Question: - What are the dimensions of the feet in the 100-pin TQFP package? - What size should the pads on my board be for a 100-pin TQFP device? - Suggestions for how to lay out board?
Answer: Basically, the "foot" size of the CY part is about 0.6 mm by 0.22 mm, which translates to about 24 mils by 9 mils, with a space of about 11 mils between 2 individual feet. Now for the pad (on the PCB) where each foot will be sitting on: Cypress suggests a size of about 44 mils by 11 mils, with 9 mils between 2 individual feet. This translates to about 1.12 mm by 0.28 mm pad size. One can increase the pad length to 1.2 mm or 1.5 mm depending on preference. Please note that this is only a suggestion and that the designer must take into account individual manufacturing recommendations. These will differ depending on board material, layer thickness, etc.
