Modeling of additive effects on the electroplating of a through‐hole

Abstract

A mathematical model of copper plating of a through-hole is developed which relates uniformity of deposition to bulk electrolyte composition, applied potential difference, aspect ratio, through-hole diameter, and deposition kinetics. The electrochemical transport equations governing plating in a through-hole are solved assuming that the fluid within the through-hole is stagnant. Conditions for uniform plating are determined both for Butler-Volmer kinetics considering the effects of dissociation of bisulfate ions in the electrolytic solution and for kinetics limited by complexation of cupric ions with an adsorbed neutral additive species.

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

“…For nickel displacing deposition into porous silicon in the present study, there is no potential field factor but mass transport becomes critically important because of the active sidewall of the PS and ultrahigh aspect ratio. The nickel distribution inside the pores is determined by a polarization parameter, the ratio of the surface reaction rate to the diffusion rate, which is similar to plating into a trench [51] and through-hole plating under mass transport control [22]. Improvement of nickel deposition uniformity can be made by lowering the value of the polarization parameter, such as, increasing nickel ion concentration and lowering bath solution pH.…”

“…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].…”

Polyquaternium-2: A New Levelling Agent for Copper Electroplating from Acidic Sulphate Bath

“…The dominant problem in the TH electroplating is that the uneven local current density distribution gives rise to an uneven plating thickness in the TH. 5,6 The plating thickness at the mouth (high current density) is thicker than that at the center (low current density) of the TH. As the aspect ratio of the TH increasing, the difference of the plating thickness between the mouth and the center of the TH increase.…”

“…5,7,8 Organic additives are widely used in copper electrodeposition as an effective way to control the current distribution in TH during electroplating or other certain properties of the copper deposit. [9][10][11] The additive system, used for PCB electroplating, generally includes accelerator (i.e., bis(3-sulfopropyl) disulfide), inhibitor (i.e., poly (ethyleneglycol)) and leveler (i.e., Janus Green B).…”

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

“…Without additives, the deposition rates currently achieved in through-holes would be impossible (1). Our previous model of through-hole plating considering a stagnant fluid in the hole incorporated the effects of plating additives (7,8). Other models of throughhole electropla-ting in the literature have examined various limiting plating conditions, which have included diffusive control (9), diffusive-convective control (10), ohmic control (11, 12), ohmic-diffusive control (13), and distinct regions of ohmic control and diffusive-convective control (12, 14-18).…”