Degassing with APD+

Degassing, also called outgassing, is a common feature in IC package designs. Degassing is a process where you perforate power planes, voltage planes, and filled shapes in your design. Degassing holes let the gas escape from beneath the metal during manufacturing of the substrate.

Reasons to go for degassing:

• Prevents forming of gas bubbles under the metal (Otherwise, it would cause the surface of the metal to become uneven.)
• Lowers the density of metal in a region or across an entire layer of your design
• Improves the vacuum-lamination and pattern-plating manufacturing processes

The degassing feature in Allegro Package Designer Plus is an automated process where you can specify the details of the perforation array pattern. This generates the exact placement of voids across the entire shape. The tool does not create a void in the pattern if, in doing so, it violates any of the spacing or manufacturing requirements for degassing.

Users can also set layer-based parameters for degassing. This feature has the ability to define degassing per layer. It provides a quick way to set up layer-based degassing parameters both at the hierarchical level and individual level.

Allegro Package Designer Plus with the Silicon Layout option provides the Advanced Shape Degassing command in the Si Layout menu. This command uses the new data model. It provides significant memory and file size reduction, and speeds up overall performance.

You can also use the Off-Grid Degassing Holes command to add holes for metal areas where regular degassing pattern and matrix-based holes cannot be added due to conflicts with the routing, teardrops, vias, small metal areas, and shape edges.

Team PCBTech

Cadence Design Systems