Detailed explanation of common packaging sizes for surface mount resistors
SMD resistors have become the most mainstream type of resistor in modern electronic products due to their small size and suitability for automated production. Its packaging size is represented by standardized codes, mainly based on the length and width of the components (in units of one percent of an inch). Understanding these encapsulated codes is crucial for circuit design, PCB layout, and component procurement.
The following are the most commonly used chip resistor packaging sizes and their characteristics:
2512 (Imperial)/6432 (Metric)
Dimensions: Length 0.250 inches (6.35mm) x Width 0.120 inches (3.18mm)
Features: Large size, high rated power (usually 1W or higher), and good heat dissipation capacity.
Application: Commonly used in situations that require handling high power, such as power circuits, power amplifiers, etc.
2010 (Imperial)/5025 (Metric)
Size: Length 0.200 inches (5.08mm) x Width 0.100 inches (2.54mm)
Features: The power capacity is between 1206 and 2512 (commonly 1/2W or 3/4W). The usage frequency is relatively low and is gradually being replaced by other packages.
Application: In situations where power is required but space is relatively spacious.
1812 (Imperial)/4532 (Metric)
Size: Length 0.180 inches (4.57mm) x Width 0.120 inches (3.18mm)
Features: Wide in appearance, mainly used for high-power (up to 1W, 2W or even higher) or high-voltage applications. Often used as power resistors or high-voltage resistors.
Applications: Switching power supplies, industrial controls, high-voltage power modules, and other applications that require high power or high voltage resistance.
1210 (Imperial)/3225 (Metric)
Dimensions: 0.120 inches (3.20mm) long x 0.100 inches (2.54mm) wide or 0.12 inches (3.05mm) long x 0.10 inches (2.54mm) wide
Features: Slightly wider than 1206, providing slightly higher power (commonly 1/3W or 1/4W). Used in situations where slightly higher power or tolerance than 1206 is required, with slightly higher precision requirements.
Application: General circuit, slightly higher power applications.
1206 (Imperial)/3216 (Metric)
Dimensions: 0.120 inches (3.20mm) long x 0.060 inches (1.60mm) wide or 0.12 inches (3.05mm) long x 0.06 inches (1.52mm) wide
Characteristic: Very mainstream packaging size. A good balance has been achieved between power capacity (commonly 1/4W), size, and ease of manual welding. Rich variety and high cost-effectiveness.
Application: Extremely versatile, suitable for most general electronic devices.
0805 (Imperial)/2012 (Metric)
Dimensions: Length 0.080 inches (2.00mm) x Width 0.050 inches (1.25mm) or Length 0.08 inches (2.03mm) x Width 0.05 inches (1.27mm)
Characteristic: One of the most popular small and medium-sized packages. The power (commonly 1/8W or 0.125W) and size are moderate, making it very suitable for high-density PCB design. Easy to automate mounting and manual welding.
Application: Extremely versatile, it is one of the preferred sizes for modern compact electronic devices.
0603 (Imperial)/1608 (Metric)
Dimensions: Length 0.060 inches (1.60mm) x Width 0.030 inches (0.80mm) or Length 0.06 inches (1.52mm) x Width 0.03 inches (0.76mm)
Features: Small size, low power (commonly 1/10W or 0.1W). More precise mounting equipment is required, and manual welding may be difficult but feasible. It can significantly save PCB space.
Applications: Space limited portable devices, consumer electronics, mobile phones, laptops, etc.
0402 (Imperial)/1005 (Metric)
Dimensions: Length 0.040 inches (1.00mm) x Width 0.020 inches (0.50mm) or Length 0.04 inches (1.02mm) x Width 0.02 inches (0.51mm)
Features: Compact packaging. The power is very small (usually 1/16W or 0.0625W). High precision is required for surface mount machines and PCB manufacturing processes (pad design, solder mask), and manual soldering is very difficult, usually requiring a microscope.
Application: Highly integrated micro devices, such as high-end smartphones, wearable devices, and micro module interiors.
0201 (Imperial)/0603 (Metric)
Dimensions: Length 0.020 inches (0.60mm) x Width 0.010 inches (0.30mm) or Length 0.024 inches (0.61mm) x Width 0.012 inches (0.30mm)
Features: Ultra small packaging. Extremely low power (about 1/20W or 0.05W). Very high-precision surface mount equipment and strict process control are required, and manual welding is not possible. The requirements for PCB design and materials are extremely high.
Application: The most cutting-edge ultra compact electronic products, such as miniature sensors, modules with extremely small internal space, and core areas of some high-end mobile phones.
01005 (Imperial)/0402 (Metric)
Dimensions: Length 0.016 inches (0.40mm) x Width 0.008 inches (0.20mm) or Length 0.4mm x Width 0.2mm
Feature: Currently one of the smallest commercially available chip resistor packages. The power is very small (about 1/32W or 0.03W). The requirements for production equipment, processes, and testing are at the forefront of the industry, relying entirely on automated production.
Application: Mainly used for advanced electronic products that pursue ultimate miniaturization, such as cutting-edge smartphones, micro medical implant devices, ultra dense integrated circuit carriers, etc.
Important Notice
Naming convention: The most common encapsulation codes (such as 0402, 0603, 0805, etc.) are in English units (measured in hundredths of an inch). The metric codes in parentheses (such as 1005, 1608, 2012, etc.) are in millimeters (length x width).
Minor differences in size: Different standard organizations (such as EIA) or manufacturers may have extremely subtle differences in the specific size definitions for the same packaging code (usually less than 0.1mm), but the code is universal.
Power and Voltage Resistance: The packaging size is directly related to the rated power and maximum operating voltage of the component. When choosing a package, it is necessary to ensure that its power and withstand voltage meet the circuit design requirements, and not just look at the resistance value.
Feasibility of manual welding: Packages of 0603 and above can usually be manually welded (requiring skills and appropriate tools). 0402 manual welding is very difficult and prone to damage. 0201 and 01005 cannot be manually welded.
Special packaging: In addition to the standard rectangular packaging mentioned above, there are also some power type surface mount resistors with special shapes or sizes (such as wide body, with heat sink, etc.).
When choosing a chip resistor package, it is necessary to comprehensively consider factors such as circuit power requirements, available PCB space, production process capability (chip accuracy), cost, and whether manual maintenance is required. The size range from 1206 to 0402 is currently the most mainstream and widely used.