Research on the uniformity of massive mass transfer in electroplating of ceramic substrates

The ceramic substrate has the capability of vertical interconnection and hermetic packaging, and is widely used in high-power devices and high-temperature packaging. The ceramic substrate relies on massive electroplating to prepare copper conductors to meet the large-scale and mass manufacturing requirements. However, the non-uniform electric field distribution between the large-area electrode and array substrates makes the current density distribution non-uniform. This research studied the distribution of the electric field intensity distribution and current density distribution on the the ceramic substrate surface during the mass transfer electroplating process. We clearly explain the cause of the non-uniform electric field in the massive mass transfer electroplating process. The numerical simulation of the electroplating process can effectively predict the trend of coating thickness. There is an accumulation of electric field lines at the edge of the cathode plate of the electroplating tank, resulting in the coating thickening. There is also an edge effect on each hanging plate, which makes the electric field intensity distribution of the outermost hanging plate obviously uneven. Finally, based on the principle of electric field shielding, we propose a three-dimensional shielding optimization design scheme to obtain a uniform electric field. Setting the auxiliary cathode can make the coating more uniform to a certain extent. The optimized plating bath model is obtained by taking the average electric field intensity of the cathode plate as the optimization objective through the response surface optimization method. The calculation shows that the electric field intensity deviation after setting the auxiliary cathode is reduced from 31.91% to 17.79%.