Patent Publication Number: US-2002001020-A1

Title: Heater chip module for use in an ink jet printer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     [0001] This application is related to contemporaneously filed patent applications U.S. Ser. No. ______, entitled “AN INK JET HEATER CHIP MODULE WITH SEALANT MATERIAL,” having Attorney Docket No. LE9-97-109; U.S. Ser. No. ______, entitled “A HEATER CHIP MODULE AND PROCESS FOR MAKING SAME,” having Attorney Docket No. LE9-97-115; U.S. Ser. No. ______, entitled “A PROCESS FOR MAKING A HEATER CHIP MODULE,” having Attorney Docket No. LE9-97-111; U.S. Ser. No. ______, entitled “AN INK JET HEATER CHIP MODULE INCLUDING A NOZZLE PLATE COUPLING A HEATER CHIP TO A CARRIER,” having Attorney Docket No. LE9-98-003; and U.S. Ser. No. ______, entitled “AN INK JET HEATER CHIP MODULE,” having Attorney Docket No. LE9-97-064, the disclosures of which are incorporated herein by reference. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] This invention relates to an ink jet heater chip module adapted to be secured to an ink-filled container.  
       BACKGROUND OF THE INVENTION  
       [0003] Drop-on-demand ink jet printers use thermal energy to produce a vapor bubble in an ink-filled chamber to expel a droplet. A thermal energy generator or heating element, usually a resistor, is located in the chamber on a heater chip near a discharge nozzle. A plurality of chambers, each provided with a single heating element, are provided in the printer&#39;s printhead. The printhead typically comprises the heater chip and a nozzle plate having a plurality of the discharge nozzles formed therein. The printhead forms part of an ink jet print cartridge which also comprises an ink-filled container.  
       [0004] A plurality of dots comprising a swath of printed data are printed as the ink jet print cartridge makes a single scan across a print medium, such as a sheet of paper. The data swath has a given length and width. The length of the data swath, which extends transversely to the scan direction, is determined by the size of the heater chip.  
       [0005] Printer manufacturers are constantly searching for techniques which may be used to improve printing speed. One possible solution involves using larger heater chips. Larger heater chips, however, are costly to manufacture. Heater chips are typically formed on a silicon wafer having a generally circular shape. As the normally rectangular heater chips get larger, less of the silicon wafer can be utilized in making heater chips. Further, as heater chip size increases, the likelihood that a chip will have a defective heating element, conductor or other element formed thereon also increases. Thus, manufacturing yields decrease as heater chip size increases.  
       [0006] Accordingly, there is a need for an improved printhead or printhead assembly which allows for increased printing speed yet is capable of being manufactured in an economical manner.  
       SUMMARY OF THE INVENTION  
       [0007] In accordance with the present invention, a heater chip module is provided comprising a rigid carrier, a heater chip and a nozzle plate. The carrier is adapted to be secured directly to a container for receiving ink. It includes a support section. The heater chip is coupled to the carrier support section. The support section includes at least one passage which defines a path for ink to travel from the container to the heater chip. The nozzle plate is coupled to the heater chip.  
       [0008] Two or more heater chips, aligned end to end or at an angle to one another, may be coupled to a single carrier. Thus, two or more smaller heater chips can be combined to create the effect of a single, larger heater chip. That is, two or more smaller heater chips can create a data swath that is essentially equivalent to one printed by a substantially larger heater chip.  
       [0009] Each of two or more heater chips coupled to a single carrier may be dedicated to a different color. For example, three heater chips positioned side by side may be coupled to a single carrier, wherein each heater chip receives ink of one of the three primary colors.  
       [0010] Preferably, the carrier is formed from a thermally conductive material such as a ceramic metallic composite, a metal, a ceramic or silicon. The thermally conductive material provides a dissipation path for heat generated by the one or more heater chips coupled to the carrier.  
       [0011] Because the rigid carrier does not expand or contract significantly in response to temperature or humidity changes experienced during printing, the spacing between adjacent heater chips coupled to a single carrier does not vary significantly. Further, because “good” chips, i.e., chips which have passed quality control testing, are assembled to the carrier, higher manufacturing yields are achieved.  
       [0012] Bond pads on the heater chips can be coupled to traces on one or more flexible circuits via wire-bonding. Separate wires extend between sections of the traces to the bond pads on the heater chip. The trace sections and the bond pads are substantially coplanar with a bottom surface of the nozzle plate. Further, the wires are generally positioned between a bottom surface of the ink-filled container, which surface is closest to a paper substrate being printed, and the paper substrate.  
       [0013] In the illustrated embodiment, the heater chip module comprises a “top shooter” module or printhead, wherein the nozzles are in a direction normal to the surfaces of the resistive heating elements on the heater chip(s). 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0014]FIG. 1 is a perspective view, partially broken away, of an ink jet printing apparatus having a print cartridge constructed in accordance with the present invention;  
     [0015]FIG. 2 is a plan view of a portion of a heater chip module constructed in accordance with a first embodiment of the present invention;  
     [0016]FIG. 2A is a view taken along view line  2 A- 2 A in FIG. 2;  
     [0017]FIG. 2B is a view taken along view line  2 B- 2 B in FIG. 2;  
     [0018]FIG. 2C is a plan view of the support substrate, spacer and heater chip of the module illustrated in FIGS. 2, 2A and  2 B with the nozzle plate and flexible circuit removed  
     [0019]FIG. 2D is a cross sectional view of a portion of a flexible circuit of the module illustrated in FIG. 2;  
     [0020]FIG. 3 is a cross sectional view of a portion of a heater chip module constructed in accordance with a second embodiment of the present invention;  
     [0021]FIG. 4 is a plan view of a portion of the heater chip module illustrated in FIG. 3; and  
     [0022]FIGS. 5 and 6 are cross sectional views of portions of heater chip modules constructed in accordance with further embodiments of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0023] Referring now to FIG. 1, there is shown an ink jet printing apparatus  10  having a print cartridge  20  constructed in accordance with the present invention. The cartridge  20  is supported in a carriage  40  which, in turn, is slidably supported on a guide rail  42 . A drive mechanism  44  is provided for effecting reciprocating movement of the carriage  40  and the print cartridge  20  back and forth along the guide rail  42 . As the print cartridge  20  moves back and forth, it ejects ink droplets onto a paper substrate  12  provided below it.  
     [0024] The print cartridge  20  comprises a container  22 , shown only in FIG. 1, filled with ink and a heater chip module  50 , shown in FIG. 2. The container  22  may be formed from a polymeric material. In the illustrated embodiment, the container  22  is formed from polyphenylene oxide, which is commercially available from the General Electric Company under the trademark “NORYL SE-1.” The container  22  may be formed from other materials not explicitly set out herein.  
     [0025] In the embodiment illustrated in FIG. 2, the module  50  comprises a substantially rigid carrier  52 , an edge-feed heater chip  60  and a nozzle plate  70 . The heater chip  60  includes a plurality of resistive heating elements  62  which are located on a base  64 . In the illustrated embodiment, the base  64  is formed from silicon. The nozzle plate  70  has a plurality of openings  72  extending through it which define a plurality of nozzles  74  through which ink droplets are ejected. The carrier  52  is secured directly to a bottom side (not shown) of the container  22 , i.e., the side in FIG. 1 closest to the paper substrate  12 , such as by an adhesive (not shown). Thus, in the illustrated embodiment, there is no other element positioned between the carrier  52  and the container  22  except for the adhesive. An example adhesive which may be used for securing the carrier  52  to the container  22  is one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation “ECCOBOND 3193-17.” 
     [0026] The nozzle plate  70  may be formed from a flexible polymeric material substrate which is adhered to the heater chip  60  via an adhesive (not shown). Examples of polymeric materials from which the nozzle plate  70  may be formed and adhesives for securing the plate  70  to the heater chip  60  are set out in commonly assigned patent application, U.S. Ser. No. 08/966,281, entitled “METHOD OF FORMING AN INKJET PRINTHEAD NOZZLE STRUCTURE,” by Ashok Murthy et al., filed on Nov. 7, 1997, which is a continuation-in-part application of patent application, U.S. Ser. No. 08/519,906, entitled “METHOD OF FORMING AN INKJET PRINTHEAD NOZZLE STRUCTURE,” by Tonya H. Jackson et al., filed on Aug. 28, 1995, the disclosures of which are hereby incorporated by reference. As noted therein, the plate  70  may be formed from a polymeric material such as polyimide, polyester, fluorocarbon polymer, or polycarbonate, which is preferably about 15 to about 200 microns thick, and most preferably about 20 to about 80 microns thick. Examples of commercially available nozzle plate materials include a polyimide material available from E.I. DuPont de Nemours &amp; Co. under the trademark “KAPTON” and a polyimide material available from Ube (of Japan) under the trademark “UPILEX.” The adhesive for securing the plate  70  to the heater chip  60  may comprise a phenolic butyral adhesive. The nozzle plate  70  may be is bonded to the chip  60  via any technique such as a thermocompression bonding process. A polyimide substrate/phenolic butyral adhesive composite material is commercially available from Rogers Corporation, Chandler, AZ, under the product name “RFLEX 1100.” An intermediate Photoimageable planarizing epoxy layer (as disclosed in U.S. application Ser. No. 09/064,019, filed Apr. 21, 1998) is employed between the heater chip  60  and the adhesive composite material.  
     [0027] When the plate  70  and the heater chip  60  are joined together, sections  76  of the plate  70  and portions  66  of the heater chip  60  define a plurality of bubble chambers  65 . Ink supplied by the container  22  flows into the bubble chambers  65  through ink supply channels  65   a . As is illustrated in FIG. 2A, the supply channels  65   a  extend from the bubble chambers  65  beyond first and second outer edges  60   a  and  60   b  of the heater chip  60 . The resistive heating elements  62  are positioned on the heater chip  60  such that each bubble chamber  65  has only one heating element  62 . Each bubble chamber  65  communicates with one nozzle  74 .  
     [0028] In the embodiment illustrated in FIGS. 2, 2A, and  2 B, the carrier  52  comprises a support substrate  54  and a spacer  56  secured to the support substrate  54 . The spacer  56  has a generally rectangular opening  56   a  defined by inner side walls  56   b . The support substrate  54  has first and second outer surfaces  54   a  and  54   b  and a portion  54   c  which defines a carrier support section  52   a  to which the edge feed heater chip  60  is secured. An upper surface  54   d  of the support substrate portion  54   c  and the inner side walls  56   b  of the spacer  56  define an inner cavity  58  of the carrier  52 . The edge feed heater chip  60  is located in the carrier inner cavity  58  and secured to the carrier support section  52   a . The support substrate  54  has a thickness T P  of from about 400 microns to about 1000 microns and, preferably, from about 500 microns to about 800 microns. The spacer  56  has a thickness Ts of from about 400 microns to about 1000 microns and, preferably, from about 500 microns to about 800 microns.  
     [0029] The portion  54   c  includes two passages  54   g  extending from the first outer surface  54   a  of the support substrate  54  to the inner cavity  58 . Hence, the passages  54   g  communicate with the inner cavity  58  so as to define paths for ink to travel from the container  22  to the inner cavity  58 . From the inner cavity  58 , the ink flows into the ink supply channels  65   a . The passages  54   g  have a generally rectangular shape in the illustrated embodiment. They may, however, have an elliptical or other geometric shape. Further, each passage  54   g  may comprise a plurality of smaller passages or channels which are spaced apart from one another.  
     [0030] The support substrate  54  is preferably formed from a thermally conductive material. Example thermally conductive materials include ceramics, including ceramic metallic composites, silicon, and metals, such as stainless steel, aluminum, copper, zinc, nickel and alloys thereof. In the illustrated embodiment, the support substrate  54  is formed from steel using any process for making cut metal sheet parts such as stamping, chemical etching, or laser cutting. The thermally conductive material provides a dissipation path for heat generated by the heater chip  60  coupled to the carrier  52 .  
     [0031] The spacer  56  may be formed from a metal such as steel, aluminum, copper, zinc and nickel, or from a moldable, machinable or otherwise formable polymeric material such as a polyetherimide, which is commercially available from GE Plastics under the product name “ULTEM.” 
     [0032] The spacer  56  is secured to the support substrate  54  by an adhesive  55 . Example adhesives which may be used for securing the spacer  56  to the support substrate  54  include a thermally curable B-stage adhesive (polysulfone) film preform which is commercially available from Alpha Metals Inc. under the product designation “Staystik 415” and another adhesive material which is commercially available from Mitsui Toatsu Chemicals Inc. under the product designation “REGULUS.” 
     [0033] It is further contemplated that two or more inner cavities  58  and a like number of substrate portions  54   c  may be formed in a single carrier  52  such that the single carrier  52  is capable of receiving two or more heater chips  60 . It is also contemplated that two or more heater chips  60  may be provided in a single inner cavity  58  and secured to a single substrate portion  54   c . In either of the two alternative embodiments, the heater chips  60  may be positioned side by side, end to end or at an angle to one another.  
     [0034] If two or more heater chips  60  are coupled to a single carrier  52 , a like number of nozzle plates  70  may be provided such that a separate nozzle plate  70  is coupled to each heater chip  60 . Alternatively, a single, much larger nozzle plate (not shown) may be provided to which the two or more heater chips  60  are coupled.  
     [0035] The inner cavity  58  and the heater chip  60  are sized such that opposing side portions  60   c  and  60   d  of the heater chip  60  are spaced from adjacent inner side walls  56   b  of the spacer  56  to form gaps  80   a  and  80   b  of a sufficient size to permit ink to flow freely between the chip side portions  60   c  and  60   d  and the adjacent inner side walls  56   b , see FIG. 2A.  
     [0036] The nozzle plate  70  is sized to extend over an outer portion  56   c  of the spacer  56  surrounding the inner cavity  58  such that the inner cavity  58  is sealed to prevent ink from leaking from the cavity  58 . As noted above, the passages  54   g  provide paths for ink to travel from the container  22  to the inner cavity  58 . From the inner cavity  58 , the ink flows into the ink supply channels  65   a.    
     [0037] The resistive heating elements  62  are individually addressed by voltage pulses provided by a printer energy supply circuit (not shown). Each voltage pulse is applied to one of the heating elements  62  to momentarily vaporize the ink in contact with that heating element  62  to form a bubble within the bubble chamber  65  in which the heating element  62  is located. The function of the bubble is to displace ink within the bubble chamber  65  such that a droplet of ink is expelled from a nozzle  74  associated with the bubble chamber  65 .  
     [0038] A flexible circuit  90 , secured to the container  22  and the carrier  52 , is used to provide a path for energy pulses to travel from the printer energy supply circuit to the heater chip  60 . As shown in FIG. 2D, the flexible circuit  90  comprises first and second outer substrate layers  90   a  and  90   b  formed from a polymeric material such as a polyimide or polyester_material, first and second inner adhesive layers  90   c  and  90   d  comprising, for example, an acrylic, polyester, phenolic or epoxy adhesive material, and metal traces  90   e , copper in the illustrated embodiment, positioned between the adhesive and polymeric layers.  
     [0039] In the illustrated embodiment, the flexible circuit  90  is formed by providing a laminate comprising a substrate layer  90   b , an adhesive layer  90   d  and a sheet of copper material. Such a laminate is commercially available from E.I. DuPont de Nemours &amp; Co. under the product designation “Pyralux WA/K Copper Clad Laminate.” A photoresist material, such as a negative photoresist material, is applied to the copper sheet. A mask, having a plurality of blocked or covered areas and unblocked areas, is positioned over the photoresist material. The unblocked portions of the mask correspond to the traces. Thereafter, unblocked portions of the photoresist are exposed to ultraviolet light to effect curing or polymerization of the exposed portions. The unexposed or uncured portions are then removed using a conventional developer. The pattern formed in the photoresist layer is transferred to the copper sheet using a conventional etching process. After etching has been completed, the photoresist material remaining on the copper sheet is removed via a conventional stripping process. Finally, a laminate comprising a substrate layer  90   a  and an adhesive layer  90   c , one of which is commercially available from E.I. DuPont de Nemours &amp; Co. under the product designation “Pyralux WA/K Bond Ply” is laminated to the traces  90   e  and the substrate and adhesive layers  90   b  and  90   d  via a hot press process. Preferably, the substrate and adhesive layers  90   a  and  90   c  are prepunched so as to include one or more openings  90   g  therein before being laminated to the layers  90   b ,  90   d  and  90   e.    
     [0040] The bond pads  68  on the heater chip  60  are wire-bonded to sections  90   f  of the traces  90   e  within the flexible circuit  90  such that a single wire  91  extends from each bond pad  68 , through an opening  90   g  in the flexible circuit  90 , to a section  90   f  of a metal trace  90   e , see FIGS. 2 and 2D. The wires  91  further extend through windows or openings  71  formed in the nozzle plate  70 . It is also contemplated that the nozzle plate  70  may be sized as described in the above-referenced patent application entitled “AN INK JET HEATER CHIP MODULE WITH SEALANT MATERIAL” such that the wires  91  do not extend through windows in the nozzle plate  70 . Current flows from the printer energy supply circuit to the traces  90   e  within the flexible circuit  90  and from the traces  90   e  to the bond pads  68  on the heater chip  60 . Conductors (not shown) are formed on the heater chip base  64  and extend from the bond pads  68  to the heating elements  62 . The current flows from the bond pads  68  along the conductors to the heating elements  62 . Alternatively, a flexible circuit having traces which are TAB bonded to bond pads on a heater chip, such as described in copending patent application U.S. Ser. No. 08/827,140, entitled “A PROCESS FOR JOINING A FLEXIBLE CIRCUIT TO A POLYMERIC CONTAINER AND FOR FORMING A BARRIER LAYER OVER SECTIONS OF THE FLEXIBLE CIRCUIT AND OTHER ELEMENTS USING AN ENCAPSULANT MATERIAL,” filed Mar. 27, 1997, the disclosure of which is incorporated herein by reference, may be used in place of the circuit  90  described above.  
     [0041] The process for forming the heater chip module  50  illustrated in FIG. 2 will now be described for a wire-bond embodiment. As noted above, the nozzle plate  70  comprises a flexible polymeric material substrate. In the illustrated embodiment, the flexible substrate is provided with an overlaid layer of phenolic butyral adhesive for securing the nozzle plate  70  to the heater chip  60  and the carrier  52 .  
     [0042] Initially, the nozzle plate  70  is aligned with and mounted to the heater chip  60 . At this point, the heater chip  60  has been separated from other heater chips  60  formed on the same wafer. Alignment takes place as follows. One or more openings  77  are provided in the nozzle plate  70  which arc aligned with one or more fiducials  67  formed on the heater chip  60 . After the nozzle plate  70  is aligned to and located on the heater chip  60 , the plate  70  is tacked to the heater chip  60  using, for example, a conventional thermocompression bonding process. The phenolic butyral adhesive on the nozzle plate  70  is not cured after the tacking step has been completed.  
     [0043] If two or more heater chips  60  are coupled to a single, larger nozzle plate, alignment of the heater chips  60  to the nozzle plate is effected in substantially the same manner. That is, openings in the single, larger nozzle plate are aligned with fiducials provided on the two or more heater chips  60 .  
     [0044] Either before or after the nozzle plate  70  is tacked to the heater chip  60 , the spacer  56  is bonded to the support substrate  54 . A layer of the adhesive  55 , examples of which are noted above, is applied to the second outer surface  54   b  of the support substrate  54  where the spacer  56  is to be positioned. The spacer  56  is then mounted to the support substrate  54 . Thereafter, the adhesive  55  is fully cured using heat and pressure.  
     [0045] A further adhesive material (not shown), such as a 0.002 inch thick, die-cut phenolic adhesive film, which is commercially available from Rogers Corporation (Chandler, Ariz.) under the product designation “1000B200,” is placed on a portion of the carrier  52  to which the flexible circuit  90  is to be secured. After the adhesive film is placed on the carrier, the flexible circuit  90  is positioned over the adhesive film and tacked to the carrier  52  using heat and pressure.  
     [0046] The nozzle plate/heater chip assembly is then mounted to the carrier  52 . Initially, a conventional die bond adhesive  110 , such as a thermally conductive die bond adhesive, one of which is commercially available from Alpha Metals Inc. under the product designation “Polysolder LT,” is applied to the upper surface  54   d  of the substrate portion  54   c  at locations where one or more heater chips  60  are to be located. Thereafter, openings (not shown) in the nozzle plate  70  are aligned with structural features (not shown) on the carrier  52 .  
     [0047] The nozzle plate/heater chip assembly is tacked to the carrier  52  so as to maintain the assembly and the carrier  52  joined together until the die bond adhesive  110  is cured. Before the nozzle plate/heater chip assembly is aligned with and mounted to the carrier  52 , a conventional ultraviolet (UV) curable adhesive (not shown), such as one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation UV9000, is applied to one or more locations on the carrier  52  where corners of the heater chip  60  are to be located. After the nozzle plate/heater chip assembly is mounted to the carrier  52 , exposed UV adhesive is cured using ultraviolet radiation to effect tacking. It is also contemplated that a conventional cationic cured adhesive material may be used for tacking the heater chip  60  to the carrier  52 . One such adhesive is commercially available from Electronic Materials Inc. under the product designation “Emcast 700 Series.” This material is also cured via UV radiation.  
     [0048] Next, the nozzle plate/heater chip assembly and the support substrate/spacer assembly are heated in an oven at a temperature and for a time period sufficient to effect the curing of the following materials: the phenolic butyral adhesive that bonds the nozzle plate  70  to the heater chip  60  and the carrier  52 ; the phenolic adhesive film which joins the flexible circuit  90  to the carrier  52 ; and the die bond adhesive  10  which joins the heater chip  60  to the substrate portion  54   c.    
     [0049] After the nozzle plate/heater chip assembly and the flexible circuit  90  have been bonded to the carrier  52 , sections  90   f  of the traces  90   e  on the flexible circuit  90  are wire-bonded to the bond pads  68  on the heater chip  60 . It is also contemplated that trace end sections may be coupled to the bond pads via a conventional Tape Automated Bonding (TAB) process such as described in the above referenced patent application entitled “AN INK JET HEATER CHIP MODULE INCLUDING A NOZZLE PLATE COUPLING A HEATER CHIP TO A CARRIER.” After wire-bonding or TAB bonding, a liquid encapsulant material  144  (shown only in FIG. 2B), such as an ultraviolet (UV) curable adhesive, one of which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation “LV9000,” is applied over the trace sections  90   f , the bond pads  68 , the windows  71  and the wires  91  extending between the trace sections and the bond pads. The UV adhesive is then cured using ultraviolet light.  
     [0050] The heater chip module  50 , which comprises the nozzle plate/heater chip assembly and the carrier  52 , and to which the flexible circuit  90  is bonded, is aligned with and bonded to a polymeric container  22 . An adhesive (not shown) such as one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation “ECCOBOND 3193-17” is applied to a portion of the container where the module  50  is to be located. The module  50  is then mounted to the container portion.  
     [0051] Next, the heater chip module  50  and container  22  are heated in an oven at a temperature and for a time period sufficient to effect the curing of the adhesive which joins the module  50  to the container  22 .  
     [0052] A portion of the flexible circuit  90  which is not joined to the carrier  52  is bonded to the container  22  by, for example, a conventional free-standing pressure sensitive adhesive film, such as described in copending patent application U.S. Ser. No. 08/827,140, entitled “A PROCESS FOR JOINING A FLEXIBLE CIRCUIT TO A POLYMERIC CONTAINER AND FOR FORMING A BARRIER LAYER OVER SECTIONS OF THE FLEXIBLE CIRCUIT AND OTHER ELEMENTS USING AN ENCAPSIJLANT MATERIAL,” filed Mar. 27, 1997, the disclosure of which is incorporated herein by reference.  
     [0053] It is also contemplated that the heater chip  60  may be secured to the carrier  52  by eutectic bonding or any other known bonding process.  
     [0054] A heater chip module  250 , formed in accordance with a second embodiment of the present invention, is shown in FIGS. 3 and 4, wherein like reference numerals indicate like elements. Here, the support substrate  154  of the carrier  152  is formed having only one passage  154   g  for each heater chip  160 . The heater chip  160  comprises a conventional center feed heater chip having a center ink-receiving via  162 . Ink from the container  22  travels through the passage  154   g  in the support substrate  154  to the via  162 . From the via  162 , the ink passes through supply channels  165   a  in the nozzle plate  170  to bubble channels  165  defined by portions of the heater chip  160  and sections of the nozzle plate  170 .  
     [0055] The support substrate  154  and spacer  156  may be formed from substantially the same materials from which the support substrate  54  and spacer  56  in the FIG. 2 embodiment are formed. However, only one passage  154   g  is formed in the support substrate  154  for each heater chip  160 .  
     [0056] Assembly of the components of the heater chip module  250  may occur in the following manner. Initially, the nozzle plate  170  is aligned with and mounted to the heater chip  160 . Typically, a plurality of heater chips  160  are formed on a single wafer. In this embodiment, a nozzle plate  170  is mounted to each heater chip  160  before the wafer is diced. Alignment may take place as follows. One or more openings  277  are formed in a nozzle plate  170  which are aligned with one or more fiducials  267  formed on a heater chip  160 . After each nozzle plate  170  is aligned to and located on a corresponding heater chip  160 , the plate  170  is tacked to that heater chip  160 . It is further contemplated that a single, larger nozzle plate (not shown) could be bonded to two or more heater chips. In such an embodiment, the heater chips are aligned with the nozzle plate  170  after the heater chips have been separated from the heater chip wafer.  
     [0057] The nozzle plate  170  includes one or more openings  177  which, in the illustrated embodiment, are triangular in shape, see FIG. 4. The openings  177  may be circular, square or have another geometric shape. An ultraviolet (UV) curable adhesive (not shown), such as one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation LV-4359-88 is applied over the openings  177  so as to contact both the nozzle plate  170  and the heater chip  160 . Thereafter, the adhesive is cured using UV radiation to effect tacking. Each heater chip  160  on the heater chip wafer receives a nozzle plate  170  which is tacked to its corresponding heater chip  160  in this manner. After tacking has been completed, the nozzle plates  170  are permanently bonded to the heater chips  160  on the wafer by curing the layer of phenolic butyral adhesive provided on the underside of each nozzle plate  170  using, for example, a conventional thermocompression bonding process. Thereafter, the heater chip wafer is diced so as to separate the nozzle plate/heater chip assemblies from one another.  
     [0058] After the heater chip wafer has been diced, a flexible circuit  190  is attached to the heater chip  160  of each nozzle plate/heater chip assembly. End sections  192   a  of traces  192  on the flexible circuit  190  are TAB bonded to the bond pads  168  on the heater chip  160 , see FIGS. 3 and 4. In this embodiment, the flexible circuit  190  comprises a single layer substrate, such as a polyimide substrate  190   a , and copper traces  192  which are formed on the underside of the substrate  190   a . It is also contemplated that trace sections may be coupled to the bond pads  168  via a wire-bonding process. However, such a wire-bonding step would most likely occur after the flexible circuit  190  is attached to the spacer  156 .  
     [0059] Either before or after the nozzle plate  170  is tacked to the heater chip  160 , the spacer  156  is bonded to the support substrate  154  using the same process and adhesive described above for bonding the spacer  56  to the support substrate  54 .  
     [0060] A further adhesive material (not shown), such as a 0.002 inch die-cut phenolic adhesive film, which is commercially available from Rogers Corporation under the product designation “1000B200,” is placed on a portion  156   e  of the spacer  156  to which the flexible circuit  190  is to be secured.  
     [0061] After the nozzle plate  170  has been bonded to the heater chip  160 , the spacer  156  has been bonded to the support substrate  154 , and the phenolic adhesive film has been placed on the spacer  156 , the nozzle plate/heater chip assembly is aligned with and tacked to the support substrate/spacer assembly. Initially, a die bond adhesive  110  is applied to a carrier support section  152   a  where the heater chip  160  is to be located.  
     [0062] Thereafter, openings (not shown) in the nozzle plate  170  are aligned with structural features (not shown) on the carrier  152 .  
     [0063] The nozzle plate/heater chip assembly is tacked to the support substrate/spacer assembly, i.e., the carrier  152 , so as the maintain the two assemblies joined together until the die bond adhesive  110  is cured. Before the nozzle plate/heater chip assembly is mounted onto the support substrate/spacer assembly, a conventional ultraviolet (UV) curable adhesive (not shown), such as one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation UV9000, is applied to one or more locations on the support substrate  154  where corners of the heater chip  160  are to be positioned. After the nozzle plate/heater chip assembly is mounted to the support substrate/spacer assembly, exposed adhesive is cured using ultraviolet radiation to effect tacking. Once the nozzle plate/heater chip assembly is mounted to the support substrate/spacer assembly, the flexible circuit  190  contacts the phenolic adhesive film placed on the spacer  156 .  
     [0064] Next, the nozzle plate/heater chip assembly and the support substrate/spacer assembly are heated in an oven at a temperature and for a time period sufficient to effect the curing of the following materials: the phenolic adhesive film which joins the flexible circuit  190  to the spacer  156  and the die bond adhesive  110  which joins the heater chip  160  to the support substrate  154 .  
     [0065] A liquid encapsulant material (not shown) such as an ultraviolet (UV) curable adhesive, one of which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation UV9000, is then applied over the trace end sections  192   a  and the bond pads  168 . Thereafter, the UV adhesive is cured using UV light.  
     [0066] The heater chip module  250 , which comprises the nozzle plate/heater chip assembly and the support substrate/spacer assembly, and to which the flexible circuit  190  is bonded, is aligned with and bonded directly to a polymeric container  22 . An adhesive (not shown) such as one which is commercially available from Emerson and Cuming Specialty Polymers, a division of National Starch and Chemical Company under the product designation “ECCOBOND 3193-17” is applied to a portion of the container where the module  250  is to be located. The module  250  is then mounted to the container portion.  
     [0067] Next, the heater chip module  250  and the container  22  are heated in an oven at a temperature and for a time period sufficient to effect the curing of the adhesive that joins the heater chip module  250  to the container  22 .  
     [0068] A portion of the flexible circuit  190  which is not joined to the spacer  156  is bonded to the container  22  by, for example, a conventional free-standing pressure sensitive adhesive film.  
     [0069] A heater chip module  350 , formed in accordance with a third embodiment of the present invention, is shown in FIG. 5, wherein like reference numerals indicate like elements. The heater chip module  350  is constructed in essentially the same manner as the module  50  illustrated in FIG. 2A except that the carrier  352  comprises a substantially rigid, single layer substrate  353 . The single layer substrate  353  is preferably formed from a thermally conductive material such as a ceramic, a metal or silicon. In the illustrated embodiment, the single layer substrate  353  is formed from a metal such as stainless steel, e.g., type  316  stainless steel, using any process for making cut metal sheet parts such as is stamping, chemical etching, or laser cutting.  
     [0070] A heater chip module  450 , formed in accordance with a fourth embodiment of the present invention, is shown in FIG. 6, wherein like reference numerals indicate like elements. The heater chip module  450  is constructed in essentially the same manner as the module  250  illustrated in FIG. 3 except that the carrier  452  comprises a substantially rigid, single layer substrate  453 . The single layer substrate  453  is preferably formed from a thermally conductive material such as a ceramic, a metal or silicon.