JP2000006414A - Ink-jet recording head and ink-jet recording apparatus using the head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a reliability on durability, etc., and a recording performance by setting an organic insulating layer at a part under an ink passage on an oxide coat except at a part which becomes an opening part of a heat-generating resistance body to the ink passage and making a part of the oxide coat at the opening part thicker than the coat under the organic insulating layer. SOLUTION: This ink-jet recording head features a thickness difference between oxide coats 4a and 4b and also a constitution in which the thick oxide coat 4b is not in touch with an organic insulating layer 5. In the presence of the thickness difference between the oxide coats, when electricity is supplied to a heat-generating resistance body 2a, a resistance at a part of the thick oxide coat becomes larger than at a part of the thin oxide coat and therefore, the heat-generating resistance body 2a generates heat primarily under the thick oxide coat part 4b, with restricting accumulation of heat under the organic insulating layer 5 and preventing generation of a break or the like defect in the vicinity of an end part of the organic insulating layer 5 on the heat-generating resistance body 2a. The thickness difference of oxide coats is preferably not smaller than 1 μm, and more preferably not smaller than 3 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head for generating droplets of a recording liquid (ink) used in an ink jet recording system (also referred to as a liquid jet recording system), and uses the ink jet recording head. The present invention relates to an inkjet recording apparatus.

[0002]

2. Description of the Related Art The ink jet recording system is capable of high-speed and high-density recording, and is suitable for color images and miniaturization of apparatuses.

In this recording method, recording is performed by generating droplets of a recording liquid (hereinafter referred to as ink) and attaching the droplets to a recording medium such as paper. The method is adopted.

[0004] A recording head of a system in which thermal energy is applied to ink to generate bubbles by generating foams has a heat acting portion for applying heat to the ink. The heat acting portion has a portion directly in contact with the ink, and also has a mechanical impact (cavitation erosion) due to repeated foaming and defoaming of the ink, and a rise and fall of a temperature close to 1000 ° C. in a short time of several microseconds. The exposed part is required to have sufficient durability.
That is, the durability of the heat acting portion is one of the characteristics that greatly affects the reliability of the recording head.

Therefore, in the conventional ink jet recording head (for example, FIG. 9), the heating resistor 2a and the electrode 3
For example, electric insulating layers 5 and 10 made of SiO ₂ , SiC, Si ₃ N _{4 and the} like for preventing oxidation and electrolytic corrosion, and Ta,
It is general that the heat acting portion and its vicinity are protected by providing a cavitation-resistant erosion layer 11 such as described above.

Although the ink jet recording head having such a structure is practically satisfactory in terms of durability and the like,
In order to further improve the durability of the recording head, there is a limit in terms of overall production cost and recording performance.

For example, the inorganic insulating protective layers 5 and 10 made of SiO ₂ or the like are provided to protect both the heating resistor and the electrode from electrolytic corrosion by ink and the like.
If its thickness is made sufficiently thick, its protection characteristics will be greatly improved. However, if the thickness of the protective layer 10 is too large, the efficiency of heat transfer from the heating resistor to the ink is significantly reduced, the power consumption is increased, causing a problem in the performance as a recording device, and There is a problem that the manufacturing cost is increased due to an increase in the film formation time. Conversely, if the protective layer is made thinner, the problem relating to heat transfer to the ink and the layer formation time during the production of the protective layer is solved,
The possibility that a pinhole is formed in the protective layer on the heating resistor or a problem occurs in the coverage of the cross section of the electrode to cause a serious defect in reliability is increased. The cavitation-resistant erosion layer 11 has the same problem.

Further, when multi-nozzles are used to increase the recording speed, the arrangement density of the heating resistors and electrodes is further increased, and the above-mentioned problem is more remarkably generated.

For the purpose of solving such a problem, Japanese Patent Application Laid-Open No. 63-191646 discloses a method in which an electrode 3 and a part of a heating resistor 2a are made of an organic insulating material such as photosensitive polyimide as shown in FIG. The surface of the heating resistor 2a in the opening which is not covered with the organic insulating layer is covered with the layer 5 and the anodic oxide coating 4 is provided on the portion exposed to the opening by anodic oxidation. Protection.

Japanese Patent Application Laid-Open No. 63-191647 proposes a configuration in which the pattern configuration is changed between an anodized portion and an organic insulating layer as shown in FIG.

On the other hand, Japanese Patent Application Laid-Open No. 63-191648 proposes a configuration in which the surfaces of the heat generating resistor and the electrode are anodized almost over the entire surface and an organic insulating layer is further provided.

[0012]

However, in the structure using an anodic oxide layer and an organic insulating layer instead of the inorganic insulating layer,
Although satisfactory in terms of simplification of the configuration and improvement of the thermal efficiency, etc., in order to obtain higher reliability, for example, durability over a long period of time, it still has individual problems to be improved as follows. Was.

In the structures disclosed in JP-A-63-191646 and JP-A-63-191647, only a part of the surface of the heat generating resistor is anodized, and the other electrodes and the heat generating member are heated. Although the protection of the resistor portion is performed only by the organic insulating layer, it is difficult to secure these electrical insulating properties with the organic insulating layer alone, and there is a limit in further improving the durability. .

Further, Japanese Patent Application Laid-Open No. 63-191646,
JP-A-63-191647 and JP-A-63-19
In any of the configurations disclosed in US Patent No. 1648, the heating resistor is divided into a portion covered with the organic insulating layer and a portion not covered with the organic insulating layer at the end of the organic insulating layer. In some cases, defects such as breakage near the boundary due to the edge of the organic insulating layer may occur.

The cause is described in JP-A-63-1916.
In the configuration disclosed in Japanese Patent Publication No. 47 and JP-A-63-191648, the resistance distribution of the heating resistor is substantially uniform, and the heat generation per unit area is the same. It is considered that the heat storage of the coated portion is higher than that of the uncoated portion and becomes higher in temperature, and a break occurs due to a temperature difference at the boundary between the ends of the organic insulating layer.

On the other hand, in the structure disclosed in Japanese Patent Application Laid-Open No. 63-191646, the heat generating resistor under the organic insulating layer has a portion that is not anodized, and the resistance of the portion is low, and the heat generation amount is also small. However, since the anodized portion is formed up to the edge of the organic insulating layer, heat is generated at the boundary portion of the edge of the organic insulating layer and the temperature becomes high, so that a temperature difference also occurs and defects such as breakage occur. It is considered something.

An object of the present invention is to provide an ink jet recording head having a configuration capable of comprehensively satisfying reliability such as durability, production cost, and recording performance, and an ink jet recording apparatus using the same.

[0018]

An ink jet recording head according to the present invention comprises a base, a heat storage layer provided on the base,
A heating element substrate having a heating resistor provided on the heat storage layer, and a pair of electrodes electrically connected to the heating resistor at predetermined intervals; and a heating element corresponding to the heating resistor. It has an ink flow path provided on the element substrate, and an ink discharge port communicating with the ink flow path, and at least a portion of the surface of the heating resistor and the electrode corresponding to the area under the ink flow path is an oxide film. In an ink jet recording head which is provided with an organic insulating layer at least in a portion located below the ink flow path on the oxide film, and other than a part serving as an opening to the ink flow path of the heating resistor. The thickness of at least a part of the oxide film in the opening is thicker than that under the organic insulating layer.

In the ink jet recording head according to the present invention, the thick portion of the oxide film on the heating resistor is provided on the entire surface of the opening except the end where the organic insulating layer and the heating resistor overlap. Is preferred.

Further, in the ink jet recording head according to the present invention, the heating resistor has an edge portion in the opening, and at least an edge forming the opening in the opening of the edge portion and the organic insulating layer. It is preferable that a thick portion of the oxide film is provided also in a portion located under the subordinate.

Further, in the ink jet recording head of the present invention, the heating resistor has an edge located below the organic insulating layer, and at least a part of the edge has a thick portion of the oxide film. Preferably, a thick oxide film at the edge of the heating resistor is further provided.
More preferably, it is provided over a width wider than the opening width. An anodic oxide film can be used as the oxide film.

An ink jet recording apparatus according to the present invention comprises the above ink jet recording head, a member for mounting the recording head, and a discharge port of the ink jet recording head which faces a recording surface of a recording medium. Means for discharging ink from an outlet in accordance with a recording signal.

According to the present invention, it is possible to obtain an ink jet recording head which is excellent in the electrical insulation properties of the electrodes and the heating resistor, and is also excellent in the cavitation erosion resistance. Moreover, these excellent characteristics are shown in FIG.
This can be realized with a simpler configuration without providing an inorganic insulating layer or an anti-cavitation erosion layer as shown in the conventional example, and the manufacturing cost can be reduced. Furthermore, the recording head is excellent in terms of thermal efficiency, and power consumption during use can be reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical example of the present invention will be described below with reference to the drawings. The ink jet recording head shown in FIGS. 1A and 1B has an insulating substrate provided with a heat storage layer (not shown) for efficiently converting electric energy applied to a heating resistor into heat energy. 1, a heating resistor layer 2, electrode layers 3 and 6, oxide films 4a and 4b, and an organic insulating layer 5 are laminated.

The electrode layer forms the individual electrode 3 and the common electrode 6, and a portion where the ends of these electrode layers oppose at a predetermined interval exposes a part of the heating resistor layer 2, thereby forming the heating resistor 2a. Is formed. The common electrode 6 includes a portion 6b connected to each heating resistor 2a and a portion 6
a. Each electrode is provided with a portion 7 for making an electrical connection to the outside, and no oxide film is provided on this portion. Further, the individual electrodes 3 can independently drive the heat generation in each heat generating portion 2a.

The oxide film 4a is formed on the individual electrode 3, the common electrode 6
The heating resistor 2a is provided over a part of the heating resistor 2a, and has a thickness smaller than that of the oxide film 4b provided on the heating resistor 2a. Further, the organic insulating layer 5 is coated on the entire surface of the portion requiring insulation except for the portion to be the opening 8 of the heating resistor 2a and the external connection portion 7 of the electrode.

The main feature of this ink jet recording head is that the oxide films 4a and 4b have different thicknesses and the thick oxide film 4b is not in contact with the organic insulating layer 5. As described above, when a difference in film thickness is provided between these oxide films, when the heating resistor 2a is energized, the resistance of the thick portion of the oxide film becomes higher than that of the thin portion. Is mainly performed under the thick portion 4b of the oxide film, the heat storage under the organic insulating layer 5 is suppressed, and defects such as breakage near the end of the organic insulating layer 5 on the heating resistor 2a are generated. Can be prevented.

The difference between the thicknesses of the oxide films having different thicknesses may be within the range in which the object of the present invention can be achieved, but is preferably 1 μm or more, more preferably 3 μm or more. The upper limit is preferably 10 μm. Further, the change in the film thickness from the thin portion to the thick portion of the oxide film may be a continuous change or a step change of one or more steps.

Next, the ink jet recording head shown in FIG. 1 can be manufactured by the following method, for example.

First, as shown in FIGS. 2 (a-1) and (a-2), an insulating substrate 1 made of, for example, single-crystal silicon, ceramic, glass, a metal substrate coated with an insulating material, or the like is used. The heating resistor layer 2 is laminated on the surface in a predetermined pattern. Note that a heat storage layer (not shown) is usually provided on the surface of the base 1. This heat storage layer is made of, for example, SiO ₂
Etc. can be formed. The layer thickness of the heat storage layer can be a commonly used layer thickness. Formation of the SiO ₂ layer, the method according to the vacuum deposition such as sputtering, various film forming methods Si _x formed by N _y, the layer such as SiC can be formed by a method such as thermal oxidation process.

The heat-generating resistor layer 2 can be formed with an oxide film layer having a function as a protective layer by oxidizing the surface, and is a resistor material such as Ta or T, which is excellent in heat resistance.
a and V, Nb, Zr, Mg, Zn, Ni, Gd, C
It can be formed from an alloy composition of o, Al, a nitride, or the like. For the formation of the heating resistor layer 20, a normal film forming method and a patterning method by photolithography can be used.

Next, as shown in FIGS. 2 (b-1) and (b-2), an electrode material is laminated on the heating resistor layer 2 and patterned into a predetermined shape. As the electrode material, any material can be used as long as an oxide film having a function as a protective layer can be formed on the surface by oxidation treatment, and any material having excellent electric conductivity can be used. For example, Al or an Al alloy is used. be able to. An ordinary film forming method and a patterning method by photolithography can be used for lamination and patterning of the electrode material layer. The thickness of the electrode material layer is
For example, it is about 0.5 μm.

In the illustrated example, the electrode 3 is formed as an individual electrode, the electrodes 6a and 6b are formed as common electrodes, and the portion of the heating resistor layer where the electrode layer is not provided becomes the heating resistor. Further, the wiring pattern of the electrode can be changed according to a desired design.

In this state, (c-1) and (c-
As shown in 2), the exposed portion of the heating resistor layer and a predetermined portion of the electrode layer are subjected to a first oxidation treatment to form an oxide film on the surface. In the illustrated example, oxidation is performed except for a portion that becomes a connection terminal of the electrode. For this oxidation, a normal anodic oxidation method performed by masking a portion other than the oxidation portion with a resist can be used. The conditions of the anodic oxidation are such that an anodic oxide film of a predetermined thickness having sufficient properties as a protective film such as insulation and durability can be obtained. The thickness of the oxide film can be made smaller than the thickness of a normal protective film.
μm or less.

After completion of the first oxidation treatment, predetermined treatments such as washing and drying are performed, and then, (a-1) of FIG.
And (a-2), the second oxidation treatment is performed only on a predetermined portion of the heating resistor. The conditions of the second oxidation treatment are set so that a film thicker than the oxide film obtained by the first oxidation treatment is formed. The thickness difference between the films obtained by the first oxidation treatment and the second oxidation treatment may be set so as to achieve the object of the present invention, but as described above, preferably 1 μm or more, more preferably Is preferably 3 μm or more. Anodization can also be suitably used for the second oxidation treatment.

At the stage where the second oxidation treatment has been completed, cleaning,
After performing necessary processing such as drying, the organic insulating layer 5 is formed at a predetermined position as shown in (b-1) and (b-2) of FIG. This organic insulating layer can also be formed by a usual material and method.

As described above, an ink chamber having a structure as shown in FIG.
An ink jet recording head can be formed by forming an orifice (ejection port) and the like.

On the other hand, the shape of the oxide film provided on the predetermined portion of the heating resistor of the ink jet recording head of the present invention and the area covered with the organic insulating layer are not limited to those shown in FIG. Can be appropriately changed within a range in which is achieved.

For example, in the example shown in FIG. 4, a structure is adopted in which a thick oxide film is provided almost all over the edge portion of the heating resistor located in the opening so as to extend below the organic insulating layer 5. I have. Here, the edge portion refers to a side end surface of the layer of the heating resistor and a corner portion between the side end surface and the upper surface. Note that a thick oxide film may also be provided on the corner between the lower surface and the side end surface as needed.

With this configuration, the reliability at the edge of the heating resistor can be further improved. That is, in etching when patterning the heating resistor into a predetermined shape, the edge portion of the heating resistor layer is excessively etched and the shape of the edge portion becomes non-uniform, or the heat storage layer below the heating resistor layer is formed. When the lower surface is exposed at the edge of the heating resistor layer due to etching, a sufficient protection function may not be obtained with a thin anodic oxide layer in the first anodic oxidation treatment. In such a case, it is possible to cope by increasing the etching accuracy. However, as shown in FIG. 4, at least a portion of the edge portion of the heating resistor that is not covered with the organic insulating layer is sufficiently subjected to anodizing treatment. By using a thick anodic oxide layer, the reliability of the edge portion can be sufficiently ensured without significantly increasing the etching accuracy. Moreover, in the example shown in FIG. 4, except for the edge of the heating resistor, a predetermined interval is provided between the edge of the thick anodic oxide layer and the edge of the organic insulating layer. Most of the current flowing through the space flows through the portion provided with the thin anodic oxide layer located at the space, so that defects such as breakage of the heating resistor can be prevented from occurring as in the configuration shown in FIG.

On the other hand, in the example shown in FIG. 5, the edge of the heating resistor is further covered with an organic insulating layer, so that the reliability of the edge can be further improved.

The structure of the ink jet recording head of the present invention has, in addition to the structure having a linear ink flow path shown in FIG. With a structure in which ink is ejected in a direction perpendicular to the ink jet head, and for example, US Pat. No. 4,558,333
And US Pat. No. 4,459,600 also include a configuration in which a heating resistor is arranged in a bent region.

In addition, for example, JP-A-59-123670
JP-A-59-138461 discloses a configuration in which a common slit is used as a discharge portion (orifice) for a plurality of heating resistors as disclosed in JP-A-59-138461. A configuration in which the opening that absorbs the air corresponds to the discharge unit is also applicable to the present invention.

Further, as a full-line type recording head having a length corresponding to the maximum recording medium width (for example, the maximum width of recording paper) that can be recorded by the recording apparatus, a configuration in which the length is satisfied by a combination of a plurality of recording heads. Alternatively, the recording head may be configured as one integrally formed recording head.

In addition, the ink jet recording head according to the present invention is a replaceable chip type recording head which can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being mounted on the apparatus main body. Alternatively, the recording head may be configured as an ink cartridge type recording head in which an ink tank is provided integrally with the recording head itself.

In the recording apparatus equipped with the recording head of the present invention, it is preferable to add recovery means for the recording head, preliminary auxiliary means, and the like. These means include a capping means for the recording head, a cleaning means, a pressure or suction means, a heating resistor or another heating element, or a preheating means using a combination thereof, and a separate recording means. Performing a preliminary ejection mode for performing ejection is also effective for performing stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, and the recording head may be formed integrally or by combining a plurality of recording heads.
The present invention is also very effective for an apparatus provided with at least one of multiple colors of different colors or full color by mixing colors.

The ink used in the recording head of the present invention is not particularly limited as long as it can be applied to an ink jet recording system utilizing thermal energy. In addition, the ink is used in the liquid at the time of use for recording or at the time of handling, for example, those that are solidified at room temperature or lower but soften at room temperature, or those that are liquid, or In the method in which the viscosity of the ink is adjusted to a stable ejection range by temperature control, recording is usually performed by adjusting the temperature of the ink to 30 to 70 ° C., so that the ink may be in a liquid state when the use recording signal is applied.

In addition, a recording signal such as an ink in which a temperature rise due to thermal energy is positively used as energy for changing the state of the ink from a solid state to a liquid state, an ink which solidifies in a standing state for the purpose of preventing evaporation of the ink, and the like. Ink that liquefies as a result of the application of thermal energy according to the application of ink and that is ejected as a liquid, or ink that begins to solidify by thermal energy, such as ink that begins to solidify when it reaches the recording medium, is also applicable. It is possible. In such a case, as described in JP-A-54-56874 or JP-A-60-71260, in a state of being held as a liquid or solid in a porous sheet recess or through hole, A configuration in which the heating resistor is opposed to the heating resistor may be adopted.

FIG. 8 is an external perspective view showing an example of an ink jet recording apparatus (IJRA) in which the ink jet recording head of the present invention is mounted as an ink jet head cartridge (IJC). In the figure, 120 is a platen 1
An ink jet head cartridge (IJC) including a nozzle group including an ink flow path for performing ink discharge and a discharge unit (orifice) facing the recording surface of the recording paper (recording medium) sent on the recording paper 24. 116 is IJC (12
0) is a carriage (HC) holding two guide shafts 1 connected to a part of a drive belt 118 for transmitting the driving force of the drive motor 117 and arranged in parallel with each other.
By making it slidable with 19A and 119B, IJ
A reciprocating motion over the full width of the recording paper of C (120) is enabled.

Reference numeral 126 denotes a head recovery device, which is an IJC
It is arranged at one end of the movement route of (120), for example, at a position facing the home position. The head recovery device 126 is driven by the driving force of the motor 122 via the transmission mechanism 123.
To perform capping of the IJC (120).
In connection with the capping of the head recovery device 126 to the IJC (120) by the cap portion 126A, the ink is absorbed by an appropriate suction means provided in the head recovery device 126 or provided on the ink supply path to the IJC (120). An ink is fed by an appropriate pressurizing means, and an ejection recovery process such as removing the thickened ink in the nozzle by forcibly discharging the ink from the ejection port is performed. Also,
By performing capping at the end of recording, etc., IJC
(120) is protected.

Reference numeral 130 denotes a blade disposed on the side surface of the head recovery device 126 and formed of silicon rubber as a wiping member. The blade 131 is held in a cantilever form by a blade holding member 131A, and is operated by a motor 122 and a transmission mechanism 123, like the head recovery device 126, to be able to engage with the ejection surface of the IJC (120). Thereby, at an appropriate timing in the recording operation of the IJC (120) or the head recovery device 126
After the ejection recovery process using the IJC
IJC (120)
As a result, the dew condensation, wetness, dust, and the like on the ejection surface of the IJC (120) can be wiped off.

[0053]

EXAMPLE 1 A heating element substrate for an ink jet recording head was manufactured as follows using the steps shown in FIGS.

First, S is applied to one surface of a substrate made of Si.
A heat storage layer was provided by iO ₂ . Next, a heating resistive layer of a predetermined pattern made of Ta is provided on the surface on which the heat storage layer is provided by a conventional method, and further, an electrode layer is laminated on a predetermined portion on the heating resistive layer by a conventional method to form individual electrodes and In addition to the common electrodes, a heating resistor having a heating resistor layer exposed at predetermined intervals between the ends of these electrodes was formed.

The surface of the substrate was covered with a resist layer by photolithography so that only the portion to be anodized was exposed, and a first anodic oxidation treatment was performed using the resist layer as a mask under the following conditions. First anodizing condition: Counter electrode: Pt Current voltage condition: Final voltage 100V, current density 2A / c
A low current was applied at m ² and held for 10 minutes after the voltage became low.

When the first anodic oxidation was completed, the resist layer was peeled off with a predetermined stripping solution, and the substrate surface was washed and dried by a conventional method.

Next, in the same manner as in the first anodic oxidation treatment, a resist layer is formed so that only a predetermined portion of the heating resistor is exposed, and the second anode is formed using this resist layer as a mask under the following conditions. An oxidation treatment was performed. Second anodizing condition: Counter electrode: Pt Current voltage condition: Final voltage 150V, current density 2A / c
A low current was applied at m ² and held for 10 minutes after the voltage became low.

At the end of the second anodizing treatment,
Stripping and cleaning of the resist were performed in the same manner as in the first anodic oxidation treatment.

A polyether amide (trade name: HIMAL, manufactured by Hitachi Chemical Co., Ltd.) was applied to the thus obtained substrate having two kinds of anodized layers, and then subjected to predetermined baking conditions (240 ° C., 2 ° C.).
Time) to form an organic insulating film having a thickness of 2 μm. On the organic insulating film, a resist layer is further laminated by photolithography so as to cover a predetermined portion, and using the mask as a mask, etching is performed by an etching method using oxygen plasma to pattern the organic insulating layer.
A heating element substrate having the structure shown in FIG.

Example 2 A heating element substrate was obtained in the same manner as in Example 1 except that the structure on the heating resistor was changed as shown in FIG.

Example 3 A heating element substrate was obtained in the same manner as in Example 1 except that the structure on the heating resistor was changed as shown in FIG.

FIG. 6 shows the relationship between the hazard failure rate and the relative life of the heating element substrates obtained in Examples 1 to 3 and the conventional example.

[0063]

According to the present invention, it is possible to provide an ink jet recording head having a configuration capable of comprehensively satisfying reliability such as durability, production cost, and recording performance, and an ink jet recording apparatus using the same.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams schematically showing a main part of a heating element substrate included in an ink jet recording head of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA ′.

FIG. 2 is a diagram illustrating main steps in an example of a method for manufacturing a heating element substrate included in an inkjet recording head according to the present invention, wherein (a-1) to (c-1) are plan views and (a-2). ) To (c-2) are described with reference to cross-sectional views taken along line AA ′.

FIG. 3 is a diagram showing main steps in an example of a method for manufacturing a heating element substrate included in the ink jet recording head of the present invention, wherein (a-1) to (b-1) are plan views and (a-2). ) To (b-2) are described with reference to cross-sectional views taken along line AA ′.

FIG. 4 is a diagram schematically illustrating a main part of another example of the heating element substrate included in the inkjet recording head of the present invention;
(A) is a plan view, (b) is a sectional view taken along line AA ', and (c) is a sectional view taken along line BB'.

FIG. 5 is a diagram schematically illustrating a main part of another example of the heating element substrate included in the inkjet recording head of the invention.
(A) is a plan view, (b) is a sectional view taken along line AA ', and (c) is a sectional view taken along line BB'.

FIG. 6 is a diagram showing a relationship between a hazard failure rate and a relative life.

FIG. 7 is a perspective view schematically showing a typical configuration of an ink jet recording head.

FIG. 8 is a perspective view schematically illustrating a typical configuration of an inkjet recording apparatus.

9A and 9B are diagrams schematically illustrating a main part of a heating element substrate included in a conventional inkjet recording head, where FIG. 9A is a plan view and FIG. 9B is a cross-sectional view taken along line AA ′.

FIG. 10 is a cross-sectional view schematically illustrating a main part of a heating element substrate included in a conventional inkjet recording head.

FIG. 11 is a cross-sectional view schematically illustrating a main part of a heating element substrate included in a conventional inkjet recording head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Heating resistance layer 2a Heating resistor 3 Electrode (individual electrode) 4, 4a, 4b Oxide film 5, 10 Protective layer 6, 6a, 6b Common electrode 7 External connection part 8 Opening part 9 Ink supply port 11 Resistance Cavitation erosion layer 12 Discharge port 13 Nozzle forming material 14 Top plate 15 Ink liquid chamber 16 Heating element substrate 116 Carriage (HC) 117 Drive motor 118 Drive belt 118 119A, 119B Guide shaft 120 Ink jet cartridge (IJC) 122 Motor 123 Transmission mechanism 124 Platen 126 Head recovery device 126A Cap part 130 Blade 131A Blade holding member

Claims (21)

[Claims] 1. A base, a heat storage layer provided on the base,
A heating element substrate having a heating resistor provided on the heat storage layer, and a pair of electrodes electrically connected to the heating resistor at predetermined intervals; and a heating element corresponding to the heating resistor. It has an ink flow path provided on the element substrate, and an ink discharge port communicating with the ink flow path, and at least a portion of the surface of the heat generating resistor and the electrode corresponding to the lower part of the ink flow path is an oxide film. In an ink jet recording head which is provided with an organic insulating layer at least in a portion located under the ink flow path on the oxide film, except for a part which becomes an opening of the heating resistor to the ink flow path. Wherein the thickness of at least a part of the oxide film on the heating resistor that is not covered with the organic insulating layer is made thicker than the part that is not covered with the organic insulating layer. Head. 2. The heat-generating resistor according to claim 1, wherein the thick portion of the oxide film on the heat-generating resistor is provided on the entire surface of the opening except the end where the organic insulating layer and the heat-generating resistor overlap. Inkjet recording head. 3. The heating resistor has an edge in the opening, and at least a portion of the edge located in the opening and below an end of the organic insulating layer that forms the opening. 3. The ink jet recording head according to claim 1, wherein a thick portion of the coating is provided. 4. The heating resistor according to claim 1, wherein the heating resistor has an edge located below the organic insulating layer, and at least a part of the edge is provided with a thick portion of the oxide film. The inkjet recording head according to the above. 5. The ink jet recording head according to claim 4, wherein the thick oxide film at the edge of the heating resistor is provided over a width wider than the width of the opening. 6. The ink jet recording head according to claim 1, wherein the change in film thickness from a thin oxide film to a thick oxide film is a continuous change. 7. The ink jet recording head according to claim 1, wherein the change in the thickness of the oxide film from a thin film to a thick film is a stepwise change. 8. The ink jet recording head according to claim 1, wherein a difference in thickness of the oxide film is 1 μm or more. 9. The ink jet recording head according to claim 9, wherein the difference in the thickness of the oxide film is 3 μm or more. 10. The ink jet recording head according to claim 1, wherein said oxide film is an anodic oxide film. 11. An ink jet recording head according to claim 1, a member for mounting said recording head, and a discharge port of said ink jet recording head facing a recording surface of a recording medium. Means for discharging ink from the discharge port in accordance with a recording signal. 12. A base, a heat storage layer provided on the base, a heating resistor provided on the heat storage layer, and a pair of electrodes electrically connected to the heating resistor at predetermined intervals. A heating element substrate having: a heating element substrate; an ink channel provided on the heating element substrate corresponding to the heating resistor; and an ink discharge port communicating with the ink channel. A portion of the surface of the body and the electrode corresponding to the ink flow path is covered with an oxide film, and at least a portion of the surface of the oxide film located below the ink flow path, the ink flow path of the heating resistor In a method of manufacturing an ink jet recording head provided with an organic insulating layer other than a portion serving as an opening to the substrate, the formation of the heating element substrate is performed on a substrate provided with the heat storage layer, the heating resistor,
Providing a pair of electrodes electrically connected to the heating resistor at a predetermined interval; and forming a surface of the heating resistor on at least a portion of the surface of the electrode and the heating resistor below the ink flow path. A step of providing an oxide film such that the film thickness of the upper predetermined portion is thicker than the other film thickness, and forming an organic insulating layer on a portion of the oxide film other than the portion where the thick oxide film is provided. Forming the opening by coating. 13. A heating device according to claim 1, wherein the thick portion of the oxide film on the heating resistor is provided on the entire surface of the opening except for the end where the organic insulating layer and the heating resistor overlap.
3. The method for manufacturing an ink jet recording head according to item 2. 14. The heat-generating resistor has an edge in the opening, and at least a part of the edge located in the opening and below an end of the organic insulating layer forming the opening is formed. 14. The method according to claim 12, wherein a thick portion of the coating is provided. 15. The heat generating resistor according to claim 12, wherein the heat generating resistor has an edge portion located below the organic insulating layer, and at least a part of the edge portion is provided with a thick portion of the oxide film. A method for manufacturing an ink jet recording head. 16. The method for manufacturing an ink jet recording head according to claim 15, wherein a thick oxide film on an edge portion of the heating resistor is provided over a width wider than the width of the opening. 17. The method according to claim 12, wherein the change in the thickness of the oxide film from a thin film to a thick film is a continuous change. 18. The method according to claim 12, wherein the change in the thickness of the oxide film from a thin film to a thick film is a stepwise change. 19. The method for manufacturing an ink jet recording head according to claim 12, wherein the difference in the thickness of the oxide film is 1 μm or more. 20. The method according to claim 20, wherein the difference in the thickness of the oxide film is 3 μm or more. 21. The method according to claim 12, wherein the oxide film is formed by anodic oxidation.