Current Carrying Capacity of Vias

摘要

As operators of a service bureau, we are frequently asked for details on the current carrying capacity of vias. To our ledge, there have been no studies of this particular topic. Here's our take on it. When current flows along a trace, there is an i~2R (power) loss that results in localized heating. This causes the trace to increase in temperature. The trace cools by conduction into neighboring materials or convection into the environment. Stability, and therefore a stable temperature, is reached when the rate of heating equals the rate of cooling. We have reported in the past on some studies of this effect.