Chip (EIA) Component Packages

Overview

Chip Packages And The EIAJ Standard

The following are a description of the most popular chip packages. Chip packages are standardized small SMT footprints primarily used for 2 lead passive components such as resistors, capacitors and ferrite beads. They are defined by four-digit number which represents the total footprint width and height, respectively (assuming the two footprint pads are on the left and right rather than the top or bottom, or more formally, the axis of the component runs parallel to the width).

The standard is to define them in the metric scale, however most manufacturers, and hence suppliers still use the imperial units. In metric units, the format is to use two number each to describe the width and height in tenths of a millimeter, e.g. a chip package size ‘2012’ tells you the width is 2.0mm and the height is 1.2mm. In imperial, the numbers are in hundredths of an inch (which is NOT mills; that is thousandths of an inch). For example, an 0805 chip package tells you the width is 0.08inch, and the height 0.05inch. This is equivalent to the ‘2012’ metric representation. Below is a short description on the most popular chip packages. The imperial size of the footprint is listed first, and then the metric equivalent is followed in brackets.

Sorted from smallest to largest package size.

The following image shows how you can easily route an 0.2mm thick trace between the pads of a 0805 component.

The following image is of 0603 (imperial) SMD components inside a small container.

SMD Chip Resistors

The following table shows the range of chip resistors package sizes (based on the EIAJ Chip Packages above), and typical parameters for each. Note that the maximum current rating is based on the thermal properties of the package and its leads, and does not take into account the actual resistance of the resistor (e.g. tested with a 0Ω). Obviously, the actual allowable current is likely to be much less due to resistance.

Reverse-Aspect Chip Capacitors (LICC)

Reverse-aspect chip capacitors (a.k.a LICC) have their leads on the long sides of the chip, as opposed to standard chip components which have the leads on the short sides. This reverse-geometry reduces the inductance in the PCB-to-capacitor connection, and is in high-speed designs where ultra-low inductance is required.

They are normally named the same as normal aspect chip capacitors except with the two numbers in reverse order, i.e. an 0603 sized capacitor now becomes a 0306 capacitor.