Patent Application
20220402645
The disclosure is directed to fluid supply cartridges for fluid ejection devices and in particular to hybrid fluid supply cartridges that provide improved dimensional stability for ejecting a variety of fluids.
A conventional fluid cartridge body is typically constructed of one or more plastic materials to which a semiconductor ejection head chip is directly attached by means of a die bond adhesive. Due to unequal expansion between the plastic cartridge body and the silicon semiconductor ejection head chip, misalignment and ejection head chip cracking may occur during manufacturing and use of the fluid cartridge. Thermal or mechanical stresses on the ejection head chip during die bonding and use may also result in distortion of the ejection head nozzles and bowing of the nozzle plate. While plastic fluid cartridges have been suitable for aqueous fluids as inks, the plastic fluid cartridges are not particularly useful for non-aqueous fluids such as solvents and organic liquids which may cause the plastic fluid cartridge body to swell. When the fluid ejection head is attached directly to the plastic fluid body, swelling of the cartridge body puts stresses on the ejection head causing ejection head cracking and nozzle plate distortion. Accordingly, what is needed is a dimensionally stable surface that has a coefficient of thermal or mechanical expansion similar to that of the semiconductor ejection head chip to which the ejection head chip is attached. What is also needed is an ejection head bonding surface that is chemically stable for use with fluids that cause plastic materials to swell.
In view of the foregoing, the disclosure provides a fluid cartridge that includes a plastic fluid body having a front wall, a rear wall opposite the front wall, left and right side walls attached to the front wall and to the rear wall, a bottom wall attached to the front wall and the rear wall, and to the left and right side walls. A die bond member is attached to the plastic fluid body adjacent to the bottom wall and an ejection head chip is disposed on the die bond member so that the die bond member is between the bottom wall and the ejection head chip.
In another embodiment, there is provided a method for eliminating mechanical stresses on an ejection head chip. The method includes providing a plastic fluid body having a front wall, a rear wall opposite the front wall, left and right side walls attached to the front wall and to the rear wall, a bottom wall attached to the front wall and the rear wall, and to the left and right side walls. A die bond member is attached to the plastic fluid body adjacent to the bottom wall. An ejection head chip is attached to the die bond member so that the die bond member is between the plastic fluid body and the ejection head chip, whereby mechanical stresses from the plastic fluid body are isolated from the ejection head chip.
In some embodiments, the die bond member further includes a filter tower riser, and the plastic fluid body further comprises a seal circumscribing the filter tower riser.
In some embodiments, the die bond member is a metal frame having a front arm adjacent to the front wall, a rear arm adjacent to the rear wall, and a bottom frame member attached to the front arm and to the rear arm, the bottom frame member being adjacent to the bottom wall, wherein the plastic body is press-fit into the metal frame.
In some embodiments, the metal frame includes a filter tower riser, and the plastic fluid body further includes a seal circumscribing the filter tower riser.
In some embodiments, the seal is an o-ring seal disposed in a recess in the plastic fluid body.
In some embodiments, the plastic body contains a retention tab on each of the front wall and the rear wall, and the metal frame has a retention aperture disposed in each of the front arm and rear arm of the metal frame for engaging the front wall retention tab and the rear wall retention tab.
In some embodiments, the die bond member further includes a chip pocket for attaching the ejection head chip therein.
In some embodiments, the die bond member is a metal selected from the group consisting of stainless steel, aluminum, titanium, and alloys of steel and titanium.
In some embodiments, the die bond member is a chemically resistant carbon filled, carbon fiber filled, or glass fiber filled polymeric material selected from polyamides, polybutylene terephthalate, polycarbonate, polyethylene, polyphenyleneoxide, polyphenylenesulfide, and polytetrafluoroethylene.
With reference to
In some embodiments, as shown in
In some embodiments, the die bond member 12 in the shape of a stamped U-shaped frame includes apertures 38a and 38b in the front arm 26 and rear arm 30, respectively, for engaging retention tabs 40a and 40b, respectively, on the plastic cartridge body 10. The retention tabs 40a and 40b and apertures 38a and 38b provide locking engagement between the frame of the die bond member 12 and the cartridge body 10 to prevent disengagement of the cartridge body 10 from the die bond member 12.
When the die bond member 12 includes a stamped metal U-shaped frame, the stamped metal frame may be made of a metal selected from stainless steel, aluminum, titanium, and alloys of steel and titanium. The metal frame may have a thickness ranging from about 1 to about 2 mm and a bend radius of about 1.5 to about 1.65 mm between the front arm 26 and rear arm 30 with the bottom frame member 34 to provide positive engagement of the apertures 38a and 38b in the arms 26 and 30 with the retention tabs 40a and 40b on the cartridge body 10.
In some embodiments, the die bond member made be made of a chemically resistant polymeric material that is reinforced with carbon, carbon fibers or glass fibers. Suitable carbon filled, carbon fiber filled, or glass fiber filled polymeric materials may be selected from, but not limited to, polyamides, polybutylene terephthalate, polycarbonate, polyethylene, polyphenyleneoxide, polyphenylenesulfide, and polytetrafluoroethylene.
Having the ejection head 14 attached directly to the die bond member 12 rather than to the plastic cartridge body 10 provides a mechanically stable surface for the ejection head 14 so that swelling or distortion of the plastic cartridge body 10 is isolated from the ejection head 14. In some embodiments, when using a metal die bond member, the die bond member 14 may also provide a heat sink for cooling the ejection head 14 during fluid ejection.
A conventional ejection head 14 is illustrated in
In some embodiments, as shown in
It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or can be presently unforeseen can arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they can be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
