Patent Description:
A fluid dispensing device can include fluidic actuators that when activated cause dispensing (e.g., ejection or other flow) of a fluid. For example, the dispensing of the fluid can include ejection of fluid droplets by activated fluidic actuators from respective nozzles of the fluid dispensing device. In other examples, an activated fluidic actuator (such as a pump) can cause fluid to flow through a fluid conduit or fluid chamber. Activating a fluidic actuator to dispense fluid can thus refer to activating the fluidic actuator to eject fluid from a nozzle or activating the fluidic actuator to cause a flow of fluid through a flow structure, such as a flow conduit, a fluid chamber, and so forth.

In some examples, the fluidic actuators include thermal-based fluidic actuators including heating elements, such as resistive heaters. When a heating element is activated, the heating element produces heat that can cause vaporization of a fluid to cause nucleation of a vapor bubble (e.g., a steam bubble) proximate the thermal-based fluidic actuator that in turn causes dispensing of a quantity of fluid, such as ejection from an orifice of a nozzle or flow through a fluid conduit or fluid chamber. In other examples, a fluidic actuator may be a deflecting-type fluidic actuator such as a piezoelectric membrane based fluidic actuator that when activated applies a mechanical force to dispense a quantity of fluid.

In examples where a fluid dispensing device includes nozzles, each nozzle can include an orifice through which fluid is dispensed from a fluid chamber, in response to activation of a fluidic actuator. Each fluid chamber provides the fluid to be dispensed by the respective nozzle. In other examples, a fluid dispensing device can include a microfluidic pump that has a fluid chamber.

Generally, a fluidic actuator can be an ejecting-type fluidic actuator to cause ejection of a fluid, such as through an orifice of a nozzle, or a non-ejecting-type fluidic actuator to cause displacement of a fluid.

In some examples, a fluid dispensing device can be in the form of a fluidic die. A "die" refers to an assembly where various layers are formed onto a substrate to fabricate circuitry, fluid chambers, and fluid conduits. Multiple fluidic dies can be mounted or attached to a support structure.

In some examples, a fluidic die can be a printhead die, which can be mounted to a print cartridge, a carriage assembly, and so forth. A printhead die includes nozzles through which a printing fluid (e.g., an ink, a liquid agent used in a 3D printing system, etc.) can be dispensed towards a target (e.g., a print medium such as a paper sheet, a transparency foil, a fabric, etc., or a print bed including 3D parts being formed by a 3D printing system to build a 3D object).

A fluidic die includes fluidic elements and circuitry that control fluid dispensing operations of the fluidic elements. The circuitry includes logic that is responsive to address signals and control signals to produce output signals that control switching elements used for activating respective fluidic actuators in the fluid elements.

A fluidic element includes flow structures that provide for fluid flow in the fluidic element. Examples of flow structures include any or some combination of the following: a fluid chamber that stores a fluid to be dispensed by the fluid element, an orifice through which fluid can pass from the fluid chamber to a region outside the fluid chamber, a fluid feed hole that is used to communicate fluid between a fluid flow conduit and the fluid chamber in the fluid element, a fluid channel to transport fluid, and a fluidic actuator that when activated causes dispensing of a fluid by the fluid element (a fluidic actuator can include a thermal-based fluidic actuator or a deflecting-type fluidic actuator, for example).

In some examples, a fluidic die includes fluidic elements contained in fluidic architecture regions that do not include circuitry with active devices. In such examples, the fluidic die is partitioned into the fluidic architecture regions and circuit regions that are outside of the fluidic architecture regions. The circuit regions include circuit elements that include active devices.

As used here, an "active device" can refer to a device that can be switched between different states, such as an on state at which electrical current flows through the device, and off state at which electrical current does not flow through the device (or the amount of electrical current flow is negligible or below a specified threshold). An example of an active device is a transistor, such as a field effect transistor (FET). A transistor has a gate that is connected to a signal ("gate signal") to control the state of the transistor. When the gate signal is at an active level (e.g., a low voltage or a high voltage depending on the type of transistor used), the transistor turns on to conduct electrical current between two other nodes of the transistor (e.g., a drain node and a source node of an FET). On the other hand, if the gate signal is at an inactive level (e.g., a high voltage or a low voltage depending on the type of transistor used), then no electrical current flows through the transistor (or the amount of electrical current through the transistor is negligible or below a specified threshold). In some cases, the gate signal to the transistor can be set at an intermediate level between the active level or the inactive level, which causes the transistor to conduct an intermediate amount of electrical current.

Another example of an active device is a diode. If the voltage across two nodes of the diode exceeds a threshold voltage, then the diode turns on to conduct electrical current through the diode. However, if the voltage across that the two nodes of the diode is less than the threshold voltage, and the diode remains off.

Partitioning a fluidic die between fluidic architecture regions and circuit regions may simplify the interface between the circuit elements and the fluidic elements, or may be performed because of the arrangement of fluid feed slots in the fluidic die. A fluid feed slot refers to a fluid conduit that may run along an entire actuator column of the fluidic die. The fluid feed slot is used to carry fluid to and from the fluidic elements of the fluidic die.

Certain types of fluidic dies may employ a sparse arrangement of fluidic elements (the fluidic elements are arranged in patterns of lower density than fluidic elements in other fluidic dies). If a fluidic die has a sparse arrangement of fluidic elements, then the fluidic architecture regions would consume a larger area of the fluidic die than fluidic architecture regions of a fluidic die with a denser arrangement of fluidic elements. Given the same size of a fluidic die and assuming a same quantity of fluidic elements is used (compared to another fluidic die with a denser arrangement of fluidic elements), the larger fluidic architecture regions of the sparse arrangement would result in smaller circuit regions in the fluidic die, which leads to greater compaction of circuit elements. In some cases, there may not be sufficient space for circuit elements in a fluidic die with a sparse arrangement of fluidic elements.

Circuit elements of a fluidic die can include high-voltage circuit elements and low-voltage circuit elements. The low-voltage circuit elements are operable at a first power supply voltage, and the high-voltage circuit elements are operable at a second power supply voltage greater than the first power supply voltage. A "power supply voltage" refers to a voltage provided to power circuit elements. For example, a low-voltage circuit element powered by the first power supply voltage can produce an output based on the first power supply voltage. For example, the output can be driven to the first power supply voltage when the low-voltage circuit element is activated (e.g., when a transistor is turned on). In this example, the low-voltage circuit element is able to transition between a low voltage (e.g., zero volts or V) and the first power supply voltage. Alternatively, the output can be driven to a voltage level that is a specified amount less than the first power supply voltage when the low-voltage circuit element is activated (e.g., a diode when turned on produces an output that is a threshold voltage less than the first power supply voltage).

Similarly, a high-voltage circuit element powered by the second power supply voltage can produce an output based on the second power supply voltage. For example, the high-voltage circuit element is able to transition between a low voltage (e.g., zero volts) and the second power supply voltage. Alternatively, the high-voltage circuit element when turned on produces an output that is a specified amount less than the second power supply voltage.

In some examples, the second power supply voltage is greater than <NUM> V, or greater than <NUM> V, or greater than <NUM> V, and so forth. In some examples, the first power supply voltage is between <NUM> V and <NUM> V, or between <NUM> V or <NUM> V, or between 3V and 5V, and so forth.

In accordance with some implementations of the present disclosure, as shown in <FIG>, a fluidic die <NUM> includes fluidic elements in the form of fluidic cells <NUM>. A "fluidic cell" refers to a collection of flow structures, and the fluidic cell can be repeated across the fluidic die <NUM>, such as to form an array. The fluidic cells <NUM> are interspersed with low-voltage circuit elements (represented as blocks labeled with "LVC" in <FIG>) along multiple different axes across a substrate (of the fluidic die) on which the fluidic elements and the low-voltage circuit elements are commonly formed. Fluidic cells are interspersed with low-voltage circuit elements if along a given axis, successive fluidic cells are separated by low-voltage circuit element(s), and successive low-voltage circuit elements are separated by fluidic cell(s).

In addition, high-voltage circuit elements (arranged in blocks labeled with "HVC") that include active devices are placed in a region outside of a fluidics boundary <NUM> defining a space in which the fluidic cells <NUM> and the low-voltage circuit elements are placed. None of the high-voltage circuit elements in the blocks HVC are placed within the fluidics boundary <NUM>. Note that in some examples, other high-voltage circuit elements may be placed at any or some combination of the four sides of the fluidics boundary <NUM>, just within the fluidics boundary <NUM>. Also, other low-voltage circuit elements may be placed on the substrate <NUM> outside the fluidics boundary <NUM>.

In some examples, the active devices of the high-voltage circuit elements include power transistors <NUM> (e.g., power FETs) that when activated drive signals to activate respective fluidic actuators <NUM> in the fluidic cells <NUM>. A power transistor when activated can drive a signal to the second power supply voltage, which is provided to a respective fluidic actuator <NUM> (e.g., a resistive heater).

A high-voltage circuit element such as a power transistor has an area efficiency that depends upon a physical structure or layout of integrated circuit layers used to form the power transistor. The area efficiency can be expressed as an amount of electrical current per unit area, which represents how much electrical current can be driven by the power transistor given an area of the layers used to form the power transistor. A power transistor has a better area efficiency if the area of the layers used to form the power transistor is a single uninterrupted region as compared to an area formed using discrete sub-areas. Since the regions without flow structures between the fluidic cells <NUM> within the fluidics boundary <NUM> are relatively small (as compared to regions of the fluidic die <NUM> outside the fluidics boundary <NUM>, arranging the high-voltage circuit elements outside the fluidics boundary <NUM> can achieve more efficient performance of the high-voltage circuit elements. Placing the high-voltage circuit elements in the regions between the fluidics cells <NUM> may involve breaking up each high-voltage circuit element into discrete sub-areas, which may cause a reduced efficiency of the high-voltage circuit element.

Low-voltage circuit elements are generally smaller than high-voltage circuit elements, and thus are able to fit more effectively in the regions between the fluidic cells <NUM> within the fluidics boundary <NUM>.

The multiple different axes along which the fluidic cells <NUM> are interspersed with the low-voltage circuit elements include a first axis <NUM> and a second axis <NUM> that is substantially orthogonal to the first axis <NUM>. The first axis <NUM> and the second axis <NUM> are substantially orthogonal if the first axis <NUM> has an angle with respect to the second axis <NUM> that is in any of the following ranges: between <NUM>° and <NUM>°, between <NUM>° in <NUM>°, between <NUM>° and <NUM>°, and so forth.

Each low-voltage circuit element LVC includes an active device or multiple active devices. In some examples, active devices of a low-voltage circuit element LVC can be interconnected to provide a logical operation, such as a logical AND, a logical OR, a logical inversion, and so forth. Active devices of a low-voltage circuit element LVC can also be used to perform other types of operations, such as to provide a latch, a register, or another storage element, to provide a variable resistance, and so forth. As an example, a low-voltage circuit element LVC can be part of control circuitry of the fluidic die <NUM>, where the control circuitry is used to control an operation of the fluidic cells <NUM> (and more specifically, the fluidic actuators <NUM> in the fluidic cells <NUM>), in response to input signals, such as address signals, control signals, data, and so forth. The input signals may be received from a controller of fluid dispensing system, such as a print controller of a printing system.

In further examples, the active devices of a low-voltage circuit element LVC can be used to implement analog circuitry. As noted above, examples of active devices include transistors and diodes, or any other device that can be switched between different states in response to an input signal.

In the example of <FIG>, the fluidic cells <NUM> are arranged in a two-dimensional array, along the first axis <NUM> and the second axis <NUM>. In other examples, the array of fluidic cells <NUM> can have a different pattern; for example, instead of a row or column that is generally parallel to the axis <NUM> or <NUM>, respectively, a line of fluidic cells <NUM> may be slanted with respect to the axis <NUM> or <NUM>. Moreover, instead of the fluidic cells <NUM> having a regular pattern, the fluidic cells <NUM> may have an irregular pattern or even a random pattern across the substrate <NUM> of the fluidic die <NUM>.

In some examples, a first quantity of low-voltage circuit elements interspersed in regions between the fluidic cells <NUM> along the axis <NUM> is greater than a specified number (e.g., <NUM>, <NUM>, etc.), and a second quantity of low-voltage circuit elements interspersed in regions between the fluidic cells <NUM> along the axis <NUM> is greater than a specified number (e.g., <NUM>, <NUM>, etc.).

Each fluidic cell <NUM> includes a respective fluid feed hole <NUM> and a fluid chamber <NUM> into which a fluid can be fed through the fluid feed hole <NUM>, in the example of <FIG>. The fluidic cell <NUM> can also include a fluidic actuator <NUM>, which when activated causes the fluid in the fluid chamber to be dispensed through an orifice (not shown in <FIG>) of the fluidic cell <NUM>. In further examples, a fluidic cell <NUM> can include multiple fluid feed holes and/or multiple orifices.

Although specific flow structures have been identified as being part of the fluidic cell <NUM>, it is noted that in other examples, additional or alternative types of flow structures can be included in each fluidic cell <NUM>.

In the example of <FIG>, an array of fluid feed holes <NUM> is arranged in multiple dimensions (e.g., along the axes <NUM> and <NUM>). The array of fluid feed holes <NUM> include distinct fluid feed holes that extend along a first dimension of the multiple dimensions, and distinct fluid feed holes that extend along a different second dimension of the multiple dimensions. "Distinct" fluid feed holes refer to fluid feed holes that are individually separate from one another, as opposed to a fluid feed slot that can extend a relatively long length to feed multiple fluidic cells, such as a column of fluidic cells. The fluid feed holes <NUM> are used to communicate fluid with respective fluid chambers of the fluidic cells <NUM>.

The fluidic die <NUM> has multiple outer edges <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, which collectively form a general rectangle (when viewed from the top or bottom) in the example of <FIG>. An "outer edge" of a fluidic die refers to a segment of an outermost boundary of the fluidic die <NUM>. In other examples, the fluidic die <NUM> can have different shapes.

In some examples, either the first dimension or the second dimension of the multiple dimensions along which the array of fluid feed holes <NUM> is arranged can be parallel to an outer edge (one of <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>) of the fluidic die <NUM>. In further examples, both the first dimension and the second dimension are parallel to respective outer edges of the fluidic die <NUM>.

In addition, each of multiple fluid feed holes along the first dimension (e.g., along the axis <NUM>) is distinct from multiple fluid feed holes along the second dimension (e.g., along the axis <NUM>). For example, in the first row <NUM> of the array of fluidic cells <NUM> shown in <FIG>, each of fluid feed holes <NUM> in the fluidic cells <NUM> in the second column <NUM> and the third column <NUM> is distinct from multiple fluid feed holes <NUM> in the fluidic cells <NUM> in the second row <NUM> and last row <NUM> of the first column <NUM> of the array. Even though there is a common fluidic cell <NUM> at the intersection of the first row <NUM> and the first column <NUM>, the first row <NUM> has multiple fluidic cells (in columns other than the first column <NUM>) that are distinct from multiple fluidic cells in the first column <NUM> (in rows other than the first row <NUM>).

In some examples, the fluidic die <NUM> can be mounted on a support structure (e.g., a print cartridge, a carriage, etc.), which is relatively moveable with respect to a target to which fluid of the fluidic die <NUM> is to be dispensed. For example, the target can be a print substrate onto which printing fluid is to be dispensed in a 2D printing system, or a 3D build part onto which liquid agents are to be dispensed during a 3D build operation of a 3D printing system. The fluidic die <NUM> is relatively moveable with respect to the target if either or both of the fluidic die <NUM> and the target is (are) moveable. In some examples, the fluidic die <NUM> is relatively moveable with respect to the target along a direction that is parallel to either axis <NUM> or <NUM>.

Regions that are without flow structures are provided between successive fluidic cells <NUM> along both the first axis <NUM> and the second axis <NUM>. Such regions are not used by the fluidic cells <NUM> for fluid flow. The low-voltage circuit elements are placed in the regions between the fluidic cells <NUM>. As a result, the low-voltage circuit elements are interspersed with the fluidic cells <NUM> along both the axes <NUM> and <NUM>. The elements of the fluidic cells <NUM> being interspersed with the low-voltage circuit elements result in an alternating arrangement of fluidic elements and low-voltage circuit elements along the different axes <NUM> and <NUM>.

By alternating the fluidic elements with the low-voltage circuit elements in multiple different axes, more space on the substrate <NUM> of the fluidic die <NUM> is provided to accommodate the low-voltage circuit elements while still allowing for a sparse arrangement of the fluidic cells <NUM>, in some examples.

The fluidic cells <NUM>, the low-voltage circuit elements, and the high-voltage circuit elements are formed on a common substrate, i.e., the substrate <NUM> of the fluidic die <NUM>. The substrate <NUM> can be a silicon substrate, or a substrate formed of another semiconductor material or a different material. Forming the fluidic cells <NUM>, the low-voltage circuit elements, and the high-voltage circuit elements on a common substrate refers to forming layers of the fluidic cells <NUM>, the low-voltage circuit elements, and the high-voltage circuit elements as part of an integrated circuit processing flow for a single integrated circuit device, which in <FIG> is the fluidic die <NUM>. Circuit elements (low-voltage and high-voltage circuit elements) and fluidic cells <NUM> formed on different substrates, such as being part of different integrated circuit devices formed using different integrated circuit process flows, would not be considered to be formed on a common substrate.

<FIG> is a schematic sectional view of a portion of a fluidic die <NUM> attached to an interposer <NUM> or another type of structure, according to further examples. The fluidic die <NUM> includes layers <NUM>, <NUM>, <NUM>, and <NUM>. A "layer" (any of <NUM>, <NUM>, <NUM>, and <NUM>) can include a single layer or multiple layers, possibly formed of different materials. The layers <NUM> and <NUM> make up a substrate for the fluidic die <NUM>. The layers <NUM> and <NUM> can include an epoxy-based photoresist (e.g., SU-<NUM>), silicon, another semiconductor material, or a different material.

<FIG> shows layers of a fluidic cell <NUM> and a low-voltage circuit element (<NUM> represents active low-voltage circuit element layers, such as layers of an active device or multiple active devices). The low-voltage circuit element layers <NUM> can include any or some combination of metal layers, polysilicon layers, doped regions, and so forth. Doped regions can be formed into the layer <NUM>. Metal layers and polysilicon layers of active devices can be formed over the doped regions. A thin film interconnect layer or layers <NUM> (including a metal or another electrically conductive material) can be formed over the layer <NUM>, where the thin film interconnect layer <NUM> can form an electrical contact or via to electrically connect to an active device.

The fluidic cell <NUM> can be arranged in similar manner as the fluidic cell <NUM> of <FIG> (i.e., multiple fluidic cells <NUM> can be arranged in an array along multiple axes, such as the axes <NUM> and <NUM> shown in <FIG>). The low-voltage circuit elements formed using low-voltage circuit element layers <NUM> can also be interspersed with the fluidic cells <NUM> along multiple different axes.

The fluidic cell <NUM> includes an orifice layer <NUM> in which an orifice <NUM> (or multiple orifices) is (are) formed. A chamber layer <NUM> is provided under the orifice layer <NUM>, and the chamber layer <NUM> defines a fluid chamber <NUM>. The layers <NUM> and <NUM> include any of various different types of materials, such as epoxy, silicon, and so forth.

A fluidic actuator <NUM> is formed over the layer <NUM> in the fluid chamber <NUM>. If the fluidic actuator is a resistive heater, the fluidic actuator <NUM> can be formed using a thin film of an electrically resistive material (such as tungsten-silicon nitride, polysilicon or any other material that exhibits electrical resistivity). Activation of the fluidic actuator <NUM> causes fluid in the fluid chamber <NUM> to be expelled through the orifice <NUM>.

In some examples, the low-voltage circuit element layers <NUM> are formed on the substrate (including layers <NUM> and <NUM>) of the fluidic die <NUM> before various layers of the fluidic cell <NUM>. A layer is on the substrate if the layer is directly on the substrate, or if the layer is supported by the substrate through other layer(s). The chamber layer <NUM> is formed over the layer <NUM> as well as over thin film layers (the thin film layer for the fluidic actuator <NUM> and the thin film interconnect layer <NUM>). Thus, in <FIG>, the low-voltage circuit element layers <NUM> are formed over the substrate (including layers <NUM> and <NUM>) prior to the layers <NUM> and <NUM> for the fluidic cell <NUM>. After the low-voltage circuit element layers <NUM> are formed over the substrate, the thin film layers (the thin film layer for the fluidic actuator <NUM> and the thin film interconnect layer <NUM>) are formed, followed by the fluidic cell layers <NUM> and <NUM> over the active circuit element layers <NUM>.

In the example of <FIG>, two fluid feed holes <NUM> and <NUM> are formed in a feed hole layer <NUM> (by etching the feed hole layer <NUM> to form the fluid feed holes, for example). The fluid feed hole <NUM> is an inlet fluid feed hole that allows fluid to flow into the fluid chamber <NUM>. The fluid feed hole <NUM> is an outlet fluid feed hole from which fluid in the fluid chamber <NUM> flows. The inlet fluid feed hole <NUM> is in communication with a high pressure chamber <NUM>, and the outlet fluid feed hole <NUM> is in communication with a low pressure chamber <NUM>. The high pressure chamber <NUM> and the low pressure chamber <NUM> are formed in a layer <NUM> (by etching the layer <NUM> to form the chambers <NUM> and <NUM>, for example). The high pressure chamber <NUM> is divided from the low pressure chamber <NUM> by a wall <NUM> of the layer <NUM>.

The pressure in the high pressure chamber <NUM> and the pressure in the low pressure chamber <NUM> can be controlled by respective pressure regulators (not shown). The high pressure chamber <NUM> has a pressure that is higher than the pressure of the low pressure chamber <NUM>.

The arrangement of the fluidic cell <NUM> allows for fluid recirculation along fluid path <NUM>. Fluid can flow from the high pressure chamber <NUM> into the inlet fluid feed hole <NUM>, which is then passed to the fluid chamber <NUM>. The fluid exits from the fluid chamber <NUM> through the outlet fluid feed hole <NUM> to the low pressure chamber <NUM>.

Recirculation can be performed to carry any contaminants or non-homogeneity of the fluid in the fluid chamber <NUM> out of the fluid chamber <NUM> to be replaced by fresh and uncontaminated fluid. In other examples, recirculation of fluid through the fluid chamber <NUM> can be performed for other purposes.

Although a specific arrangement is shown in <FIG> to enable fluid recirculation in the fluidic cell <NUM>, recirculation can be enabled using other arrangements in other examples.

The low-voltage circuit element layers <NUM> are formed in a region <NUM> that is devoid of flow structures of the fluid cell <NUM>. The region <NUM> is between successive fluidic cells <NUM> in each of multiple axes, such as axes <NUM> and <NUM> shown in <FIG>.

The interposer <NUM> is a structure that is attached to the fluidic die <NUM>. The interposer <NUM> can include fluid flow channels (not shown) to communicate fluid with the chambers <NUM> and <NUM>. The interposer <NUM> can be a die that is separate from the fluidic die <NUM>.

<FIG> is a block diagram of a portion of a fluidic die according to further examples, in which fluidic cells <NUM> and low-voltage circuit elements (represented by blocks labeled with "LVC") are interspersed along different axes <NUM> and <NUM>. The fluidic cells <NUM> in <FIG> have a stepped arrangement with respect to the axis <NUM>. Thus, unlike the arrangement of <FIG> where the fluidic cells <NUM> are aligned in rows and columns that are generally parallel to the respective axes <NUM> and <NUM>, the arrangement of the fluidic cells <NUM> in <FIG> is a stepped arrangement in which the fluidic cells <NUM> are stepped downwardly with respect to the axis <NUM> such that a line of fluidic cells <NUM> (extending generally along <NUM>) is not parallel to the axis <NUM>. The line (<NUM>) of fluidic cells is angled (slanted) with respect to the axis <NUM>. In the stepped arrangement, each successive fluidic cell <NUM> along the line <NUM> is shifted downwardly (along the axis <NUM>) from the immediately preceding fluidic cell <NUM> along the line <NUM>, so that the line <NUM> of fluidic cells <NUM> progressively step downwardly along the axis <NUM> relative to the axis <NUM>.

Along the orthogonal axis <NUM>, the fluidic cells <NUM> are lined up generally parallel to the axis <NUM>.

Each fluidic cell <NUM> includes fluid feed holes <NUM> and <NUM> (e.g., similar to the fluid feed holes <NUM> and <NUM> shown in <FIG>). Also, each fluidic cell <NUM> includes orifices <NUM> and <NUM>. For example, the orifice <NUM> is larger than the orifice <NUM>.

The fluidic cells <NUM> and the low-voltage circuit elements are arranged in an interspersed manner within a fluidics boundary <NUM>. High-voltage circuit elements (represented by a block labeled with "HVC") are arranged outside the fluidics boundary <NUM>.

<FIG> is a block diagram of a fluidic die <NUM> according to further examples. The fluidic die <NUM> includes a first interspersed arrangement <NUM>-<NUM> of fluidic elements and low-voltage circuit elements, and a second interspersed arrangement <NUM>-<NUM> of fluidic elements and low-voltage circuit elements. Each interspersed arrangement <NUM>-<NUM> or <NUM>-<NUM> of fluidic elements and low-voltage circuit elements can be similar to the arrangement shown in any of <FIG> and <FIG>.

The first interspersed arrangement <NUM>-<NUM> of fluidic elements and low-voltage circuit elements is included within a fluidics boundary <NUM>-<NUM>, and the second interspersed arrangement <NUM>-<NUM> of fluidic elements and low-voltage circuit elements is included within a fluidics boundary <NUM>-<NUM>.

The fluidic die <NUM> further includes high-voltage circuit elements in blocks <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. Note that some of the blocks <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may be omitted in further examples. The high-voltage circuit elements are placed outside each of the fluidics boundaries <NUM>-<NUM> and <NUM>-<NUM>, such that none of the high-voltage circuit elements in the blocks <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are placed in the fluidics boundary <NUM>-<NUM>, and none of the high-voltage circuit elements in the blocks <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are placed in the fluidics boundary <NUM>-<NUM>.

<FIG> is a flow diagram of a process <NUM> of forming a fluidic die according to some examples of the present disclosure.

The process <NUM> includes forming (at <NUM>) layers for first circuit elements and second circuit elements on a substrate, where each circuit element of the second circuit elements includes an active device, where the first circuit elements are operable at a first power supply voltage, and the second circuit elements operable at a second power supply voltage greater than the first power supply voltage.

The process <NUM> includes forming (at <NUM>) layers for fluidic elements over the layers for the first and second circuit elements, where the fluidic elements are to dispense a fluid, an arrangement of the fluidic elements across the substrate has regions without flow structures between successive fluidic elements, and each fluidic element of the fluidic elements includes a fluidic actuator and a fluid chamber.

The process <NUM> includes interspersing (at <NUM>) the first circuit elements in the regions between the fluidic elements along different axes of the fluidic die.

The process <NUM> includes placing (at <NUM>) the second circuit elements in a region outside of a boundary defining a space in which the fluidic elements and the first circuit elements are placed.

The process <NUM> includes forming (at <NUM>) an array of fluid feed holes in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions.

<FIG> is a block diagram of a fluidic die <NUM> according to further examples. The fluidic die <NUM> includes a substrate <NUM> and an arrangement of fluidic elements <NUM> to dispense a fluid, each fluidic element of the fluidic elements including a fluidic actuator <NUM> and a fluid chamber <NUM>. The arrangement of fluidic elements <NUM> includes first fluidic elements along a first axis <NUM> across the substrate <NUM>, and second fluidic elements along a different second axis <NUM> across the substrate <NUM>.

Low-voltage circuit elements <NUM> are interspersed between the fluidic elements along each of the first axis <NUM> and the second axis <NUM>, where each low-voltage circuit element is operable at a first power supply voltage and includes an active device, and where greater than <NUM> low-voltage circuit elements are arranged along the first axis <NUM> in first regions between successive first fluidic elements <NUM>, and greater than <NUM> low-voltage circuit elements are arranged along the second axis <NUM> in second regions between successive second fluidic elements <NUM>.

High-voltage circuit elements <NUM> are placed in a region outside of a fluidics boundary <NUM> defining a space in which the fluidic elements <NUM> and the low-voltage circuit elements <NUM> are placed, where each high-voltage circuit element <NUM> includes an active device operable at a second power supply voltage greater than the first power supply voltage. The fluidic elements <NUM>, the low-voltage circuit elements <NUM>, and the high-voltage circuit elements <NUM> are commonly formed on the substrate <NUM>.

Interspersed arrangements of fluidic elements and low-voltage and high-voltage circuit elements according to some examples of the present disclosure may provide various benefits. For example, greater space is provided on the substrate of a fluidic die to accommodate circuit elements in a sparse arrangement of fluidic elements. Also, low-voltage circuit elements being placed closer to fluidic elements can reduce parasitic impedances in signals transmitted by the low-voltage circuit elements. Interspersing low-voltage circuit elements with fluidic elements allows for a greater density of the low-voltage circuit elements without increasing the overall size of a fluidic die. Also, placing high-voltage circuit elements outside a fluidics boundary containing an interspersed arrangement of fluidic elements and low-voltage circuit elements provides high-voltage circuit elements of greater efficiency.

Claim 1:
A fluidic die (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
an arrangement of fluidic elements (<NUM>) to dispense a fluid, each fluidic element of the fluidic elements (<NUM>) comprising a fluidic actuator (<NUM>, <NUM>, <NUM>) and a fluid chamber;
an array of fluid feed holes (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) in a plurality of dimensions across the substrate (<NUM>, <NUM>) to communicate the fluid with the fluidic elements (<NUM>), wherein each of multiple fluid feed holes (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) along a first dimension of the plurality of dimensions across the substrate (<NUM>, <NUM>) is distinct from multiple fluid feed holes (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) along a second dimension of the plurality of dimensions across the substrate (<NUM>, <NUM>);
first circuit elements operable at a first power supply voltage; and
second circuit elements operable at a second power supply voltage greater than the first power supply voltage, the second circuit elements comprising active devices and placed in a region outside of a boundary defining a space in which the fluidic elements (<NUM>) and the first circuit elements are placed,
characterised in that
the first circuit elements are interspersed in regions between the fluidic elements (<NUM>) along different axes (<NUM>, <NUM>, <NUM>, <NUM>) of the fluidic die (<NUM>, <NUM>, <NUM>, <NUM>) resulting in an alternating arrangement of fluidic elements (<NUM>) and the first circuit elements along the different axes (<NUM>, <NUM>, <NUM>, <NUM>).