Detailed explanation of chip resistor package identification and model

With the increasing popularity of electronic products,Chip resistorAs a basic component in electronic components, it is widely used in various circuit designs. patchresistanceWith small size and stable performance, it is an indispensable key component of modern electronic equipment. This article will comprehensively introduce the package identification and model of chip resistors to help engineers and electronics enthusiasts better understand and select chip resistors.

Surface Mount Resistor (SMD resistor for short) is a resistive component mounted on a circuit board through surface mount technology. Compared with traditional lead resistors, chip resistors have the advantages of small size, light weight, vibration resistance, and ease of automated production. They are widely used in mobile phones, computers, home appliances, industrial equipment and other fields.

The package size of chip resistors is an important basis for identification and selection. Common package dimensions are based on the imperial unit "inches". Common models include:

0201（0.6mm×0.3mm）

0402（1.0mm×0.5mm）

0603（1.6mm×0.8mm）

0805（2.0mm×1.25mm）

1206（3.2mm×1.6mm）

Resistors of different sizes are suitable for different circuit design needs. The smaller the size, the better for high-density mounting, but the power handling capacity is usually lower.

To identify the package size of chip resistors, it is mainly judged by measuring the length and width of the resistor. Typically, package size is determined by the length of the long and short sides in millimeters. Engineers can use calipers or microscopes to measure during the procurement and assembly process to ensure that the selected resistors meet the design specifications.

The model number of chip resistors usually includes information such as package size, resistance value, power level and tolerance level. Common model codes are such as "RC0402FR-0710KL", where:

RC stands for resistor type

0402 is the package size

F means the tolerance is ±1%

R represents the resistance value in ohms

0710K means the resistance is 10kΩ

Through the model code, users can quickly determine the specifications of the resistor.

The resistance value of chip resistors is usually identified by a numerical code, and a common three-digit or four-digit representation is:

Three-digit method: the first two digits are significant digits, and the third digit is the multiplier. For example, "103" means 10×10^3=10kΩ

Four-digit method: the first three digits are significant digits, and the fourth digit is the multiplier. For example, "1001" means 100×10^1=1kΩ

In addition, some small-sized resistors use letter codes to identify their resistance values, which need to be identified in conjunction with the manufacturer's manual.

The power level of the chip resistor determines its maximum carrying current and heat dissipation capacity. Common power levels are 1/16W, 1/10W, 1/8W, 1/4W, etc. Power level is often associated with package size, for example:

0201 and 0402 packages are mostly 1/16W

0603 packages are mostly 1/10W

0805 packages are mostly 1/8W

1206 package is mostly 1/4W

Understanding the power level will help you choose the appropriate resistor during circuit design to avoid overload damage.

The tolerance of chip resistors represents the error range of the resistance value. Common tolerance levels include ±1%, ±5%, etc. Tolerance classes are generally identified by letters or numbers in the model number. Temperature coefficient (TCR) indicates the degree to which the resistance value changes with temperature, usually in ppm/℃. Key applications require low temperature coefficient resistors to ensure stability.

In addition to ordinary resistors, there are also chip resistors with special functions, such asfuse resistor(PTC), precision resistors,Low value resistorwait. These resistors may have special markings on the model and package. Please check the product specifications carefully when purchasing.

The package identification and model of chip resistors are important links in electronic design and production. By understanding common package sizes, model codes, resistance value markings, power levels, and tolerance temperature coefficients, engineers can accurately select appropriate chip resistors to ensure circuit performance and reliability. Mastering the identification skills of chip resistors will help improve the design efficiency and quality of electronic products, and is an indispensable basic knowledge in the electronics field.