Abstract: A thermal head according to the present disclosure includes a substrate, a plurality of heat generating portions, a plurality of first electrodes, and a second electrode. The plurality of heat generating portions are located on the substrate. The plurality of first electrodes are located on the substrate and respectively connected to the plurality of heat generating portions. The second electrode is located on the substrate and is located across the plurality of first electrodes. The second electrode includes protruding portions protruding in a first direction from the second electrode toward corresponding ones of the first electrodes and being in contact with the corresponding ones of the first electrodes.

Abstract: A thermal print head includes a substrate; a protrusion formed on an obverse surface of the substrate and extending in a main scanning direction; heat generating parts disposed on a top surface of the protrusion and arranged along the main scanning direction; and columnar heat storage members embedded in the protrusion and disposed in a given area having a width in a sub-scanning direction and being elongated in the main scanning direction. Each of the columnar heat storage members is elongated in a thickness direction of the substrate and has an upper end and a lower end, with the upper end being disposed at the same level of the top surface of the protrusion.

Abstract: Systems and methods for optimizing morphology and electrical properties of silver printed on a substrate with a particular implementation in photovoltaic manufacturing techniques. The system comprises a substrate, a printer jet head having a nozzle to dispense a reactive metal ink and a solvent onto the substrate, and wherein the solvent and a temperature of the substrate are controlled during deposition of the reactive metal ink onto the substrate to produce a dense film in the absence of sintering.

Abstract: A fluid ejection device, comprising: a chamber; a membrane, with a first side and a second side opposite to one another, where the first side faces the chamber; an actuator, of a piezoelectric type, which extends on the second side of the membrane and is operatively coupled to the membrane for causing, in use, a vibration of the membrane; a passivation layer, which extends only alongside, or partially on, the actuator; and a protection layer, which extends on the actuator at least in surface portions of the latter that are free from the passivation layer, and has a Young's modulus lower than the Young's modulus of the passivation layer.

Abstract: A method of adhering a cover layer to a substrate includes forming an array of nano-structures on a substrate. A flowable material is applied to the substrate, the flowable material substantially enveloping the nano-structures on the substrate. The flowable material is solidified to form a cover layer on the substrate, the cover layer being anchored to the substrate via the nano-structures.

Abstract: Provided is a liquid ejecting head including: a first substrate in which a space serving as a flow path is formed in a state of having an opening on a surface of one side thereof; and a second substrate which seals the opening from the surface on the one side of the first substrate, divides the flow path, and is made of resin, in which the first substrate and the second substrate adhere to each other via a first adhesive layer which is laminated on the surface on the one side of the first substrate and which is made of a silicone-based adhesive and a second adhesive layer which is laminated on the first adhesive layer and which is made of an epoxy-based adhesive.

Abstract: A liquid discharge head comprising a silicon substrate; an insulating layer A formed on a first surface of the silicon substrate, a protective layer A that includes metal oxide and is formed on the insulating layer A, the structure that is formed on the protective layer A by direct contact with the protective layer A, includes organic resin, and forms a part of a flow path for liquid, and an element that is formed on a second surface of the silicon substrate on a side opposite to the first surface, and is configured to generate energy used for discharging the liquid.

Abstract: In some examples, an integrated circuit device includes a substrate, a memristor over the substrate and comprising a first metal layer as a first electrode, a second metal layer as a second electrode, and a switching oxide layer between the first and second metal layers, and a thermal resistor layer over the substrate.

Abstract: An electronic device includes a plurality of substrates joined together in a stacked state, a space formed in one substrate out of the plurality of substrates, and a movable region configured by one face out of faces bounding the space. The movable region includes a recess indented from a space side to partway along a thickness direction of the movable region. An internal dimension of the recess in a direction perpendicular to a substrate stacking direction is larger than an internal dimension of the space in the direction perpendicular to the substrate stacking direction, and a wall bounding the space in the one substrate, and at least a portion of a bottom face of the recess, are adhered together by an adhesive.

Abstract: A recording-element substrate includes a substrate including a base member, a pair of electrodes, a heating element formed of a thermal resistor layer between the electrodes, a surface on which an electroconductive film coating the heating element has been formed, and an insulating film between the heating element and the electroconductive film and a flow-path-forming member including walls forming a liquid flow path toward the heating element while being disposed on the substrate's surface side. The substrate includes an electric connecting portion in contact with the electroconductive film to connect the electroconductive film with the base member. The shortest distance between the electric connecting portion and a portion where an angle formed by the walls is 120 degrees or smaller when viewed from a direction orthogonal to the surface is smaller than that between a boundary between the electrodes and the heating element and the portion.

Abstract: Printheads having memories formed thereon are disclosed. An example apparatus includes a printhead body comprising a first metal layer. The example apparatus also include a memory formed on the print-head body. The memory includes the first metal layer as a first electrode, a second metal layer as a second electrode, and a switching oxide layer between the first and second metal layers.

Abstract: A method for manufacturing a liquid supply member that supplies a discharge port with liquid includes preparing a transparent member and an absorption member, at least one of both members having a groove for a supply path; bringing both members into contact; and forming the supply path by emitting laser beams simultaneously from a plurality of laser beam sources, toward a contact portion, which is provided in a vicinity of the groove and at which both members are in contact, to weld both members. Laser beams are emitted during the forming such that a total laser-beam irradiation amount per unit area for a first portion included in the contact portion and located in a vicinity of an end in a longitudinal direction of the groove is larger than that for part with a smallest irradiation amount of a second portion other than the first portion of the contact portion.

Abstract: According to the present disclosure, a manufacturing method of a fine wiring pattern is disclosed. The manufacturing method includes preparing a support member, forming a first layer on the support member by thick-film printing, and forming a second layer including Ag on the first layer by the thick-film printing. The method also includes forming a predetermined fine wiring pattern by performing an etching process upon the first layer and the second layer.

Abstract: Provided are a liquid ejecting method, a liquid ejecting device, and a liquid ejecting system which can avoid damage of an electro-thermal conversion element caused by cavitation and can prolong a life thereof even in a case that handling with a configuration of an ejecting port is difficult. For that purpose, ejection is performed for a low-duty region by controlling such that variation in an ejection speed is made smaller, and ejection is performed for a high-duty region by controlling such that variation in the ejection speed is made larger.

Abstract: A method for manufacturing a liquid ejection head includes the following processes in the following order: forming a first metal layer containing a first metal material on an insulating layer of a base on which a plurality of thermal energy generating elements and the insulating layer are laminated in this order; forming a second metal layer containing a second metal material on the first metal layer, and then patterning the second metal layer to form a plurality of protective portions; patterning the first metal layer to form a connection portion for electrically connecting the plurality of protective portions; inspecting the conduction of the connection portion and the plurality of energy generating elements; and patterning the connection portion to thereby electrically isolate the plurality of protective portions and form a plurality of close contact portions which are electrically isolated from each other.

Abstract: There are provided a substrate for an inkjet head and an inkjet head wherein in a case where a protection layer of heating resistors is energized, an electrical connection with portions around the protection layer is more reliably cut. A first protection layer provided for the substrate for an inkjet head includes individual sections provided at positions corresponding to the plurality of heating resistors and a common section which commonly connects the plurality of individual sections. The individual sections and the common section are connected via connect sections which are eluted and connect in a case where an electrochemical reaction occurs between the connect sections and ink when electricity flow therethrough, so that an electrical connection between the individual sections and the common section is cut.

Abstract: A substrate for a liquid discharge head includes an upper protection film that covers at least a region corresponding to each of thermal energy generation elements. The upper protection film and at least one of the upper protection films adjacent to the upper protection film within a liquid chamber are respectively connected to different external electrodes, and a voltage can be applied therebetween via the different external electrodes.

Abstract: An inkjet nozzle device for symmetrically constrained bubble formation includes: a firing chamber having and an end wall, opposite sidewalls and a nozzle aperture defined in a roof thereof; a baffle plate positioned between the sidewalls of the firing chamber, such that a pair of firing chamber entrances are defined between side edges of the baffle plate and the sidewalls; and an elongate heating element bonded to a floor of the firing chamber, the heater element extending longitudinally between the baffle plate and the end wall. The baffle plate is wider than the heater element. Further, a centroid of the heater element coincides with a midpoint between the baffle plate and the end wall.

Abstract: A liquid ejecting head suppresses erosion of silicon substrates by liquid, and whereby suppresses leakage of liquid, discharging failure of liquid droplets, and peeling-off of laminated substrates. The liquid ejecting head includes at least a nozzle plate on which nozzle openings for discharging liquid are provided, and a flow path formation substrate on which a pressure generation chamber communicating with the nozzle openings is provided. The nozzle plate is formed with a silicon substrate. At least the flow path formation substrate and the nozzle plate are bonded to each other after providing a tantalum oxide film formed by atomic layer deposition on the entire surfaces including a bonded surface.

Abstract: A liquid ejection head substrate includes a substrate, an element disposed on the substrate that generates thermal energy used for ejecting liquid, and a protective layer disposed at least at a position corresponding to the element. The protective layer contains iridium and has a density in the range of 21.0 g/cm3 to 22.7 g/cm3.

Abstract: According to a liquid ejecting head, it is possible to suppress erosion of a vibrating plate by liquid, suppress generation of variation in a vibrating property, and realize a thin head. The liquid ejecting head includes a flow path formation substrate on which a pressure generation chamber communicating with nozzle openings for discharging liquid is provided, an elastic film which is provided on one surface side of the flow path formation substrate and seals the pressure generation chamber, and a piezoelectric actuator which is a pressure generation unit which is provided on the elastic film to deform the elastic film. A tantalum oxide film which is formed by atomic layer deposition is provided at least on an inner wall of the pressure generation chamber.

Abstract: An inkjet print head includes a jet assembly which includes a nozzle plate, the nozzle plate including an ink transferring path on a bottom surface of the nozzle plate, and a jet jetting a transferred ink out of the head. A printed circuit substrate is connected to the jet assembly and includes an integrated circuit and a connection electrode. A barrier coating layer covers a surface of the printed circuit substrate and an inner surface and an outer surface of the jet assembly except a bottom surface of the nozzle plate and a surface of the connection electrode of the jet assembly and the printed circuit substrate being connected with each other. The barrier coating layer has a layered structure which includes a flexible layer, a diffusion barrier layer, and a hydrophobic layer.

Abstract: Performing a high-speed recording operation using a slender liquid discharge head substrate causes an uneven temperature distribution for each energy generating element because the center portion of the liquid discharge head substrate is more liable to accumulate heat than the end portion thereof, which may affect the quality of a recorded image. For this reason, the surface of the energy generating element which contacts liquid is separated into a first region and a second region in which a protection film is thicker than the one in the first region, and the area in the first region for the element positioned at the end portion of the array of the elements is made greater than that in the first region at the center portion thereof.

Abstract: The reduction in reliably of a liquid discharge head due to the dissolution of a protective layer is suppressed. A substrate for a liquid discharge head includes a base substrate, a heat-generating resistive layer placed on the base substrate, a pair of lines placed on the base substrate, and a protective layer covering the heat-generating resistive layer and the lines. The protective layer contains a material represented by the formula SixCyNx, where x+y+z=100, 30?x?59, y?5, and z?15 on an atomic percent basis.

Abstract: A liquid discharge head, contains: an energy generating element which generates thermal energy and contains a heat generation resistant layer and a pair of electrode layers whose end surfaces are separated from each other; an insulating layer covering the pair of electrode layers and the heat generation resistant layer and containing an insulating material; a protective layer provided above the insulating layer at least at a position corresponding to the energy generating element and containing a metal material containing iridium or ruthenium; and a covering layer provided at a position covering at least portions of the protective layer corresponding to the end surfaces of the pair of electrode layers in such a manner that a part of the protective layer is exposed and containing a metal material containing tantalum or niobium.

Abstract: A liquid recording head includes a protective layer having resistance to liquid and an adhesiveness improving film disposed on a second surface of a silicon substrate, opposite to a first surface. The first surface and the second surface have a plane direction (100). The protective layer is disposed in a peripheral region of an opening of a liquid supply port. A liquid ejection chip is bonded to a head substrate with an adhesive so that the liquid supply port communicates with a liquid introduction port on a side of the second surface of the silicon substrate.

Abstract: A method for preparing an integrated circuit or micro-electro-mechanical system chip sample for ion cross-section polishing is provided. The method includes preparing a polymer coating formulation. The polymer coating formulation includes a novolac epoxy resin, a bisphenol-A/epichlorhydrin epoxy resin, a photoacid generator, an adhesion promoter, and a mixture of acetophenone, cyclohexanone and butyrolactone organic solvents. The integrated circuit or micro-electro-mechanical system chip sample is encapsulated by the polymer coating formulation, wherein the chip sample is then ready for ion beam cross-section polishing. A cross-section sample of integrated circuit or micro-electro-mechanical system chip is prepared by polishing the obtained polymer encapsulated integrated circuit or micro-electro-mechanical system chip with ion beam cross-section polisher. The disclosed method allows the cross-section sample to be obtained at a reduced polishing time.

Abstract: An inkjet printhead has a plurality of nozzles; a bubble forming chamber corresponding to each of the nozzles; and a heater element disposed in each of the bubble forming chambers. The heater element is configured for heating an ejectable liquid above its boiling point to form a gas bubble that causes the ejection of a drop from the nozzle. The heater element is comprised of titanium aluminum nitride.

Abstract: A droplet ejection head includes: a nozzle plate which has a nozzle aperture for ejecting droplets of liquid; a flow channel structure including a pressure chamber which contains the liquid and is connected to the nozzle aperture through a flow channel; and a pressure generating element which applies pressure to the liquid in the pressure chamber, wherein an ejection surface of the nozzle plate where the droplets of the liquid are ejected is made of a fluorine-containing DLC film.

Abstract: An inkjet printhead is provided for a digitally controlled inkjet printing apparatus wherein the inkjet printhead is comprised of a material layer and a drop formation mechanism positioned in or on the material layer, that is substantially improved in chemical resistance and thermally stability. A chemically resistant and thermally stable multilayer coating is provided onto and in contact with the inkjet printhead, wherein the multilayer coating includes one or more thin film layers comprised primarily of hafnium oxide or zirconium oxide and one or more thin film layers comprised primarily of tantalum oxide, the multilayer coating being located on the material layer.

Abstract: A liquid ejector includes a substrate, a heating element, a dielectric material layer, and a chamber. The substrate includes a first surface. The heating element is located over the first surface of the substrate such that a cavity exists between the heating element and the first surface of the substrate. The dielectric material layer is located between the heating element and the cavity such that the cavity is laterally bounded by the dielectric material layer. The chamber, including a nozzle, is located over the heating element. The chamber is shaped to receive a liquid with the cavity being isolated from the liquid.

Abstract: A fluid ejector having an inner surface, an outer surface, and an orifice that allows fluid in contact with the inner surface to be ejected. The fluid ejector has a non-wetting monolayer covering at least a portion of the outer surface of the fluid ejector and surrounding an orifice in the fluid ejector. Fabrication of the non-wetting monolayer can include removing a non-wetting monolayer from a second region of a fluid ejector while leaving the non-wetting monolayer on a first region surrounding an orifice in the fluid ejector, or protecting a second region of a fluid ejector from having a non-wetting monolayer formed thereon, wherein the second region does not include a first region surrounding the orifice in the fluid ejector.

Abstract: According to one embodiment, when an electrode protection film of an inorganic material, which is apt to form a pin hole by influence of roughness of a ground, is used, an electrode as a smoothed electrode is formed on the ground of the electrode protection film by a plating method, or a film is formed as a smoothed layer (film) by an inorganic coating material such as SIRAGUSITAL (trade name: New Technology Creating Institute Co., Ltd.), such that the thickness of the electrode protection film is 1.0 ?m or more, and the average surface roughness of the ground of the electrode protection film is 0.6 ?m or less.

Abstract: In an ink jet head using a thermal energy for ejecting ink, this invention aims to reliably and uniformly remove kogations deposited on a heat application portion in contact with the ink. To realize this objective, the upper protective layer is arranged in an area including the heat application portion so that it can be electrically connected to serve as an electrode which causes an electrochemical reaction with the ink. The upper protective layer is formed of a material containing a metal which is dissolved by the electrochemical reaction and which does not form, on heating, an oxide film which hinders the dissolution. With this arrangement, a reliable electrochemical reaction can be produced to dissolve a surface layer of the upper protective layer, thereby removing kogations on the heat application portion reliably and uniformly.

Abstract: A method of hydrophobizing a frontside surface of an integrated circuit. The method includes the steps of: (a) depositing a hydrophobic polymeric layer onto the frontside surface; (b) depositing a protective metal film onto the hydrophobic polymeric layer; (c) depositing a sacrificial material onto the metal film; (d) patterning the sacrificial material; (e) etching through the metal film, the hydrophobic polymeric layer and the frontside surface; (f) performing MEMS processing steps on a backside of the integrated circuit; (g) subjecting the integrated circuit to an oxidizing plasma, wherein the metal film protects the hydrophobic polymeric layer from the oxidizing plasma; and (h) removing the protective metal film to provide an integrated circuit having a relatively hydrophobic patterned frontside surface.

Abstract: A liquid discharge head, contains: an energy generating element which generates thermal energy and contains a heat generation resistant layer and a pair of electrode layers whose end surfaces are separated from each other; an insulating layer covering the pair of electrode layers and the heat generation resistant layer and containing an insulating material; a protective layer provided above the insulating layer at least at a position corresponding to the energy generating element and containing a metal material containing iridium or ruthenium; and a covering layer provided at a position covering at least portions of the protective layer corresponding to the end surfaces of the pair of electrode layers in such a manner that a part of the protective layer is exposed and containing a metal material containing tantalum or niobium.

Abstract: A fluid ejector includes a substrate, a MEMS transducing member, a compliant membrane, walls, and a nozzle. First portions of the substrate define an outer boundary of a cavity. Second portions of the substrate define a fluidic feed. A first portion of the MEMS transducing member is anchored to the substrate. A second portion of the MEMS transducing member extends over at least a portion of the cavity and is free to move relative to the cavity. The compliant membrane is positioned in contact with the MEMS transducing member. A first portion of the compliant membrane covers the MEMS transducing member. A second portion of the compliant membrane is anchored to the substrate. Partitioning walls define a chamber that is fluidically connected to the fluidic feed. At least the second portion of the MEMS transducing member is enclosed within the chamber. The nozzle is disposed proximate to the second portion of the MEMS transducing member and distal to the fluidic feed.

Abstract: An ink jet head includes a Si substrate with a surface having a {100} orientation; a passage holding ink on the Si substrate; an ink discharge port which is communicatively connected to the passage and through which ink is ejected; and a supply port which extends through the Si substrate, which is communicatively connected to the passage, and which supplies ink to the passage. The supply port has walls having two {111} planes facing each other.

Abstract: When an insulating layer is provided in order to protect an energy generating element, there arises a possibility that the layer dissolves in a contacting liquid. Therefore, in order to eject liquid, a first protection layer containing metal is provided on the insulating layer facing a substrate for a liquid-ejection head and a second protection layer containing metal is provided on the surface of a liquid supply port to which a base containing silicon is exposed.

Abstract: A printhead is provided having a casing mounted on a molding to define a fluid reservoir and a first passage in fluid communication between the fluid reservoir, a wafer at least defining at least a part of a channel spaced from the first passage and at least a part of a second passage arranged to provide fluid communication between the first passage and channel, a plurality of ink ejection devices in fluid communication with the channel, and a metal cap portion which encloses the casing and molding.

Abstract: A fin-shaped heater stack includes first strata configured to support and form fluid heater elements responsive to repetitive electrical activation and deactivation to produce repetitive cycles of ejection of a fluid, and second strata on the first strata to protect the fluid heater elements from adverse effects of the repetitive cycles of fluid ejection and of contact with the fluid. The first strata include a substrate having a front surface, and heater substrata supported on the front surface. The heater substrata have opposite facing side surfaces which extend approximately perpendicular to the front surface and an end surface interconnecting the side surfaces which extends approximately parallel to the front surface such that the heater substrata is provided in either an upright or inverted fin-shaped configuration on the substrate with the fluid heater elements forming the opposite facing side surfaces of the heat substrata.

Abstract: A thermal inkjet printhead integrated circuit has an array of ink chambers formed on a wafer substrate, each having a nozzle aperture and a thermal actuator. The thermal actuator has a heater element extending between two contacts. The printhead IC also has CMOS (complementary metal-oxide semiconductor) drive circuitry formed by a plurality of flat, metal layers interleaved with interlayer dielectric for selectively providing the thermal actuators of the array with drive signals. The CMOS drive circuitry has a top-most metal layer providing electrodes for each of the thermal actuators respectively. The electrodes each have a flat surface that the contacts of each of the thermal actuators overlie for face to face contacting engagement. The contacts and the heater element are coplanar such that the thermal actuator is an integral planar structure.

Abstract: In order to hermetically seal more surely a gap between a back surface of a liquid discharge substrate and a front surface of a support member, and an electrode portion etc., without adversely affecting discharge performance, a liquid discharge head includes a first sealing resin coated on a portion between the liquid supply port and the pad on the support surface so as to surround a tip end portion at the liquid supply port of the support member and a second sealing resin for sealing a gap between the support member and the liquid discharge substrate, and a peripheral part of the liquid supply port.

Abstract: A fluid ejection module includes a flow-path body, a first oxide layer, a membrane, and a second oxide layer. The flow-path body has a first outer surface and an opposing second outer surface and a plurality of flow paths, each flow path extending at least from the first outer surface to the second outer surface. The first oxide layer coats at least an interior surface of each of the flow paths and the first and second outer surfaces of the flow-path body and has a thickness that varies by less than 5% along {100} planes. The membrane has a first outer surface. The second oxide layer is coated on the first outer surface of the membrane and has a thickness that varies by less than 5% along {100} planes and is bonded to the first oxide layer.

Abstract: A liquid ejection head includes a substrate, having a front surface and a back surface, provided on the front surface with an energy generating element for generating energy used for ejecting liquid; a supply port, provided so as to penetrate between the front surface and the back surface of the substrate, for supplying the liquid to the energy generating element; a first film provided on the front surface of the substrate; and a second film provided so as to coat a wall of the substrate defining the supply port. The first film and the second film surface-contact each other with respect to two directions substantially perpendicular to each other.

Abstract: A method for manufacturing a liquid discharge head provided with a substrate which has a layer made of silicon nitride and with a discharge port forming member which is disposed above the layer made of silicon nitride and has a discharge port for discharging liquid. The method includes providing a photosensitive layer that is to be the discharge port forming member above the layer made of silicon nitride, and forming the discharge port by exposing the photosensitive layer to i-line. The layer made of silicon nitride has a refractive index of 2.05 or more to light of a wavelength of 633 nm and irradiation with the i-line is performed in the exposure.

Abstract: A heater stack includes first strata configured to 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 and a planar upper surface on the heater substrata.

Abstract: An ink jet printing head substrate has a high adhesion between an electrode layer and a nozzle formation member and the corrosion or electrolysis, for example, of an electrode due to the contact between the electrode and ink can be reduced. The ink jet printing head includes an electrode layer for supplying power to a heat-generating portion that is provided on a substrate and that generates thermal energy for ejecting ink; and a resin layer provided on the electrode layer via a nickel-containing layer. The electrode layer includes precious metal as a main component. The nickel-containing layer consists of a gold-nickel alloy containing nickel.

Abstract: An ink jet recording head includes a substrate, having a front surface and a back surface opposite from the front surface, provided above the front surface with an energy generating element for generating energy used for ejecting ink; an ink supply port provided so as to penetrate between the front surface and the back surface of the substrate; a first layer provided on or above the front surface of the substrate; a protection layer which is provided so as to coat a wall of the substrate defining the ink supply port and which continuously extends onto the first layer; and a second layer located above the front surface of the substrate and including a portion provided on the protection layer and another portion provided on the first layer by penetrating through the protection layer.

Abstract: In an ink jet head using a thermal energy for ejecting ink, this invention aims to reliably and uniformly remove kogations deposited on a heat application portion in contact with the ink. To realize this objective, the upper protective layer is arranged in an area including the heat application portion so that it can be electrically connected to serve as an electrode which causes an electrochemical reaction with the ink. The upper protective layer is formed of a material containing a metal which is dissolved by the electrochemical reaction and which does not form, on heating, an oxide film which hinders the dissolution. With this arrangement, a reliable electrochemical reaction can be produced to dissolve a surface layer of the upper protective layer, thereby removing kogations on the heat application portion reliably and uniformly.