JP2003072075A - Ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable ink jet head which can record favorable images with reduced distortion and density irregularities at high speed. SOLUTION: The ink jet head is provided with a head substrate having a heating resistor and a pair of electrodes set over, and a top plate arranged above the head substrate. The ink jet head discharges ink filled between the head substrate and the top plate from ink discharge holes by heat of the heating resistor. The heating resistor is formed of a TiC-SiO2 based resistance material, and a TiC content in the resistance material is set to be 55 mol%-90 mol%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head which forms an image by depositing ink droplets on a recording paper in a predetermined pattern.

[0002]

2. Description of the Related Art Conventionally, an ink jet head has been used as a recording device for forming an image on recording paper.

The recording method of an ink jet head uses a thermal energy generated by a heating resistor to eject ink droplets toward a recording paper, uses a deformation of a piezoelectric element, and further irradiates an electromagnetic wave. There is a type that uses the heat generated along with it, and among these, the type that uses the heat energy of the heating resistor is a heating resistor with a small area in addition to easy patterning of the heating resistor. However, since it can generate a relatively large amount of heat energy, it is attracting attention as being suitable for high density recording.

As such a conventional ink jet head, a head substrate having a large number of heating resistors and a pair of electrodes connected to both ends of the heating resistors on the upper surface of a base plate, and the heating resistors. A top plate having a large number of one-to-one ink ejection holes is arranged so as to form a predetermined gap therebetween, and the gap between the head substrate and the top plate is filled with ink. While the recording paper is being conveyed along the outer surface of the top plate, the heating resistors are individually and selectively heated based on image data from the outside, and this thermal energy generates bubbles in the ink. At the same time, a part of the ink is ejected to the outside from the ink ejection hole by the pressure of the generated bubbles, and these ink droplets are adhered to the recording paper to record a predetermined image.

Incidentally, Ta ₂ N, TaAl, TaSi, HfB ₂ or the like is generally used as an electric resistance material for forming the heating resistor, and a pulse width of 10 μs is used during a recording operation.
By applying a power pulse of ec to 12 μsec and a power value of 0.33 W to 0.40 W to the heating resistor, Joule heat is generated in the heating resistor, and bubbles are generated in the ink.

[0006]

By the way, in recent years, in printing using an ink jet head, a driving cycle of 0.
In order to support high-speed recording of 1 msec or less, it is required to shorten the time required for ejecting ink droplets as much as possible, and in order to meet this requirement, the heating resistor is set to a large power pulse (pulse width 0.5 μsec). ~ 2.0μ
It is considered that the temperature of the heating resistor is raised to a predetermined temperature necessary for printing in a short time by heating and driving at a power value of 1.60 to 4.10 W for sec.

However, in the above-mentioned conventional ink jet head, the heating resistor is Ta ₂ N or TaA.
It is formed of an electric resistance material such as l, and these resistance materials contain a relatively large amount of metal components such as Ta and Al. Therefore, the above-mentioned power pulse is applied to the heating resistor to perform high-speed recording. If this is done, the heating resistor may be annealed and crystallized by the heat generated by itself, and the resistance value may fluctuate significantly. In that case, since it is impossible to heat the heating resistor at a desired temperature, there is a drawback that the discharge amount and the discharge speed of the ink droplets vary, which causes printing defects such as image distortion and density unevenness. Was.

Further, a heating resistor containing a large amount of a metal component such as Ta ₂ N or TaAl has a large stress accumulated therein when formed by sputtering or the like.
Therefore, the mechanical strength tends to be poor, and when a large impact when the bubbles generated in the ink disappear is repeatedly applied to the heating resistor, these impacts cause damage such as cracking to the heating resistor. The drawback to be induced.

The present invention has been devised in view of the above drawbacks, and an object thereof is to provide a highly reliable ink jet head capable of recording a good image with little distortion and uneven density at high speed. .

[0010]

An ink jet head according to the present invention comprises a head substrate on which a heating resistor and a pair of electrodes are adhered, and a top plate arranged above the head substrate. In an ink jet head in which the ink filled between the plates is ejected from the ink ejection holes by the heat of the heating resistor, the heating resistor is formed of a TiC-SiO ₂ -based resistance material, and the TiC content of the resistance material is 55 mol. % To 90 mol% is set.

Further, the ink jet head of the present invention is characterized in that the heating resistor is covered with a protective film formed of an inorganic compound containing oxygen (O) in an amount of 0.5 atom% or more. is there.

Further, the ink jet head of the present invention is
The protective film is formed of a Si—O—N based inorganic compound.

Furthermore, the ink jet head of the present invention is characterized in that the oxygen content in the protective film is gradually increased toward the heating resistor side.

Furthermore, in the ink jet head of the present invention, the pair of electrodes is made of aluminum (Al),
It is characterized by containing 0.01 atomic% to 0.1 atomic% of silicon (Si) near the interface with the heating resistor.

According to the ink jet head of the present invention,
The heating resistor is made of a TiC-SiO ₂ -based resistance material, and the TiC content in the resistance material is 55 mol.
% To 90 mol%, so that even if a large power pulse is repeatedly applied to the heating resistor to perform high-speed printing with a driving cycle of 0.1 msec or less,
Crystallization of the electric resistance material forming the heating resistor is effectively suppressed by the action of silicon oxide (SiO ₂ ), and the resistance value of the heating resistor is kept substantially constant for a long period of time. Therefore, the heating resistor can be made to generate heat at a desired temperature, and the ejection amount and ejection speed of the ink droplets can be made uniform, and a good print with less distortion and uneven density can be formed.

Further, according to the ink jet head of the present invention, the heating resistor formed of the TiC-SiO ₂ -based resistance material has a TiC content of 55 mol% to 90 mol%.
Therefore, when the heating resistor is formed, the stress accumulated inside the heating resistor can be remarkably reduced, and the mechanical strength of the heating resistor can be increased. Therefore, even if a large shock when the bubbles generated in the ink disappear is repeatedly applied to the heating resistor, such a shock hardly causes damage such as cracking in the heating resistor, and the reliability of the inkjet head is improved. It can also improve the sex.

According to the ink jet head of the present invention, the heating resistor is covered with a protective film formed of an inorganic compound containing oxygen (O) in an amount of 0.5 atomic% or more. Of oxygen (O) of the heating resistor and silicon (Si) in the heating resistor can be firmly bonded to increase the adhesion strength of the protective film to the heating resistor, and to prevent thermal stress between the heating resistor and the protective film. It is possible to effectively prevent the peeling of the protective film due to this.

Further, according to the ink jet head of the present invention, by adjusting the oxygen content so that the oxygen content in the protective film gradually increases toward the heating resistor side, the oxygen content in the vicinity of the heating resistor is improved. A large amount of oxygen in the protective film can be distributed, and by bonding a large amount of these oxygen with silicon in the heating resistor, the adhesion strength of the protective film to the heating resistor can be further increased.

Further, according to the ink jet head of the present invention, the pair of electrodes connected to the heating resistor is formed of aluminum, and the silicon existing in the heating resistor in the lower region of these electrodes is 0.01. Atomic% -0.1 atomic%
By diffusing only the above, silicon and aluminum are favorably bonded in the vicinity of the interface between the heating resistor and the pair of electrodes, and the pair of electrodes can be firmly adhered to the heating resistor. . Therefore, it is possible to effectively prevent the problem that the pair of electrodes is separated from the heating resistor due to a large impact when the bubbles generated in the ink disappear.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below in detail with reference to the accompanying drawings. 1 is an exploded perspective view of an inkjet head according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the inkjet head of FIG. 1. The inkjet head shown in FIG. Are arranged substantially parallel to each other so as to form a predetermined gap, and the gap is filled with the ink 8.

The head substrate 1 uses, for example, a plate made of single crystal silicon whose surface is covered with an insulating film made of silicon oxide (SiO ₂ ) as the base plate 2. Heating resistor 3 and a pair of electrodes 4
Etc. are deposited in a predetermined pattern, and these are covered with a protective film 5.

The base plate 2 functions as a support base material for supporting the heating resistor 3, the pair of electrodes 4, etc. on its upper surface, and when it is made of single crystal silicon, the conventionally known Czochralski method ( It is manufactured by slicing a single crystal silicon ingot (lump) formed by a pulling method) to a predetermined thickness, and the surface of the obtained base plate 2 is oxidized to a predetermined depth region by using a conventionally known thermal oxidation method. By doing so, the above-mentioned insulating film is formed.

A large number of heating resistors 3 provided on the upper surface of the base plate 2 are, for example, 600 dpi (dot).
They are arranged linearly in a main scanning manner at a density of per inch), and each of them is formed of a TiC-SiO ₂ -based resistance material.

Therefore, the power source power (pulse width 0.5 μsec to 2.0 μsec, power value 1.6 W) is applied to the heating resistors 3 via the pair of electrodes 4 connected to both ends of each heating resistor 3.
~ 4.1W) is applied, Joule heat is generated,
The temperature reaches a predetermined temperature (500 ° C. to 800 ° C.) required to generate bubbles A in the ink 8.

The heating resistor 3 made of the TiC-SiO ₂ system resistance material has a TiC content of 55 mol% to 55 mol%.
It was set to 90 mol% and the balance was SiO ₂ and a trace amount (0.
5 wt% or less) of impurities.

Since the crystallization of the heating resistor 3 made of such an electric resistance material is effectively suppressed by the action of silicon oxide (SiO ₂ ), the heating resistor 3 is used to perform high-speed printing with a driving cycle of 0.1 msec or less. Even if a large power pulse is repeatedly applied to the body 3, the resistance value of the heating resistor 3 can be kept substantially constant for a long period of time, and the heating resistor 3 can always generate heat at a desired temperature.

The heating resistor 3 has a TiC content of 55 mol% to 90 mol% and its mechanical strength is effectively increased. Therefore, even if a large impact when the bubble A generated in the ink 8 disappears is repeatedly applied to the heat generating resistor 3, the heat generating resistor 3 hardly breaks due to such impact, It is also possible to improve the reliability of the inkjet head.

Here, the reason why the TiC content in the heating resistor 3 is set within the range of 55 mol% to 90 mol% is that the specific resistance of the heating resistor 3 is increased when the content of TiC exceeds 90 mol%. Since it becomes very small, the film thickness of the heating resistor 3 must be set to be extremely thin in order to obtain a desired resistance value. When a current is passed through such a heating resistor 3, the current density becomes excessively large. May accelerate the crystallization of the heating resistor 3 and shorten the life of the heating resistor 3. If the content of TiC is less than 55 mol%, the mechanical strength of the heating resistor 3 is insufficient and the bubbles A disappear. This is because if a large impact is repeatedly applied to the heating resistor 3, the heating resistor 3 is more likely to be damaged.

Therefore, it is important to set the TiC content in the heating resistor 3 within the range of 55 mol% to 90 mol%.

The heating resistor 3 is formed by a well-known sputtering method, for example, and a resistor film is formed by depositing the above-described electric resistance material on the base plate 2 to a predetermined thickness. It is formed by processing this into a predetermined pattern by a conventionally known photolithography technique and etching technique. Further, as a target material used in sputtering, (TiC) ₆₀ (S
When iO ₂ ) ₄₀ is used, it is produced, for example, by mixing TiC and SiO ₂ powders in a molar ratio of 60:40 and sintering the mixture.

The pair of electrodes 4 connected to the heating resistor 3 are adhered and formed by a metal such as aluminum (Al) or copper (Cu) so as to form a predetermined pattern. This serves to apply the power supplied via the IC or the like to the heating resistor 3.

Here, the pair of electrodes 4 are made of aluminum, and the vicinity of the interface with the heating resistor 3 (from the interface, 20 Å
~ 100Å electrode 4 side area) with 0.01 atomic% of silicon
If it is contained in an amount of ˜0.1 atomic%, silicon and aluminum are bonded in this region, and the pair of electrodes 4 can be firmly adhered to the heating resistor 3. Therefore, even if a large impact generated when the air bubbles A generated in the ink 8 disappear is repeatedly applied to the heating resistor 3, it is possible to effectively prevent the problem that the pair of electrodes 4 is separated from the heating resistor 3. You can

If the content of silicon contained in the electrodes 4 made of aluminum is less than 0.01 atomic%, the number of silicon atoms bonded to aluminum is too small, and the pair of electrodes 4 are connected to the heating resistor 3. However, if the silicon content exceeds 0.1 atomic%, the amount of silicon atoms in the vicinity of the interface between the heating resistor 3 and the electrode 4 becomes excessive, There is an inconvenience that the electric resistance of this portion becomes large.

Therefore, the pair of electrodes 4 are formed of aluminum, and silicon is formed in the vicinity of the interface with the heating resistor 3 by 0.01%.
It is preferable to contain only atomic% to 0.1 atomic%.

For such a pair of electrodes 4, a well-known thin film technique, specifically, sputtering, photolithography technique, etching technique, or the like is adopted, and metal such as aluminum is formed on the base plate 2 in a predetermined thickness and a predetermined pattern. It is formed by depositing.

In the lower region of the electrode 4, specifically, in the vicinity of the interface with the heating resistor 3, silicon is added in an amount of 0.01 atomic% to 0.
In order to contain only 1 atom%, after forming the heating resistor 3 and the pair of electrodes 4, these are heated at a temperature of 380 ° C. to 550 ° C. for about 120 seconds to 700 seconds, and the silicon in the heating resistor 3 is heated. Is diffused into the electrode 4 by a predetermined amount.

A protective film 5 is deposited on the upper surfaces of the heating resistor 3 and the pair of electrodes 4 described above, and the protective film 5 covers the heating resistor 3 and the pair of electrodes 4.

The protective film 5 is made of, for example, Si ₃ N ₄ or SiO.
It is formed of a dense inorganic compound such as N, and has a function of protecting the heat generating resistor 3 and the like from corrosion due to contact of water contained in the ink.

Here, if the protective film 5 is formed of an inorganic compound containing 0.5 atomic% or more of oxygen (O), the oxygen (O) in the protective film 5 and the heat generating resistor 3 are contained. Silicon (Si) is firmly bonded to increase the adhesion strength of the protective film 5 to the heating resistor 3, and the protective film 5 is peeled off due to thermal stress between the heating resistor 3 and the protective film 5. Will be effectively prevented.

Therefore, it is preferable that the protective film 5 is formed of an inorganic compound containing 0.5 atom% or more of oxygen (O).

Further, the oxygen content in the protective film 5 is adjusted so that the oxygen content in the protective film 5 gradually increases toward the heating resistor 3 side. Since a large amount of oxygen (O) can be distributed, the adhesion strength of the protective film 5 to the heat generating resistor 3 can be further increased by combining a large amount of oxygen with silicon in the heat generating resistor 3.

The protective film 5 is formed by depositing the above-mentioned inorganic material on the upper surface of the heat-generating resistor 3 or the like to a predetermined thickness by conventional well-known sputtering or the like.

In order to gradually increase the oxygen content in the protective film 5 toward the heating resistor 3 side, in the above-described sputtering process, the concentration of oxygen gas injected into the chamber of the sputtering apparatus is gradually decreased. However, the protective film 5 may be formed.

On the other hand, the top plate 6 is arranged substantially parallel to the head substrate 1 so that a gap of, for example, 20 μm to 300 μm is formed between the top plate 6 and the head substrate 1.

The top plate 6 has a large number of ink ejection holes 7 which correspond to the heating resistors 3 in a one-to-one correspondence, and these ink ejection holes 7 are located right above the heating resistors 3. Then, it is arranged and fixed on the head substrate 1.

The ink discharge hole 7 of the top plate 6 is set to have a diameter of 10 μm to 100 μm, and bubbles A in the ink 8 due to heat generation of the heat generating resistor 3 during the recording operation of the ink jet head. Occurs, the ink droplet i is ejected from the ink ejection hole 7 by the pressure when the bubble is generated.

The top plate 6 is made of a metal such as molybdenum, an electrically insulating material such as alumina ceramics, or a photosensitive resin. For example, when the top plate 6 is made of molybdenum, a molybdenum ingot (lump) is formed by a conventionally known metal working method. Is formed into a plate body having a predetermined thickness, and the obtained plate body is manufactured by forming ink ejection holes 7 in the thickness direction by a well-known laser processing, and the obtained top plate 6 is formed on the head substrate 1. It is fixed at a predetermined position on the head substrate 1 by placing it through the spacer.

Ink 8 is filled in the gap formed between the head substrate 1 and the top plate 6. As such an ink 8, for example, a pigment type water-based ink, a water-based dye ink, or the like is used, and the ink 8 is supplied from an ink tank (not shown) between the head substrate 1 and the top plate 6, and the heating resistor 3 described above is used. When a bubble A is generated in the ink 8 due to the heat energy associated with the heat generation of the ink, a part of the ink 8 becomes an ink droplet i due to the pressure of the bubble A and the ink ejection hole 7
Is discharged to the outside.

Thus, the above-described ink jet head selects a large number of heating resistors 3 individually based on image data from the outside while conveying the recording paper along the outer surface of the top plate 6 onto the ink ejection holes 7. Heat is generated to generate bubbles A in the ink 8 on the heating resistor 3 and the pressure of the generated bubbles A causes a part of the ink 8 to be ejected from the ink ejection holes 7 to the outside. A predetermined print is formed by attaching these ink droplets i to the recording paper.

At this time, as described above, the heating resistor 3 always generates heat at a desired temperature, so that the ejection amount and ejection speed of the ink droplet i are made uniform.
It is possible to form a good print with little distortion and uneven density.

The present invention is not limited to the above-mentioned embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, the ink discharge hole 7 is provided in the top plate 6 and the ink discharge hole 7 is arranged directly above the heat generating resistor 3. However, instead of this,
The ink ejection holes 7 may be arranged so as to be offset from the heating resistor 3, or the present invention may be applied to an edge shooter type ink jet head that ejects the ink droplet i from the edge of the head substrate 1. I do not care.

Further, in the above-mentioned embodiment, the driver I for controlling the heat generation of the heating resistor 3 on the base plate 2.
It goes without saying that the C may be mounted.

(Experimental Example) Next, the operation and effect of the present invention will be described based on an experimental example. First, eight ink jet head samples (Sample No. 1 to No. 8) were prepared by changing the TiC content in the heating resistor made of TiC-SiO ₂ based resistance material.
After measuring the resistance change rate ΔR / R of the heating resistor for each of these samples individually, check for damage to the heating resistor during this measurement, and finally use the sample after the measurement. A print was formed on the recording paper and examined for image distortion.

Here, the "rate of change in resistance value ΔR / R" means the initial resistance value of the heating resistor Ω ₁ , and a power pulse (pulse width 0.6 μsec, power value 2.6 W) to the heating resistor 3. 1
When the resistance value after applying 1.0 × 10 ⁸ times at the frequency of 0 kHz is represented by Ω ₂ , (Ω ₁ −Ω ₂ ) / Ω ₁ × 100
(%) Is the value obtained.

All the heating resistors of the ink jet head sample used in this experiment had a size of 25 μm.
The thickness was adjusted to 25 μm and the thickness was adjusted to 0.06 μm. The results of these experiments are shown in Table 1.

[0057]

[Table 1]

According to the experimental results shown in Table 1, for the ink jet head samples No. 2 to No. 6 in which the TiC content in the heating resistor was set in the range of 55 mol% to 90 mol%, the heating resistor was There is no sample in which damage occurred, and the resistance value change rate ΔR / R is within a narrow range of R of −2% to −5%, and a good image with no distortion is obtained even in the printing test. .

In particular, the TiC content should be 60 mol% to 80 m.
For No.3, No.4, and No.5 inkjet head samples set within the range of ol%, the resistance change rate ΔR / R
Is within a very narrow range of -3% or less, and it can be seen that the resistance value variation of the heating resistor is suppressed to an extremely small value.

On the other hand, the TiC content is 55 mol%
In the case of the No. 1 inkjet head sample, which is smaller than the above, the heating resistor is damaged before the power pulse is applied to the heating resistor by 1.0 × 10 ⁸ times, and thus it cannot be used as an inkjet head. became.

Further, the TiC content exceeds 90 mol%.
No. In the No. 7 and No. 8 inkjet head samples, although the heating resistor was not damaged, the resistance value change rate ΔR /
R was a large value exceeding -9%, and image distortion was also confirmed in the print test.

From the above experimental results, in order to effectively prevent breakage of the heating resistor and suppress variations in the resistance value of the heating resistor to obtain a good image without distortion, the TiC content in the heating resistor should be determined. It was found that the ratio should be set to 55 mol% to 90 mol%, and in particular, the TiC content should be 60 mol%.
It can be seen that the variation in the resistance value of the heating resistor can be suppressed more effectively by setting it in the range of 80% by mol to 80 mol%.

[0063]

According to the ink jet head of the present invention, the heating resistor is made of a TiC-SiO ₂ type resistance material and the TiC content in the resistance material is 55 m.
Since it was set to ol% to 90 mol%,
Even if a large power pulse is repeatedly applied to the heating resistor in order to perform high-speed printing with a driving cycle of 0.1 msec or less, crystallization of the electric resistance material forming the heating resistor is effective due to the action of silicon oxide (SiO ₂ ). Therefore, the resistance value of the heating resistor can be kept substantially constant for a long period of time. Therefore, the heating resistor can be made to generate heat at a desired temperature, and the ejection amount and ejection speed of the ink droplets can be made uniform, and a good print with less distortion and uneven density can be formed.

Further, according to the ink jet head of the present invention, the heating resistor formed of the TiC-SiO ₂ -based resistance material has a TiC content of 55 mol% to 90 mol%.
Therefore, when the heating resistor is formed, the stress accumulated inside the heating resistor can be remarkably reduced, and the mechanical strength of the heating resistor can be increased. Therefore, even if a large shock when the bubbles generated in the ink disappear is repeatedly applied to the heating resistor, such a shock hardly causes damage such as cracking in the heating resistor, and the reliability of the inkjet head is improved. It can also improve the sex.

According to the ink jet head of the present invention, the heating resistor is covered with a protective film formed of an inorganic compound containing oxygen (O) in an amount of 0.5 atomic% or more. Of oxygen (O) of the heating resistor and silicon (Si) in the heating resistor can be firmly bonded to increase the adhesion strength of the protective film to the heating resistor, and to prevent thermal stress between the heating resistor and the protective film. It is possible to effectively prevent the peeling of the protective film due to this.

Further, according to the ink jet head of the present invention, the oxygen content is adjusted so that the oxygen content in the protective film gradually increases toward the heating resistor side. A large amount of oxygen in the protective film can be distributed, and by bonding a large amount of these oxygen with silicon in the heating resistor, the adhesion strength of the protective film to the heating resistor can be further increased.

Further, according to the ink jet head of the present invention, the pair of electrodes connected to the heating resistor is formed of aluminum, and the silicon existing in the heating resistor in the lower region of these electrodes is 0.01. Atomic% -0.1 atomic%
By diffusing only the above, silicon and aluminum are favorably bonded in the vicinity of the interface between the heating resistor and the pair of electrodes, and the pair of electrodes can be firmly adhered to the heating resistor. . Therefore, it is possible to effectively prevent the problem that the pair of electrodes is separated from the heating resistor due to a large impact when the bubbles generated in the ink disappear.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the inkjet head of FIG.

[Explanation of symbols]

1 ... Head substrate, 2 ... Base plate, 3 ...
・ Heating resistor, 4 ... a pair of electrodes, 5 ... protective film,
6 ... Top plate, 7 ... Ink ejection hole, 8 ... Ink

Claims (5)

[Claims] 1. A head substrate having a heating resistor and a pair of electrodes adhered thereto, and a top plate disposed above the head substrate. The ink filled between the head substrate and the top plate is heated by the heating resistor. In the ink jet head for ejecting from the ink ejection hole by the heat of No. 3, the heating resistor is made of a TiC-SiO ₂ -based resistance material, and the TiC content in the resistance material is set to 55 mol% to 90 mol%. Inkjet head to do. 2. The ink jet head according to claim 1, wherein the heating resistor is covered with a protective film formed of an inorganic compound containing oxygen (O) in an amount of 0.5 atomic% or more. . 3. The ink jet head according to claim 2, wherein the protective film is formed of a Si—O—N based inorganic compound. 4. The ink jet head according to claim 2, wherein the oxygen content in the protective film is gradually increased toward the heating resistor side. 5. The pair of electrodes is made of aluminum (Al), and silicon (Si) is formed in the vicinity of the interface with the heat generating resistor.
The inkjet head according to any one of claims 1 to 4, wherein the inkjet head contains 0.1 at% to 0.1 at%.