METHOD OF FABRICATING A LAYERED CERAMIC SUBSTRATE
A method of fabricating a mounting substrate for an inkjet printhead, the method includes providing a plurality of layers of unfired ceramic, wherein a first layer and a second layer of the plurality of layers are each patterned to have unfired ceramic in one region and no unfired ceramic in a second region; stacking the plurality of layers in a predetermined order; and firing the stack of layers to make a co-fired ceramic substrate including a first ink channel corresponding to the first layer and a second ink channel corresponding to the second layer.
Reference is made to commonly assigned and concurrently filed U.S. patent application Ser. No. ______ (Docket #K000434) filed herewith by Dwight Petruchik et al., entitled “Inkjet Printhead with Layered Ceramic Mounting Substrate”, the disclosure of which is herein incorporated by reference.
FIELD OF THE INVENTIONThe present invention relates generally to a fluid ejection assembly, such as an inkjet printhead, that includes a mounting substrate for a fluid ejection device, and more particularly to a mounting substrate having closely spaced fluid passageways.
BACKGROUND OF THE INVENTIONInkjet printing has become a pervasive printing technology. Inkjet printing systems include one or more arrays of drop ejectors provided on an inkjet printing device, in which each drop ejector is actuated at times and locations where it is required to deposit a dot of ink on the recording medium to print the image. A drop ejector includes a pressurization chamber, a drop forming mechanism (e.g. a heater or a piezoelectric structure) and a nozzle. An inkjet printing device is an example of a fluid ejection device. Typically, inkjet printing devices or fluid ejection devices are fabricated as a plurality of die on a wafer. One or more die are then fluidically connected to a mounting substrate as part of the fluid ejection assembly, such as an inkjet printhead.
One way to reduce the cost of an inkjet printhead is to reduce the size of the fluid ejection device, i.e. the printhead die, which typically includes not only the fluid inlets and the arrays of drop ejectors, but also includes logic and switching electronics, as well as electrical interconnections. Due to advances in microelectronic fabrication processes, making the electronics on the die fit within a smaller space is now possible, so that the fluid inlets on the printhead die can be spaced as close together as 0.8 mm center-to-center or closer. The problem that remains is providing a mounting substrate having a die-attach portion with multiple fluid feed slots at the same spacing as the fluid inlet spacing on the printhead die.
Commonly assigned US Published Application No. 2008/0149024 (incorporated herein by reference) discloses a printhead substrate arrangement in which the portion of the substrate that includes the fluid feed slots or channels is made from a ceramic material, while the remaining portion of the substrate arrangement is made by insert molding, i.e. by molding plastic material around the ceramic portion. This arrangement provides for a ceramic mounting surface that is flat and stable and that has a coefficient of thermal expansion that is similar to that of the printhead die in order to facilitate low stress in the printhead die in the assembled printhead. However, the minimum slot to slot pitches typically achieved in a ceramic part made by a low cost powder compaction or dry press process, as might typically have been used to form the ceramic portion of the substrate in US Published Application No. 2008/0149024, are about 1.5 mm (0.7 mm wide slots with 0.8 mm thick walls).
What is needed is a mounting substrate where the widths of the fluid feed slots and the lands between the fluid feed slots are reduced to enable the overall reduction in the size of the corresponding printhead die to be attached. It is further desirable to have a mounting substrate that is low cost.
SUMMARY OF THE INVENTIONA method of fabricating a mounting substrate for an inkjet printhead, the method comprising: providing a plurality of layers of unfired ceramic, wherein a first layer and a second layer of the plurality of layers are each patterned to have unfired ceramic in one region and no unfired ceramic in a second region; stacking the plurality of layers in a predetermined order; and firing the stack of layers to make a co-fired ceramic substrate including a first ink channel corresponding to the first layer and a second ink channel corresponding to the second layer.
The above and other objects, features, and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein:
Referring to
In the example shown in
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
Not shown in
Also shown in
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. The mounting orientation of printhead 250 is rotated relative to the view in
A variety of rollers are used to advance the medium through the printer as shown schematically in the side view of
The motor that powers the paper advance rollers is not shown in
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
Multilayer ceramic substrates have been used before in inkjet printheads. U.S. Pat. No. 6,322,206 discloses a multilayer ceramic substrate including both circuitry and ink passageways for the printhead die that are bonded to its surface. However, in U.S. Pat. No. 6,322,206 the layers include overlapping slots such that when the layers are stacked together, ink channels are defined for carrying ink from one side of the substrate to the other. In other words, unlike the present invention where the planes of the layers are perpendicular to the die-attach surface 239, in U.S. Pat. No. 6,322,206 the planes of the layers are parallel to the die-attach surface. As a result, in U.S. Pat. No. 6,322,206 the printhead die are attached to a single top layer, rather than to a plurality of layers of ceramic.
For embodiments described above, each ink channel is formed in a single layer of the multilayer substrate, so that the spacing and the widths of the openings at die-attach surface 239 are the same as the spacing and widths of the inlet openings at inlet surface 240 of die-attach portion 230.
In some embodiments the solid layers such as third layer 213 and fourth layer 214 surrounding patterned first layer 211, or the third layer 213 and the fifth layer 215 surrounding patterned second layer 212 (
Having described embodiments of the mounting substrate, a context has been provided for describing methods of fabricating the mounting substrate. In a preferred embodiment, a plurality of layers of unfired ceramic are provided. At least a first layer and a second layer of the plurality of layers are each patterned to have unfired ceramic disposed in one region and no unfired ceramic in another region. Patterning of the layers can be done for example by tape casting the layers from ceramic slurry or by laser cutting the unfired ceramic. In some embodiments a punching operation can be used to remove material from layers (such as the first layer and the second layer) that include portions of ink channels in order to provide the ink channels. Laser cutting can be preferable if a layer includes connecting features as described above. The plurality of layers are stacked in a predetermined order, typically with at least one unpatterned layer between the first layer and the second layer. The stack of layers is fired to make a co-fired multilayer substrate including a first ink channel through the substrate corresponding to the first layer and a second ink channel through the substrate corresponding to the second layer. A die-attach surface of the mounting substrate is in a plane that is perpendicular to the planes of the layers. The die-attach surface defines a first ink channel opening corresponding to the first layer and a second ink channel opening corresponding the second layer. Because the thickness of each layer can be on the order of 0.4 mm, the center-to-center spacing of the ink channel openings at the die attach surface can be approximately 0.8 mm as required. In order to facilitate a good fluidic seal and good alignment for the printhead die that will later be attached to the mounting substrate, typically the die-attach surface is then flattened by a grinding operation.
For economical fabrication, many such co-fired multilayered substrates can be made at the same time.
As mentioned above, in order to make mounting substrates in a low cost fashion, typically only the die-attach portion would be fabricated as a multilayer ceramic part. The die-attach portions would then be insert molded together with a plastic housing portion to provide widely spaced alignment features in the mounting substrate.
In order to make a printhead, one or more printhead die, including a first nozzle array and a second nozzle array, is then attached to the die-attach surface of the mounting substrate, so that an ink feed that is configured to feed ink to the first nozzle array is fluidically connected to the first ink channel opening, and a second ink feed that is configured to feed ink to the second nozzle array is fluidically connected to the second ink channel opening. Attaching the printhead die is typically done by applying an adhesive to the die-attach surface of the mounting substrate, aligning the printhead die (for example to the alignment features provided in the plastic housing portion), and curing the adhesive. The cured adhesive provides an ink-tight seal that extends around the first ink channel opening and the second ink channel opening.
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)
- 141 Ink feed
- 142 Ink feed
- 143 Ink feed
- 144 Ink feed
- 181 Droplet(s) (ejected from first nozzle array)
- 182 Droplet(s) (ejected from second nozzle array)
- 200 Carriage
- 211 First layer
- 212 Second layer
- 213 Third layer
- 214 Fourth layer
- 215 Fifth layer
- 216 Sixth layer
- 217 Seventh layer
- 218 Eighth layer
- 219 Ninth layer
- 220 Mounting substrate
- 222 Housing portion
- 224 Alignment feature(s)
- 226 Bolt hole(s)
- 230 Die-attach portion
- 231 Ink channel
- 232 Ink channel
- 233 Ink channel
- 234 Ink channel
- 235 Opening
- 236 Opening
- 237 Opening
- 238 Opening
- 239 Die-attach surface
- 240 Inlet surface
- 241 Inlet opening
- 242 Inlet opening
- 243 Inlet opening
- 244 Inlet opening
- 245 Supplementary layer
- 246 Connecting feature
- 248 Panel
- 250 Printhead
- 251 Printhead die
- 252 Printhead die
- 253 Nozzle array
- 254 Nozzle array direction
- 255 Ink manifold
- 256 Encapsulant
- 257 Flex circuit
- 258 Connector board
- 259 Bonding surface
- 262 Multi-chamber ink supply
- 264 Single-chamber ink 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
Claims
1. A method of fabricating a mounting substrate for an inkjet printhead, the method comprising:
- providing a plurality of layers of unfired ceramic, wherein a first layer and a second layer of the plurality of layers are each patterned to have unfired ceramic in one region and no unfired ceramic in a second region;
- stacking the plurality of layers in a predetermined order; and
- firing the stack of layers to make a co-fired ceramic substrate including a first ink channel corresponding to the first layer and a second ink channel corresponding to the second layer.
2. The method according to claim 1 further comprising grinding a surface of the co-fired ceramic substrate.
3. The method according to claim 2, wherein the surface defines a first ink channel opening corresponding to the first layer, and a second ink channel opening corresponding to the second layer.
4. The method according to claim 1, the plurality of layers being configured as panels including multiple substantially identical parts.
5. The method according to claim 4 further comprising separating the multiple substantially identical parts after firing the stack of layers.
6. The method according to claim 1, wherein providing the plurality of layers further comprises tape casting the layers from ceramic slurry.
7. The method according to claim 1, wherein patterning the first layer and the second layer further comprises laser cutting the first layer and the second layer.
8. The method according to claim 1, wherein patterning the first layer and the second layer further comprises punching the first layer and the second layer.
9. The method according to claim 1 further comprising insert molding the co-fired substrate to provide alignment features for the mounting substrate, the alignment features being formed in plastic.
10. A method of making an inkjet printhead comprising:
- providing a plurality of layers of unfired ceramic, wherein a first layer and a second layer of the plurality of layers are each patterned to have unfired ceramic in one region and no unfired ceramic in a second region;
- stacking the plurality of layers in a predetermined order; and
- firing the stack of layers to make a co-fired ceramic substrate, wherein a surface of the mounting substrate defines a first ink channel opening corresponding to the first layer, and a second ink channel opening corresponding to the second layer;
- providing a printhead die including a first nozzle array that is configured to be fed with ink by a first ink feed, and a second nozzle array that is configured to be fed with ink by a second ink feed; and attaching the printhead die to the surface of the mounting substrate so that the first ink feed is fluidically connected to the first ink channel opening and the second ink feed is fluidically connected to the second ink channel opening.
11. The method according to claim 10 further comprising grinding a surface of the co-fired ceramic substrate before attaching the printhead die.
12. The method according to claim 10, wherein attaching the printhead die further comprises:
- applying an adhesive to the surface of the mounting substrate;
- aligning the printhead die; and
- curing the adhesive.
13. The method according to claim 12, wherein the cured adhesive provides a seal that extends around the first ink channel opening and the second ink channel opening.
14. The method according to claim 10, the plurality of layers being configured as panels including multiple substantially identical parts.
15. The method according to claim 14 further comprising separating the multiple substantially identical parts after firing the stack of layers.
16. The method according to claim 10, wherein providing the plurality of layers further comprises tape casting the layers from ceramic slurry.
17. The method according to claim 10, wherein patterning the first layer and the second layer further comprises laser cutting the first layer and the second layer.
18. The method according to claim 10, wherein patterning the first layer and the second layer further comprises punching the first layer and the second layer.
19. The method according to claim 10 further comprising insert molding the co-fired substrate to provide alignment features for the mounting substrate, the alignment features being formed in plastic.
20. The method according to claim 19, wherein attaching the printhead die further comprises:
- applying an adhesive to the surface of the mounting substrate;
- aligning the printhead die to the alignment features formed in plastic; and
- curing the adhesive.
Type: Application
Filed: Jul 27, 2011
Publication Date: Jan 31, 2013
Inventors: Dwight J. Petruchik (Honeoye Falls, NY), Mario J. Ciminelli (Rochester, NY)
Application Number: 13/191,495
International Classification: B21D 53/76 (20060101);