Abstract: A die attach composition is used for bonding a silicon chip on a flat substrate. The die attach composition includes a cross-linkable epoxy resin having a rigid backbone, an epoxy siloxane resin, a fumed silica filler, an amine curing agent, and a silane coupling agent. The die attach composition is particularly useful in bonding silicon heater chips on flat ceramic substrate in forming an inkjet printhead assembly. The die attach composition allows accurate placement of silicon heater chips on flat ceramic substrate and exhibits good ink resistance.

Abstract: A liquid composition used in combination with an ink containing a coloring material is ejected by the action of thermal energy from a recording head including a heating resistor having a protecting layer that contains at least one of a metal and a metal oxide and that is to come into contact with the liquid composition. The liquid composition contains an organic acid having a carboxy group, an alkali metal ion, an organic acid having a sulfonate group, a polyvalent metal ion, and water.

Abstract: A fluid ejection device includes a chamber, and first and second electrodes configured to generate an electric field within the chamber. A related method includes, in a firing chamber, separating whole ink into colloidal particles and ink vehicle such that the firing fluid within the chamber comprises primarily ink vehicle.

Abstract: This invention relates to a printhead element substrate having a plurality of electrothermal transducers and a plurality of switching elements which drive the plurality of electrothermal transducers. The element substrate has a level converter which is shared by adjacent electrothermal transducers and steps up an input driving signal, and a switch circuit which supplies the driving signal output from the level converter to one of the adjacent electrothermal transducers. The switch circuit switches the supply destination of the driving signal in accordance with an external input selection signal.

Abstract: A solvent-based ink composition for a thermal inkjet printhead. The composition includes: (a) 10-80 wt. % of a compound of formula (B): wherein: R5 is a C1-6 alkyl group and R6 is a C1-6 alkyl group; or R5 and R6 are together joined to form a C3-12 cycloalkylene group; (b) 10-80 wt. % of a C1-6 alcohol; and (c) 0.01-25 wt. % of a surface-modified pigment.

Abstract: A liquid dispenser includes a liquid supply channel, a liquid dispensing channel including an outlet opening, a liquid return channel, and a liquid cooling channel positioned relative to the liquid dispensing channel. A liquid supply provides liquid under pressure from the liquid supply channel through the liquid dispensing channel to the liquid return channel. A diverter member is selectively actuatable using heat energy to divert a portion of the liquid toward outlet opening of the liquid dispensing channel, the diverter member including a first side that faces the liquid dispensing channel and a second side that faces the liquid cooling channel.

Abstract: There is provided a substrate for an inkjet printing head and a method for manufacturing the same, in which the substrate has a structure that different kinds of metals do not come into contact with ink or moisture. For this purpose, the structure is constituted such that a diffusion preventing layer for mainly protecting a lower layer among power wiring metals is covered by a metal layer for mainly supplying power, in connection with its upper surface and at least part of a side surface. Herewith, since a single metal appears on a surface of the power wiring including up to its side surface, even circumstance occurs of coming into contact with the ink or the moisture, a battery reaction accompanied by difference of ionization tendency is not generated, and thus corrosion or short-circuit of the power wiring is suppressed.

Abstract: An inkjet recording method includes recording by ejecting liquid droplets of an ink onto a recording medium from an ejection head that ejects, by heat, the liquid droplets of the ink at an ejection amount with respect to one droplet of from 1 ng to 2 ng to thereby attach the liquid droplets of the ink to the recording medium, wherein the ink comprises a pigment having a volume average particle diameter of from 100 nm to 400 nm and has a dynamic contact angle of from 30° to 60°, 50 seconds after dropwise addition of 3 ?l of the ink to plain paper.

Abstract: In a liquid-ejecting method for ejecting liquid contained in a liquid chamber from a nozzle as a liquid droplet group, the ejection amount of each liquid droplet of the continuously ejected liquid-droplet group can be stabilized corresponding to a wide frequency band of a pulse signal. Also, when one pixel is formed with a plurality of liquid droplets using a head capable of deflecting the ejecting direction of the liquid droplet, the image quality is improved by reducing the landing positional displacement between plural liquid droplets for forming the one pixel.

Abstract: A print head formed in a simplified and less costly manufacture process can be effective in preventing the peeling-off between a substrate and a flow passage forming member. In the print head, a protective layer is formed between the flow passage forming member and a heat generating portion. The protective layer contains a noble metal. On a side of the flow passage forming member, the surface of the protective layer is made of an oxide of a noble metal, except in a portion corresponding to the heat generating portion, while in the portion corresponding to the heat generating portion on the flow passage forming member side, the surface thereof is made of the noble metal.

Abstract: A nozzle arrangement for an inkjet printhead includes an ink inlet; a static ink ejecting member bounding the ink inlet; an active ink ejecting member having a roof defining an ink ejection port and sidewalls depending from the roof, the active ink ejecting member and the static ink ejecting member together defining a nozzle chamber; and an actuator arrangement for reciprocating the active ink ejection member relative to the static ink ejecting member. The static ink ejecting member includes a sealing structure defined along an edge thereof, the sealing structure shaped to form a fluidic seal between the active and the static ink ejecting members by surface tension of a fluid in the nozzle chamber.

Abstract: A liquid discharge head is arranged in a manner that in the cross-section of a discharge port perpendicular to a liquid discharge direction, the discharge port includes at least one projection that is convex inside the discharge port; a first area, for holding a liquid surface connecting a pillar-shaped liquid that is elongated outside the discharge port; and second areas where a fluid resistance is lower than that in the first area so as to pull the liquid in the discharge port in a direction opposite to the liquid discharge direction. The first area is formed in the direction in which the projection is convex, and the second areas are formed on both sides of the projection.

Abstract: There is provided a printing head which improves durability and increases reliability by reducing stress occurring in a bonding part between an electrode pad and an inner lead at cooling. The electrode pad and the inner lead are electrically connected in such a manner that in the bonding portions between the electrode pad and a stud bump, only a part of contacting portions between the electrode and the stud bump is bonded.

Abstract: A method of ejecting droplets of liquid from a paired drop ejector, the method includes the steps of providing a chamber having a dividing wall that forms a first and second portion and the first portion includes a first nozzle mated with a first heater and the second portion includes a second nozzle mated with a second heater; providing liquid to the first portion and second portions of the chamber through an open end of the enclosure; providing a first electrical pulse to the first heater to provide thermal energy for ejecting a droplet of liquid from the first nozzle; and providing a second electrical pulse to the second heater to provide thermal energy for ejecting a droplet of liquid from the second nozzle; wherein the second electrical pulse is delayed relative to the first electrical pulse by a first predetermined delay time.

Abstract: A photoresist composition including an oxetane-containing compound represented by Formula 1 or 2, an oxirane-containing compound represented by Formula 3 or 4, a photoinitiator, and a solvent, a method of forming a pattern using the photoresist composition, and an inkjet print head including a polymerization product of the photoresist composition. The photoresist composition provides a polymerization product which resists formation of cracks due to an inner stress, and has excellent heat tolerance, excellent chemical resistance, excellent adhesiveness, and excellent durability.

Abstract: A heating channel unit which includes a communicating channel for supplying liquid from a liquid supply source to a liquid ejecting head. The heating channel unit is detachably mounted between the liquid supply source and the liquid ejecting head, and includes a heat generator which heats the liquid in the communicating channel.

Abstract: There is inexpensively and simply provided a highly reliable printing head including a printing element substrate which is located with high positioning precision and therefore causes no occurrence of ink leak regardless of the printing head having a large printing width. An ink jet printing head comprises a plurality of printing element substrates, in each of which a plurality of ejecting openings, printing elements and an ink supply opening are provided, a support member and an ink supply member. The support member is formed of a first member and a second member that is integral with the first member so as to surround the first member, and the support member and the ink supply member are bonded in such a manner that bonding faces of the first member and the second member, and the second member are not in contact with the opening.

Abstract: The present invention provides a higher density, higher resolution, higher durability and lower cost circuit substrate. In a circuit substrate in which a circuit including: a plurality of heat generating elements in which a pair of electrodes opposing each other to form a predetermined gap is provided on a resistor 16 and a portion where a resistor layer is positioned between the electrodes is taken as a resistor portion; and first and second wiring layers 12 and 15 for energizing the pair of electrodes of each heat generating element; is mounted on a substrate 10, the substrate is formed of Si, the first wiring layer is formed of a metal material containing at least Si, the first wiring layer is electrically connected to the substrate, the second wiring layer is provided on the first wiring layer through a metal film 14 for preventing Si from diffusing and a resistor is provided over the second wiring layer.

Abstract: A stationary pagewidth inkjet printhead is comprised of a plurality of printhead integrated circuits butted end-on-end across the pagewidth. The printhead includes one or more nozzle rows extending along a longitudinal axis of the printhead, each nozzle row comprising a plurality of nozzles. One or more of the nozzles are configured to fire a droplet of ink at a plurality of predetermined different dot positions along the longitudinal axis.

Abstract: A head substrate is capable of integrating driver transistors while keeping the size small even at high nozzle density, while integrating a functional circuit such as a temperature sensor or energy adjustment circuit. An ink supply port, a heater array which is arrayed along the longitudinal direction of the ink supply port and includes a plurality of heaters, a transistor array which is arrayed along the arrayed direction of the heater array and includes a plurality of transistors for driving a plurality of heaters, and a logic circuit which drives the transistor array are arranged on the head substrate. The logic circuit is arranged between the heater array and the transistor array.

Abstract: A liquid ejection head and a method of forming the same. The liquid ejection head includes a substrate, an ejection port, a liquid channel, and a supply port. The substrate has, above one side thereof, an energy generating element configured to generate energy used to eject liquid. The ejection port, from which a liquid is ejected, is located at a position corresponding to the energy generating element. The liquid channel communicates with the ejection port and penetrates the substrate from the one side to another side of the substrate. The supply port communicates with the liquid channel. The substrate has a projecting layer extending inward of an inner peripheral portion of an opening in the supply port in the one side, and the projecting layer and the energy generating element are formed of the same material.

Abstract: There is described a method for depositing at least one biological fluid onto a surface (12) of a substrate (10), the method comprising the steps of (i) providing at least one thermal bubble-jet printhead (T1, T2, T3) loaded with at least one biological fluid, (ii) positioning the printhead (T1, T2, T3) next to the substrate, and (iii) supplying the printhead (T1, T2, T3) with energy thereby depositing the biological fluid onto the surface (12). The printhead (T1, T2, T3) is supplied with an energy E such that E>1.6*Eth where Eth is the threshold energy of the printhead (T1, T2, T3). There are also described an apparatus (DA) for depositing at least one biological fluid onto a surface (12) of a substrate (10) and a microarray (MA) obtained by carrying out the depositing method.

Abstract: A chip used for dispensing a fluid such as ink provides ink-dispensing ejectors having an ink cavity over a supporting substrate, and further provides a heater for heating the ink in the cavity. The heater can be interposed between the substrate and the ink cavity to provide direct heating of ink as it is being dispensed. Various embodiments further comprise the use of the heater structure as a temperature probe to measure the temperature of the ink in the ink cavity. Other embodiments provides a chip having both a temperature probe and a heater as separate structures interposed between the ink cavity and the substrate. Further described is a temperature probe and/or heater which traverses a majority of a width of a substrate, and surrounds each drop ejector on at least two sides.

Abstract: A microfiltration apparatus and method for separating cells, such as circulating tumor cells, from a sample using a microfiltration device having a top porous membrane and a bottom porous membrane. The porous membranes are formed from parylene and assembled using microfabrication techniques. The porous membranes are arranged so that the pores in the top membrane are offset from the pores in the bottom membrane.

Abstract: A liquid jet recording head includes a substrate on which are formed recording elements that generate energy for ejecting liquid, and a flow passage forming member that is in contact with the substrate and in which are formed ejection ports that eject liquid and flow passages that supply liquid to the ejection ports. The flow passage forming member has a groove formed along the longitudinal direction of the flow passage forming member, and each end of the groove is located nearer to the middle in the width direction of the flow passage forming member than the other part of the groove is.

Abstract: An inkjet head may comprise an ejection port which ejects ink and an ink flow path which supplies the ink to the ejection port. The inkjet head may also comprise an ejection actuator which supplies ejection energy to the ink in the ink flow path. The ejection energy may cause the ink to be ejected from the ejection port. The inkjet head may also comprise a wall portion. The wall portion may be located at a position farther from the ejection port along the ink flow path with respect to a position at which the ejection energy is supplied. The wall portion may define an inner wall surface of the ink flow path. The wall portion may deform to decrease a cross section of the ink flow path in a direction orthogonal to an ink-flow direction as a temperature of the ink in the ink flow path increases. The wall portion may deform to increase a cross section of the ink flow path in a direction orthogonal to an ink-flow direction as the temperature of the ink in the ink flow path decreases.

Abstract: An inkjet nozzle assembly includes a nozzle chamber comprising a floor and a roof. The roof has a moving portion which is moveable relative to the floor. A thermal bend actuator is configured for actuating the moving portion. The thermal bend actuator includes an active beam for connection to drive circuitry and a passive beam mechanically cooperating with the active beam. When a current is passed through the active beam, the active beam expands relative to the passive beam resulting in bending of the moving portion towards the floor of the nozzle chamber. The nozzle opening is defined in the moving portion of the roof, such that the nozzle opening is moveable relative to the floor.

Abstract: A printing head is provided in which a distance between an ejection port face of the printing head and a print medium is reduced to improve an ink ejection accuracy during a printing operation. The printing head of the present invention is a back shooting-type printing head. The heater and an electrode connected thereto are formed at the back face of the substrate. The electrode and an in-support-base wiring for supplying electricity to the heater via the electrode are connected to each other at the back face side of the substrate. The substrate and the support base have therebetween a liquid chamber wall member including therein a space. The substrate, the support base, and the liquid chamber wall member constitute a liquid chamber that communicates with the ejection port and that stores ink supplied to the ejection port.

Abstract: A liquid ejecting head includes a substrate, a nozzle forming member for forming on a principal surface of the substrate a nozzle comprising a flow passage of liquid and an orifice for ejecting the liquid, and a dummy pattern. The dummy pattern has substantially the same dimension as at least a part of the nozzle and is formed so that a cross-section of the dummy pattern is exposed at an end surface of the nozzle forming member.

Abstract: A solvent-based ink composition for a thermal inkjet printhead includes (a) 55-90 wt. % of an organic solvent including a ketone and a C1 to C4 alcohol; and (b) 0.01-10 wt. % of a colorant.

Abstract: The impact accuracy of ejected droplets, the quality of printed images, and print speed can be improved in a print head having an ink channel for which the width thereof in a direction orthogonal to an ink supply direction in which ink is supplied from an ink supply port to a pressure chamber is smaller than that of a pressure chamber. In the print head, the center of a heater along the ink supply direction is offset from the center of the pressure chamber along the ink supply direction, toward the side of the pressure chamber far from the ink supply port in the ink supply direction.

Abstract: A nozzle assembly for an inkjet printhead is disclosed. The nozzle assembly includes an inkjet nozzle having an actuator for ejecting an ink droplet from the inkjet nozzle when a resistive element of the actuator is heated by an electrical current. A drive transistor provides an energy pulse to the resistive element of the actuator upon receipt of a control pulse. Each energy pulse has energy of less than 200 nanojoule.

Abstract: A method for printing a decoration image on a substrate with a thermal ink jet printer includes providing a thermal ink jet printer and providing an ink composition for the ink jet printer. The ink composition includes water and a colorant. Both the substrate and the ink are soluble or dispersible in water. Droplets of the ink composition are applied to the substrate by the thermal ink jet printer. The ink droplets are allowed to dry, thereby printing an image on the substrate.

Abstract: An ink-jet recording head includes a discharge-port portion including a first discharge-port portion continuing from a discharge port, and a second discharge-port portion communicating the first discharge-port portion with a bubble generation chamber. The second discharge-port portion has an end surface that includes a border portion bordering the first discharge-port portion and is parallel to a main surface of an element substrate. The cross-sectional area of the second discharge-port portion, anywhere from an opening surface facing the bubble generation chamber to an end surface facing the first discharge-port portion, that is parallel to the main surface of the element substrate, is larger than the area of the border portion. The cross-section of the opening surface of the second discharge-port portion has a length in a direction perpendicular to an arrangement direction of the discharge ports that is greater than its length in a direction parallel to the arrangement direction.

Abstract: A liquid ejection recording head includes an element substrate having plural ejection energy generating elements, an ejection outlet array of plural ejection outlets, and bubble generation chambers. The element substrate includes a first liquid supply port provided along an arrangement direction of the ejection outlets, and plural second ink supply ports disposed between a lateral end of the substrate and the chambers. Each bubble generation chamber communicates with the first and second liquid supply ports through first and second liquid supply passages, respectively. The element substrate has a thermal resistance against heat flowing from the ejection energy generating elements along a direction perpendicular to the array direction and parallel to a surface of the substrate. The thermal resistance, per unit length with respect to the array direction, at both end portions of the array is larger than that at a central portion of the ejection outlet array.

Abstract: Disclosed is a printhead having at least one ink drop generator region, which includes an ink chamber, an orifice through which ink drops are ejected, and a heating element positioned below the ink chamber. The heating element includes a resistor defined therein and a nano-structured surface that is exposed to the ink fluid supplied to the ink chamber. The nano-structured surface takes the form of an array of nano-pillars. The printhead is fabricated by a method that includes: forming a heating element having an oxidizable metal layer as the uppermost layer; forming an aluminum-containing layer on the oxidizable metal layer; anodizing the aluminum-containing layer to form porous alumina; anodizing the oxidizable metal layer so as to partially fill the pores in the porous alumina with metal oxide material; and removing the porous alumina by selective etching to produce a nano-structured surface.

Abstract: The liquid ejection head comprises: a nozzle from which liquid is ejected; a pressure chamber which accommodates the liquid to be ejected from the nozzle; a pressurizing device which deforms to pressurize the liquid in the pressure chamber to eject the liquid from the nozzle; and a nozzle flow channel through which the pressurized liquid flows from the pressure chamber to the nozzle, the nozzle flow channel having at least a portion in which forces acting toward an axis of the nozzle flow channel onto the liquid flowing inside the nozzle flow channel are not uniform within a cross-section perpendicular to the axis.

Abstract: An image forming apparatus performs an image forming operation by driving a ejecting element of a recording head with an ink ejecting drive voltage for ejecting ink, detects a temperature of ink to be flown into the recording head and a temperature of ink to be discharged respectively with a first temperature detection section and a second temperature detection section, and corrects the ink ejecting drive voltage on the basis of a temperature of ink being heat-transferred with the ejecting element, which is estimated with a predetermined conversion formula on the basis of the detected ink temperatures, for controlling an ink amount to be ejected.

Abstract: Methods for fabricating micro-fluid ejection heads and micro-fluid ejection heads are provided herein, such as those that use non-conventional substrates. One such micro-fluid ejection head includes a substrate having first and second glass layers disposed adjacent to a surface thereof and a plurality of fluid ejection actuators disposed adjacent to the second glass layer. The first glass layer is thicker than the second glass layer and the second glass layer has a surface roughness of no greater than about 75 ? Ra.

Abstract: A single phase aqueous composition suitable for thermal inkjet printing comprises a mixture of curable materials including at least two curable oligomers; and one or more co-solvents for the curable materials.

Abstract: A method for forming a floating heater element includes processing a silicon substrate to form a heater stack having the heater element on the substrate with peripheral edge portions, processing the heater stack by depositing and patterning a layer of photoresist or hard mask thereon to substantially mask the heater stack and form a trench through the photoresist or hard mask exposing a surface area of the substrate extending along the peripheral edge portions of the heater element, and processing the masked heater stack and exposed surface area of the substrate by sequentially removing the photoresist and portions of the substrate at the exposed surface area and that underlie the heater element so as to create a well in the substrate undercutting the heater element and open along the peripheral edge portions thereof, the well being capable of filling with a fluid so as to produce the floating heater element.

Abstract: A nozzle arrangement includes a substrate defining an ink supply passage; a first endless wall extending from the substrate and bounding the ink supply passage; an elongate actuator anchored at a fixed end to the substrate and configured to reciprocally bend towards and away from the substrate on receipt of an electrical current; and a cover terminating a free end of the actuator, the cover defining a second endless wall suspended from the cover within the confines of the first endless wall to define an ink chamber with the first endless wall. The reciprocal bending of the actuator varies a volume of the ink chamber and effects ejection of ink from the ink chamber through an ink ejection port defined in the cover. The first and second endless walls define a gap having a width conducive to the formation of a fluidic seal effected via surface tension of the ink.

Abstract: An ejection nozzle arrangement is provided having a fluid chamber having a wall and a fluid port, an arm extending through an aperture in the wall, a dynamic structure cantilevered from the wall adjacent the aperture, a static structure cantilevered from the wall adjacent the dynamic structure. The arm is connected to the dynamic and static structures at a point distal from the aperture such that thermal expansion of the dynamic structure moves the arm upwards in the chamber to eject fluid from the chamber through the port.

Abstract: A liquid ejecting head that includes a fluid channel formation substrate and pressure generation units. The fluid channel formation substrate is made of a silicon single crystal substrate having a crystal face orientation of. The fluid channel formation substrate has a plurality of separate flow channels that include at least pressure generation chambers demarcated by partition walls, each of the pressure generation chambers being in communication with a nozzle opening that ejects liquid drops. The fluid channel formation substrate further has a communication portion that is in communication with each of the separate flow channels. The pressure generation units are provided so as to correspond to the pressure generation chambers and generate a pressure change in the pressure generation chambers so as to cause ejection of liquid drops.

Abstract: An inkjet printer that has an array of ink chambers, each with a nozzle, a droplet stem anchor and a thermal actuator. The thermal actuator generates a vapor bubble in the ink chamber to eject ink through the nozzle. The thermal actuator has a plurality of heater elements connected in parallel with a cross bracing structure extending between the heater elements. The cross bracing structure also providing the droplet stem anchor. During use, the vapor bubble generated by the thermal actuator grows until it vents to atmosphere through the nozzle and the ink ejected from the nozzle is attached to the droplet stem anchor by an ink stem until the stem breaks and the ejected ink forms a separate drop.

Abstract: A heater stack includes first strata configured to support and form a fluid heater element responsive to energy from repetitive electrical activation and deactivation to fire repetitive cycles of heating and ejecting fluid from an ejection chamber above the fluid heater element and second strata overlying the first strata and contiguous with the ejection chamber to provide protection of the fluid heater element. The first strata includes a substrate and a heater substrata overlying the substrate and including a resistive layer having lateral portions spaced apart, a central portion extending between the lateral portions and defining the fluid heater element, and transitional portions interconnecting the central portion and lateral portions and elevating the central portion relative to the lateral portions and above the substrate to form a gap between the lateral portions and between the central portion and substrate insulating the substrate from the fluid heater element.

Abstract: A fluid ejector device, including: a fluid nozzle layer defining an orifice therein; and at least one epoxy resin layer established on the nozzle layer, the at least one epoxy resin layer having first and second opposed surfaces with a thickness there between and a fluorine gradient formed therein such that the gradient extends into at least a portion of the thickness of the at least one epoxy resin layer, wherein an amount of a fluorinated species present in the at least one epoxy resin layer at the first opposed surface is greater than an amount of the fluorinated species present in the at least one epoxy resin layer at the second opposed surface that is adjacent the fluid nozzle layer.

Abstract: A unit cell for an inkjet printhead includes a substrate that defines an ink inlet passage, the substrate incorporating drive circuitry. Side walls are arranged on the substrate. A nozzle plate is arranged on the side walls such that the nozzle plate and the side walls define an ink chamber in fluid communication with the inlet passage. The nozzle plate defines an aperture in fluid communication with the ink chamber. A heater element is connected to the drive circuitry. The heater element is configured to generate a bubble of ink to be ejected from the aperture on receipt of an electrical signal from the drive circuitry. The heater element is suspended in the ink chamber such that, when ink is supplied to the chamber, the heater element is immersed in the ink. The heater element is configured so that a collapse point of the bubble is at a position spaced from the heater element.

Abstract: A paired drop ejector includes a chamber having a first wall and a second wall opposite the first wall and a dividing wall disposed between the first and second wall; wherein the first and second wall include a first length and the dividing wall includes a second length less than the first length in which the dividing wall forms first and second portions of the chamber; a first heater disposed in the first portion of the chamber in fluid relation with a first nozzle in which the first heater provides thermal energy to eject a droplet of ink through the first nozzle; and a second heater disposed in the second portion of the chamber in fluid relation with a second nozzle in which the second heater provides thermal energy to eject a droplet of ink through the second nozzle.

Abstract: A reliable print head with improved reliability is less likely to be damaged by possible cavitation in ink inside a bubbling chamber. A plurality of ink supply paths through which the ink is supplied to the bubbling chamber are connected to the bubbling chamber. Communication positions where the plurality of ink supply paths communicate with the energy acting chamber are formed such that distances from a heater formation surface of the communication positions are different from each other along a direction orthogonal to the heater formation surface.