Patent Description:
<CIT> discloses a Liquid Crystal Polymer (LCP) fluidic carrier member. Printhead Integrated Circuits are attached to the LCP member by a polymer sealing film. <CIT> discloses printhead dies molded into an elongated monolithic body of moldable material.

Examples of the present disclosure are directed to a fluid ejection device, and a method of manufacturing a fluid ejection device in a manner that reduces or eliminates the formation of epoxy molding compound (EMC) on contact pads positioned near ends of the fluid ejection die. This unintended EMC formation on the contact pads is referred to as EMC flash. During the process, an upper mold chase is applied to the back-side surface of the fluid ejection die. The EMC is then applied to the fluid ejection die using a transfer molding process. The upper mold chase includes a slot forming feature that covers ink feed holes of the fluid ejection die during the application of the EMC, and defines a slot in the resulting EMC panel for providing fluid to the ink feed holes. The length of the feature of the upper mold chase defines the length of the slot, and this length is less than the length of the fluid ejection die. Reducing the space between an end of the feature and an end of the fluid ejection die can reduce or eliminate EMC flash on the contact pads. In one example, the process results in a fluid ejection device with a length between an end of the slot and an end of the fluid ejection die that is less than <NUM>.

<FIG> is a diagram illustrating a fluid ejection die <NUM> according to one example. Die <NUM> includes a first longitudinal end portion <NUM> that includes a plurality (e.g., six in the illustrated example) of contact pads <NUM>, a second longitudinal end portion <NUM> that includes a plurality (e.g., six in the illustrated example) of contact pads <NUM>, and a fluid ejection portion <NUM> that includes a plurality of fluid actuation devices <NUM>. The contact pads <NUM> in the second longitudinal end portion <NUM> are longitudinally aligned with the contact pads <NUM> in the first longitudinal end portion <NUM>, and are positioned at a distance <NUM> (i.e., along the Y axis) from the contact pads <NUM> in the first longitudinal end portion <NUM>.

The plurality of fluid actuation devices <NUM> is disposed longitudinally to the contact pads <NUM> in the first longitudinal end portion <NUM> and the contact pads <NUM> in the second longitudinal end portion <NUM>. The plurality of fluid actuation devices <NUM> is also arranged between the contact pads <NUM> in the first longitudinal end portion <NUM> and the contact pads <NUM> in the second longitudinal end portion <NUM>. In the illustrated example, the contact pads <NUM> in the first longitudinal end portion <NUM>, the contact pads <NUM> in the second longitudinal end portion <NUM>, and the plurality of fluid actuation devices <NUM> are each arranged in a column, and the three columns are longitudinally aligned (i.e., not laterally offset from one another). In one example, fluid actuation devices <NUM> are nozzles or fluidic pumps to eject fluid drops.

Die <NUM> includes an elongate semiconductor (e.g., silicon) substrate <NUM> having a length <NUM> (along the Y axis) between lateral ends <NUM> and <NUM>, a thickness <NUM> (along the Z axis), and a width <NUM> (along the X axis) between lateral ends <NUM> and <NUM> of the die <NUM>. In one example, the length <NUM> is at least twenty times the width <NUM>. The width <NUM> may be <NUM> or less and the thickness <NUM> may be less than <NUM> microns. The fluid actuation devices <NUM> and the contact pads <NUM> are provided on the elongate substrate <NUM> and are arranged along the length <NUM> of the elongate substrate. The fluid actuation devices <NUM> have a swath length <NUM> less than the length <NUM> of the elongate substrate <NUM>. In one example, the swath length <NUM> is at least <NUM>. The contact pads <NUM> in the first longitudinal end portion <NUM> may be arranged near a first longitudinal end <NUM> of the elongate substrate <NUM>. The contact pads <NUM> in the second longitudinal end portion <NUM> may be arranged near a second longitudinal end <NUM> of the elongate substrate <NUM> opposite to the first longitudinal end <NUM>.

<FIG> is a diagram illustrating a fluid ejection device <NUM> according to one example. Fluid ejection device <NUM> includes a fluid ejection die <NUM> attached to a carrier <NUM>. In one example, the carrier <NUM> is a rigid, molded carrier that is formed by a transfer molding processes. A slot <NUM> is formed in the carrier <NUM> to provide fluid to the back side of the fluid ejection die <NUM>. In one example, the slot <NUM> extends longitudinally along the fluid ejection die <NUM>, and is longitudinally aligned (i.e., not laterally offset) with the plurality of fluid actuation devices <NUM> (<FIG>).

<FIG> are diagrams illustrating a method of forming the fluid ejection device <NUM> shown in <FIG> according to one example. As shown in <FIG>, fluid ejection die <NUM> is positioned on a release tape layer <NUM>, which is positioned on a die carrier <NUM>. More specifically, fluid ejection die <NUM> is positioned with a front-side surface <NUM> facing the release tape layer <NUM> and the die carrier <NUM>. A nozzle layer <NUM> is formed on the front-side surface <NUM> of the fluid ejection die <NUM>. Upper mold chase <NUM> is positioned over fluid ejection die <NUM> (and die carrier <NUM>). More specifically, upper mold chase <NUM> is positioned over fluid ejection die <NUM> with back-side surface <NUM> of fluid ejection die <NUM> facing upper mold chase <NUM>. Upper mold chase <NUM> includes a slot forming feature <NUM> that seals fluid feed holes formed in fluid ejection die <NUM> to protect the fluid feed holes during molding. Upper mold chase <NUM> includes a bottom surface that defines cavities <NUM>(<NUM>) and <NUM>(<NUM>) (collectively referred to as cavities <NUM>) between upper mold chase <NUM> and die carrier <NUM>.

In one example, a release liner <NUM> is positioned along the bottom surface of upper mold chase <NUM> so as to be positioned between fluid ejection die <NUM> and upper mold chase <NUM>. Release liner <NUM> helps to prevent contamination of upper mold chase <NUM> and minimize flash during the molding process.

As shown in <FIG>, cavities <NUM> are filled with mold material <NUM>, such as an epoxy mold compound, plastic, or other suitable moldable material. Filling cavities <NUM> with mold material <NUM> forms a carrier <NUM> around fluid ejection die <NUM>. In one example, the molding process is a transfer molding process and includes heating the mold material <NUM> to a liquid form and injecting or vacuum feeding the liquid mold material into cavities <NUM> (for example, through runners that communicate with cavities <NUM>). The feature <NUM> of the upper mold chase <NUM> (as positioned along back-side surface <NUM> of fluid ejection die <NUM>) helps to prevent the mold material from entering the fluid feed holes of die <NUM> as cavities <NUM> are filled.

As shown in <FIG>, after the mold material cools and hardens to a solid, upper mold chase <NUM> and liner <NUM> are removed, and fluid ejection die <NUM> and carrier <NUM> are removed or released from die carrier <NUM>. Thus, carrier <NUM> is molded to include molded back-side surface <NUM> and molded front-side surface <NUM>, with molded front-side surface <NUM> substantially coplanar with front-side surface <NUM> of fluid ejection die <NUM>, and molded back-side surface <NUM> extending beyond back-side surface <NUM> of fluid ejection die <NUM>. As such, carrier <NUM> has a thickness that is greater than the thickness of fluid ejection die <NUM>. In addition, front-side surface <NUM> of fluid ejection die <NUM> and a portion of back-side surface <NUM> of fluid ejection die <NUM> both remain exposed from carrier <NUM> (i.e., are not covered by mold material of carrier <NUM>). While one fluid ejection die <NUM> is illustrated in <FIG> as being molded into carrier <NUM>, a greater number of fluid ejection dies <NUM> may be molded into carrier <NUM>.

The shape of the slot <NUM> is usually a result of particular slotting process (e.g., laser, anisotropic wet etch, dry etch, or a combination of these), and these processes may have a limited influence on the profile of the slot <NUM> that can be produced. Examples disclosed herein enable a transfer mold process with slot molding by reducing or eliminating the contact pad EMC flash issue, as described in further detail below.

<FIG> is a diagram illustrating the application of an upper mold chase <NUM> to a fluid ejection die <NUM> according to one example. As shown in <FIG>, a nozzle layer <NUM> is formed on the front-side surface <NUM> of the fluid ejection die <NUM>, and the die <NUM> and the nozzle layer <NUM> are positioned on a release tape layer <NUM>. The release tape layer <NUM> is positioned on die carrier <NUM>. Feature <NUM> of upper mold chase <NUM> is positioned over fluid ejection die <NUM> with back-side surface <NUM> of fluid ejection die <NUM> facing feature <NUM>. A plurality of fluid feed holes <NUM> extend through the fluid ejection die <NUM>. Although two fluid feed holes <NUM> are shown in <FIG> to simplify the Figure, the fluid ejection die <NUM> may include more or less than two fluid feed holes <NUM>, and the fluid feed holes <NUM> may be positioned across the length of the fluid ejection portion <NUM> of the die <NUM>. The feature <NUM> seals the fluid feed holes <NUM> formed in fluid ejection die <NUM> to protect the fluid feed holes <NUM> during molding. Release liner <NUM> is positioned along the bottom surface of feature <NUM> so as to be positioned between fluid ejection die <NUM> and feature <NUM>.

One challenge in the slot molding process is keeping the contact pads <NUM> at the longitudinal ends <NUM> and <NUM> of the die <NUM> free from the EMC flash. The fluid ejection die <NUM> sits on top of the release tape layer <NUM>, which, in one example, is a compliant layer that is about <NUM> thick. The feature <NUM> of the upper mold chase <NUM> contacts and applies force to the fluid ejection portion <NUM> of the fluid ejection die <NUM>, but not the end portions <NUM> and <NUM> of the die <NUM>. This force can cause the fluid ejection portion <NUM> of the die <NUM> to sink into the release tape layer <NUM>, and cause the end portions <NUM> and <NUM> to tilt up toward the upper mold chase <NUM> during the molding process. This tilting can cause a gap <NUM> that results in EMC flash in the regions of the contact pads <NUM>.

The length <NUM> between the end of the feature <NUM> and the end <NUM> of the die <NUM> is referred to herein as the cantilever length, which plays a role in addressing the contact pad EMC flash issue. Examples of the present disclosure use a short cantilever length <NUM> to reduce or eliminate the contact pad EMC flash issue. In one example, one or both of the end portions <NUM> and <NUM> have a cantilever length <NUM> that is less than <NUM>. In another example, one or both of the end portions <NUM> and <NUM> have a cantilever length <NUM> that is less than <NUM>. In yet another example, one or both of the end portions <NUM> and <NUM> have a cantilever length <NUM> that is less than <NUM>.

<FIG> are diagrams illustrating a top view of a portion of the fluid ejection device <NUM> shown in <FIG> according to one example. As shown in <FIG>, contact pads <NUM> are positioned on the front side <NUM> of the die <NUM>. Slot <NUM> is positioned on the back side <NUM> of the die, and is, therefore, shown with dashed lines in <FIG>. The slot <NUM> has a uniform width or a substantially uniform width along its length. The length between the longitudinal end <NUM> of the die and the longitudinal end <NUM> of the slot <NUM> defines the cantilever length <NUM>.

Extending the length of the feature <NUM> (<FIG>) of the upper mold chase <NUM> results in an increase in the slot length of the slot <NUM> and a reduction in the cantilever length <NUM>. Increasing the slot length helps to reduce or eliminate the contact pad EMC flash issue. However, increasing the slot length may result in an increase in the distance between the longitudinal end <NUM> of the slot <NUM> and the fluid actuation device <NUM> (<FIG>) that is closest to the end <NUM>. This portion of the slot <NUM> that extends beyond that fluid actuation device <NUM> may be referred to herein as dead space, since there are no fluid actuation devices <NUM> positioned directly above that space. Some examples of the present disclosure modify the shape of the slot <NUM> near the longitudinal end <NUM> to reduce the volume of the dead space. Two such examples are shown in <FIG> and described below.

As shown in <FIG>, the slot <NUM> includes a narrower slot portion <NUM> longitudinally extending from a wider slot portion <NUM> near the longitudinal end <NUM> of the slot <NUM>. The narrower slot portion <NUM> has a uniform width or a substantially uniform width that is less than a uniform width or substantially uniform width of the wider slot portion <NUM>. In one example, the width of the narrower slot portion <NUM> is about <NUM>-<NUM>% of the width of the wider slot portion <NUM>. In one example, there are no fluid actuation devices <NUM> positioned directly above (i.e., along the Z axis in <FIG>) the narrower slot portion <NUM>.

As shown in <FIG>, the slot <NUM> includes slot portion <NUM> longitudinally extending from slot portion <NUM>, and slot portion <NUM> longitudinally extending from slot portion <NUM> near the longitudinal end <NUM> of the slot <NUM>. Slot portions <NUM> and <NUM> each have a uniform width or a substantially uniform width that is less than a uniform width or substantially uniform width of the slot portion <NUM>. In one example, the width of the slot portion <NUM> is about <NUM>-<NUM>% of the width of the slot portion <NUM>, and the width of the slot portion <NUM> is about <NUM>-<NUM>% of the width of the slot portion <NUM>. In one example, there are no fluid actuation devices <NUM> positioned directly above (i.e., along the Z axis in <FIG>) the slot portions <NUM> and <NUM>.

<FIG> is a block diagram illustrating a fluid ejection system <NUM> according to one example. Fluid ejection system <NUM> includes a fluid ejection assembly, such as printhead assembly <NUM>, and a fluid supply assembly, such as ink supply assembly <NUM>. In one example, printhead assembly <NUM> may include a fluid ejection device <NUM> of <FIG>. In the illustrated example, fluid ejection system <NUM> also includes a service station assembly <NUM>, a carriage assembly <NUM>, a print media transport assembly <NUM>, and an electronic controller <NUM>. 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 <NUM> includes at least one printhead or fluid ejection die <NUM> previously described and illustrated with reference to <FIG>, which ejects drops of ink or fluid through a plurality of orifices or nozzles <NUM>. In one example, the drops are directed toward a medium, such as print media <NUM>, so as to print onto print media <NUM>. In one example, print media <NUM> includes any type of suitable sheet material, such as paper, card stock, transparencies, Mylar, fabric, and the like. In another example, print media <NUM> 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 <NUM> are arranged in at least one column or array such that properly sequenced ejection of ink from nozzles <NUM> causes characters, symbols, and/or other graphics or images to be printed upon print media <NUM> as printhead assembly <NUM> and print media <NUM> are moved relative to each other.

Ink supply assembly <NUM> supplies ink to printhead assembly <NUM> and includes a reservoir <NUM> for storing ink. As such, in one example, ink flows from reservoir <NUM> to printhead assembly <NUM>. In one example, printhead assembly <NUM> and ink supply assembly <NUM> are housed together in an inkjet or fluid-jet print cartridge or pen. In another example, ink supply assembly <NUM> is separate from printhead assembly <NUM> and supplies ink to printhead assembly <NUM> through an interface connection <NUM>, such as a supply tube and/or valve.

Carriage assembly <NUM> positions printhead assembly <NUM> relative to print media transport assembly <NUM>, and print media transport assembly <NUM> positions print media <NUM> relative to printhead assembly <NUM>. Thus, a print zone <NUM> is defined adjacent to nozzles <NUM> in an area between printhead assembly <NUM> and print media <NUM>. In one example, printhead assembly <NUM> is a scanning type printhead assembly such that carriage assembly <NUM> moves printhead assembly <NUM> relative to print media transport assembly <NUM>. In another example, printhead assembly <NUM> is a non-scanning type printhead assembly such that carriage assembly <NUM> fixes printhead assembly <NUM> at a prescribed position relative to print media transport assembly <NUM>.

Service station assembly <NUM> provides for spitting, wiping, capping, and/or priming of printhead assembly <NUM> to maintain the functionality of printhead assembly <NUM> and, more specifically, nozzles <NUM>. For example, service station assembly <NUM> may include a rubber blade or wiper which is periodically passed over printhead assembly <NUM> to wipe and clean nozzles <NUM> of excess ink. In addition, service station assembly <NUM> may include a cap that covers printhead assembly <NUM> to protect nozzles <NUM> from drying out during periods of non-use. In addition, service station assembly <NUM> may include a spittoon into which printhead assembly <NUM> ejects ink during spits to ensure that reservoir <NUM> maintains an appropriate level of pressure and fluidity, and to ensure that nozzles <NUM> do not clog or weep. Functions of service station assembly <NUM> may include relative motion between service station assembly <NUM> and printhead assembly <NUM>.

Electronic controller <NUM> communicates with printhead assembly <NUM> through a communication path <NUM>, service station assembly <NUM> through a communication path <NUM>, carriage assembly <NUM> through a communication path <NUM>, and print media transport assembly <NUM> through a communication path <NUM>. In one example, when printhead assembly <NUM> is mounted in carriage assembly <NUM>, electronic controller <NUM> and printhead assembly <NUM> may communicate via carriage assembly <NUM> through a communication path <NUM>. Electronic controller <NUM> may also communicate with ink supply assembly <NUM> such that, in one implementation, a new (or used) ink supply may be detected.

Electronic controller <NUM> receives data <NUM> from a host system, such as a computer, and may include memory for temporarily storing data <NUM>. Data <NUM> may be sent to fluid ejection system <NUM> along an electronic, infrared, optical or other information transfer path. Data <NUM> represent, for example, a document and/or file to be printed. As such, data <NUM> form a print job for fluid ejection system <NUM> and includes at least one print job command and/or command parameter.

In one example, electronic controller <NUM> provides control of printhead assembly <NUM> including timing control for ejection of ink drops from nozzles <NUM>. As such, electronic controller <NUM> defines a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on print media <NUM>. 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 <NUM> is located on printhead assembly <NUM>. In another example, logic and drive circuitry forming a portion of electronic controller <NUM> is located off printhead assembly <NUM>.

Examples disclosed herein provide the following features: (<NUM>) Enable the use of a slot molding process by reducing or eliminating the contact pad EMC flash issue; (<NUM>) use a robust mold process that is less sensitive to slot misalignment; (<NUM>) eliminate the silicon slotting process, which reduces the die cost; (<NUM>) minimize die cracking by avoiding mechanical/laser damage to the silicon; and (<NUM>) superior slot sidewall quality/smoothness to avoid particle shedding issues.

One example of this disclosure is directed to a fluid ejection device, which includes a fluid ejection die including a first end portion positioned adjacent a first end of the fluid ejection die, and a fluid ejection portion positioned adjacent the first end portion. The fluid ejection die includes a contact pad positioned in the first end portion, and a fluid actuation device positioned in the fluid ejection portion. A carrier is attached to the fluid ejection die. The carrier includes a slot to provide fluid to the fluid actuation device. The slot extends longitudinally along the fluid ejection portion to a first slot end. A length from the first slot end to the first end of the fluid ejection die is less than <NUM>.

The first end may be a first longitudinal end of the fluid ejection die. The length from the first slot end to the first end of the fluid ejection die may be less than <NUM>. The length from the first slot end to the first end of the fluid ejection die may be less than <NUM>. The slot may decrease in width from a first width along the fluid ejection portion to a second, smaller width along an end portion of the slot adjacent the first slot end. The fluid ejection die may include a second end portion positioned adjacent a second end of the fluid ejection die. The fluid ejection die may include a contact pad positioned in the second end portion. The slot may extend longitudinally along the fluid ejection portion to a second slot end. A length from the second slot end to the second end of the fluid ejection die may be less than <NUM>. The second end may be a second longitudinal end of the fluid ejection die. The carrier may be a rigid carrier. The carrier may be a molded carrier, and the slot may be a molded slot.

Another example of this disclosure is directed to a fluid ejection device, which includes a fluid ejection die including a first end portion positioned adjacent a first end of the fluid ejection die, a second end portion positioned adjacent a second end of the fluid ejection die, and a fluid ejection portion positioned between the first and second end portions. The fluid ejection die includes a fluid actuation device positioned in the fluid ejection portion. A rigid carrier is attached to the fluid ejection die. The rigid carrier includes a slot to provide fluid to a back side of the fluid ejection die. The slot extends longitudinally along the fluid ejection portion to a first slot end adjacent the first end portion. A length from the first slot end to the first end of the fluid ejection die is less than <NUM>.

The fluid ejection die may include a first contact pad positioned in the first end portion, and a second contact pad positioned in the second end portion. The slot may extend longitudinally along the fluid ejection portion to a second slot end adjacent the second end portion, and a length from the second slot end to the second end of the fluid ejection die may be less than <NUM>.

Yet another example of this disclosure is directed to a method, which includes applying a mold chase to a fluid ejection die, wherein the mold chase at least partially defines at least one cavity, and wherein the mold chase includes a slot forming feature having a first longitudinal end positioned less than <NUM> from a first longitudinal end of the fluid ejection die. The method includes filling the at least one cavity with a mold compound to generate a carrier to support the fluid ejection die, wherein the carrier includes a slot defined by the slot forming feature.

The slot forming feature may cover fluid feed holes of the fluid ejection die. The slot forming feature may have a second longitudinal end positioned less than <NUM> from a second longitudinal end of the fluid ejection die.

Claim 1:
A fluid ejection device (<NUM>), comprising:
a fluid ejection die (<NUM>) including
an elongate semiconductor substrate (<NUM>),
a first longitudinal end portion (<NUM>) positioned adjacent a first longitudinal end (<NUM>) of the fluid ejection die (<NUM>),
and a fluid ejection portion (<NUM>) positioned adjacent the first longitudinal end portion (<NUM>), wherein the fluid ejection die (<NUM>) includes a contact pad (<NUM>) positioned in the first longitudinal end portion, and a fluid actuation device (<NUM>) positioned in the fluid ejection portion (<NUM>); and
a carrier (<NUM>) attached to the fluid ejection die (<NUM>), wherein the carrier (<NUM>) includes a slot (<NUM>) to provide fluid to the fluid actuation device (<NUM>), wherein the slot (<NUM>) extends longitudinally along the fluid ejection portion (<NUM>) to a first slot end (<NUM>), characterized in that a length (<NUM>) from the first slot end (<NUM>) to the first longitudinal end (<NUM>) of the fluid ejection die (<NUM>) is less than <NUM>.