Chip-type fixed resistors, directly translated from Chip Fixed Resistor, commonly known as SMD Resistors, are one of the metallic glass uranium resistors. Is a combination of metal powder and glass uranium powder, printed on the substrate printed on the substrate made of the resistor. Resistant to moisture, high temperature, low temperature coefficient. (Note: The following chip fixed resistors are called chip resistors)
Chip resistance classification
Chip resistors are divided into the following categories:

Type reference international classification

Conventional series of thick film chip resistors

General purpose General purpose, 0201 - 0805

General purpose, 1206 - 2512

High precision and high stability chip resistance

High precision - high stability High precision - high stability, 0201 - 0603

High precision - high stability, 0805 - 1210

High precision - high stability, 2010 - 2512

Conventional series of film chip resistors

General purpose thin film General purpose thin film, 0201-2512

Low resistance chip resistors

Low ohmic low ohmic, 0402 - 1206

Low ohmic, 2010 - 2512

Chip Resistor Array

Arrays Arrays, convex and concave

Chip current sensor

SMD current sensors Current Sensors - Low TCR

Patch network resistor

Network Network, T-type and L-type
Chip Resistor Package and Size
Chip resistors are packaged and dimensioned as follows:

Inch (mm) length (t) (mm) a (mm) b (mm)

0201 0603 0.60 ± 0.05 0.30 ± 0.05 0.23 ± 0.05 0.10 ± 0.05 0.15 ± 0.05

0402 1005 1.00 ± 0.10 0.50 ± 0.10 0.30 ± 0.10 0.20 ± 0.10 0.25 ± 0.10

0603 1608 1.60 ± 0.15 0.80 ± 0.15 0.40 ± 0.10 0.30 ± 0.20 0.30 ± 0.20

0805 2012 2.00 ± 0.20 1.25 ± 0.15 0.50 ± 0.10 0.40 ± 0.20 0.40 ± 0.20

1206 3216 3.20 ± 0.20 1.60 ± 0.15 0.55 ± 0.10 0.50 ± 0.20 0.50 ± 0.20

1210 3225 3.20 ± 0.20 2.50 ± 0.20 0.55 ± 0.10 0.50 ± 0.20 0.50 ± 0.20

1812 4832 4.50 ± 0.20 3.20 ± 0.20 0.55 ± 0.10 0.50 ± 0.20 0.50 ± 0.20

2010 5025 5.00 ± 0.20 2.50 ± 0.20 0.55 ± 0.10 0.60 ± 0.20 0.60 ± 0.20

2512 6432 6.40 ± 0.20 3.20 ± 0.20 0.55 ± 0.10 0.60 ± 0.20 0.60 ± 0.20
The relationship between chip resistive package and power
Chip resistor package and power relationship as follows:

Package Rated Power @ 70 ° C Maximum Operating Voltage (V) Imperial (mil) Metric (mm) Conventional Power Series Upgraded Power Series

0201 0603 1 / 20W / 25

0402 1005 1 / 16W / 50

0603 1608 1 / 16W 1 / 10W 50

0805 2012 1 / 10W 1 / 8W 150

1206 3216 1 / 8W 1 / 4W 200

1210 3225 1 / 4W 1 / 3W 200

1812 4832 1 / 2W / 200

2010 5025 1 / 2W 3 / 4W 200

2512 6432 1W / 200

Note: voltage = √ power x resistance value (P = V2 / R) or the maximum working voltage of the smaller value
Characteristics of chip resistors
Small size and light weight

· Adaptation reflow and wave soldering;

· Stable electrical performance, high reliability;

· Low cost of assembly and matching with automatic loading and unloading equipment;

· High mechanical strength, high frequency characteristics.
The naming method of chip resistors
The naming method of the domestic chip resistors:

1,5% accuracy of the name: RS-05K102JT

2,1% accuracy of the name: RS-05K1002FT

R - represents resistance

S is the power of 0402 is 1 / 16W, 0603 is 1 / 10W, 0805 is 1 / 8W, 1206 is 1 / 4W, 1210 is 1 / 3W, 1812 is 1 / 2W, 2010 is 3 / 4W, 2512 is 1W.

05 - indicates size (inches): 02 means 0402,03 means 0603,05 means 0805, 06 represents 1206, 1210 represents 1210, 1812 represents 1812, 10 represents 1210, 12 represents 2512.

K - indicates a temperature coefficient of 100 PPM,

102-5% Accuracy Resistance Representation: The first two digits indicate the effective number, the third bit indicates how many zero, the basic unit is Ω, 102 = 10000Ω = 1KΩ. 1002 is 1% resistance representation: the first three digits indicate the effective number, the fourth bit indicates how many zero, the basic unit is Ω, 1002 = 10000Ω = 10KΩ.

J - indicates an accuracy of 5% and F- indicates an accuracy of 1%.

T - indicates tape packing

Chip resistance resistance error accuracy of ± 1%, ± 2%, ± 5%, ± 10% accuracy, the most commonly used is ± 1% and ± 5%

± 5% accuracy of the conventional three-digit is to represent the example 512, the first two are valid figures, the third digit 2 that the number of zero, the basic unit is Ω, this is 5100 ohms, 1000Ω = 1KΩ, 1000000Ω = 1MΩ

In order to distinguish ± 5%, ± 1% of the resistance, then ± 1% of the resistance of the conventional majority with 4 digits,

So that the first three are valid numbers, the fourth said that the number of zero 4531 is 4530Ω, it is equal to 4.53KΩ
Chip resistors are available
Surface assembly technology (SMT) applications have been very common, the use of SMT assembly of the proportion of electronic products has more than 90%. China began to use SMT from the eighties. With the development of small SMT production equipment, SMT applications in the further expansion of the aviation, aerospace, instrumentation, machine tools and other fields are also using SMT production of various small quantities of electronic products or components.

In recent years, in addition to electronic product developers with patch-type devices to develop new products, maintenance personnel have begun to repair a large number of SMT assembly of electronic products. This article will introduce the application of the largest chip resistors, capacitors and inductors of the main parameters and specifications, in order to developers, maintenance personnel to buy these patch-type components help.

The current chip resistors are not uniform models, set by the manufacturers themselves, and the model is particularly long (by a dozen letters and numbers). In the purchase when the correct placement of the various parameters and specifications of the chip resistance, it can be very easy to buy (or order) to the required resistance.

Chip resistors have five parameters, namely size, resistance, tolerance, temperature coefficient and packaging.

1. The size series of chip resistors are generally available in 7 sizes and are represented by two sizes. A size code is a 4-digit EIA (American Electronics Industry Association) code, the first two and the last two said the resistance of the length and width, in inches. The other is a metric code, also represented by a four-digit number, in millimeters. Different sizes of resistors, the power rating is also different. Table 1 lists the code and power ratings for these seven resistor sizes.

2. Resistance series The nominal resistance is determined by series. Each series is divided by the tolerance of the resistance (the smaller the tolerance is the more the resistance is divided), the most commonly used is E-24 (tolerance of ± 5%), as shown in Table 2 The

The spot resistance is represented by a three-digit number on the surface of the chip, where the first bit, the second bit is the effective number, and the third digit indicates the number of subsequent zeros. Has a decimal point with "R" to represent, and account for a significant number of digits. The nominal resistance code is shown in Table 3.

3. Tolerance Chip resistors (carbon film resistors) Tolerances are 4, ie F, ± 1%; G, ± 2%; J, ± 5%; K, ± 10%.

4. Temperature coefficient The temperature coefficient of the chip resistance is 2, that is, w level, ± 200ppm / ℃; X grade, ± 100ppm / ℃. Only the tolerance for the F-class resistance was used x-level, the other level of tolerance is generally w-level.

5. There are two main packaging and bulk packaging.

Chip resistor operating temperature range of -55 - +125 ℃, the maximum operating voltage and size: 0402 and 0603 for the 50V, 0805 for the 150V, other sizes of 200V.

At present the most widely used patch resistor size code is 0805 and 1206. And gradually have the trend to 0603 development. The most commonly used tolerance is J level.