Investigation On Thickness Uniformity Of Micro Parts Deposited By Near-cathode Scanning Wire-shape Anode Electrodeposition

Precision micro metal structures and components are often one of the main carrier of properties and special high-tech products.Owing to advantages like high reproduction precision of component,high surface finishing and low operating temperature etc,Through mask electrodeposition(TM-ECD),is often viewed as favorable alternatives for manufacturing high-end or special components in a single operation.However,limitations like uniformity and defection of deposit thickness in macro as well as in micro fabrications may hamper its range of application areas.In this work,an extraordinarily novel method,Near-cathode Scanning Wire-shape anode Electrodeposition(NCSW-ED),was proposed in contrast to traditional TM-ECD.This work was in progress by the financial support of the National Natural Science Foundation of China(No.51875178).Some main researches of this work and conclusions are as follows.(1)Current density distribution of substrate and profile of the deposit was calculated by numerical simulation based on physical model of coupling of flow field and electric field.The results shows that: there is no peak or valley of current density distribution in the pattern of micro scale,shows higher uniformity.Current density distribution in the pattern of macro scale is like shape of saddle.Profiles of deposit of micro scale as well as micro are high at edge and low at middle,the differences between height of these two are eliminated by increasing the localization of wire-shape anode.(2)uniformity of micro parts was studied by controlling parameters of NCSW-ED,the results shows that: uniformity of micro part was enhanced by reducing machining gap 0.7mm to 0.1mm,and the optimum parameter,0.3mm,is selected by comprehensive consideration of other factors.Uniformity of micro part was increased initially and then decreased with applied voltage increased,2.8V is favorable voltage to achieve flat top surface.Scanning velocity shows no significantly influence on uniformity.The deposition rate was then discussed.(3)Uniformity of components of cross scale including micro scale as well as micro deposited by NCSW-ED was investigated emphatically.The results shows that: the uniformity of array of miro components and macro components deposited by NCSW-ED reaches to 88.0% and 95.2% respectively,much higher than traditional TM-ED of which uniformity is 74.6%.and 76.1%.Profile of single part deposited by NCSW-ED like shape of saddle,shows not apparently superior to traditional TM-ED.Thickness differences between macro parts and micro parts was reduced drastically by NCSW-ED from 12.31μm(traditional TM-ED)to 4.05μm.