Patent Abstract:
A method for making a printed wiring member including wire-bondable contact pads and wear-resistant connector pads, the method includes a) providing a blank printed wiring member comprising a copper foil laminated to a dielectric substrate; b) masking the blank printed wiring member to protect regions of the copper foil; c) removing copper in unprotected regions of the blank printed wiring member to form a patterned printed wiring member including contact pads and connector pads; d) depositing a nickel coating on the patterned printed wiring member; e) electrolytically depositing a hard gold layer on the nickel coating; and f) depositing palladium on a surface of the hard gold layer to improve bondability of the contact pads while preserving wear resistance of the connector pads.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Reference is made to commonly assigned, copending U.S. patent application Ser. No. 12/627,133, filed Nov. 30, 2009 by Samuel Chen, et al., entitled “Bondable Printed Wiring with Improved Wear Resistance”, and Ser. No. 12/627,161, filed Nov. 30, 2009 by Samuel Chen, et al., entitled “Method of Making Bondable Printed Wiring Member”. 
     FIELD OF THE INVENTION 
     The present invention relates generally to a method of making a printed wiring member having wire-bondable contact pads and wear resistant connector pads. 
     BACKGROUND OF THE INVENTION 
     Printed wiring members are commonly used as ways to electrically interconnect electronic components in low cost fashion. Some types of printed wiring members are designed for direct interconnection to semiconductor chips by wire bonding or tape automated bonding, for example. Furthermore, some types of printed wiring members are designed to have connector pads that are intended to disconnectably mate multiple times with an electrical connector that connects the printed wiring member with other circuitry in an electronic system. An example of a printed wiring member that both directly interconnects to a semiconductor chip and also has disconnectable connection pads is an inkjet printhead. In this example, the semiconductor chip is the inkjet printhead die, which typically contains the nozzles, the drop forming mechanisms to eject drops from the nozzles, and electronics associated with the drop forming mechanisms. Because printheads typically do not last the entire lifetime of the printer, many types of printheads are designed to be disconnectable from the printer to allow replacement. 
     Although nominally a printhead would only need to be installed and uninstalled once, it is preferable to design the printhead connector pads to withstand more than 10-20 installation cycles in order to improve reliability of the system. One well-known way of making connector pads reliably connectable for many cycles is to provide a top metallization of hard gold on the connector pads. Hard gold is made hard during the plating process by adding cobalt and/or nickel at levels of approximately 0.1% to 0.3%, although higher levels of impurities can be incorporated. As is well-known in the art, however, hard gold is not readily wire-bondable. In order to provide a printed wiring member with bondable gold at the contact pads and wear resistant gold at the connector pads, one approach would be to do two separate masking and plating steps to provide soft gold (around 99.9% pure) at the contact pads and hard gold at the connector pads, but this is relatively costly. 
     U.S. Pat. No. 5,910,644 discloses metallization electroplated onto the copper contact pads and connector pads of a printed wiring member having both bondability and wear resistance. The disclosed metallization includes 80-200 microinches (2-5 microns) of nickel plated onto the copper, nominally 35 microinches (0.9 micron) of palladium plated onto the nickel, and 5-30 microinches (0.1-0.75 micron) of soft gold plated onto the palladium. The high purity soft gold provides for high yield wire bonding while the palladium ensures adequate wear resistance to provide stable electrical connection in the event that wear through of the soft gold surface finish of the connector pads occurs. A drawback of this process is that relatively thick layers of the costly palladium and high purity gold are required. 
     U.S. patent application Ser. Nos. 12/627,133 and 12/627,161 respectively disclose a printed wiring member and a method for making a printed wiring member that has wire bondable contact pads and wear-resistant connector pads. In particular, it is disclosed that a palladium layer is electrolessly deposited over a layer of high purity soft gold. The palladium is sufficiently bondable for the contact pads, and also provides additional wear resistance for the connector pads. The resulting structure can be connected and disconnected more than 20 times without excessive wear for at least some connector designs. However, if the connector produces an aggressive wiping motion across the connector pads, or if the connector pins are somewhat rough, achieving more than 20 connects and disconnects without excessive wear can be marginal. 
     Consequently, a need exists for a method of making a printed wiring member that provides reliable bondability and improved wear-resistant connector pads for repetitive printhead installations. Although an inkjet printhead is a familiar example of such a need, there are other examples in the chip-on-board industry of the need for a method of making a printed wiring member that provides reliable bondability and wear-resistant connector pads for repetitive component installations. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the invention, the invention resides in a method for making a printed wiring member including wire-bondable contact pads and wear-resistant connector pads, the method includes a) providing a blank printed wiring member comprising a copper foil laminated to a dielectric substrate; b) masking the blank printed wiring member to protect regions of the copper foil; c) removing copper in unprotected regions of the blank printed wiring member to form a patterned printed wiring member including contact pads and connector pads; d) depositing a nickel coating on the patterned printed wiring member; e) electrolytically depositing a hard gold layer on the nickel coating; and f) depositing palladium on a surface of the hard gold layer to improve bondability of the contact pads while preserving wear resistance of the connector pads. 
     These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of an inkjet printer system of the present invention; 
         FIG. 2  is a perspective view of a portion of a printhead of the present invention; 
         FIG. 3  is a perspective view of a portion of a carriage printer of the present invention; 
         FIG. 4  is a perspective view of a carriage of the present invention; 
         FIG. 5  is a schematic side view of an exemplary paper path in a carriage printer of the present invention; 
         FIG. 6  is a schematic top view of a printed wiring member according to an embodiment of the present invention; 
         FIG. 7  is a schematic top view of several printhead die that are wire bonded to the printed wiring member of  FIG. 6  of the present invention; 
         FIG. 8  is a process flow chart for making printed wiring members according to an embodiment of the present invention; and 
         FIG. 9  schematically shows an electrolytic plating process. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a schematic representation of an inkjet printer system  10  is shown, for its usefulness with the present invention and is fully described in U.S. Pat. No. 7,350,902, and is incorporated by reference herein in its entirety. Inkjet printer system  10  includes an image data source  12 , which provides data signals that are interpreted by a controller  14  as being commands to eject drops. Controller  14  includes an image processing unit  15  for rendering images for printing, and outputs signals to an electrical pulse source  16  of electrical energy pulses that are inputted to an inkjet printhead  100 , which includes at least one inkjet printhead die  110 . 
     In the example shown in  FIG. 1 , there are two nozzle arrays. Nozzles  121  in the first nozzle array  120  have a larger opening area than nozzles  131  in the second nozzle array  130 . In this example, each of the two nozzle arrays has two staggered rows of nozzles, each row having a nozzle density of 600 per inch. The effective nozzle density then in each array is 1200 per inch (i.e. d= 1/1200 inch in  FIG. 1 ). If pixels on the recording medium  20  were sequentially numbered along the paper advance direction, the nozzles from one row of an array would print the odd numbered pixels, while the nozzles from the other row of the array would print the even numbered pixels. 
     In fluid communication with each nozzle array is a corresponding ink delivery pathway. Ink delivery pathway  122  is in fluid communication with the first nozzle array  120 , and ink delivery pathway  132  is in fluid communication with the second nozzle array  130 . Portions of ink delivery pathways  122  and  132  are shown in  FIG. 1  as openings through printhead die substrate  111 . One or more inkjet printhead die  110  will be included in inkjet printhead  100 , but for greater clarity only one inkjet printhead die  110  is shown in  FIG. 1 . The printhead die are arranged on a support member as discussed below relative to  FIG. 2 . In  FIG. 1 , first fluid source  18  supplies ink to first nozzle array  120  via ink delivery pathway  122 , and second fluid source  19  supplies ink to second nozzle array  130  via ink delivery pathway  132 . Although distinct fluid sources  18  and  19  are shown, in some applications it may be beneficial to have a single fluid source supplying ink to both the first nozzle array  120  and the second nozzle array  130  via ink delivery pathways  122  and  132  respectively. Also, in some embodiments, fewer than two or more than two nozzle arrays can be included on printhead die  110 . In some embodiments, all nozzles on inkjet printhead die  110  can be the same size, rather than having multiple sized nozzles on inkjet printhead die  110 . 
     The drop forming mechanisms associated with the nozzles are not shown in  FIG. 1 . Drop forming mechanisms can be of a variety of types, some of which include a heating element to vaporize a portion of ink and thereby cause ejection of a droplet, or a piezoelectric transducer to constrict the volume of a fluid chamber and thereby cause ejection, or an actuator which is made to move (for example, by heating a bi-layer element) and thereby cause ejection. In any case, electrical pulses from electrical pulse source  16  are sent to the various drop ejectors according to the desired deposition pattern. In the example of  FIG. 1 , droplets  181  ejected from the first nozzle array  120  are larger than droplets  182  ejected from the second nozzle array  130 , due to the larger nozzle opening area. Typically other aspects of the drop forming mechanisms (not shown) associated respectively with nozzle arrays  120  and  130  are also sized differently in order to optimize the drop ejection process for the different sized drops. During operation, droplets of ink are deposited on a recording medium  20 . 
       FIG. 2  shows a perspective view of a portion of a printhead  250 , which is an example of an inkjet printhead  100 . Printhead  250  includes three printhead die  251  (similar to printhead die  110  in  FIG. 1 ), each printhead die  251  containing two nozzle arrays  253  so that printhead  250  contains six nozzle arrays  253  altogether. The six nozzle arrays  253  in this example can each be connected to separate ink sources (not shown in  FIG. 2 ); such as cyan, magenta, yellow, text black, photo black, and a colorless protective printing fluid. Each of the six nozzle arrays  253  is disposed along nozzle array direction  254 , and the length of each nozzle array along the nozzle array direction  254  is typically on the order of 1 inch or less. Typical lengths of recording media are 6 inches for photographic prints (4 inches by 6 inches) or 11 inches for paper (8.5 by 11 inches). Thus, in order to print a full image, a number of swaths are successively printed while moving printhead  250  across the recording medium  20 . Following the printing of a swath, the recording medium  20  is advanced along a media advance direction that is substantially parallel to nozzle array direction  254 . 
     Referring to  FIGS. 2 and 7 , there is shown a printed wiring member  220 , flexible in this embodiment, to which the printhead die  251  are electrically interconnected as described in detail below. It is noted for clarity that the printed wiring member  220  may be flexible or rigid as discussed in detail below. The printed wiring member  220  is affixed to printhead body  257  of printhead  250  and bends around an edge of printhead body  257 . Conductor traces  225  extend from contact pads  224  to connector pads  226 . Encapsulant  256  (typically thermally cured) encapsulates the contact pads and the wire bonds to form a protective covering. When printhead  250  is mounted into the carriage  200  (see  FIGS. 3 and 4 ), the array of connector pads  226  are electrically connected to a corresponding array of pins on electrical connector  244  on the carriage  200  so that electrical signals can be transmitted to the printhead die  251 . 
       FIG. 3  shows a portion of a desktop carriage printer. Some of the parts of the printer have been hidden in the view shown in  FIG. 3  so that other parts can be more clearly seen. Printer chassis  300  has a print region  303  across which carriage  200  is moved back and forth in carriage scan direction  305  along the X axis, between the right side  306  and the left side  307  of printer chassis  300 , while drops are ejected from printhead die  251  (not shown in  FIG. 3 ) on printhead  250  that is mounted on carriage  200 . Carriage motor  380  moves belt  384  to move carriage  200  along carriage guide rail  382 . An encoder sensor (not shown) is mounted on carriage  200  and indicates carriage location relative to an encoder fence  383 . 
     Printhead  250  is mounted in carriage  200 , and multi-chamber ink supply  262  and single-chamber ink supply  264  are mounted in the printhead  250 .  FIG. 4  shows carriage  200  without printhead  250  installed, in order to show connector  244  that connects to connector pads  226  of  FIG. 2 . In  FIG. 3 , the mounting orientation of printhead  250  is rotated relative to the view in  FIG. 2  so that the printhead die  251  are located at the bottom side of printhead  250 , the droplets of ink being ejected downward onto the recording medium in print region  303  in the view of  FIG. 3 . Multi-chamber ink supply  262 , in this example, contains five ink sources: cyan, magenta, yellow, photo black, and colorless protective fluid; while single-chamber ink supply  264  contains the ink source for text black. Paper or other recording medium (sometimes generically referred to as paper or media herein) is loaded along paper load entry direction  302  toward the front of printer chassis  308 . 
     A variety of rollers are used to advance the medium through the printer as shown schematically in the side view of  FIG. 5 . In this example, a pick-up roller  320  moves the top piece or sheet  371  of a stack  370  of paper or other recording medium in the direction of arrow, paper load entry direction  302 . A turn roller  322  acts to move the paper around a C-shaped path (in cooperation with a curved rear wall surface) so that the paper continues to advance along media advance direction  304  from the rear  309  of the printer chassis (with reference also to  FIG. 3 ). The paper is then moved by feed roller  312  and idler roller(s)  323  to advance along the Y axis across print region  303 , and from there to a discharge roller  324  and star wheel(s)  325  so that printed paper exits along media advance direction  304 . Feed roller  312  includes a feed roller shaft along its axis, and feed roller gear  311  is mounted on the feed roller shaft. Feed roller  312  can include a separate roller mounted on the feed roller shaft, or can include a thin high friction coating on the feed roller shaft. A rotary encoder (not shown) can be coaxially mounted on the feed roller shaft in order to monitor the angular rotation of the feed roller. 
     The motor that powers the paper advance rollers is not shown in  FIG. 3 , but the hole  310  at the right side of the printer chassis  306  is where the motor gear (not shown) protrudes through in order to engage feed roller gear  311 , as well as the gear for the discharge roller (not shown). For normal paper pick-up and feeding, it is desired that all rollers rotate in forward rotation direction  313 . Toward the left side of the printer chassis  307 , in the example of  FIG. 3 , is the maintenance station  330 . 
     Toward the rear of the printer chassis  309 , in this example, is located the electronics board  390 , which includes cable connectors  392  for communicating via cables (not shown) to the printhead carriage  200  and from there to the printhead  250 . Also on the electronics board are typically mounted motor controllers for the carriage motor  380  and for the paper advance motor, a processor and/or other control electronics (shown schematically as controller  14  and image processing unit  15  in  FIG. 1 ) for controlling the printing process, and an optional connector for a cable to a host computer. 
       FIG. 6  shows a schematic top view of a printed wiring member  220  according to an embodiment of the present invention. Printed wiring member  220  is formed on a dielectric substrate  222 . For embodiments where printed wiring member  220  bends around a corner as seen in  FIG. 2 , dielectric substrate  222  needs to be flexible. Flexible dielectric substrates include materials such as polyimide or polyether ether ketone (PEEK). In other embodiments where the printed wiring member  220  is planar (i.e., flat or substantially flat), the dielectric substrate  222  can be a rigid material such as woven glass impregnated with epoxy resin. Printed wiring member  220  includes contact pads  224 , connector pads  226 , and conductor traces  225  to provide conductive paths between contact pads  224  and connector pads  226 . For simplicity, not all of the conductor traces  225  between contact pads  224  and connector pads  226  are shown in  FIG. 6 . In this example, printed wiring member  220  also includes an opening  228 . 
     Contact pads  224 , connector pads  226  and conductor traces  225  are generally copper, with other metallizations deposited on the copper as needed. For clarity of the present invention, a brief description of prior art printed wiring members is described in this paragraph. In this regard, typically the contact pads and connector pads have several microns of nickel plated on the copper and a thin layer of gold plated on the nickel. The gold layer, which is typically about 0.5 micron thick for the case of electroplated soft gold or about 0.1 micron thick for electrolessly plated gold, is conventionally used as a bonding metallization surface for the contact pads, and as a corrosion resistant surface for connector pads. Conventionally, gold for contact pads is required to be high purity soft gold for reliable bondability of wire bonds to the contact pads. Conventionally, gold for connector pads is preferably hard gold alloyed with approximately 0.1% to 0.3% cobalt and/or nickel in order to provide wear resistance for connector pads so that repeated connection cycles are reliable. Conductor traces can also be coated with other metals, or they can just be copper. 
     Returning to the description of the present invention,  FIG. 7  shows a schematic top view of printed wiring member  220  in relationship with three printhead die  251  which have been bonded within opening  228  of printed wiring member  220 . Each printhead die  251  includes bond pads  252  at both ends, as well as nozzle arrays  253 . For simplicity, wire bonds  255  are only shown for the upper printhead die  251  in  FIG. 7 . Wire bonds  255  are typically aluminum and are ultrasonically welded at one end to bond pads  252  and at the other end to contact pads  224  on printed wiring member  220 . If the printed wiring member  220  is used in a printhead configuration such as that shown in  FIG. 2 , where the printhead die  251  are on one surface and the connector pads are on another surface, it is required that the dielectric substrate  222  of the printed wiring member  220  be flexible enough to bend in a region  229  including connector traces  225 . In some embodiments, other electrical components can be bonded (for example by solder bonding) to the printed wiring member to form a printed circuit. In such embodiments, the metallization of the solder bond site needs to be conducive to reliable solder bonding. 
       FIG. 8  shows a process flow chart for making printed wiring member  220  in a preferred embodiment. The steps denoted  405 ,  410 ,  415  and  420  are steps typically used in patterning the copper on the printed wiring member. The steps denoted  425 ,  440  and  445  are steps that are commonly used to provide plated nickel and hard gold. The steps denoted  455  and  460  are typical finishing operations in making printed wiring members. It is step  450  (highlighted with bold outline in  FIG. 8 ), i.e., plating of palladium over the hard gold (deposited in the step denoted  445 ) that provides the wire bondability for the contact pads  224  without compromising the wear resistance of the connector pads  226  of the present invention. 
     As is well known in the art, fabrication of a printed wiring member  220  typically begins with a blank printed wiring member that includes a thin copper foil laminated to the dielectric substrate  222 . Generally the blank printed wiring member is significantly larger than a single printed wiring member  220 . Many printed wiring members  220  are typically fabricated in a panel  272  (see  FIG. 9 ) of blank printed wiring material, and then cut apart after fabrication is completed. Regions where copper is desired to remain are masked photolithographically (step denoted  405 ). Copper is removed in the exposed (non-masked) regions, typically by etching (step denoted  410 ) to provide a patterned printed wiring member having contact pads, connector pads and conductive traces formed from the copper foil. The mask is then stripped from the copper that remains (step denoted  415 ). Copper is not suited for direct wire bonding contact pads or for connector pads so conventionally a diffusion barrier layer of nickel and a top layer of gold are plated over the copper. Optionally, a protective organic dielectric layer is applied over the copper conductive traces to mask them (step denoted  420 ) so that the nickel and gold do not plate in these regions, thus saving plated material cost. 
     Plating of the nickel (step  440  of  FIG. 8 ) can be done using an electrolytic process or an electroless process. In an electrolytic process illustrated schematically in  FIG. 9 , panel  272  including a plurality of printed wiring members is immersed in a plating tank  270  containing a solution of electrolyte(s) including nickel ions. A first electrode  274  is attached to a conductor (not shown) on the panel  272 . Conductive lines (not shown) lead from the conductor to each of the printed wiring members on panel  272 . A second electrode  276  is immersed in the electrolyte solution. The negative terminal of power supply  278  is attached to the first electrode and the positive terminal is attached to the second electrode so that a current is passed between the first electrode  274  and the second electrode  276  through the electrolytic solution, thereby depositing nickel on the exposed metal printed wiring members in panel  272 . 
     Hard gold is then electrolytically deposited over the nickel-coated printed wiring member(s) using a plating process similar to that described above relative to  FIG. 9 . The electrolyte solution used for plating of the hard gold typically includes gold cyanide, as well as cobalt and/or nickel ions as hardening additives and can also include copper ions. The electrolytic plating of hard gold in some embodiments results in a hard gold layer including copper or nickel or copper plus nickel at or near the surface of the hard gold layer at a total concentration that is between 0.5% and 10% of the concentration of gold in the hard gold layer, as measured for example by X-ray photoelectron spectroscopy. An appropriate thickness of the hard gold layer is between 0.2 micron and 1.0 micron. 
     A differentiating step of the present invention that provides wire bondability to the contact pads  224  without compromising the wear resistance of the hard gold on the connector pads  226  is the step denoted  450  in which palladium is deposited by plating on the exposed hard gold layer. Electrolytic plating of palladium can be done over the exposed hard gold layer as described above with reference to  FIG. 9  and using an electrolyte solution including palladium ions. Alternatively, electroless plating of palladium on the exposed hard gold can be done in a solution containing palladium ions using an aqueous palladium sulfate solution (PdSO 4 ) with 1% sulfuric acid, for example, as was done in the previously performed surface activation step denoted  435 . It has been observed that palladium is not readily electrolessly plated on high purity gold that has been electroplated to a thickness of about 0.5 micron. Without being bound by theory, it is thought that impurities such as nickel, copper or cobalt in the hard gold layer deposited in the step denoted  445  allow ion exchange and chemical reduction of the palladium ions in the palladium sulfate solution. The palladium can be deposited in a noncontinuous layer on the gold, particularly for short plating times and/or low concentrations of palladium in the solution. At longer plating times, the noncontinuous regions tend to merge to provide a continuous layer on the gold. A time duration of the electroless plating of palladium over the gold between about 5 seconds and about 10 minutes, more preferably between 20 seconds and 300 seconds has been shown to provide improved wire bondability of the contact pads  224  (relative to hard gold) if the electroless plating of palladium is done at room temperature. It is not required that electroless plating of palladium occur at room temperature, but it simplifies the process in some embodiments. The preferred duration of the palladium electroless plating step also depends partly on the concentration of palladium in solution. The nominal time durations cited above are for a palladium concentration of about 100 ppm. For higher concentration of palladium, shorter plating times can be used for equivalent amount of palladium deposited. Thickness of the palladium on the gold is typically between 0.02 micron and 0.2 micron 
     After the plating of the palladium on the hard gold, the panel  272  of printed wiring members is rinsed and dried (step denoted  455 ) and separated into a plurality of printed wiring members  220 , for example by cutting, in the step denoted  460 . Optionally the printed wiring member  220  is also plasma cleaned. 
     In an inkjet printer, such as the one shown in  FIG. 3 , where a printhead  250  is replaceably installed in a carriage  200  (see also  FIG. 4 ), electrical connector  244  has an array of spring-loaded pins  243  for making electrical connection with connector pads  226  of printed wiring member  220  ( FIG. 6 ). The connector pads  226  are disposed on a substantially flat surface of the printhead body  257 , but in some embodiments, the printed wiring member  220  is mounted in a non-rigid fashion on printhead body  257 , such that the connector pad region of printed wiring member  220  can move somewhat. When printhead  250  (similar to that shown in  FIG. 2 ) is installed in carriage  200 , pins  243  move inward somewhat into electrical connector  244 . In other words, they move substantially perpendicular to the plane of the plurality of connector pads  226 . During installation, printhead  250  is first moved in printhead installation direction  245  ( FIG. 4 ), and then the inside of printhead  250  (an inner face corresponding to outside face  248 ) is rocked toward carriage  200  until lip  247  of printhead  250  is latched by latch  249  of carriage  200 . During the rocking motion, the connector pads  226  are wiped by corresponding pins  243 . Such a wiping motion is preferred for establishing a reliable connection. However, if the wiping motion is too aggressive or the metallization of connector pads  226  is too soft, repeated wipings occurring during repetitive installations can wipe away sufficient metallization on the connector pads  226  that future electrical connection during printhead installation can become unreliable. The present invention of depositing palladium on top of the hard gold provides a more wire bondable coating of the contact pads  224 . Because the connector pads  226  include a hard gold layer below the palladium, even if the connector pads  226  are aggressively wiped during repeated installations, they are able to withstand more than 100 cycles of the printhead  250  into carriage  200  without causing excessive wear on the connector pads  226 . 
     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. 
     PARTS LIST 
     
         
           10  Inkjet printer system 
           12  Image data source 
           14  Controller 
           15  Image processing unit 
           16  Electrical pulse source 
           18  First fluid source 
           19  Second fluid source 
           20  Recording medium 
           100  Inkjet printhead 
           110  Inkjet printhead die 
           111  Substrate 
           120  First nozzle array 
           121  Nozzle(s) 
           122  Ink delivery pathway (for first nozzle array) 
           130  Second nozzle array 
           131  Nozzle(s) 
           132  Ink delivery pathway (for second nozzle array) 
           181  Droplet(s) (ejected from first nozzle array) 
           182  Droplet(s) (ejected from second nozzle array) 
           200  Carriage 
           220  Printed wiring member 
           222  Dielectric substrate 
           224  Contact pads 
           225  Conductor traces 
           226  Connector pads 
           228  Opening 
           229  Bend region 
           243  Pin 
           244  Electrical connector 
           245  Printhead installation direction 
           247  Lip 
           248  Outside face 
           249  Latch 
           250  Printhead 
           251  Printhead die 
           252  Bond Pads 
           253  Nozzle array 
           254  Nozzle array direction 
           255  Wire bond 
           256  Encapsulant 
           257  Printhead Body 
           262  Multi-chamber ink supply 
           264  Single-chamber ink supply 
           270  Plating tank 
           272  Panel 
           274  First electrode 
           276  Second electrode 
           278  Power supply 
           300  Printer chassis 
           302  Paper load entry direction 
           303  Print region 
           304  Media advance direction 
           305  Carriage scan direction 
           306  Right side of printer chassis 
           307  Left side of printer chassis 
           308  Front of printer chassis 
           309  Rear of printer chassis 
           310  Hole (for paper advance motor drive gear) 
           311  Feed roller gear 
           312  Feed roller 
           313  Forward rotation direction (of feed roller) 
           320  Pick-up roller 
           322  Turn roller 
           323  Idler roller 
           324  Discharge roller 
           325  Star wheel(s) 
           330  Maintenance station 
           370  Stack of media 
           371  Top piece of medium 
           380  Carriage motor 
           382  Carriage guide rail 
           383  Encoder fence 
           384  Belt 
           390  Printer electronics board 
           392  Cable connectors 
           405 - 460  Steps (in fabrication process)

Technology Classification (CPC): 7