This standard covers thick film general purpose rectangular leadless discrete fixed resistors with temperature coefficients of ± 350 PPM/ºC (ranging from ± 50 PPM/ºC to ± 350 PPM/ºC) and greater and resistance tolerances of ± 5% (ranging from ± 0.5% to ± 5%) and greater for use in surface mounting applications using soldering techniques. If the supplier chooses, it may include in the qualification test plan one of the test condition options of ANSI/EIA-977 Test Method - Electronic Passive Components Exposure to Atmospheric Sulfur to qualify the product family as resistant to the known effects of environmental sulfur on silver.

Typical Construction Characteristics

The termination shall include a leach-resistant barrier layer, made of nickel or an equivalent material. The barrier layer shall be covered with a layer of solderable material.

Style

The style is identified by two letters describing the type of surface mount component (Resistor Chip) followed by four digits giving the resistor’s nominal length and width in millimeters per Table I.

Characteristics

The characteristic is identified by a single letter in accordance with Table II. Individual part requirements shall be specified in Table II and the test paragraphs.

Resistance

The nominal resistance expressed in ohms is identified by three digits for 5% and 2% tolerance devices; the first two digits represent significant figures and the last digit specifies the number of zeros to follow. For 1% and 0.5% tolerance devices, nominal resistance is identified by four digits; the first three digits represent significant figures and the last digit represents the number of zeros to follow. When the value of resistance is less than 100 ohms for 5% and 2% tolerance and less than 1000 Ohms for 1% and 0.5% tolerance, the letter R shall be substituted for one of the significant digits to represent the decimal point. When the letter "R" is used, succeeding digits of the group represent significant figures. The resistance value designations are shown in Table III. Zero ohm jumper chip resistors are identified by three zeros.

Standard Values

The standard values for every decade shall follow the sequence of IEC Publication 63. Refer to Table IV.

Resistance Tolerance

The resistance tolerance is identified by a single letter: “D” for 0.5%, “F” for 1%, “G” for 2%, and “J” for 5%.

Resistance Range

The resistance range applicable to this standard is 0.10 ohms to 22 mega ohm, inclusive. Characteristics for nominal resistance values less than 10 ohms or greater than 1 mega ohm may differ from those specified in Table II.