The effect of spray characteristics on the etching of invar alloy with FeCl3 solution

Abstract

NOMENCLATURE D 32 = Sauter mean diameter d i = droplet diameter E R = etching rate I F = impact force P i = spray pressure R D = radial distance T E = etchant temperature U = axial velocity of droplets ∆t = sampling time Z = distance from the nozzle tip α = intercept β = slope

Analysis of the relationship between electrolyte characteristics and electrochemical machinability in PECM on invar (Fe-Ni)fine sheet

“…This value is 10 times lower than that of STS 304 and 100 times lower than that of iron [1][2][3]. Because of its characteristics, invar alloy is used in ultra-high-definition mobile displays, fine parts for precise devices, and the aerospace industry [4]. Invar fine sheet is currently manufactured by etching processes or electroforming, and still other methodologies have been suggested.…”

“…Several studies have been conducted to fabricate micro holes on invar fine sheet for organic light emitting diode (OLED) shadow masks by etching [4][5][6]. However, etching has some problems generating non-machined area.…”

Improved shape evolution of copper interconnects prepared by jet-stream etching

“…For preparing fine, nano-sized interconnects in IC chips, an additive method of electrochemical deposition is generally used [1][2][3]. For those in PCBs and lead frames, however, a subtracting method of wet chemical etching is the conventional approach [4][5][6][7][8][9][10][11][12][13][14]. The additive method of electrochemical deposition is not suitable for fabricating interconnects on PCBs since it is relatively time-consuming and more expensive.…”

“…As an alternative, the spray etching technique was developed in the late 1970s. It is currently the most adopted method because it improves the quality of etched interconnects and shortens the etching time [9][10][11][12][13][14].…”

“…The time to achieve a preset E ind on the copper interconnects determines the traveling time of the board and the dimension of the spray etching system. The spray etching technique delivers the electrolyte solution to the PCB with an impinging force and thus increase the anisotropy of the etching process [9,10]. Although the spray etching technique further increases the E ind of copper interconnects to values higher than 5 [9,[11][12], there exists the problem of puddling.…”