PTOISBIDS (04-05)
`Approved for use through 07/31/2006. OMB 0651-0032
`U.S. Patent and Trademark Office. US. DEPARTMENT OF COMMERCE
`Under the Paerwork Reduction Act of 1995 no ersons are reuired to resond to a collection of information unless it disla s a valid OMB control number.
`
`UTILITY‘
`PATENT APPLICATION
`TRANSMITTAL
`(Only for new nonpmvisionai applications under 37 CFR 1. 53(1)»
`
`APPLICATION ELEMENTS
`See MPEP chapter 600 concerning utility patent application contents.
`
`Attorney Docket No.
`First inventor
`
`ZEO68US
`l-(ia Silverbrook
`
`Title
`
`Carrier Of A Metal Alloy
`
`Express Mail Label No.
`
`ADDRESS TO.‘
`
`Commissioner for Patents
`P.O. Box 1450
`Alexandria VA 22313-1450
`
`
`
`
`
`IIIIIIIIIIIIIIIIIIIIIIIIIII
`
`1.
`
`3.
`
`Fee Transmittal Form (e.g., PTOlSB/17)
`(Submit an original and a duplicate for fee processing)
`2. CI Applicant claims small entity status.
`See 37 CFR 127.
`20
`[Total Pages
`Specification
`Both the claims and abstract must start on a new page
`(For information on the preferred anangement, see MPEP 608, 01(a))
`[Total Sheets
`19
`Drawing(s) (35 Ll.S.C. 113)
`4.
`5. Oath or Declaration
`[Total Sheets
`a.
`Newly executed (original or copy)
`b.
`A copy from a pnor application (37 CFR 1.63(d))
`for continuation/divisional with Box 18 completed)
`DELETION OF |NVENTOR(S
`Signed statement attached deleting inventor(s)
`name in the prior application, see 37 CFR
`1.63(d)(2) and 1.33(b).
`
`1
`
`i
`
`ACCOMPANYING APPLICATION PARTS
`
`9.
`
`Assignment Papers (cover sheet 8. document(s))
`
`Name of Assignee Silverbrook Research Pty Ltd
`
`10. 1:] 37 CFR 3.73(b) Statement
`(when there is an assignee)
`
`Power of
`Attorney
`
`11. |:] English Translation Document (if applicable)
`
`12.
`
`Infofition Disclosure Statement (PTOISBIOB or PTO-1449)
`Copies of citations attached
`
`13. I:I Preliminary Amendment
`
`14.
`
`Return Receipt Postcard (MPEP 503)
`(Should be specifically itemized)
`
`15. D Certified Copy of Priority Document(s)
`(ii foreign priority is claimed)
`
`16. E] Nonpublication Request under 35 U.S.C. 122(b)(2)(B)(i).
`Applicant must attach form PTOISB/35 or equivalent.
`
`5.
`
`Application Data sheet see 37 CFR 176
`
`7. I: CD-ROM or CD-R in duplicate, large table or
`puter Program (Appendix)
`Landscape Table on CD
`
`8. Nucleotide andlor Amino Acid Sequence Submission
`(if applicable, items a. — c. are required)
`a. C] Computer Readable Form (CRF)
`b.
`Specification Sequence Listing on:
`
`i. I:I
`ii. I:
`
`CD-ROM or CD-R (2 copies); or
`Paper
`
`17. CI Other:
`
`c. I: Statements verifying identity of above copies
`18. If a CONTINUING APPLICATION, check appropriate box, and supply the requisite information below and in the first sentence of the
`specification following the title, or in an Application Data Sheet under37 CFR 1. 76.‘
`See attached Application
`of prior application No.: .$h9e.t. .
`. .
`. . . . . . . . . . ..
`Art Unit: 2853
`
`Continuation
`Prior application infonnation;
`
`I: Divisional
`CI Continuation»in-part (CIP)
`Examiner Juanita Stephens
`1 9. CORRESPONDENCE ADDRESS
`
`The address associated with Customer Number:
`Name
`
`KIA SILVERBROOK
`
`Address
`
`City
`Country
`Signature
`
`393 Darling Street
`Balmain
`Austr'a
`
`State
`Telephone
`
`1 1
`
`OR I: Correspondence address below
`
`NSW
`ZipCode | 2041
`+61 -2-981 8 6633
`Ema"
`info@silverbrookresearcncom
`Date April 24, 2006
`Registration No.
`
`5 required to obtain or retain a benefit by the public which is to file (and by the
`This collection of information is required by 37 CFR 1.53(b). The informati
`USPTO to process) an application. Confidentiality is governed by 35 US.
`. 122 and 37 CFR 1.11 and 1.14. This collection is estimated to take 12 minutes to
`complete, including gathering, preparing, and submitting the completed ap ' ation form to the USPTO. Time will vary depending upon the individual case. Any
`comments on the amount of time you require to complete this form andlor suggestions for reducing this burden, should be sent to the Chief information Officer,
`U.S. Patent and Trademark Office, US. Department of Commerce, P.O. Box 1450, Alexandria, VA 22313-1450. DO NOT SEND FEES OR COMPLETED
`FORMS TO THIS ADDRESS. SEND TO: Commissioner for Patents, P.O. Box 1450, Alexandria, VA 22313-1450.
`If you need assistance in completing the foml, call 1-800-PTO-9199 and select option 2.
`
`HP 1003
` Page 1 of 93
`
`

`
`iiiiiiiiiiiiiiiiiiii
`
`PTO/SB/17 (12—04v2)
`Approved for use through 07/31/2006. OMB 0651-0032
`U.S. Patent and Trademark Office; U.S. DEPARTMENT OF COMMERCE
`
`Effective on 12/03/2004.
`' . ees nursuanl to the Consolidated Anommiafions Act. 2005 (HR. 4818).
`
`FEE TRANSMITTAL
`For FY 2005
`
`D Applicant claims small entity status. See 37 CFR 1.27
`TOTAL AMOUNT OF PAYMENT
`($)
`1,oao_oo
`
`METHOD OF PAYMENT (check all that apply)
`
`Complete if Known
`
`Application Number
`Filing Date
`First Named Inventor Kia Silverbrook
`Examiner Name
`An Unit
`
`Attorney Docket No.
`
`ZEOGBUS
`
`Check I:I Credit Card I:I Money Order I:I None I:IOther (please identify):
`I:I Deposit Account Deposit Account Number:
`Deposit Account Name:
`Forthe above-identified deposit account, the Director is hereby authorized to: (check all that apply)
`
`I:|Charge fee(s) indicated below
`I:I Charge fee(s) indicated below, except for the filing fee
`C C”
`Charge any additional fee(s) or underpayments of tee(s)
`I: re ' any °VerpaymemS
`under 37 CFR 1.16 and 1.17
`WARNING: Information on this form may become public. Credit card Information should not be included on this form. Provide credit card
`information and authorization on PTO-2038.
`FEE CALCULATION
`
`1. BASIC FILING, SEARCH, AND EXAMINATION FEES
`FILING FEES
`SEARCH FEES
`Small Entity
`5
`|| E (E1
`Fee (§)
`mFaee (E).
`I50
`250
`I00
`50
`I00
`I50
`I 50
`250
`I00
`0
`
`Fee (§I
`500
`I00
`300
`
`500
`0
`
`E9_e_(§;)
`300
`200
`200
`
`300
`200
`
`Fifi)
`200
`I30
`I60
`
`EXAMINATION FEES
`Small Entity
`E.e_e,l,$_l
`I00
`65
`80
`300
`0
`
`600
`0
`
`Fees Paid (Q
`(1.09;
`
`Application Type
`Utility
`Design
`Plant
`Rcissuc
`Provisional
`2. EXCESS CLAIM FEES
`Fee Description
`Each claim over 20 (including Reissues)
`Each independent claim over 3 (including Reissues)
`Multiple dependent claims
`Total Claims
`Extra Claims
`x
`9
`- 20 or HP =
`HP = highest number of total claims paid for, if greater than 20‘
`lndep. Claims
`Extra Claims
`Fee (§)
`—
`X
`-3orHF’=
`HP = highest number of independent claims paid for, ifgreater than 3.
`‘
`_
`3. APPLICATION SIZE FEE .
`Ifthe specification and drawings exceed 100 sheets of paper (excluding electronically filed sequence or computer
`listings under 37 CFR I.S2(e)), the application size fee due is $250 ($125 For small entity) for each additional 50
`sheets or fraction thereof. See 35 U.S.C. 4l(a)(l )(G) and 37 CFR l.l6(s).
`Total Sheets
`_ Extra Sheets
`Number of each additional 50 or fraction thereof
`/50=
`39
`- 100 =
`(round up to a whole number)
`x
`4. OTHER FEE(S)
`$130 fee (no small entity discount)
`Non-English Spccitication,
`Other (c.g., late filing surcharge):Recording each patent assignment per property (X 2
`SUBMITTED BY
`.
`
`Small Entig
`Fee (§)
`EI%(§)5
`50
`100
`200
`I80
`360
`Multiple Dependent Claims
`Fee t§[
`Fee Paid (§)
`
`Fee (§)
`
`Fee Paid (§)
`
`Fee Paid t§)
`
`Fee (§)
`
`Fee Paid Q)
`
`Fees Paid (§)
`
`80.00
`
`_)_
`
`f -'
`
`'
`
`t
`
`‘
`
`N .
`
`Te'e-Phone +61-2-9818 6633
`.
`.
`. V
`Date April 24, zoos
`Name (PrintlTvpe) Kia
`i|verbrook;Tobin Allen King
`This collection of information is required by 37 CFR 1.136‘ The infonnation is required to obtain or retain a benefit by the public which is to tile (and by the
`USPTO to process) an application. Confidentiality is governed by 35 U.S.C. 122 and 37 CFR 1.14. This collection is estimated to take 30 minutes to complete,
`including gathering. preparing, and submitting the completed application form to the USPTO. Time will vary depending upon the individual case. Any comments
`on the amount of time you require to complete this form and/or suggestions for reducing this burden, should be sent to the Chief Information Officer, U.S. Patent
`and Trademark Office, U.S. Department of Commerce, PO. Box 1450, Alexandria, VA 22313-1450. DO NOT SEND FEES OR COMPLETED FORMS TO THIS
`ADDRESS. SEND TO: Commissioner for Patents, P.O. Box 1450, Alexandria, VA 22313-1450.
`If you need assistance in completing the fomi, call 1-800-PTO-9199 and select option 2‘
`
`HP 1003
` Page 2 of 93
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`

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`MODULAR PRINTHEAD ASSEMBLY WITH A CARRIER OF
`A METAL ALLOY
`
`_
`CROSS REFERENCE TO RELATED APPLICATION
`This is a Continuation Application of USSN 11/250,450 filed on October 17, 2005,
`
`which is a Continuation Application of USSN 10/728,-922 filed December 8, 2003, now US
`
`patent No. 6,997,545 which is a Continuation Application of USSN 10/102,700 filed on
`
`March 22 2002, now US patent No. 6,692,113 all of which is herein incorporated by
`
`reference.
`
`CO-PENDING APPLICATIONS
`Various methods, systems and apparatus relating to the present invention are
`
`disclosed in the fol-lowing co—pending applications filed by the applicant or assignee of the
`present invention: O9/575,141 (6,428,133); 09/575,125 (6,526,658), 09/575,108
`
`(6,795,215), 09/575,109..
`The disclosures of these co—pending applications are incorporated herein by
`
`reference.
`
`BACKGROUND OF THE INVENTION
`
`. The following invention relates to a printhead module assembly for a printer.
`
`More particularly, though not exclusively,‘ the invention relates to a printhead
`
`module assembly for an A4 pagewidth drop on demand printer capable of printing up to
`1600 dpi photographic (quality at up to 160 pages per minute.
`The overall design of a printer in which the printhead module assembly can be
`
`utilized revolves around the use of replaceable printhead modules in an array approximately
`
`8,‘/2 inches (21 cm) long. An advantage of such a system is the ability to easily remove and I
`
`,
`
`replace any defective modules in a printhead array. This would eliminate having to scrap an
`entire printhead if only one chip is defective.
`A printhead module in such a printer can be comprised of a “Memj et” chip, being a
`
`chip having mounted thereon a vast number of thermo-actuators in micro—mechanics and
`micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in
`
`U.S. Patent No. 6,044,646 to the present applicant, however, might be other MEMS print
`
`chips.
`
`ZEOGBUS
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`

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`In a typical embodiment, eleven “Memj et” tiles can butt together in a metal charmel
`
`to form a complete 8'/2 inch printhead assembly.
`
`The printhead, being the environment within which the printhead module
`
`assemblies of the present invention are to be situated, might typically have six ink chambers
`
`and be capable of printing four color process’ (CMYK) as well as infrared ink and fixative;
`
`‘
`
`An air pump would supply filtered air through a seventh chamber "to the printhead, which
`
`could be used to keep foreign particles away from its ink nozzles.
`
`Each printhead module receives ink via an elastomeric extrusion that transfers the
`
`ink. Typically, the printhead assembly is suitable for printing A4 paper without the need for
`
`scanning movement of the printhead across the paper width.
`The printheads themselves are modular, so printhead arrays can be configuredto
`form printheads of arbitrary width.
`I
`I
`A
`
`Additionally, a second printhead assembly can be mounted on the opposite side of a
`paper feed‘ path to enable double-sided l1igh—speed printing.
`
`OBJECTS OF .THE INVENTION
`
`It is an object of the present invention to provide an improved printhead module
`
`assembly.
`
`_
`
`It is another object of the invention to provide a printhead assembly having
`
`improved modules therein.
`
`SUMMARY OF THE INVENTION
`
`According to afirst aspect of the invention, there is provided a printhead assembly
`which comprises
`I
`an elongate charmel member having a floor and a pair of opposed side walls, the
`
`elongate channel member being of a metal having thermal expansion properties that are
`
`similar to thermal expansion properties of silicon; and
`
`at least one printhead module positioned in the support structure, along a length of
`
`the support structure, the, or each, printhead module comprising
`
`an elongate ink supply assembly that is positioned in the channel, the ink
`
`supply assembly being configured to receive a supply of ink and to provide a
`
`plurality of ink flow paths interposed between the supply of ink and a plurality of
`
`outlet openings defined by the ink supply assembly; and
`
`ZEO68US
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`an elongate printhead chip that is mounted on the ink supply assembly to be
`
`fed with ink from the ink supply assembly.
`
`The elongate channel may be of a nickel iron alloy. In particular, the elongate
`
`channel may be a 36% nickel iron alloy.
`
`The printhead assembly mayinclude a number of ink printhead modules positioned
`in the channel member such that the ink supply assemblies are positioned end-to-end in the
`
`A channel member and the printhead chips define an array that spans a print medium, in use.
`
`A The elongate ink supply assembly of each module may include an ink ‘feed member
`
`that is positioned on the floor of the charmel member and defines a number of ink charmels,
`
`extending longitudinally with respect to the channel member and in fluid communication
`
`with an ink supply and a plurality of outlet openings in fluid communication with
`
`respective ink channels from which ink can be fed.
`
`An ink delivery assembly may be positioned on each ink feed member. Each ink
`
`delivery assembly may define a mounting formation to permit the printhead chip to be
`
`mounted on the ink delivery system, a plurality of ink inlets that are in fluid communication
`
`with theoutlet openings of the ink feed member, a plurality of exit holes and tortuous ink
`
`flow paths from each ink inlet to a number of respective exit holes. Each printhead chip
`
`may incorporate a plurality of nozzle arrangements that extend along a length of the chip.
`
`The printhead chip may be positioned so that the ink can be fed from the exit holes to the
`
`printhead chip.
`
`Each ink feed member may be in the form of an extrusion of an elastomeric
`
`material. The channels may extend longitudinally in the extrusion and the outlet openings
`
`may be holes defined in a surface of the extrusion to be in fluid communication with
`
`respective ink channels.
`
`Each ink delivery assembly may include a pair of micro-moldings that are
`
`positioned so that a lower micro-molding is interposed between an upper micro-molding
`
`and the ink feed member. The lower micro-molding may define a plurality of ink chambers
`
`ZE068US
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`in fluid communication with respective outlet openings of the ink feed member, via the ink
`
`inlets. The upper micro-molding may define the exit holes in fluid communication with the
`
`ink chambers.
`
`According to a second aspect of the invention, there is provided a printhead module
`for a printhead assembly incorporating a plurality of said modules positioned substantially
`
`across a pagewidth in a drop on demandink jet printer, comprising:
`
`an upper micro-molding locating a print chip having a plurality of ink jet nozzles,
`
`the upper micro—molding having ink channels delivering ink to said print chip,
`
`a lower micro-molding having inlets through which ink is received from a source of
`
`ink, and
`
`a mid-package film adhered between said upper and lower micro-moldings and
`
`having holes through which ink passes from the lower micro-molding to the upper micro-
`
`molding.
`
`Preferably the mid—package film is made of an inert polymer.
`
`Preferably the holes of the mid-package film are laser ablated.
`
`Preferably the mid-package film has an adhesive layer on opposed faces thereof,
`
`’ providing adhesion between the upper micro-molding, the mid-package film and the lower
`
`micro-molding.
`
`Preferably the upper micro-molding has an alignment pin passing through an
`
`aperture in the mid-package film and received within a recess in the lower micro-molding,
`
`the pin serving to align the upper micro-molding, the mid-package film and the lower
`
`micro-molding when they are bonded together.
`
`Preferably the inlets of the lower micro-molding are formed on an underside
`
`thereof.
`
`ZEOSBUS
`
`Preferably six said inlets are provided for individual inks.
`
`Preferably the lower micro-molding also includes an air inlet.
`
`Preferably the air inlet includes a slot extending across the lower micro—molding.
`
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`Preferably the upper micro-molding includes exit holes corresponding to inlets on a
`
`backing layer of the print chip.
`
`Preferably the backing layer is made of silicon.
`
`Preferably the printhead module further comprises an elastomeric pad on an edge of
`
`5
`
`the lower micro-molding.
`
`Preferably the upper and lower micro—moldings are made of Liquid Crystal Polymer
`
`(LCP).
`
`'
`
`Preferably an upper surface of the upper micro-molding has a series of alternating
`
`air inlets and outlets cooperative with a capping device toredirecta flow of air through the
`
`upper micro-molding.
`
`Preferably each printhead module has an elastomeric pad on an edge of its lower
`
`micro-molding, the elastomeric pads bearing against an inner surface of the channel to
`
`positively locatethe printhead modules within the charmel._
`
`As used herein, the term “ink” is intended to mean any_fl_uid which flows through
`
`the printhead to be delivered to print media. The fluid may be one of many different colored
`
`inks, infra-red ink, a fixative or the like.
`
`BRIEF DESCRIPTION OFTHE DRAWINGS
`A preferred fonnof the present invention will now be described by way of example with
`_ reference to the accompanying drawings wherein:
`I
`Fig. 1 is a schematic overall view of a printhead;
`
`Fig. 2 is a schematic exploded view of the printhead of Fig. 1;
`Fig. 3 is a schematic exploded view of an ink jet module;
`
`Fig. 3a is a schematic exploded inverted illustration of the ink jet module of Fig. 3;
`
`Fig. 4 is a schematic illustration of an assembled ink jet module;
`
`_Fig. 5 is a schematic inverted illustration ‘of the module of Fig. 4;
`Fig. 6 is a schematic close-up illustration of the ‘module of Fig. 4;
`Fig. 7 is a schematic illustration of a chip sub—assembly;
`
`T
`
`Fig. 8a is a schematic side elevational view of the printhead of Fig. 1;
`
`Fig. 8b is a schematic plan view of the printhead of Fig. 8a;
`
`ZEOGBUS
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`Fig. 8c is a schematic side view (other side) of the printhead of Fig. 821;
`
`Fig. 8d is a schematic inverted plan view of the printhead of Fig. 8b;
`
`Fig. 9 is a schematic cross—sectional end elevational view of the printhead of Fig. 1;
`
`Fig. 10 is a schematic illustration of the printhead of Fig. 1 in an uncapped
`
`- configuration;
`
`Fig. -11 is a schematic illustration of the printhead of Fig. 10 in a capped
`
`‘
`configuration;
`F 12a is a schematic illustration of a capping device;
`Fig. 12b is a schematic illustration of the capping device of Fig. 12a, viewed from a
`
`different angle;
`
`Fig. 13 is a schematic illustration-showing the loading of an ink jet module into a h
`_ printhead;
`-
`I
`
`Fig.- 14 is a schematicend elevational view of the printhead illustrating the
`
`printhead module loading method;
`
`Fig. 15 is a schematic cut-away illustration. of the printhead assembly of Fig. 1;
`Fig. 16 is a schematic close-up illustration of a portion of the printhead of Fig. 15
`
`showing greater detail in the area of the “Memjet” chip;
`
`Fig. 17 is a schematic illustration of the end portion of a metal channel and a
`
`printhead location molding;
`
`Fig. 18a is a schematic illustration of’an end portion of an elastomeric ink delivery
`
`_
`extrusion and a molded end cap; and
`Fig. 18b is a schematic illustration of the end ‘cap of Fig. 18a in an out-folded
`configuration.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`In Fig. l of the accompanying drawings there is schematically depicted an overall
`
`view of a printhead assembly. Fig. 2 shows the core components of the assembly in an
`
`exploded configuration. The printhead assembly 10 of the preferred embodiment comprises
`
`eleven printhead modules 11 situated along a metal “Invar” channel 16. At the heart of each
`
`printhead module 11 is a “Memjet” chip 23 (Fig. 3). The particular chip chosen in the
`
`preferred embodiment being a six-color configuration.
`
`The “Memj et” printhead modules 11 are comprised of the “Memjet” chip 23, a fine
`
`pitch flex PCB 26 and two micro-moldings 28 and 34 sandwiching a mid—package film 35.
`
`Each module 1 1 forms a sealed unit with independent ink chambers 63 (Fig. 9) which feed
`
`ZE068US
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`

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`the chip 23. The modules 11 plug directly onto a flexible elastomeric extrusion 15 which
`
`Ca.rries air, ink and fixitive (see channels 49-55 in Fig. 15). The upper surface of the
`
`extrusion 15 has repeated patterns of holes 21 which align with ink inlets 32 (Fig. 3a) on
`
`' the underside of each module 11. The extrusion 15 is bonded onto a flex PCB (flexible
`
`printed circuit board).
`
`The fine pitch flex PCB 26 wraps down the side of each printhead module 11 and
`
`makes contact with the flex PCB 17 (Fig. 9). The flex PCB 17 carries two busbars 19
`
`(positive) and 20 (negative) for powering each module 1 1, as well as all data connections‘.
`_ The flex PCB 17 is bonded onto the continuous metal “Invar” charmel 16. The metal
`
`7
`
`channel 16 serves to hold the modules 11 in place and is designed to have a similar
`
`coefficient of thermal expansion to that of silicon used in the modules.
`A capping device 12 is used to cover the “Memjet” chips 23 when not in use. The
`
`capping device is typically made of spring steel with an onsert molded elastomeric pad 47
`
`(Fig. 12a). The pad 47 serves to duct air into the “Memj et” chip 23 when uncapped and cut
`off air and cover a nozzle guard 24 (Fig. 9) when capped. The capping device 12 is actuated
`
`by a camshaft 13 that typically rotates throughout 180°.
`The overall thickness of the “Memj et” chip is typically 0.6 mm which includes a
`
`150-micron inlet backing layer 27 and a nozzle guard 24 of 150-micron thickness. These
`
`elements are assembled at the wafer scale.
`
`The nozzle guard 24 allows filtered air into an 80—micron cavity 64 (Fig. 16) above
`
`the “Memjet” ink nozzles 62. The pressurized air flows through microdroplet holes 45 in
`
`the nozzle guard 24 (with the ink during a printing operation) and serves to protect the
`
`delicate “Memj et” nozzles 62 by repelling foreign particles.
`
`A silicon chip backing layer 27 ducts ink from the printhead module packaging
`
`directly into the rows of “.Memj et” nozzles 62. The “Memjet” chip 23 is wire bonded 25
`
`from bond pads on the chip at 1 16 positions to the fine pitch flex PCB 26. The wire bonds
`
`are on a 120-micron pitch and are cut as they are bonded onto the fine pitch flex PCB pads
`
`(Fig. 3). The fine pitch flex PCB 26 carries data and power from the flex PCB 17 via a
`
`series of gold contact pads 69 along the edge of the flex PCB.
`
`The wire bonding operation between chip and fine pitch flex PCB 26 may be done
`
`remotely, before transporting, placing and adhering the chip assembly into the printhead
`
`module assembly. Alternatively, the “Memjet” chips 23 can be adhered into the upper
`
`micro-molding 28 first and then the fine pitch flex PCB 26 can be adhered into place. The
`
`ZEOGBUS
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`wire bonding operation could then take place in situ, with no danger of distorting the
`
`moldings 28 and 34. The upper micro-molding 28 can be made of a Liquid Crystal Polymer
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`(LCP) blend. Since the crystal structure of the upper micro-molding 28 is minute, the heat
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`distortion temperature (180°C —260°C), the continuous usage temperature (200°C—240°C)i
`and soldering heat durability (260°C for 10 seconds to 310°C for 10 seconds) are "high,
`T
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`g
`regardless of the relatively low melting point. .
`1 Each printhead module 1 1 includes an upper micro-molding 28 and a lower micro-
`molding 34 separated by a mid-package film layer 35 shown in Fig. 3.
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`The mid-package film layer 35 can be an inert polymer such as polyimide, which
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`has good chemical resistance and dimensional stability. The mid-package film layer 35 can
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`have laser ablated holes 65 and can comprise a double-sided adhesive (ie. an adhesive layer
`on both faces) providing adhesion between the upper micro-molding, the mid-package film ‘
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`layer and the lower micro-molding.
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`The upper micro-molding 28 has a pair of alignment pins 29 passing through
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`corresponding apertures in the midipackage film layer 35 to be received within
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`corresponding recesses 66 in-the lower micro-molding 34. This serves to align the
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`components when they are bonded together. Once bonded together, the upper and lower
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`_ micro-moldings form a tortuous ink and air path in the complete “Memjet” printhead
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`module 11. In addition, an upper surface of the upper micro-molding 28 has a pair of
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`opposed recesses 39 which serve as robot pick-up points for picking and placing the micro-
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`molding.
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`There are armular ink inlets 32 -in the underside of the lower micro-molding 34. In a
`preferred‘ embodiment, there are six such inlets 32 for various inks (black, yellow) magenta,
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`cyan, fixitive and infrared). There is also provided an air inlet slot 67. The air inlet slot 67
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`extends across the lower micro-molding 34 to a secondary inlet which expels air through an
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`exhaust hole 33, through an aligned hole 68 in fine pitch flex PCB 26. This serves to repel
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`the print media from the printhead during printing. The ink inlets 32 continue in the
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`undersurface of the upper micro-molding 28 as does a path from the air inlet slot 67. The
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`ink inlets lead to 200 micron exit holes also indicated at 32 in Fig. 3. These holes
`correspond to the inlets on the silicon backing layer 27 of the “Memjet” chip 23.
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`There is a pair of elastomeric pads 36 on an edge of the lower micro-molding 34.
`These serve to take up tolerance and positively located the ‘printhead modules 11 into the
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`metal channel 16 when the modules are micro-placed during assembly.
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`A preferred material for the “Memjet” micro-moldings is a LCP. This has suitable
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`flow characteristics for the fine detail in the moldings and has a relatively low coefficient of
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`thermal expansion.
`Robot picker details are included in the upper microemolding 28 to enable accurate
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`placement of the printhead modules 11 duringassembly.
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`The upper surfaceuof the upper micro—molding 28 as shown in Fig.3 has a series of
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`alternating air inlets and outlets 31. These act in conjunction with the capping device 12
`and are either sealed off or grouped into air inlet/outlet chambers, depending upon the
`position of the capping device 1-2. They connect air diverted from the inlet slot 67 to the
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`chip 23 depending upon whether the unit is capped or uncapped.
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`' A capper cam detail 40 including a ramp for the capping device is shown at two
`locations in the upper surface of the upper micro—molding 28. This facilitates a desirable
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`movement of the capping device 12 to cap or uncap the chip and.the air chambers. That is, _
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`__
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`.1
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`as the capping device is caused to move laterally across the print chip during a capping or
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`uncapping operation, the ramp of the capper cam detail 40 serves to elastically distort and
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`capping device as it is moved by operation of the camshaft 13 so as to prevent scraping of
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`, the device against the nozzle guard 24.
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`The “Memjet” chip assembly 23 is picked and bonded into the uppermicro-molding
`28 on the printhead module 1 1. The fine pitch flex PCB 26 is bonded ‘and wrapped around
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`the side of the assembled printhead module 11 as shown in Fig. 4. After this initial bonding
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`operation, the chip 23 has more sealant or adhesive 46 applied to its long edges. This serves
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`to “pot” the bond wires 25 (Fig.6), seal the “Memjet” chip 23 to the molding 28 and form a
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`sealed gallery into which filtered air can flow and exhaust through the nozzle guard 24.
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`The flex PCB 17 carries all data and power connections from the main PCB (not
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`shown) to each “Memj et” printhead module 11. The flex PCB 17 has a series of gold
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`plated, domed contacts 69 (Fig. 2) which interface with contact pads 41, 42 and 43 that are
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`located, together with section 44, on the fine pitch flex PCB 26 of each “Memj et”
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`printhead module 1 1.
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`Two copper busbar strips 19 and 20, typically of 200 micron thickness, are jigged
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`and soldered into place on the flex PCB 17. The busbars 19 and 20 connect to a flex
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`termination which also carries data
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`The flex PCB 17 is approximately 340 mm in length and is formed from a 14 mm
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`wide strip. It is bonded into the metal channel 16 during assembly and‘ exits from one end
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`of the printhead assembly only.
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`The metal U-channel 16 into which the main components are place is of a special
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`alloy called “Invar 36”. It is a 36% nickel iron alloy possessing a coefficient of thermal
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`expansion of 1/ 1 0"‘ that ofcarbon steel at temperatures up to 400°F: The Invar is annealed
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`for optimal dimensional stability.
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`Additionally, the Invar is nickel plated to a 0.056% thickness of the wall section.
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`This helps to further match it to the coefficient of thermal expansion of silicon which is 2 x
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`10'6 perv°C.
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`V The Invar channel 16 fimctions to capture the “Memjet” printhead modules 11 in a
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`precise alignment relative to each other and to impart enough force on the modules 11 so as
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`p to form a seal between the ink inlets 32 on each printhead module and the outlet holes 21
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`that are laser ablated into the elastomeric ink delivery extrusion 15.
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`The similar coefficient of thermal expansion of the Invar charmel to the silicon chips
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`allows similar relative movement during temperature changes. The elastomeric pads 36 on
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`one side of each printhead module 11 serve to “lubricate” them within the channel 16 to
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`take up any further lateral coefficient of thermal expansion tolerances without losing
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`alignment. The Invar charmel is a cold rolled, armealed and nickel plated strip. Apart from
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`two bends that are required in its formation, the channel has two square cut-outs 80 at each
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`end. These mate with snap fittings 81 on the printhead location moldings 14 (Fig. 17).
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`The elastomeric ink delivery extrusion, 15 is a non-hydrophobic, precision
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`component. Its function is to transport ink and air to the “Memjet” printhead modules 1 1.
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`The extrusion is bonded onto the top of the flex PCB 17 during assembly and it has two
`types of molded end caps. One of these end caps is shown at 70 in Fig. 18a.
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`TA series of patterned holes 21 are present on the upper surface of the extrusion 15.
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`These are laser ablated into the upper surface. To this end, a mask is made and placed on
`the surface of the extrusion, which then has focused laser light applied to it. The holes 21
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`are evaporated from the upper surface, but the laser does not cut into the lower surface of
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`extrusion 15 due to the focal length of the laser light.
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`Eleven repeated patterns of the laser ablated holes 21 form the ink and air outlets 21
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`of the extrusion 15. These interface with the annular ring inlets 32 on the underside of the
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`“Memjet” printhead module lower micro-molding 34. A different pattern of larger holes
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`(not shown but concealed beneath the upper plate 71 of end cap 70 in Fig. 18a) is ablated
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`into one end of the extrusion 15. These mate with apertures 75 having annular ribs formed
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`in the same way as those on the underside of each lower micro-molding 34 described
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`earlier. Ink and air delivery hoses 78 are connected to respective connectors 76 that extend
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`from the upper plate 71. Due to the inherent flexibility of the extrusion 15, it can contort
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`into many ink connection mounting configurations without restricting ink and air flow. The
`molded end cap 70 has a spine 73 from which the upper and lower ‘plates are integrally
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`hinged. The spine 73 includes a row of plugs 74 that are received within the ends of the
`respective flow passages of the extrusion 15.
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`The other end of the extrusion 15 is capped with simple plugs 18 which block the
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`channels in a similar way as the plugs 74 on spine 17.
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`The end cap 70 clamps onto the ink extrusion 15 by way of snap engagement tabs
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`77. Once assembled with the delivery hoses 78, ink and air can be received from ink
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`reservoirs and an air pump, possibly with filtration means. The end cap 70 can be connected
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`to either end of the extrusion, ie. at either end of the printhead.
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`The plugs 74 are pushed into the channels of the extrusion 15 and the plates 71 and
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`72 are foldedover. The snap engagement tabs 77 clamp the molding and prevent it from
`slipping offthe extrusion. As the plates are snapped together, they form a sealed collar
`arrangement around the end of the extrusion. Instead of providing individual hoses 78
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`pushed onto the connectors 76, the molding 70 might interface directly with an ink
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`cartridge. A sealing pin arrangement can also be applied to this molding 70. For example, a
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`perforated, hollow metal pin with a