless of the level of power
applied. Therefore, check the conditions before use and optimize them so as not to damage the boards and peripheral
Make sure to contact us before using the resistors under special conditions.
3. If a transient load (heavy load in a short time) like a pulse is expected to be applied, check and evaluate the
operations of the resistors when installed in your products before use.
Never exceed the rated power. Otherwise, the performance and/or reliability of the resistors may be impaired.
4. Before using halogen-based or other high-activity flux, check the possible effects of the flux residues on the
performance and reliability of the resistors.
5. When soldering with a soldering iron, never touch the resistors'bodies with the tip of the soldering iron. When using a
soldering iron with a high temperature tip, finish soldering as quickly as possible (within three seconds at 350 °C max.).
6. As the amount of applied solder becomes larger, the mechanical stress applied to the resistors increases, causing
problems such as cracks and faulty characteristics. Avoid applying an excessive amounts of solder.
7. When the resistors' protective coatings are chipped, flawed, or removed, the characteristics of the resistors may be
impaired. Take special care not to apply mechanical shock during automatic mounting or cause damage during
handling of the boards with the resistors mounted.
8. Do not apply shock to the resistors or pinch them with a hard tool (e.g. pliers and tweezers). Otherwise, the resistors'
protective coatings and bodies may be chipped, affecting their performance.
9. Avoid excessive bending of printed circuit boards in order to protect the resistors from abnormal stress.
10. Do not immerse the resistors in solvent for a long time. Before using solvent, carefully check the effects of immersion.
11. Transient voltage
If there is a possibility that the transient phenomenon (significantly high voltage applied in a short time) may
occur or that a high voltage pulse may be applied, make sure to evaluate and check the characteristics of
Fixed Metal (Oxide) Film Resistors mounted on your product rather than only depending on the calculated
power limit or steady-state conditions to complete the design or decide to use the resistors.
12. Do not apply excessive tension to the terminals.
Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use.
Should a safety concern arise regarding this product, please be sure to contact us immediately.
02 Sep. 2014
Safety Precautions (Common precautions for Fixed Resistors)
• When using our products, no matter what sort of equipment they might be used for, be sure to make a written
agreement on the specifications with us in advance. The design and specifications in this catalog are subject
to change without prior notice.
• Do not use the products beyond the specifications described in this catalog.
• This catalog explains the quality and performance of the products as individual components. Before use, check
and evaluate their operations when installed in your products.
• Install the following systems for a failsafe design to ensure safety if these products are to be used in equipment
where a defect in these products may cause the loss of human life or other significant damage, such as damage to
vehicles (automobile, train, vessel), traffic lights, medical equipment, aerospace equipment, electric heating
appliances, combustion/gas equipment, rotating equipment, and disaster/crime prevention equipment.
✽ Systems equipped with a protection circuit and a protection device
✽ Systems equipped with a redundant circuit or other system to prevent an unsafe status in the event of a single fault
(1) Precautions for use
• These products are designed and manufactured for general and standard use in general electronic equipment
(e.g. AV equipment, home electric appliances, office equipment, information and communication equipment)
• These products are not intended for use in the following special conditions. Before using the products,
carefully check the effects on their quality and performance, and determine whether or not they can be used.
1. In liquid, such as water, oil, chemicals, or organic solvent
2. In direct sunlight, outdoors, or in dust
3. In salty air or air with a high concentration of corrosive gas, such as Cl2, H2S, NH3, SO2, or NO2
4. Electric Static Discharge (ESD) Environment
These components are sensitive to static electricity and can be damaged under static shock (ESD).
Please take measures to avoid any of these environments.
Smaller components are more sensitive to ESD environment.
5. Electromagnetic Environment
Avoid any environment where strong electromagnetic waves exist.
6. In an environment where these products cause dew condensation
7. Sealing or coating of these products or a printed circuit board on which these products are mounted, with
resin or other materials
• These products generate Joule heat when energized. Carefully position these products so that their heat will
not affect the other components.
• Carefully position these products so that their temperatures will not exceed the category temperature range due
to the effects of neighboring heat-generating components. Do not mount or place heat-generating components
or inflammables, such as vinyl-coated wires, near these products.
• Note that non-cleaning solder, halogen-based highly active flux, or water-soluble flux may deteriorate the
performance or reliability of the products.
• Carefully select a flux cleaning agent for use after soldering. An unsuitable agent may deteriorate the performance
or reliability. In particular, when using water or a water-soluble cleaning agent, be careful not to leave water
residues. Otherwise, the insulation performance may be deteriorated.
(2) Precautions for storage
The performance of these products, including the solderability, is guaranteed for a year from the date of arrival
at your company, provided that they remain packed as they were when delivered and stored at a temperature
of 5 °C to 35 °C and a relative humidity of 45 % to 85 %.
Even within the above guarantee periods, do not store these products in the following conditions. Otherwise,
their electrical performance and/or solderability may be deteriorated, and the packaging materials (e.g. taping
materials) may be deformed or deteriorated, resulting in mounting failures.
1. In salty air or in air with a high concentration of corrosive gas, such as Cl2, H2S, NH3, SO2, or NO2
2. In direct sunlight
<Package markings>
Package markings include the product number, quantity, and country of origin.
In principle, the country of origin should be indicated in English.
01 Sep. 2014