Introduction
A Euler column is also known as a doubly supported beam and is very similar to staples. Euler columns a often used to test for compressive stress in layers.
Please also refer to the documentation for the staple parameterized cell.
Theory
The Euler Buckling Stress is give by the following formula.
Where σcr is the critical buckling load, E is Young's Modulus for the material, t is the thickness of the layer, and L is the length of the beam.
Where the beam's thickness is greater than it's width, the beam will buckle laterally. The critical stress can be determined by substituting the width for thickness.
Parameters
Any parameter may be modified, if necessary, to meet design rules. Typically, this involves increasing parameters that specify distances, so that minimum line width and minimum line spacing rules will not be violated. This has been extended to the convention of specifying a zero for some parameters to obtain an instance of the minimum size.
In addition to the parameters listed below, several technology parameters also influence the implementation of parameterized cells. This data must be present in the technology library.
| Name | Description | Range | Units | P1 | P2 |
|---|---|---|---|---|---|
| length | The length of the euler column. This is the parameter "L" in the above formula for calculating the Euler Buckling stress. | [0,∞) | um | + | + |
| width | The width of the beam. While this may play a role in the Euler Buckling load, the buckling stress is independent of the width. This parameter is automatically increased if it is less than the nominal width. | [0,∞) | um | + | + |
| anchor | The size of the anchors used to connect the cantilevers to the substrate. If this value is less then the nominal width it will be increased. | [0,∞) | um | + | + |
| include_poly0 | If true, a POLY0 ground plane will be included in the cell. The POLY0 ground plane can eliminate most electrostatic attraction between the Euler column and the substrate bulk. | true/false | - | + | + |
