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The purpose of this paper is to study an electrolytic etching method to prepare fine lines on printed circuit board (PCB). And the influence of organics on the side corrosion protection of PCB fine lines during electrolytic etching is studied in detail.

In this paper, the etching factor of PCB fine lines produced by new method and the traditional method was analyzed by the metallographic microscope. In addition, field emission scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the inhibition of undercut of the four organometallic corrosion inhibitors with 2,5-dimercapto-1,3,4-thiadiazole, benzotriazole, l-phenylalanine and l-tryptophan in the electrolytic etching process.

The SEM results show that corrosion inhibitors can greatly inhibit undercut of PCB fine lines during electrolytic etching process. XPS results indicate that N and S atoms on corrosion inhibitors can form covalent bonds with copper during electrolytic etching process, which can be adsorbed on sidewall of PCB fine lines to form a dense protective film, thereby inhibiting undercut of PCB fine lines. Quantum chemical calculations show that four corrosion inhibitor molecules tend to be parallel to copper surface and adsorb on copper surface in an optimal form. COMSOL Multiphysics simulation revealed that there is a significant difference in the amount of corrosion inhibitor adsorbed on sidewall of the fine line and the etching area.

As a clean production technology, electrolytic etching method has a good development indicator for the production of high-quality fine lines in PCB industry in the future. And it is of great significance in saving resources and reducing environmental pollution.

Using an instant response device within the context of a controlled experiment, we find that people’s self‐assessment of susceptibility to normative influence (SNI) differs substantially from the actual, or true, degree to which they are influenced by the actions of others. Actual SNI, a subconscious reaction to the behavior of those around us, can be altered when participants (falsely) believe their peers differ in their willingness to sign a new lease under various rental reduction incentives when their landlord has defaulted on his mortgage. The results are insensitive to eight alternative measures of actual SNI. This study supports the behavioral finance literature relating to herding in that we show people are very much willing to follow the lead of their peers, even in situations where information gain is not the likely derived benefit. Instead, people appear to herd in our study for social reasons.