The RINGEN module automates the drawing of the power and ground rings. An easy-to-use menu enables the user to enter the desired ring widths and spacings. Default values for the design rules are read from a technology file. This module is parameter driven and currently supports two different ring geometries:

SBGA

SBGA rings are both rectangular and have radiused corners. They are used for the Amkor SBGA package design where the die pads face the bottom (ball side of the package) since a copper heatsink is laminated to the top side of the package and the bottom of the die is attached directly to the heat sink.

The radii are automatically calculated to maintain constant ring width and to maintain constant gap.

PBGA rings: the inner ground ring is square or rectangular with chamfered corners. The power ring has a circular radius. This results in a more constant length for the power wire bonds.

The ground chamfers are automatically calculated to maintain a very constant ring width and the power ring is calculated to leave the minimum gap between power and ground at the worst case location.

Each ring is built from two boundaries - an inner and outer one. Each boundary is built from an AutoCAD polyline. For the SBGA the radiused corners are true arcs - if they need to be segmented when transferring to another database this is done by the translation software. The layers are organized so that it is easy to generate RS274X data with on-the-fly filling. This results in the most precise possible artwork.

Inner Ground Ring Boundary - polyline on layer 
Outer Ground Ring Boundary - polyline on layer
Inner Power Ring Boundary  - polyline on layer
Outer Power Ring Boundary  - polyline on layer