In-plane copper imbalance for warpage prediction

摘要

A method of predicting warpage of a laminate is disclosed in which in-plane copper imbalance is calculated. A method of designing an organic build-up laminate is provided in which in-plane copper imbalance is calculated and imbalances are corrected.

主权项

1. A method of designing an organic build-up laminate comprising:
substantially completing a laminate design; calculating a copper imbalance, wherein calculating the copper imbalance is based on an in-plane copper imbalance and the out of plane copper imbalance; predicting a laminate warpage based on the copper imbalance; modifying the design by adding or removing copper from select areas to reduce the copper imbalance; recalculating the copper imbalance; and predicting the laminate warpage based on the recalculated copper imbalance, wherein an in-plane copper resistance is calculated for each layer separately using the following Equation 2:CuInplane⁢⁢Imbalance⁢⁢for⁢⁢a⁢⁢layer=4⁢(%⁢⁢Cuchip-%⁢⁢Cufanout)⁢Ac/Af(1+Ac/Af)2Equation⁢⁢2 then, the in-plane copper imbalance between the layer pair is calculated, using Equation 3:
CuIn-plane Imbalance between Layers=(CuFCxInplane Imbalance−CuBCxInplane Imbalance)  Equation 3