Patent Publication Number: US-11639055-B2

Title: Fluid ejection devices including contact pads

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. National Stage application Ser. No. 16/768,041, filed May 28, 2020, entitled “FLUID EJECTION DEVICES INCLUDING CONTACT PADS”, which is a U.S. National Stage of PCT Application No. PCT/US2019/016726, filed Feb. 6, 2019, entitled “FLUID EJECTION DEVICES INCLUDING CONTACT PADS”, both of which are incorporated herein. 
    
    
     BACKGROUND 
     An inkjet printing system, as one example of a fluid ejection system, may include a printhead, an ink supply which supplies liquid ink to the printhead, and an electronic controller which controls the printhead. The printhead, as one example of a fluid ejection device, ejects drops of ink through a plurality of nozzles or orifices and toward a print medium, such as a sheet of paper, so as to print onto the print medium. In some examples, the orifices are arranged in at least one column or array such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A and  1 B  illustrate one example of a fluid ejection die. 
         FIG.  2    illustrates one example of a portion of a fluid ejection device. 
         FIG.  3    illustrates another example of a fluid ejection device. 
         FIG.  4    is a block diagram illustrating one example of a fluid ejection system. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise. 
     In certain examples, it may be desirable to reduce the width of a semiconductor die or device including fluid actuation devices (e.g., a fluid ejection die) to reduce costs and improve manufacturability. In other examples, the design of the die may also be configured to operate with reduced logic power delivery. In one example, a device is provided with a contact pad arrangement that enables such relatively thin die and/or reduced logic power delivery. That said, the devices and contact pad arrangements discussed in this disclosure may be associated with other effects, which may or may not be addressed in this disclosure. 
     Accordingly, described herein is a device to enable fluid ejection, including contact pads arranged longitudinally with respect to the device. A first column of six contact pads may be arranged at one end of the device and a second column of six contact pads may be arranged at the other end of the device and aligned with the first column of contact pads. A column of fluid actuation devices may be arranged between the first column of contact pads and the second column of contact pads. 
       FIG.  1 A  illustrates one example of a fluid ejection die  100  and  FIG.  1 B  illustrates an enlarged view of the ends of fluid ejection die  100 . Die  100  includes a first column  102  of contact pads, a second column  104  of contact pads, and a column  106  of fluid actuation devices  108 . The second column  104  of contact pads is aligned with the first column  102  of contact pads and at a distance (i.e., along the Y axis) from the first column  102  of contact pads. The column  106  of fluid actuation devices  108  is disposed longitudinally to the first column  102  of contact pads and the second column  104  of contact pads. The column  106  of fluid actuation devices  108  is also arranged between the first column  102  of contact pads and the second column  104  of contact pads. In one example, fluid actuation devices  108  are nozzles or fluidic pumps to eject fluid drops. 
     In one example, the first column  102  of contact pads includes six contact pads. The first column  102  of contact pads may include the following contact pads in order: a data contact pad  110 , a clock contact pad  112 , a logic power ground return contact pad  114 , a multipurpose input/output contact pad  116 , a first high voltage power supply contact pad  118 , and a first high voltage power ground return contact pad  120 . Therefore, the first column  102  of contact pads includes the data contact pad  110  at the top of the first column  102 , the first high voltage power ground return contact pad  120  at the bottom of the first column  102 , and the first high voltage power supply contact pad  118  directly above the first high voltage power ground return contact pad  120 . While contact pads  110 ,  112 ,  114 ,  116 ,  118 , and  120  are illustrated in a particular order, in other examples the contact pads may be arranged in a different order. 
     In one example, the second column  104  of contact pads includes six contact pads. The second column  104  of contact pads may include the following contact pads in order: a second high voltage power ground return contact pad  122 , a second high voltage power supply contact pad  124 , a logic reset contact pad  126 , a logic power supply contact pad  128 , a mode contact pad  130 , and a fire contact pad  132 . Therefore, the second column  104  of contact pads includes the second high voltage power ground return contact pad  122  at the top of the second column  104 , the second high voltage power supply contact pad  124  directly below the second high voltage power ground return contact pad  122 , and the fire contact pad  132  at the bottom of the second column  104 . While contact pads  122 ,  124 ,  126 , 128 ,  130 , and  132  are illustrated in a particular order, in other examples the contact pads may be arranged in a different order. 
     Data contact pad  110  may be used to input serial data to die  100  for selecting fluid actuation devices, memory bits, thermal sensors, configuration modes, etc. Data contact pad  110  may also be used to output serial data from die  100  for reading memory bits, configuration modes, etc. Clock contact pad  112  may be used to input a clock signal to die  100  to shift serial data on data contact pad  110  into the die or to shift serial data out of the die to data contact pad  110 . Logic power ground return contact pad  114  provides a ground return path for logic power (e.g., about 0 V) supplied to die  100 . In one example, logic power ground return contact pad  114  is electrically coupled to the semiconductor (e.g., silicon) substrate  140  of die  100 . Multipurpose input/output contact pad  116  may be used for analog sensing and/or digital test modes of die  100 . 
     First high voltage power supply contact pad  118  and second high voltage power supply contact pad  124  may be used to supply high voltage (e.g., about 32 V) to die  100 . First high voltage power ground return contact pad  120  and second high voltage power ground return contact pad  122  may be used to provide a power ground return (e.g., about 0 V) for the high voltage power supply. The high voltage power ground return contact pads  120  and  122  are not directly electrically connected to the semiconductor substrate  140  of die  100 . The specific contact pad order with the high voltage power supply contact pads  118  and  124  and the high voltage power ground return contact pads  120  and  122  as the innermost contact pads may improve power delivery to die  100 . Having the high voltage power ground return contact pads  120  and  122  at the bottom of the first column  102  and at the top of the second column  104 , respectively, may improve reliability for manufacturing and may improve ink shorts protection. 
     Logic reset contact pad  126  may be used as a logic reset input to control the operating state of die  100 . Logic power supply contact pad  128  may be used to supply logic power (e.g., between about 1.8 V and 15 V, such as 5.6 V) to die  100 . Mode contact pad  130  may be used as a logic input to control access to enable/disable configuration modes (i.e., functional modes) of die  100 . Fire contact pad  132  may be used as a logic input to latch loaded data from data contact pad  110  and to enable fluid actuation devices or memory elements of die  100 . 
     Die  100  includes an elongate substrate  140  having a length  142  (along the Y axis), a thickness  144  (along the Z axis), and a width  146  (along the X axis). In one example, the length  142  is at least twenty times the width  146 . The width  146  may be 1 mm or less and the thickness  144  may be less than 500 microns. The fluid actuation devices  108  (e.g., fluid actuation logic) and contact pads  110 - 132  are provided on the elongate substrate  140  and are arranged along the length  142  of the elongate substrate. Fluid actuation devices  108  have a swath length  152  less than the length  142  of the elongate substrate  140 . In one example, the swath length  152  is at least 1.2 cm. The contact pads  110 - 132  may be electrically coupled to the fluid actuation logic. The first column  102  of contact pads may be arranged near a first longitudinal end  148  of the elongate substrate  140 . The second column  104  of contact pads may be arranged near a second longitudinal end  150  of the elongate substrate  140  opposite to the first longitudinal end  148 . 
       FIG.  2    illustrates one example of a portion of a fluid ejection device  200 . In one example, fluid ejection device  200  is a printhead assembly for ejecting fluid of a single color (e.g., black). Fluid ejection device  200  includes a carrier  202  and a fluid ejection die  100 . As previously described and illustrated with reference to  FIGS.  1 A and  1 B , fluid ejection die  100  includes a plurality of first contact pads arranged in a first column  102  and a plurality of second contact pads arranged in a second column  104  aligned with the first column  102 . Fluid ejection die  100  may be embedded in or adhered to carrier  202 . Carrier  202  may be a rigid carrier including an epoxy or another suitable material. 
     Carrier  202  may include a first conductive line  204  electrically coupling a first contact pad (e.g., first high voltage power supply contact pad  118 ) to a second contact pad (e.g., second high voltage power supply contact pad  124 ). Carrier  202  may also include a second conductive line  206  electrically coupling a first contact pad (e.g., first high voltage power ground return contact pad  120 ) to a second contact pad (e.g., second high voltage power ground return contact pad  122 ). 
     The first conductive line  204  may be electrically coupled to a first electrical interconnect pad  208 , and the second conductive line  206  may be electrically coupled to a second electrical interconnect pad  210 . Electrical interconnect pads  208  and  210  may be used to electrically couple fluid ejection device  200  to a fluid ejection system, such as a printer. The electrical interconnect pads  208  and  210  may be used to supply high voltage power from a fluid ejection system to fluid ejection die  100 . Additional conductive lines and additional electrical interconnect pads (not shown) may be electrically coupled to the other contact pads of first column  102  and second column  104  to provide electrical connections between fluid ejection die  100  and a fluid ejection system. 
       FIG.  3    illustrates another example of a fluid ejection device  300 . In one example, fluid ejection device  300  is a printhead assembly for ejecting fluid of three different colors (e.g., cyan, magenta, and yellow). Fluid ejection device  300  includes a carrier  302  and a plurality of fluid ejection dies  100   a - 100   c . As previously described and illustrated with reference to  FIGS.  1 A and  1 B , each fluid ejection die  100   a - 100   c  includes an elongate substrate  140   a - 140   c , respectively. The plurality of elongate substrates  140   a - 140   c  are arranged parallel to each other on the carrier  302 . Each of the plurality of elongate substrates  140   a - 140   c  may include a single color substrate and each single color substrate may be of a different color. Elongate substrates  140   a - 140   c  may be embedded in or adhered to carrier  302 . Carrier  302  may be a rigid carrier including an epoxy or another suitable material. 
     Carrier  302  includes electrical routing (e.g. conductive lines  304 ,  306 , and  312  described below) to electrical interconnect pads (e.g., electrical interconnect pads  308 ,  310 , and  314  described below) to connect a fluid ejection system circuit (e.g., a printer circuit) to the contact pads of the elongate substrates  140   a - 140   c . In one example, the electrical routing may be arranged between the elongate substrates  140   a - 140   c.    
     Carrier  302  may include a first conductive line  304  electrically coupling a first contact pad of each elongate substrate  140   a - 140   c  (e.g., the first high voltage power supply contact pad  118  of each elongate substrate  140   a - 140   c ) to a second contact pad of each elongate substrate  140   a - 140   c  (e.g., the second high voltage power supply contact pad  124  of each elongate substrate  140   a - 140   c ). Carrier  302  may also include a second conductive line  306  electrically coupling a first contact pad of each elongate substrate  140   a - 140   c  (e.g., first high voltage power ground return contact pad  120  of each elongate substrate  140   a - 140   c ) to a second contact pad of each elongate substrate  140   a - 140   c  (e.g., second high voltage power ground return contact pad  122  of each elongate substrate  140   a - 140   c ). 
     The first conductive line  304  may be electrically coupled to a first electrical interconnect pad  308 , and the second conductive line  306  may be electrically coupled to a second electrical interconnect pad  310 . Electrical interconnect pads  308  and  310  may be used to electrically couple fluid ejection device  300  to a fluid ejection system, such as a printer. The electrical interconnect pads  308  and  310  may be used to supply high voltage power from a fluid ejection system to elongate substrates  140   a - 140   c . Additional conductive lines and additional electrical interconnect pads (e.g. conductive line  312  and electrical interconnect pad  314 ) may be electrically coupled to the other contact pads of elongate substrates  140   a - 140   c  to provide electrical connections between elongate substrates  140   a - 140   c  and a fluid ejection system. The orientation of the contact pads of elongate substrates  140   a - 140   c  enables the multiple dies to be bonded in parallel with fewer flex wires and connections. 
       FIG.  4    is a block diagram illustrating one example of a fluid ejection system  400 . Fluid ejection system  400  includes a fluid ejection assembly, such as printhead assembly  402 , and a fluid supply assembly, such as ink supply assembly  410 . In one example, printhead assembly  402  may include a fluid ejection device  200  of  FIG.  2    or a fluid ejection device  300  of  FIG.  3   . In the illustrated example, fluid ejection system  400  also includes a service station assembly  404 , a carriage assembly  416 , a print media transport assembly  418 , and an electronic controller  420 . While the following description provides examples of systems and assemblies for fluid handling with regard to ink, the disclosed systems and assemblies are also applicable to the handling of fluids other than ink. 
     Printhead assembly  402  includes at least one printhead or fluid ejection die  100  previously described and illustrated with reference to  FIGS.  1 A and  1 B , which ejects drops of ink or fluid through a plurality of orifices or nozzles  108 . In one example, the drops are directed toward a medium, such as print media  424 , so as to print onto print media  424 . In one example, print media  424  includes any type of suitable sheet material, such as paper, card stock, transparencies, Mylar, fabric, and the like. In another example, print media  424  includes media for three-dimensional (3D) printing, such as a powder bed, or media for bioprinting and/or drug discovery testing, such as a reservoir or container. In one example, nozzles  108  are arranged in at least one column or array such that properly sequenced ejection of ink from nozzles  108  causes characters, symbols, and/or other graphics or images to be printed upon print media  424  as printhead assembly  402  and print media  424  are moved relative to each other. 
     Ink supply assembly  410  supplies ink to printhead assembly  402  and includes a reservoir  412  for storing ink. As such, in one example, ink flows from reservoir  412  to printhead assembly  402 . In one example, printhead assembly  402  and ink supply assembly  410  are housed together in an inkjet or fluid-jet print cartridge or pen. In another example, ink supply assembly  410  is separate from printhead assembly  402  and supplies ink to printhead assembly  402  through an interface connection  413 , such as a supply tube and/or valve. 
     Carriage assembly  416  positions printhead assembly  402  relative to print media transport assembly  418 , and print media transport assembly  418  positions print media  424  relative to printhead assembly  402 . Thus, a print zone  426  is defined adjacent to nozzles  108  in an area between printhead assembly  402  and print media  424 . In one example, printhead assembly  402  is a scanning type printhead assembly such that carriage assembly  416  moves printhead assembly  402  relative to print media transport assembly  418 . In another example, printhead assembly  402  is a non-scanning type printhead assembly such that carriage assembly  416  fixes printhead assembly  402  at a prescribed position relative to print media transport assembly  418 . 
     Service station assembly  404  provides for spitting, wiping, capping, and/or priming of printhead assembly  402  to maintain the functionality of printhead assembly  402  and, more specifically, nozzles  108 . For example, service station assembly  404  may include a rubber blade or wiper which is periodically passed over printhead assembly  402  to wipe and clean nozzles  108  of excess ink. In addition, service station assembly  404  may include a cap that covers printhead assembly  402  to protect nozzles  108  from drying out during periods of non-use. In addition, service station assembly  404  may include a spittoon into which printhead assembly  402  ejects ink during spits to ensure that reservoir  412  maintains an appropriate level of pressure and fluidity, and to ensure that nozzles  108  do not clog or weep. Functions of service station assembly  404  may include relative motion between service station assembly  404  and printhead assembly  402 . 
     Electronic controller  420  communicates with printhead assembly  402  through a communication path  403 , service station assembly  404  through a communication path  405 , carriage assembly  416  through a communication path  417 , and print media transport assembly  418  through a communication path  419 . In one example, when printhead assembly  402  is mounted in carriage assembly  416 , electronic controller  420  and printhead assembly  402  may communicate via carriage assembly  416  through a communication path  401 . Electronic controller  420  may also communicate with ink supply assembly  410  such that, in one implementation, a new (or used) ink supply may be detected. 
     Electronic controller  420  receives data  428  from a host system, such as a computer, and may include memory for temporarily storing data  428 . Data  428  may be sent to fluid ejection system  400  along an electronic, infrared, optical or other information transfer path. Data  428  represent, for example, a document and/or file to be printed. As such, data  428  form a print job for fluid ejection system  400  and includes at least one print job command and/or command parameter. 
     In one example, electronic controller  420  provides control of printhead assembly  402  including timing control for ejection of ink drops from nozzles  108 . As such, electronic controller  420  defines a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on print media  424 . Timing control and, therefore, the pattern of ejected ink drops, is determined by the print job commands and/or command parameters. In one example, logic and drive circuitry forming a portion of electronic controller  420  is located on printhead assembly  402 . In another example, logic and drive circuitry forming a portion of electronic controller  420  is located off printhead assembly  402 . 
     Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.