ECIA - EIA/ECA-576
Resistors, Thin Film Rectangular SMD on Ceramic
|Publication Date:||1 August 2020|
This standard covers thin film precision rectangular leadless discrete fixed resistors with temperature coefficients of ± 50 PPM/ºC and tighter and resistance tolerances of 1%, 0.5%, 0.25%, 0.1% and 0.05% 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.
The style is identified by three letters describing the type of surface mount component (Precision Resistor Chip) followed by four digits giving the resistor's nominal length and width in millimeters per Table I.
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.
The nominal resistance expressed in ohms 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 1000, 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.
The standard values for every decade shall follow the sequence of IEC 60063 Preferred number series for resistors and capacitors. Refer to Table IV.
The resistance tolerance is identified by a single letter: "F" for 1%, "D" for 0.5%, "C" for 0.25%, "B" for 0.1%, and "A" for 0.05%.
The resistance range applicable to this standard is 10 ohms to l megohm, inclusive. Characteristics for nominal resistance values less than 10 ohms or greater than l megohm may differ from those specified in Table II.