I am requesting your input on a hot topic within the Valor Process Engineering team this week. Namely how to calculate the aspect ratio and area ratio for stencil apertures. Now from my research so far, the most common measure of whether the aperture will release correctly has typically been the aspect ratio, however this seems to be calculated easily in simple cases of rectangles and circles. The threshold of a good aspect ratio being above 1.5. In the general case of a closed polygon, finding the “width” is extremely difficult. Therefore the area ratio, which is a function of the area of the aperture (roof) divided by the area of sides (walls) was introduced which can be calculated for any closed polygon. For aspect ratio a value of 0.66 or greater is required for correct release.
So I urge anyone to provide input on this topic for both aspect ratio and area ratio by posting their comments. Given what I have found on-line so far it will be interesting to see what is the most popular method for these types of calculation.
I look forward to hearing from you.
Appreciate your help.