The SMD resistor packages generally conform to the standard SMD outlines for passive SMD components. Needless to say, occasionally other less standard packages may be used.
There is a growing trend in new designs to migrate towards some of the very small packages where power dissipation allows. This saves board space and allows further miniaturisation of the equipment, or to pack more functionality into the same space.
|Common Surface Mount Resistor Package Details|
|Package style||Size (mm)||Size (inches)|
|2512||6.30 x 3.10||0.25 x 0.12|
|2010||5.00 x 2.60||0.20 x 0.10|
|1812||4.6 x 3.0||0.18 x 0.12|
|1210||3.20 x 2.60||0.12 x 0.10|
|1206||3.0 x 1.5||0.12 x 0.06|
|0805||2.0 x 1.3||0.08 x 0.05|
|0603||1.5 x 0.08||0.06 x 0.03|
|0402||1 x 0.5||0.04 x 0.02|
|0201||0.6 x 0.3||0.02 x 0.01|
It can be seen that the package size descriptor is taken from he measurements of the resistor package measured in inches. An 0603 SMT resistor package measures 0.06 x 0.03 inches.
SMD resistors are manufactured by a number of different companies. Accordingly the specifications vary from one manufacturer to the next. It is therefore necessary to look at the manufacturers rating for a specific SMD resistor before deciding upon exactly what is required. However it is possible to make some generalisations about the ratings that might be anticipated.
|Typical SMD Resistor Power Ratings
|Package style||Typical Power Rating (W)|
|0402||0.0625 - 0.031 (1/16 - 1/32)|