Investigation On Etching Technology And Corrosion Inhibition Mechanism Of Thick Copper Circuit

With the increasing demand for thick copper printed circuit boards,the etching factor for thick copper printed circuit produced by the existing etching solution can no longer meet the needs of downstream industries.The new thick copper printed circuit etching solution has become the focus of the industry.Based on the property of the acid thick copper printed circuit etching solution currently under use,the corrosion inhibition effects of two new acidic etching solution additives during thick copper etching is discussed from the aspects of molecular dynamics and quantum chemistry,and then the corrosion inhibition effects of the two new acidic etching solution additives were tested to finally obtain two acidic etching solution additives that improved the etching factor.In this paper,through the investigation over the property of the acid etching solution for the thick copper printed circuit currently in use,it is found that the etching factor in the etching process for the thick copper printed circuit increases with the increase of the design line-space,and the etching factor obtained at a design line-space of 254 ?m was 1.35.The adsorption energy of two new acidic etching solution additives is calculated by molecular dynamics method.The results show that the adsorption energy for the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol is-41.33 kcal/mol,the adsorption energy for the synergistic effect of Methylbenzotriazole and 2-Phenoxyethanol is-43.39 kcal/mol,the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol interacts has a stronger interaction with the copper surface has a stronger interaction with the copper surface and is less prone to desorption,which is more conducive to the improvement of the etching factor,this is consistent with the results of the adsorption energy.From the HOMO and LUMO,the quantum parameters,the condensed Fukui function of two acidic etching solution additives,it is known that the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol has a better etching effect than the synergistic effect of Methylbenzotriazole.The electrostatic potential analysis shows that the minimum electrostatic potential for the synergistic effect of Methylbenzotriazole and 2-Phenoxyethanol is more negative than the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol,which is-56.91 kcal/mol,the maximum electrostatic potential for the synergistic effect of Methylbenzotriazole and 2-Phenoxyethanol is more positive than the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol,which is +62.47 kcal/mol,indicating that it has a stronger electrostatic interaction with the copper surface.The minimum average local ionization energy for the synergistic effect of 2-Mercaptobenzothiazole and 2-Phenoxyethanol is lower than the synergistic effect of Methylbenzotriazole and 2-Phenoxyethanol,which is +8.12 eV/mol,indicating that its electronic activity is higher.Through the corrosion inhibition property test of two new acidic etching solution additives,it is found that the adsorption behavior for 2-Mercaptobenzothiazole in the low concentration range is consistent with the Langmuir isotherm equation,and Methylbenzotriazole is in the medium concentration range conforms to the simplified Temkin isotherm equation,both acidic etching solution additives are mixed additives and do not change the nature of the cathodic reaction.When the design line-space is 254 ?m,the series of acidic etching solution including 2-Mercaptobenzothiazole and 2-phenoxyethanol can increase the grain size and obtain good flatness,which can increase the thick copper etching factor to 4.8,the series of acidic etching solution including 2-Mercaptobenzothiazole and 2-Phenoxyethanol can make the copper grain small and dense,which can increase the thick copper etching factor to 4.0.2-Phenoxyethanol can significantly enhance the wetting agent of the etching solution.