Introduction: How to Choose the Correct Component Footprint

A footprint or land pattern is the arrangement of pads (in surface-mount technology) or through-holes (in through-hole technology) used to physically attach and electrically connect a component to a printed circuit board.

The land pattern on a circuit board matches the arrangement of leads on a component.

Let’s find out the components, and it’s footprint

In cad design we can categorize the components into two main groups

The First Surface Mount (SMD) components

The second the through-hole components

Step 1: SMD Components

Surface mount

assembly refers to the mounting process that surface mount components or surface mount devices (SMDs) are mounted on bare board through solder paste that plays a role as glue to stick surface mount components to board. The general process of surface mount assembly contains solder paste printing components mounting, automated optical inspection (AOI), reflow soldering, AOI or AXI etc.

Step 2: Through Hole Components

Through-hole technology (also spelled "thru-hole"), refers to the mounting scheme used for electronic components that involve the use of leads on the components that are inserted into holes drilled in printed circuit boards (PCB) and soldered to pads on the opposite side either by manual assembly (hand placement) or by the use of automated insertion mount machines.

Through-hole assembly refers to the process that through-hole components are soldered onto the bare board by a wave soldering or hand soldering with component leads going through drilled holes of PCB boards.

Step 3: Why We Choose a Specific Footprint ?

The footprint makes us know where did we put the components and it’s reliable to

1. the area of PCB

2. the value of the component

3. the component (Through-hole, SMD)

4. The availability at the local stock

5. The application of PCB