The Effect of an Impinging Fluid Jet on Mass Transfer and Current Distribution in a Circular Through‐Hole

Abstract

The effect of a single circular impinging fluid jet on hydrodynamic flow and mass transfer in a single through-hole centered at the stagnation point was investigated. Both submerged and unsubmerged jets were studied. Sectioned electrodes were used for direct experimental measurement of local rates of mass transfer and of hydrodynamic shear stress within individual through-holes. The ferricyanide system was used to obtain convective mass transfer rates upon controlled variation of jet Reynolds number, nozzle-to-workpiece distance, through-hole diameter, and aspect ratio. Data were used to establish mass-transfer correlations for both submerged and unsubmerged systems. It was found that the fluid flow in the through-hole corresponded to the hydrodynamic entrance region. A mathematical model of the current and potential distribution was used to identify dimensionless conditions for achieving uniform deposits and for insuring adequate convection rates. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 193.61.135.80 Downloaded on 2015-03-13 to IP Vol. 134, No. 5 THE EFFECT OF AN IMPINGING FLUID JET 1173 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 193.61.135.80 Downloaded on 2015-03-13 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 193.61.135.80 Downloaded on 2015-03-13 to IP

Theoretical studies of displacement deposition of nickel into porous silicon with ultrahigh aspect ratio

“…Although theoretical and experimental studies of deposition distribution for similar geometries, such as through-holes [20][21][22][23][24][25][26][27][28] and trenches or vias [20,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47], are abundant, the nature of the deposition process for the geometry in the present study is vastly different from those in literature. In through-hole plating, concerns on mass transport deficiency are unwarranted since the inside of the holes is accessible to agitation because of their relatively large dimensions; the non-uniformity caused by reactant depletion is readily avoided by adequate agitation [20,21].…”

Characterization of Through-Hole Filling by Copper Electroplating Using a Tetrazolium Salt Inhibitor

“…[1][2][3][18][19][20][21][22] However, uneven current density distributions and difficult mass transfers inside the THs, especially for a high aspect ratio (AR), commonly result in a subconformal deposition (i.e., a low throwing power and a copper overhang at the TH mouth). [8][9][10][11][12][13][14][15][16] These physical issues have been overcome by the use of chemical additives in the copper plating solution, which changes the secondary current density distribution due to the adsorption, consumption and desorption of these chemical additives inside the TH during copper electroplating. [18][19][20][21][22] Two typical chemical additives are nitrotetrazolium blue chloride monohydrate (NTBC) 19,23 and tetranitroblue tetrazolium chloride (TNBT), 20,21 and their molecular structures are illustrated in Fig.…”

Modeling of the Electroplating of a Through‐Hole Considering Additive Effects and Convection

“…Laplace's equation for the total ionic flux as a function of radial position and potential difference can be determined analytically (19). Since the flux is continuous at either end of the through- [5] hole, the analytical result for the bulk electrolyte is equal to the flux inside the through-hole, as follows…”

“…Presently, the largest through-hole aspect ratio electroplated in production facilities is approximately 6:1 (1)(2)(3), and the highest rates of plating are 20-40 mA/cm ~ (1). Instances of plating higher aspect ratio through-holes (4) and plating at higher rates (1,5) have been reported. However, these accomplishments have not yet been achieved under production conditions (1,2).…”