Browse Prior Art Database

Making Silicon Nozzles for Ink Jet Heads

IP.com Disclosure Number: IPCOM000086954D
Original Publication Date: 1976-Nov-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Doo, VY: AUTHOR

Abstract

An Si wafer 2 (Fig. 1) is polished on both major faces, oxidized, if required, and a thin layer 4 of Si(3)N(4) is deposited on one of the major faces. Windows 6 are then opened by suitable etching techniques.

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Making Silicon Nozzles for Ink Jet Heads

An Si wafer 2 (Fig. 1) is polished on both major faces, oxidized, if required, and a thin layer 4 of Si(3)N(4) is deposited on one of the major faces. Windows 6 are then opened by suitable etching techniques.

As shown in Fig. 2, a poly-Si layer 5 is deposited on the top face, oxidized, and the oxide is photoetched to provide the pattern 7. A metal layer 8 is deposited on the top face, and a wire 10 is attached to the metal layer 8. Then, insulating lacquer or wax 12 is applied to cover the metal layer and wire.

As shown in Fig. 3, the metallized assembly 14 is then immersed in an acidic electrolyte 16 consisting of HF, H(2)SO(4). Also a metal plate 18 (Pt plate) is immersed in the same electrolyte. The Pt plate is used as a cathode. The metallized Si assembly and Die Pt cathode are connected to a DC source 20.

Note that the metallized Si assembly 14 is placed in such a way that the face 22, which has exposed Si, is facing the Pt cathode 18. The electric current passes through the exposed Si --> electrolyte --> cathode. The Si dissolves in the acidic solution when electric current is on. The dissolution rate increases with current density. in a uniformly doped Si, the current density increases with decreasing path length. Thus, the region directly under the metallized contact (to Si windows) will have the highest dissolution rate. The electrochemical etch has little crystallographic orientation dependence, hence an isotropi...