An inkjet printing system, as one embodiment of a fluid ejection system, may include a printhead, an ink supply that provides liquid ink to the printhead, and an electronic controller that controls the printhead. The printhead, as one embodiment of a fluid ejection device, ejects ink drops through a plurality of orifices or nozzles.
A fluid ejection device in an inkjet printing system may include fuses as part of a programmable read-only memory (PROM). The fuses are used to store information during the manufacture or use of the device by blowing selected fuses. The blowing of fuses, however, can damage portions of a fluid ejection device. If undesirable fluidic or non-fluidic material comes into contact with a damaged portion near a blown fuse, the fuse may effectively become un-blown and thereby change the bit of information stored by the fuse. At the same time, materials disposed in close proximity to the fuse may affect the thermal or electrical environment of blowing the fuse.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the disclosed subject matter may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.
According to one embodiment, a layer of material forms a chamber adjacent to a component on a substrate. The layer of material includes a single orifice between the chamber and a top surface of the layer that is opposite of the bottom surface of the layer adjacent to the substrate. The orifice provides an access point for removing material from the layer to define the chamber. An encapsulation layer encloses the chamber by covering the orifice with an encapsulation material. The chamber provides a desired thermal and electrical environment for the component and the encapsulation layer prevents fluidic and non-fluidic materials from entering the chamber.
In one embodiment, inkjet printhead assembly 22 includes at least one printhead or printhead die 40 that ejects drops of ink through a plurality of orifices or nozzles 34 toward a print medium 36 so as to print onto print medium 36. Printhead 40 is one embodiment of a fluid ejection device. Print medium 36 may be any type of suitable sheet material, such as paper, card stock, transparencies, Mylar, fabric, and the like. Typically, nozzles 34 are arranged in one or more columns or arrays such that properly sequenced ejection of ink from nozzles 34 causes characters, symbols, and/or other graphics or images to be printed upon print medium 36 as inkjet printhead assembly 22 and print medium 36 are moved relative to each other. While the following description refers to the ejection of ink from printhead assembly 22, it is understood that other liquids, fluids or flowable materials, including clear fluid, may be ejected from printhead assembly 22.
Ink supply assembly 24 as one embodiment of a fluid supply assembly provides ink to printhead assembly 22 and includes a reservoir 38 for storing ink. As such, ink flows from reservoir 38 to inkjet printhead assembly 22. Ink supply assembly 24 and inkjet printhead assembly 22 can form either a one-way ink delivery system or a recirculating ink delivery system. In a one-way ink delivery system, substantially all of the ink provided to inkjet printhead assembly 22 is consumed during printing. In a recirculating ink delivery system, only a portion of the ink provided to printhead assembly 22 is consumed during printing. As such, ink not consumed during printing is returned to ink supply assembly 24.
In one embodiment, inkjet printhead assembly 22 and ink supply assembly 24 are housed together in an inkjet cartridge or pen. The inkjet cartridge or pen is one embodiment of a fluid ejection device. In another embodiment, ink supply assembly 24 is separate from inkjet printhead assembly 22 and provides ink to inkjet printhead assembly 22 through an interface connection, such as a supply tube (not shown). In either embodiment, reservoir 38 of ink supply assembly 24 may be removed, replaced, and/or refilled. In one embodiment, where inkjet printhead assembly 22 and ink supply assembly 24 are housed together in an inkjet cartridge, reservoir 38 includes a local reservoir located within the cartridge and may also include a larger reservoir located separately from the cartridge. As such, the separate, larger reservoir serves to refill the local reservoir. Accordingly, the separate, larger reservoir and/or the local reservoir may be removed, replaced, and/or refilled.
Mounting assembly 26 positions inkjet printhead assembly 22 relative to media transport assembly 28 and media transport assembly 28 positions print medium 36 relative to inkjet printhead assembly 22. Thus, a print zone 37 is defined adjacent to nozzles 34 in an area between inkjet printhead assembly 22 and print medium 36. In one embodiment, inkjet printhead assembly 22 is a scanning type printhead assembly. As such, mounting assembly 26 includes a carriage (not shown) for moving inkjet printhead assembly 22 relative to media transport assembly 28 to scan print medium 36. In another embodiment, inkjet printhead assembly 22 is a non-scanning type printhead assembly. As such, mounting assembly 26 fixes inkjet printhead assembly 22 at a prescribed position relative to media transport assembly 28. Thus, media transport assembly 28 positions print medium 36 relative to inkjet printhead assembly 22.
Electronic controller or printer controller 30 typically includes a processor, firmware, and other electronics, or any combination thereof, for communicating with and controlling inkjet printhead assembly 22, mounting assembly 26, and media transport assembly 28. Electronic controller 30 receives data 39 from a host system, such as a computer, and usually includes memory for temporarily storing data 39. Typically, data 39 is sent to inkjet printing system 20 along an electronic, infrared, optical, or other information transfer path. Data 39 represents, for example, a document and/or file to be printed. As such, data 39 forms a print job for inkjet printing system 20 and includes one or more print job commands and/or command parameters.
In one embodiment, electronic controller 30 controls inkjet printhead assembly 22 for ejection of ink drops from nozzles 34. As such, electronic controller 30 defines a pattern of ejected ink drops that form characters, symbols, and/or other graphics or images on print medium 36. The pattern of ejected ink drops is determined by the print job commands and/or command parameters.
In one embodiment, inkjet printhead assembly 22 includes one printhead 40. In another embodiment, inkjet printhead assembly 22 is a wide-array or multi-head printhead assembly. In one wide-array embodiment, inkjet printhead assembly 22 includes a carrier, which carries printhead dies 40, provides electrical communication between printhead dies 40 and electronic controller 30, and provides fluidic communication between printhead dies 40 and ink supply assembly 24.
During printing, ink flows from ink feed slot 46 to vaporization chamber 56 via ink feed channel 54. Nozzle opening 34 is operatively associated with firing resistor 52 such that droplets of ink within vaporization chamber 56 are ejected through nozzle opening 34 (e.g., substantially normal to the plane of firing resistor 52) and toward print medium 36 upon energization of firing resistor 52.
Example embodiments of printhead dies 40 include a thermal printhead, a piezoelectric printhead, an electrostatic printhead, or any other type of fluid ejection device known in the art that can be integrated into a multi-layer structure. Substrate 44 is formed, for example, of silicon, glass, ceramic, or a stable polymer and thin-film structure 48 is formed to include one or more passivation or insulation layers of silicon dioxide, silicon carbide, silicon nitride, tantalum, polysilicon glass, or other suitable material. Thin-film structure 48 also includes at least one conductive layer, which defines firing resistor 52 and leads 58. The conductive layer is made, for example, to include aluminum, gold, tantalum, tantalum-aluminum, or other metal or metal alloy.
In one embodiment, layer 50 comprises a photoimageable epoxy resin, for example, an epoxy referred to as SU8,marketed by Micro-Chem, Newton, Mass. Exemplary techniques for fabricating layer 50 with SU8 or other polymers are described in detail in U.S. Pat. No. 7,226,149, which is herein incorporated by reference. Other suitable materials, however, can be employed to form layer 50.
Ink feed slot 46 provides ink to each of the n drop generators 60 disposed along ink feed slot 46. Each of the n drop generators 60 includes a firing resistor 52, a vaporization chamber 56 and a nozzle 34. Each of the n vaporization chambers 56 is fluidically coupled to ink feed slot 46 through at least one ink feed channel 54. The firing resistors 52 of drop generators 60 are energized in a controlled sequence to eject fluid from vaporization chambers 56 and through nozzles 34 to print an image on print medium 36.
Layer 50 may be formed of material (e.g., a photoimagable polymer such as SU8) that is not fluid impermeable and/or has thermal or electrical properties that could potentially interfere with the desired operation of fuses 70. Ink or other fluidic or non-fluidic materials may short blown fuses 70 if allowed to come into contact with blown fuses 70. In addition, fuses may not blow properly if covered by material with undesired thermal or electrical properties. To avoid these potential problems, layer 50 forms a chamber 84 over and adjacent to each fuse 70 and chamber 84 is hermetically sealed by an encapsulation layer 78. Chamber 84 provides thermal and electrical properties that are conducive to blowing fuse 70, and encapsulation layer 78 provides a fluid impermeable layer over layer 50 to prevent ink or other fluidic or non-fluidic materials from coming into contact with fuse 70.
In the embodiment of
Encapsulation layer 78 is applied to surface 50a of layer 50 (i.e., the top surface of orifice layer 76) to enclose chamber 84 by encompassing the portion of surface 50a that includes orifice 86. Air pressure in chamber 84 provides resistance against the applied encapsulation material of encapsulation layer 78 to prevent the encapsulation material from wicking too far into orifice 86. In addition, orifice layer 76 forms orifice 86 with a size that is small enough to prevent the encapsulation material from wicking too far into orifice 86. As a result, the encapsulation material extends partially into orifice 86 when applied and forms an edge 90 in orifice 86 as will be described in additional detail below.
In other embodiments, primer layer 72 and void 82 may be omitted so that chamber 84 is formed entirely adjacent to thin film layer 48. In addition, layer 50 may include other numbers of sub-layers for forming chamber 84 and/or orifice 86 in other embodiments.
In the embodiment of
In other embodiments, layer 50 may define orifice 86 to be only partially offset from or above from fuse 70 and/or void 82 provided that chamber 84 includes a size sufficient to provide enough air pressure to prevent the applied encapsulation material from encroaching too far into orifice 86 and/or chamber 84.
In the embodiment of
Layer 50 defines sub-chamber 84A adjacent to void 82 and fuse 70, sub-chamber 84B adjacent to orifice 86, and sub-chamber 84C between sub-chambers 84A and 84B. Sub-chamber 84C is narrower than sub-chambers 84A and 84B. Narrower regions 88A and 88B of sub-chamber 84C, shown in
Encapsulation layer 78 is formed adjacent to surface 50a and encompasses the portion of surface 50a that includes orifice 86. When applied, encapsulation material may wick into at least orifice 86 as indicated by edge 90. The encapsulation material bonds printhead die 40 to printhead assembly 22 and encloses the bond pads (not shown) to prevent ink from contacting the bond pads. The encapsulation material may be any suitable viscous adhesive material that is cured to form a solid encapsulation layer 78.
In the above embodiments, other components may be formed on substrate 40 in place of fuses 70.
In the embodiment of
In one embodiment, chamber 84 may be formed using the lost wax method described in U.S. Pat. No. 7,226,149, which is herein incorporated by reference. In this embodiment, primer layer 72 (e.g., a negative photoresist such as SU8), when present, may be applied over thin film layer 48 (e.g., by spinning) and patterned to remove void 82 as shown in
Chamber layer 74 (e.g., a negative photoresist such as SU8) is applied over primer layer 72 and/or thin film layer 48 (e.g., by spinning) and patterned to remove chamber 84 and void 82 as shown in
A layer of filler material 110 (e.g., a novolac resin or a photoresist that includes novolac resin such as SPR220) is applied over chamber layer 74, primer layer 72 (if present), and thin film layer 48 as shown in
Orifice layer 76 (e.g., a negative photoresist such as SU8) is applied over chamber layer 74 and filler material 110 (e.g., by laminating a dry film of SU8) and patterned to remove orifice 86, chamber 84 and void 82 as shown in
Referring back to
With the above embodiments, a chamber may be formed over each fuse on a substrate using a single orifice to remove material in the chamber layer. The orifice may be covered with encapsulation material without the encapsulation material contacting the fuse using the air present in the chamber. Pinch points may be formed in the chamber to further ensure that the encapsulation material does not contact the fuse. In addition, the amount of material to be removed to form the chamber may be minimized by including a single fuse in each chamber. The chamber may provide a suitable thermal and electrical environment for fuses to be blow while preventing exposure of undesired materials to a blown fuse region.
Although specific embodiments have been illustrated and described herein for purposes of description of the embodiments, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. Those with skill in the art will readily appreciate that the present disclosure may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the disclosed embodiments discussed herein. Therefore, it is manifestly intended that the scope of the present disclosure be limited by the claims and the equivalents thereof.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US07/88179 | 12/19/2007 | WO | 00 | 5/11/2010 |