When designing footprints of symmetrical components like SOIC-14, it is easy to determine the top component center, but where should be the best location for an unsymmetrical component?
Is top component center used for assembly? What happens if it is put in the wrong place? Where should the top component center of a component like in the image be?
IPC7351 recommends using the centroid of the part body, generally with pin 1 in the upper left.
Each surface mount device is aligned using the body center and a starting orientation for reference. ‘‘0’’ degree is the basic orientation of the device. Rotational data must be specified from the ‘‘0’’ position in a counter-clockwise direction (typically 90°- 180 - 270). The ‘‘0’’ starting position of the component is significant. Tape and reel and JEDEC tray packaged devices for example, have an established standard for orientation.
An interesting option can be to put the footprint center in the area where the pick and place robot can take the component.
