Abstract: An improved method of fabricating a thermal ink jet printhead of the type produced by the mating of an anisotropically etched silicon substrate containing ink flow directing recesses with a substrate having heating elements and addressing electrodes is disclosed. An etch resistant material on one surface of a (100) silicon substrate is patterned to form at least two sets of vias therein having predetermined sizes, shapes, and predetermined spacing therebetween. The predetermined spacing permits selected complete undercutting by an anisotropic etchant within a predetermined etching time period.

Abstract: Three dimensional silicon structures are fabricated from (100) silicon wafers by a single side, multiple step ODE etching process. All etching masks are formed one on top of the other prior to the initiation of etching, with the coarsest mask formed last and used first. Once the coarse anisotropic etching is completed, the coarse mask is removed and the finer anisotropic etching is done. The preferred embodiment is described using a thermal ink jet channel plate as the three dimensional structure, where coarse etching step provides the reservoir and the fine etching step provides the ink channels.

Abstract: A large array ink jet printhead is disclosed having two basic parts, one containing an array of heating elements and addressing electrodes on the surface thereof, and the other containing the liquid ink handling system. At least the part containing the ink handling system is silicon and is assembled from generally identical sub-units aligned and bonded side-by-side on the part surface having the heating element array. Each channel plate sub-unit has an etched manifold with means for supplying ink thereto and a plurality of parallel ink channel grooves open on one end and communicating with the manifold at the other. The surfaces of the channel plate sub-units contacting each other are {111} planes formed by anisotropic etching. The channel plate sub-units appear to have a parallelogram shape when viewed from a direction parallel with and confronting the ink channel groove open ends.

Abstract: A method for separating chips formed on a silicon substrate is provided which uses a combination of reactive ion etching techniques combined with orientation etching to yield integrated chips having edges which can be more precisely butted together to form large area arrays.

Abstract: A thermal ink jet printhead of the type which expels droplets on demand towards a recording medium from nozzles located above and generally parallel with the bubble generating heating elements contained therein is disclosed, together with fabrication processes therefor. The droplets are propelled along trajectories that are perpendicular to the heating element surfaces and from nozzles located in the printhead roof; such configuration is generally referred to as "roofshooter". Each printhead comprises a silicon heater plate and a fluid directing structural member. The heater plate has a linear array of heating elements associated addressing electrodes, and an elongated ink fill hole parallel with the heating element array. The structural member contains at least one recessed cavity, a plurality of nozzles, and a plurality of parallel walls within the recessed cavity which define individual ink channels for directing ink to the nozzles.

Abstract: An improved ink jet printhead is disclosed which comprises an upper and a lower substrate that are mated and bonded together with a thick insulative layer sandwiched therebetween. One surface of the upper substrate has etched therein one or more grooves and a recess which, when mated with the lower substrate, will serve as capillary-filled ink channels and ink supplying manifold respectively. The grooves are open at one end and closed at other end. The open ends will serve as the nozzles. The manifold recess is adjacent the groove closed ends. Each channel has a heating element located upstream of the nozzle. The heating elements are selectively addressable by input signals representing digitized data signals to produce ink vapor bubbles. The growth and collapse of the bubbles expel ink droplets from the nozzles and propel them to a recording medium.

Abstract: An ink jet printhead having an internal, integrated filtering system and fabricating process therefor is disclosed. Each printhead is composed of two parts aligned and bonded together. One part is a substantially flat substrate which contains on a surface thereof a linear array of heating elements and addressing electrodes. The other part is a flat substrate having a set of concurrently etched recesses in one surface. The set of recesses include a parallel array of elongated recesses for use as capillary filled, ink channels having ink droplet emitting nozzles at one end and having interconnection with a common ink supplying manifold recess at the other ends. The manifold recess contains an internal, closed wall defining a chamber with an ink fill hole. Small passageways are formed in the internal chamber walls to permit passage of ink therefrom into the manifold.

Abstract: A continuous stream type ink jet printhead utilizing constant thermal pulses to perturbate the ink streams emitted through a plurality of nozzles to break up the ink streams into droplets at a fixed distance from the nozzles whereat the drops are individually charged by a charging electrode in accordance with digitized data signals. Each printhead has a manifold, a plurality of ink channels communicating at one end with the manifold and terminating at the other end with nozzles, and at least one resistor addressed by a predetermined frequency of current pulses for applying thermal pulses to the ink. In one embodiment, a resistor is positioned in each of the channels adjacent the nozzles and in another embodiment, a single resistor is located in the ink manifold. The resistors are pulsed at low power to generate a perturbation of ink properties such as density, viscosity, or surface tension without producing a phase change in the ink.

Abstract: Several fabricating processes for ink jet printheads are disclosed, each printhead being composed of two parts aligned and bonded together. One part is a substantially flat substrate which contains on the surface thereof a lineal array of heating elements and addressing electrodes, and the second part is a substrate having at least one recess anisotropically etched therein to serve as an ink supply manifold when the two parts are bonded together. A lineal array of parallel grooves are formed in the second part, so that one end of the grooves communicate with the manifold recess an the other ends are open for use as an ink droplet expelling nozzles. Many printheads can be made simultaneously by producing a plurality of sets of heating elements array with their addressing electrodes on a silicon wafer and by placing alignment marks thereon at predetermined locations.

Abstract: A carriage type, bubble jet ink printing system having improved bubble generating resistors that operate more efficiently and consume lower power, without sacrificing operating lifetimes. The resistor material is heavily doped polycrystalline silicon which can be formed on the same process lines with those for integrated circuits to reduce equipment costs and achieve higher yields. Glass mesas thermally isolate the active portion of the resistor from the silicon supporting substrate and from the electrode connecting points, so that the electrode connection points are maintained relatively cool during operation. A thermally grown dielectric layer permits a thinner electrical isolation layer between the resistor and its protective, ink interfacing tantalum layer, thus increasing the thermal energy transfer to the ink.

Abstract: A method for laser induced conversion of large predefined areas of amorphous or polycrystalline semiconductor material, upon a substrate, into single crystal areas by using an infrared laser energy source to cause the bulk of heating to occur in the substrate and not in the predefined areas so that the areas are heated to melting by the substrate. The substrate comprises a material which is highly absorptive of the laser wavelength and the predefined areas comprise a material substantially transparent to laser wavelength, and the substrate and areas have different refractive indexes.

Abstract: Several fabricating processes for ink jet printheads are disclosed, each printhead being composed of two parts aligned and bonded together. One part is a substantially flat substrate which contains on the surface thereof a lineal array of heating elements and addressing electrodes, and the second part is a substrate having at least one recess anisotropically etched therein to serve as an ink supply manifold when the two parts are bonded together. A lineal array of parallel grooves are formed in the second part, so that one end of the grooves communicate with the manifold recess an the other ends are open for use as an ink droplet expelling nozzles. Many printheads can be made simultaneously by producing a plurality of sets of heating elements array with their addressing electrodes on a silicon wafer and by placing alignment marks thereon at predetermined locations.