NOZZLE PLATE FOR AN INK JET PRINT HEAD

Abstract: A nozzle plate (200) for an ink jet print head transducer (2). The nozzle plate comprises a silicon portion (205) with two substantially parallel surfaces (235, 238). Nozzle orifices (210) are fabricated on both surfaces of silicon wafer by etching a plurality of grooves into a silicon wafer. After the grooves are etched into the surface of the silicon, a glass plate (220, 222) is laminated onto each surface of the silicon. After the glass plate is laminated onto the silicon wafer, the resulting glass-silicon-glass sandwich is diced into multiple nozzle plates.

Description: DESCRIPTION Nozzle Plate for an Ink Jet Print Head Background of the Invention 1. Field of the Invention The present invention pertains to the field of inkjet printers, and more specifically, to nozzle plates for placement on print heads used in drop-on demand ink jet printers. 2. Description of Related Art Drop-on-demand inkjet printers having piezoelectric components are well known in the art. In general, piezoelectric drop-on-demand inkjet printers are constructed with a piezoelectric transducer component which reacts to the application of an electrical signal with a mechanical movement or distortion such that a drop of ink is expelled from a print head ink channel or cavity that is in mechanical communication with the transducer component. A representative print head transducer for a drop-on demand inkjet printer is disclosed in United States Patent Application Serial No. 08/703,924, filed on August 27, 1996, and assigned to the same assignee as this present application. This application is incorporated herein by reference in its entirety. A brief discussion of the print head transducer disclosed in Application Serial No. 08/703,924 is deemed appropriate. Fig. 1 is a cross-sectional side view of a single channel of an inkjet print head structure 20 for a piezoelectric inkjet printer constructed in accordance with an embodiment of the invention disclosed in Application Serial No. 08/703,924. Print head structure 20 comprises a print head transducer 2, formed of a piezoelectric material, into which is cut an ink channel 29. The ink channel 29 is bordered along one end with a nozzle plate 33 having an orifice 38 defined therethrough. A rear cover plate 48 is suitably secured to the other end of ink channel 29. A base portion 36 of the print head transducer 2 forms the floor of the ink channel 29, while an ink channel cover 31 is secured to the upper opening of the print head transducer 2. Ink channel 29 is supplied with ink from an ink reservoir 10 through ink feed passage 47 in rear cover plate 48. The actuation of the print head transducer 2 results in the expulsion of ink drops from ink channel 29 though the orifice 38 in nozzle plate 33. Referring to Fig. 2, the print head transducer 2 of Fig. 1 is shown in greater detail. The preferred print head transducer 2 comprises a first wall portion 32, a second wall portion 34, and a base portion 36. The upper surfaces of the first and second wall portions 32 and 34 define a first face 7 of the printed head transducer 2, and the lower surface of the base portion 36 defines a second, opposite face 9 of the print head transducer 2. Ink channel 29 is defined on three sides by the inner surface of the base portion 36 and the inner wall surfaces of the wall portions 32 and 34, and is an elongated channel cut into the piezoelectric material of the print head transducer 2, leaving a lengthwise opening along the upper first face 7 of the print head transducer 2. As described above, one end of ink channel 29 is closed off by an nozzle plate 33 (Fig. 1) while the other end is closed off by a rear cover plate 48 (plates 33 and 48 are not shown in Fig. 2) . A metallization layer 24 coats the inner surfaces of ink channel 29 and is also deposited along the upper surfaces of the first wall portion 32 and second wall portion 34. An ink channel cover 31 is bonded over the first face 7 of the print head transducer 2, to close off the lengthwise lateral opening in the ink channel 29. A second metallization layer 22 coats the outer surfaces of the base portion 36, and also extends approximately halfway up each of the outer surfaces of the first and second wall portions 32 and 34. The metallization layer 22 defines an addressable electrode 60, which is connected to an external signal source to provide electrical drive signals to actuate the piezoelectric material of print head transducer 2. In the preferred embodiment, the metallization layer 24 defines a common electrode 62 which is maintained at ground potential. Alternatively, the common electrode 62 may also be connected to an external voltage source to receive electrical drive signals. However, it is particularly advantageous to maintain the common electrode 62 at ground potential since the metallization layer 24 is in contact with the ink within ink channel 29. Having the common electrode at ground minimizes possible electrolysis effects upon the common electrode 62 and the ink within ink channel 29, which may degrade the performance and structure of both the common electrode 62 and/or the ink. The preferred piezoelectric material forming the print head transducer 2 is PZT, although other piezoelectric materials may also be employed in the present invention. The overall polarization vector direction ("poling direction") of print head transducer 2 lies substantially in the direction shown by the arrow 30 in Fig. 2, extending in a perpendicular direction from the second face 9 to the first face 7 of the print head transducer 2. The print head transducer 2 may have other poling directions within the scope of the present invention, including, but not limited to, a poling direction which lies substantially opposite (approximately 180 degrees) to the direction indicated by the arrow 30 in Fig 2. In the embodiments like that disclosed in Application Serial No. 08/703,924, print head transducer 2 is preferably formed from a single piece of piezoelectric material, rather than an assembly of separate components which are secured together into the desired structure (i.e., where the respective wall portions are distinct components which are bonded or glued to a separate base portion) . By forming the entire print head transducer 2 from a single piece of piezoelectric material, the deflection capability of the print head transducer 2 is thus not limited by the strength or stiffness of glue lines or joints between different transducer components. The cuts made in the piezoelectric sheet 21 are preferably made with diamond saws, utilizing techniques and apparatuses familiar to those skilled in the semiconductor integrated circuit manufacturing arts. The ink channel cover 31 is preferably glued or bonded to the metallization layer 24 on the upper surface of sheet 21 to close off the ink channels 29. The nozzle plate 33 and rear cover plate 48 are preferably glued or bonded to the front and rear surfaces of sheet 21, respectively. The ink channel cover 31, base cover plate 61, and nozzle plate 33 should preferably be formed of a material having a coefficient of thermal expansion compatible with each other. The ink channel cover 31 and base cover plate 61 are preferably formed of PZT, although other materials may also be appropriately used, including but not limited to silicon, glass, and various metallic and ceramic materials. An advantageous aspect of this type of embodiment is that a multiple-channel print head can be formed from a single sheet of piezoelectric material that has been pre-polarized in an appropriate poling direction prior to manufacture of the print head structure 20. For multi-channel print head transducers like those disclosed in Application Serial No. 08/703,924, the spacing between the channels is critical. It is highly desirable to place the ink channels of the transducer as close together as possible. The reason for this is that the closer the channels are to each other, the higher the dot density of the print output. The higher the dot density, the higher the quality of the images printed by the print head. Thus, in a preferred print head like that disclosed in Application Serial No. 08/703,924, the distance from the ink channel center of one ink channel to the ink channel center of an adjacent ink channel is two-hundred eighty-two (282) microns. Furthermore, it is desirable for the print head transducer to have a large number of ink channels. The reason for this is as follows. Ink jet printers generally operate by moving a carriage containing the print head transducers back and forth across the print media. By increasing the number of ink channels, a larger area of the print media is covered in a single traversal of the carriage. This will result irr faster print out. Thus, in a presently preferred ink jet print head transducer, there will be two hundred sixty-four ink channels. As mentioned in Application Serial No. 08/703,924, the actuation of the print head transducer results in the expulsion of ink drops from the ink channel though an orifice in a nozzle plate. The nozzle plate is affixed to the print head transducer. One of the purposes of the nozzle plate is to increase the velocity and force upon which an ink droplet is ejected from the ink channel. Thus, it is important that each orifice of the nozzle plate be substantially smaller than the ink channel which opens to that orifice. It is also important to precisely control the size of this nozzle orifice area to obtain consistent print quality. Furthermore, the nozzle orifice must be comprised of a clean, non-wetting surface, which will not allow ink to dry thereon. In a presently preferred embodiment, the diameter of each orifice in nozzle plate is fifty-two (52) microns. In addition, each orifice in the nozzle plate must have the same distance center-to-center as the print head transducer, which as discussed, is two hundred eighty-two (282) microns. It is critical that the manufacturing tolerances for the dimensions of the orifices of the nozzle plate be kept as tight as possible. This is due to the extremely small geometries involved and the fact that variances in the nozzle plate dimensions diminish the quality of the print output. It is preferable that the dimensions be maintained within plus or minus one percent. Thus, the orifice diameter can vary by only plus or minus 0.5 microns. Prior art methods of manufacturing nozzle plates are not capable of providing manufacturing tolerances of plus or minus two percent. In a representative prior art nozzle plate, a cross sectional view of which is seen in Fig. 4a and a perspective view of which is seen in Fig. 4b, a silicon wafer 100 having a specific lattice orientation (typically 1-1-0 silicon) has an orifice 110 anisotropically etched thereon. When 1-1-0 silicon is etched in this manner, its lattice structure results in an aperture 120 with a 54.4 degree etch angle (shown in Fig. 4 as θi) . As will now be shown, in this type of nozzle plate, the diameter of the aperture is controlled by the thickness of silicon wafer 100. Silicon wafer 100 has a thickness T. The thickness T determines the diameter of the orifice because the etch angle is generally fixed. The relationship between the thickness T of the silicon wafer 100 is determined by the TANGENT of θ 2 . TAN(Θ 2 ) = 0.5(d)/T The angle θ 2 is 35.6 degrees. TAN(35.6 degrees) is equal to approximately 0.716. Thus, it is seen that to make a nozzle plate using this method where the orifice 110 has a diameter of thirty-five microns, the wafer 100 must have a thickness of approximately 24.44 microns. However, making such a nozzle plate with the proper pitch provides conflicting specifications with making a nozzle plate with the proper orifice 110 diameter d. A print head transducer capable of one-hundred dots per inch (dpi) requires a channel width of seventy-five (75) microns with a two hundred fifty-four micron center-to-center pitch (see Fig. 4b) . As the wafer 100 gets thicker, the nozzle aperture will exceed seventy-five microns. Another problem with this nozzle plate construction method is that the only variable is the thickness d of the wafer 100, which is difficult to control. Typically, the tolerance of the thickness T of wafer 100 is plus or minus one micron. Thus, the tolerance of the diameter of the orifice 110 is approximately plus or minus one and one-half microns. This, of course, is a tolerance of approximately four percent, which is too large. Thus, there is a need for a nozzle plate for an ink jet print head transducer and method for making the same which allows for small nozzle orifice diameters, small center-to- center orifice pitch, and extremely tight manufacturing tolerances . Summary of the Invention The present invention comprises a nozzle plate for an ink jet print head. The nozzle plate is constructed of a silicon section having a plurality of grooves etched on a first side thereof and a glass plate affixed thereto. The glass plate is disposed over said silicon section to cover the plurality of grooves. In the various preferred embodiments, the silicon section is cut from a silicon wafer, which can be comprised of 1-1-0 silicon. The silicon section can also have an additional plurality of grooves etched on a second side thereof, with a second glass plate affixed to said second side of said silicon section. The nozzle plate of the present invention can be constructed by etching a plurality of grooves into a first side of a silicon wafer and laminating a glass plate thereto, thereby creating a silicon-glass sandwich. The silicon-glass sandwich is then diced into a plurality of nozzle plates, each of which has a mounting side and an exposed side. After dicing, the mounting side and exposed side of each of the plurality of plates is polished to be substantially perfectly smooth. To etch the groove into the silicon wafer, a layer of silicon dioxide is applied to the wafer. A layer of light sensitive material, e.g., photo resist, is placed over the layer of silicon dioxide. Then, a light source is shined through a mask. A preferred mask comprises a plurality of opaque bars. Thus, the mask only exposes a portion of the light sensitive material to the light source. The portion of the light sensitive material exposed to the light source etches the silicon dioxide to create a plurality of silicon dioxide bars corresponding to the plurality of opaque bars. Then, etchant is applied to the silicon wafer. In a preferred embodiment, the etchant comprises potassium hydroxide and the glass plate comprises a doped glass plate. In other embodiments, the grooves can be disposed on the wafer using other photolithographies processes. In yet another embodiment, grooves can be made using microelectromechanical system (MEMS) processes . The above and other preferred features of the invention, including various novel details of implementation and combination of elements will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular methods and structures embodying the invention are shown by way of illustration only and not as limitations of the invention. As will be understood by those skilled in the art, the principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. Brief Description of the Drawings Reference is made to the accompanying drawings in which are shown illustrative embodiments of aspects of the invention, from which novel features and advantages will be apparent. Fig. 1 is a cross-sectional side view of an inkjet print head structure for a single ink channel according to an embodiment of the invention. Fig. 2 is a partial perspective view of the inkjet print head structure of Fig. 1. Fig. 3A is a front view of a portion of the structure of a sheet of transducer material for an array of ink channels according to the embodiment of the present invention shown in Fig. 2. Fig. 3B is a perspective view of the sheet of transducer material shown in Fig. 3A. Fig. 4a shows a cross sectional view of a prior art nozzle plate. Fig. 4b shows a perspective view of the prior art nozzle plate of Fig. 4a. Fig. 5 is a frontal view of a nozzle plate constructed in accordance with the present invention. Fig. 6 is a top view of a silicon wafer. Fig. 7 is a cross sectional view of a silicon wafer having silicon dioxide applied to one side thereof. Fig. 8 is a cross sectional view of a silicon wafer having silicon dioxide applied to one side thereof and a photo resist layer applied above the silicon dioxide. Fig. 9 is a top view of an exemplary mask used in various embodiments of the present invention. Fig. 10 is a cross sectional view of a silicon wafer after highly columated light has been shined through the mask of Fig. 9 onto the photo resist layer seen in Fig. 8. Fig. 11 is a cross sectional view of a silicon wafer after anisotropic etching of one side thereof in accordance with the present invention. Fig. 12 is a cross sectional view of a silicon wafer having silicon dioxide bars formed on a second side thereof. Fig. 13 is a cross sectional view of a silicon wafer after anisotropic etching of a second side thereof in accordance with the present invention. Fig. 14 is a expanded cross sectional view of a single groove, etched into a silicon wafer in accordance with the present invention. Fig. 15 is an exploded perspective view showing the affixation of glass plates to the etched silicon wafer in accordance with the present invention. Fig. 16 is a partially exploded perspective view showing the dicing of a glass-silicon-glass sandwich in accordance with the teachings of the present invention. Description of the Preferred Embodiment Turning to the figures, the presently preferred structures and methods of the present invention will now be described. Reference is made to Fig. 5 in which is shown a frontal view of a portion of a nozzle plate 200 of the present invention. Nozzle plate 200 is comprised of silicon portion 205 which has two substantially parallel surfaces 235, 238. The nozzle plate comprises nozzle orifices 210 which are placed on both surfaces of silicon wafer 205. After the nozzles are anisotropically etched into the surface of the silicon, a glass plate 220 is laminated onto each surface of the silicon 205. Thus, the edges of each nozzle orifice 210 is comprised of silicon wafer 205, silicon dioxide 215, and glass plate 220. With reference to Figs. 6-16, the preferred method of constructing nozzle plate 200 will be discussed. A top view of a silicon wafer 205 is seen in Fig. 6. In preferred embodiments, silicon wafer 205 having a lattice structure capable of being anisotropically etched to result in a groove with a 54.4 degree (for silicon) etch angle is used. An example of such a wafer is 1-1-0 silicon. The wafer 205 has an etching area 230 which can be etched on both the first side 235 of the wafer and the second side 238 of the wafer 205 (see Figs. 7-13). Wafer 205 preferably has a thickness of 3.9751 millimeters . With reference to Fig. 7, a cross-sectional view of etching area 230 of wafer 200 is shown. Note that Fig. 7 is provided for illustration purposes only. It is not drawn to scale and does not represent the entire etching area 230. A mass layer of silicon dioxide 240 is applied to the etching area 230 on the first side 235 of silicon wafer 205. Then, as seen in Fig. 8, a layer of light sensitive material 242, e.g., photo resist, is spun onto the wafer 205 such that it is layered on top of the silicon dioxide layer 240. Between each nozzle orifice 210 is silicon dioxide portion 215, which, as will be discussed below, is placed on the silicon 205 during etching of the nozzle orifices 210. It is noted that the thickness of the silicon dioxide 240 and light sensitive material 242 shown in the drawings is exaggerated so that their use can be illustrated. In actual embodiments, the thickness of the silicon dioxide 240 and light sensitive material 242 is significantly thinner than the thickness of the wafer 205 (approximately one thousand Angstroms) . After the silicon dioxide layer 240 and photo resist layer 242 are placed on the wafer 205, highly columated light is directed though a precision mask 300. An example of such a precision mask is seen in Fig. 9. Mask 300 is constructed of a glass reticle having opaque bars 310 printed thereon. Opaque bars 310 block substantially all of the light that will be shined through the mask 300. The light that passes through mask 300 interacts with the photo resist 242 spun onto wafer 205 to etch strips of the silicon dioxide layer 240 off of wafer 205. This creates silicon dioxide bars 244 on the first surface 235 of wafer 205 which correspond to the opaque bars 310 of mask 300 (see Fig. 10) . After the silicon dioxide bars 244 are formed on the first side 235 of wafer 205, the remaining photo resist 242 that remains on the silicon dioxide bars 244 (not shown) is stripped off. A cross-sectional view of this is seen in Fig. 10. The wafer 205 with the silicon dioxide bars 244 then has an etchant (not shown) suitable for anisotropic etching placed thereon. In one preferred embodiment, the etchant is applied by placing the wafer 205 with the silicon dioxide bars 244 into a bath containing potassium hydroxide. Other methods of applying the etchant, as well as other etchants, are contemplated within the scope of the present invention. As is seen in Fig. 11, this etching step anisotropically etches grooves 245 in the portion of the wafer not covered by the silicon dioxide bars 244. After grooves 245 are etched onto the first surface 235, the process is repeated for second surface 238 of wafer 205. This is seen in Figs. 12-13. It is contemplated within the scope of the invention, however, that grooves 245 could be etched into the first surface 235 and second surface 238 of wafer 205 at the same time. Such a process would speed the fabrication of wafer 205. An enlarged cross-sectional view of a groove 245 is shown in Fig. 14. The lattice structure of 1-1-0 silicon is such that grooves 245 will have the same angle θ, which is substantially 54.4 degrees. In a presently preferred embodiment, the wafer 205 is etched such that the width W of the groove 245 at the surfaces 235, 238 of the wafer is fifty- two (52) microns. With reference to Fig. 15, the next step in manufacturing the nozzle plate 200 is discussed. After the wafer 205 has had grooves 245 etched therein, the silicon dioxide bars 244 are stripped off of the wafer 205 (note that the silicon dioxide bars 244 can be stripped at any time in the manufacturing process prior to laminating glass plates 220, 222 onto the wafer 205) . Then, the wafer 205 is cut so that all that is left is the etching area 230, which now has grooves 245 disposed therein. A standard sawing method such as scribe and break, band saw, or the like, can be used for this. After the unused portions of the wafer 205 are removed, all that remains is the grooved, rectangular wafer portion 248. After this, each surface 235, 238 of wafer 205 has glass plate 220, 222, respectively, laminated thereon. Glass plates 220, 222 are highly polished, and are doped with Boron. In a presently preferred embodiment, each glass plate is comprised of Corning 7740, and has a thickness of 1.37 millimeters. Materials other than glass can be used to form this sandwich. Examples of such materials include silicon, ceramic substrates, and coated metals, which have highly polished surfaces and negatively charged dopants or ions. A Mallory process is preferably used to laminate glass plates 220, 222 to wafer portion 248. In a Mallory process, the glass plates 220, 222 and the wafer portion 228 are placed in an electrostatic bonding fixture. The ambient temperature of the environment in which the press operates is raised to approximately three hundred degrees Celsius. An electrostatic field is then induced by placing the glass plates 220, 222 at one potential and the silicon wafer portion 248 at a different potential. This potential is preferably above seven hundred fifty (750) volts. The pressure that the electric field generates to the glass-silicon-glass sandwich is on the order of approximately up to three-hundred fifty pounds per square inch (PSI) . This potential, the pressure induced by the electrostatic field and the elevated temperature, in combination with the silicon 248 and the doped glass plates 220, 222, is such that an anodic bond (also known as an electrostatic bond) is formed between glass plates 220, 222 and silicon wafer portion 248, thereby forming a glass-silicon- glass sandwich 250 (see Fig. 16) . After glass plates 220, 222 are laminated to wafer portion 242, the resulting glass-silicon-glass sandwich 250 is diced into the individual nozzle plates 200a, 200b ... 200x, where "x" is the total number of nozzle plates obtained from a single glass-silicon sandwich 250. Each nozzle plate 200a, 200b ... 200x preferably has a thickness of fifty to one hundred (50- 100) microns and a height of 6.7151 millimeters. After dicing, each nozzle plate 200a, 200b ... 200x goes through a finishing process so that each of their sides has a substantially perfectly smooth surface. A presently preferred method of finishing nozzle plate 200a, 200b ... 200x is a wafer back grinding process. In the presently preferred polishing process, each nozzle plate 200a, 200b ... 200x is temporarily mounted on a six inch wafer and then is placed in a wafer back grinding machine with the polishing surface having the finest possible grit. The machine is set for the slowest possible feed rate. The combination of fine grit and slow feed rate is selected to maximize the polish of the surfaces of the nozzle plates 200a, 200b ... 200x while minimizing the cracking occurring at the edges of each nozzle orifice 210. As discussed above, it is very important that orifices of the nozzles 210 of nozzle plate 200 have extremely small variances in size from each other. Nozzle plates like those of the prior art that have large variances in nozzle orifice size result in reduced quality printing. Nozzle plates 200 constructed in accordance with the present invention have extremely tight tolerances for the reasons which will now be discussed. As discussed, silicon with a 1-1-0 lattice structure will have an etch angle θ of 54.4 degrees, which is seen in Fig. 14. In the present invention, unlike the prior art, the wafer is not etched all the way through to create a nozzle orifice. As discussed above, when etching a silicon wafer to create an orifice in the wafer, the size of the opening, and hence the size of the nozzle, is controlled by the thickness of the wafer. As discussed, the thickness of the silicon wafer is difficult to control. As shown above, variances in the thickness of the wafer result in tolerances in the size of the nozzle orifice of approximately five percent, which is undesirable. In the embodiments of the present invention, the thickness of the wafer does not affect the size of the nozzle orifice because the nozzle orifice is not created by etching an opening in the wafer. Instead, grooves are first fabricated in the silicon wafer. The grooves are then covered by a glass plate with a highly polished surface. Because the lattice structure of silicon wafers is easily controlled, the etch angle varies only in infinitesimal amounts from wafer to wafer. Furthermore, the etch angle of each groove will be virtually identical in a single wafer, as the lattice within a single wafer is very consistent. Thus, any variances in etch angle, while extremely small, occur only from wafer-to-wafer, not on any single wafer. Finally, as discussed, the glass that is laminated onto the wafer is polished to be extremely smooth and, therefore, does not contribute to any significant variances in nozzle size. Measurements have shown that the nozzle orifices in nozzle plates constructed in accordance with the present invention have tolerances of approximately plus or minus 0.2 microns, which is less than plus or minus two percent. In a presently preferred embodiment, a four inch wafer 205 is used. This results in the production of approximately three-hundred nozzle plates having a length of 41.773 millimeters, a height of 6.7151 millimeters, and a thickness of fifty to one hundred microns thick. An additional advantage of the present invention is that it simplifies the process of mounting the nozzle plate onto the print head transducer 2. When installing the nozzle plate 200 on print head transducer 2, the nozzle plate 200 is placed over the transducer 2. Prior to fastening the nozzle plate 200 to the transducer 2, the nozzle orifices 210 must be aligned with the channels 29 of the transducer 2. With the nozzle plate 200 of the present invention, the person mounting the nozzle plate 200 on the transducer 2 can see the channels 29 through the glass plates 220, 222. Thus, prior to permanently fastening the nozzle plate 200 to the transducer 2, the nozzle orifices 210 can be accurately aligned with the channels 29. This further increases the quality of the print from the print head. Thus, a preferred nozzle plate apparatus and methods of manufacturing same have been described. While embodiments and applications of this invention have been shown and described, as would be apparent to those skilled in the art, many more embodiments and applications are possible without departing from the inventive concepts disclosed herein. The invention, therefore is not to be restricted except in the spirit of the appended claims.

Claims: Claims 1. A nozzle plate for an ink jet print head comprising: a silicon section having a plurality of grooves etched on a first side thereof; and a first glass plate affixed to said first side of said silicon section, thereby covering said plurality of grooves. 2. The nozzle plate of claim 1 wherein said silicon section is cut from a silicon wafer. 3. The nozzle plate of claim 1 wherein said silicon wafer has a lattice structure comprising 1-1-0 silicon. 4. The nozzle plate of claim 1 wherein said silicon section further comprises an additional plurality of grooves etched on a second side thereof, and a second glass plate affixed to said second side of said silicon section, thereby covering said additional plurality of grooves. 5. The nozzle plate of claim 1 wherein each of said plurality of grooves comprises a first inner wall and a second inner wall, and wherein an angle between said first inner wall and said first side of said silicon wafer is 54.4 degrees. 6. A method of constructing a nozzle plate for an ink jet print head comprising the steps of: etching a plurality of grooves into a first side of a silicon wafer; laminating a glass plate to said first side of said silicon wafer, thereby creating a silicon-glass sandwich; dicing said silicon-glass sandwich into a plurality of plates, each of said plurality of plates having a mounting side and an exposed side; and polishing said mounting side and exposed side of each of said plurality of plates. 7. The method of claim 6, wherein said etching step comprises the steps of: applying a layer of silicon dioxide to said first side of said silicon wafer; applying a light sensitive material over said layer of silicon dioxide; and shining a light source through a mask, said mask comprising a plurality of opaque bars to expose said light sensitive material to said light source, thereby etching said silicon dioxide and leaving a plurality of silicon dioxide bars corresponding to said plurality of opaque bars; and applying an etchant to said silicon wafer. 8. The method of claim 7 wherein said etchant comprises potassium hydroxide. 9. The method of claim 6 wherein said glass plate comprises a doped glass plate. 10. The method of claim 6, wherein said laminating step comprises the steps of: placing said glass plate and said silicon wafer into a press such that said glass plate is forced against said silicon wafer at a predetermined pressure; elevating the temperature of said glass plate and said silicon wafer; and inducing an electrostatic potential between said glass plate and said silicon wafer.

Inventors: BIBL ANDREAS, ROSSELL MANUEL G, BIBL, ANDREAS, ROSSELL, MANUEL, G.
Applicants: TOPAZ TECH INC, TOPAZ TECHNOLOGIES, INC.
Application year: 1998
Main classification: B41J2
IPC codes: B41J2