Research On The Regulation Of Through-hole Interconnect Electrodeposition By Bifunctional Group Organic Additives

Electroplating copper technology is one of the key technologies to realize the metallization of interlayer interconnection holes of printed circuit boards.To a certain extent,this technology determines the development of printed circuit boards.The performance of copper plating directly determines the reliability of printed circuit boards,and the use of organic additives can effectively improve the quality of copper plating and achieve good interlayer interconnection.This thesis work focuses on the effect of three bifunctional organic additives on copper electrodeposition using electrochemical experiments,simulation calculations and through-hole electroplating experiments,and the main results in this dissertation include:(1)The mechanism of bifunctional organic additives in electroplated copper was studied by electrochemical experiments and simulation calculations.When methyl orange,methyl red sodium salt are present respectively as organic additives alone in the base plating solution,they have a polarizing effect on the electrodeposition of copper.When co-existing with the lower concentration inhibitor Ethylene Oxide-Propylene Oxide Copolymer(EO/PO),methyl orange still played a polarizing effect,but methyl red sodium salt played a depolarizing effect.The results of quantum chemical calculations show that methyl orange has higher reactivity and stronger interaction with copper surface.The molecular dynamics simulation results show that the adsorption of methyl orange on the copper surface is stronger and more stable.(2)The role of two bifunctional organic additives in through-hole electroplating was verified by electroplating experiments,and the influence of different electroplating conditions on through-hole electroplating copper was explored.The plating effect of the plating solution system with EO/PO and methyl red sodium salt is better than that of the plating solution system with EO/PO and methyl orange,and the grains obtained are finer when the EO/PO content is large,and methyl red sodium salt is conducive to the formation of regular and smooth copper plating during the electroplating process.When the additive content was 200 mg/L EO/PO and 6 mg/L methyl red sodium salt,the highest TP value was 91.42%.The copper plating in the hole was flat,and there was no dog bone phenomenon in the orifice.Decrease the current density,the plating solution will become more uniform,at the same time,the roughness and copper grain size of the copper plating obtained by electroplating aree also reduced.The corrosion resistance of the copper plating obtained by electroplating at low current density is better.The larger the aspect ratio,the higher the plating difficulty.The TP value of a through-hole with an aspect ratio of 6 is about 30% higher than that of a through-hole with an aspect ratio of 10 in the same additive plating bath.(3)Taking 4’-aminoazobenzene-4-sulphonic acid as the research object,its role in copper electrodeposition was studied by electrochemical testing and simulation calculation,and the effect of it on through-hole electroplating copper was verified by electroplating experiments.In the presence of EO/PO,the depolarization of4’-aminoazobenzene-4-sulphonic acid is stronger than that of methyl red sodium salt.The ability of 4’-aminoazobenzene-4-sulphonic acid molecules to gain and lose electrons in the plating bath and the activity of the reaction is similar to the two bifunctional organic additives,Under the joint action of EO/PO,4’-aminoazobenzene-4-sulphonic acid can reduce the size of copper grains,effectively reduce the roughness of the copper surface and improve the reliability of the coating.At the same time,it makes the plating layer in the hole more flat,which plays a certain leveling role.When the amount of drumming decreases,the solution exchange rate decreases,so that the conductivity of the plating bath decreases,resulting in a decrease in the TP value.