JP2016078263A - Manufacturing method for liquid discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a liquid discharge head by which the liquid discharge head, where a thickness of a coating layer on a heating resistor is thinner than a thickness of a coating layer on an electrode layer, can be easily manufactured.SOLUTION: In order to manufacture a liquid discharge head that has a substrate 1, heating resistors 8, an electrode layer 6 electrically connected to the heating resistors 8 and a coating layer 7 that coats the heating resistors 8 and the electrode layer 6, where a thickness of the coating layer 7 on the heating resistors 8 is thinner than a thickness of the coating layer 7 on the electrode layer 6, the substrate is prepared which has the heating resistors 8, the electrode layer 6 electrically connected to the heating resistors 8 and the coating layer 7 coating the heating resistors 8 and the electrode layer 6, and a temperature of the coating layer 7 on the heating resistors 8 is made higher than a temperature of the coating layer 7 on the electrode layer 6 to etch the coating layer 7 on the heating resistors 8, so as to make the thickness of the coating layer 7 on the heating resistors 8 thinner than the thickness of the coating layer 7 on the electrode layer 6.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a liquid discharge head.

  As a liquid discharge head, there is a system in which a heating resistor in a flow path is heated and liquid is discharged from a discharge port using foaming generated in the liquid in the flow path by heating. An electrode layer is electrically connected to the heating resistor, and the electrode layer and the heating resistor are covered with a coating layer such as an insulating layer and a protective layer.

  The liquid ejection head is required to be driven with power saving. In order to enable the liquid discharge head to be driven with power saving, it is effective to make the coating layer on the heating resistor thin. When the coating layer is thin, the temperature of the liquid contact portion (heat acting portion) of the heating resistor is increased efficiently, and the input energy required for foaming is reduced. As a result, the liquid discharge head can be driven with low power consumption.

  However, when a thin coating layer is formed, the coating layer on the electrode layer connected to the heating resistor also becomes thin, and electrostatic breakdown due to electrostatic discharge is likely to occur in the coating layer on the electrode layer. Become.

  In the method of manufacturing a liquid discharge head described in Patent Document 1, after forming a first coating layer and etching the first coating layer on the heating resistor by a photolithography method to form an opening, A second coating layer is formed thereon. According to this method, since the coating layer on the heating resistor is formed thinner than the coating layer on the electrode layer, the temperature of the liquid contact portion of the heating resistor can be increased efficiently. Moreover, since the coating layer on the electrode layer can be thickened, the occurrence of electrostatic breakdown can be suppressed.

Japanese Patent No. 3397532

  However, in the method described in Patent Document 1, a first coating layer and a second coating layer are formed, a photolithography process is performed, and etching is further performed. Therefore, compared to the case where there is only one coating layer, a load is imposed on manufacturing.

  The present invention is intended to solve this problem, and a liquid capable of easily manufacturing a liquid discharge head in which the thickness of the coating layer on the heating resistor is thinner than the thickness of the coating layer on the electrode layer. An object is to provide a discharge head.

  The present invention comprises a substrate, a heating resistor, an electrode layer electrically connected to the heating resistor, and the heating resistor and a coating layer covering the electrode layer, and the heating resistor A method of manufacturing a liquid discharge head in which the thickness of the coating layer on the electrode is thinner than the thickness of the coating layer on the electrode layer, the heating resistor, and the electrode layer electrically connected to the heating resistor A step of preparing a substrate having a coating layer covering the heating resistor and the electrode layer, and a temperature of the coating layer on the heating resistor higher than a temperature of the coating layer on the electrode layer Etching the coating layer on the heating resistor, and making the thickness of the coating layer on the heating resistor thinner than the thickness of the coating layer on the electrode layer, This is a method for manufacturing a liquid discharge head.

  According to the present invention, it is possible to easily manufacture a liquid discharge head in which the thickness of the coating layer on the heating resistor is thinner than the thickness of the coating layer on the electrode layer.

The perspective view of a liquid discharge head. Sectional drawing which shows the manufacturing method of a liquid discharge head. The figure which shows a pulse generator.

  FIG. 1 is a perspective view of the liquid discharge head. The liquid discharge head includes a substrate 1 and a flow path member 12 on the substrate 1. The substrate 1 is made of silicon or the like. A liquid supply path 11 passes through the substrate 1, and heating resistors 8 are formed on both sides of the opening of the liquid supply path. The flow path member 12 is formed of a resin or an inorganic film, and is a member that forms a liquid flow path. A discharge port 13 is formed at a position facing the heating resistor 8. The liquid is supplied from the liquid supply path 11 to the flow path, and the supplied liquid is heated by the heating resistor 8 and discharged from the discharge port 13. The liquid discharged from the discharge port 13 lands on a recording medium such as paper, and images and characters are recorded.

  Next, a method for manufacturing the liquid discharge head of the present invention will be described. FIG. 2 shows a process of manufacturing the liquid discharge head in the cross section taken along the line XX ′ of the liquid discharge head shown in FIG.

  First, a substrate as shown in FIG. A thermal oxide layer 2 provided by thermally oxidizing a part of the substrate 1 and a heat storage layer 4 are provided on the substrate 1 provided with a driving element such as a transistor. The thickness of the thermal oxide layer 2 is preferably 500 nm or more and 2000 nm or less. The heat storage layer 4 is made of, for example, a silicon compound, and preferably has a thickness of 500 nm to 2000 nm. A sacrificial layer 3 made of aluminum or the like used when forming the liquid supply path 11 is formed on the substrate 1. A resistor layer 5 is formed on the heat storage layer 4. The resistor layer 5 is formed of a material that generates heat when energized. Examples of such a material include TaSiN and WSiN. The sheet resistance of the resistor layer 5 is preferably 100Ω / □ or more and 1000Ω / □ or less. An electrode layer 6 having a resistance lower than that of the resistor layer 5 is formed on the resistor layer 5 so as to be in contact with the resistor layer 5. The electrode layer 6 is made of, for example, aluminum, and preferably has a thickness of 100 nm to 2000 nm. A pair of electrode layers 6 are provided, and the exposed resistor layer 5 between the pair of electrode layers 6 is a heating resistor 8. That is, a part of the resistor layer is the heating resistor 8. When a voltage is applied to the pair of electrode layers 6, the heating resistor 8 generates heat. The heating resistor 8 and the electrode layer 6 are continuously covered with a covering layer 7. Here, the covering layer 7 is an insulating layer formed of SiN or the like. The coating layer 7 insulates the heating resistor 8 and the electrode layer 6 from the liquid, and the thickness is substantially constant at this stage.

  Next, as shown in FIG. 2B, the coating layer 7 is etched to remove a part of the coating layer 7. First, the coating layer 7 on the pad portion 9 on the right side of FIG. 2B is removed by etching to expose the pad portion 9 made of aluminum or the like.

Next, a voltage is applied to the pad portion 9 by a pulse generator as shown in FIG. A fluorine-based etching gas such as CF ₄ and CHF ₃ and an oxygen gas are introduced into the etching chamber 205 from an etching gas introduction pipe 201 and an oxygen gas introduction pipe 202, respectively. The flow rates of the etching gas and oxygen gas are controlled by mass flow controllers 206 and 207. A wafer 209 is installed in the etching chamber 205, and the pulse generator 208 and the pad unit 9 are electrically connected.

  The pad portion 9 is electrically connected to the heating resistor 8 through the electrode layer 6 and the resistor layer 5, and the heating resistor 8 is heated by applying a voltage to the pad portion 9. At this time, since the temperature of the heating resistor 8 is higher than that of the electrode layer 6, the temperature of the coating layer 7 on the heating resistor 8 is higher than the temperature of the coating layer 7 on the electrode layer 6. . In this state, the coating layer 7 is etched. At this time, the wafer stage may be heated to heat the entire substrate (wafer). The electrode layer on the wafer is thin and has good heat response. Therefore, the temperature of the coating layer on the substrate (wafer) and the electrode layer is substantially the same. Since the etching rate increases as the temperature increases, the thickness of the coating layer on the heating resistor 8 can be made thinner than the thickness of the coating layer on the electrode layer 6 due to the temperature difference. Etching includes dry etching and wet etching. Of these, dry etching is preferable, and reactive ion etching is particularly preferable.

  In the etching, the temperature of the coating layer on the heating resistor is preferably 30 ° C. or higher, more preferably 60 ° C. or higher. Moreover, it is preferable to set it as 500 degrees C or less, It is more preferable to set it as 400 degrees C or less, It is further more preferable to set it as 300 degrees C or less. Further, the temperature of the coating layer on the heating resistor is preferably higher by 50 ° C. or more than the temperature of the coating layer on the electrode layer.

  Let A be the thickness of the coating layer on the heating resistor after etching. In addition, the thickness of the coating layer on the electrode layer after etching is B. At this time, A is preferably 100 nm or more and 1000 nm or less. Further, B is preferably 100 nm or more and 1500 nm or less. B / A is preferably greater than 1.0 and 1.5 or less. In the present invention, the coating layer on the heating resistor means a coating layer on the side opposite to the substrate of the heating resistor. The thickness means the average thickness in the direction perpendicular to the substrate surface at 10 points of the coating layer on the heating resistor. Similarly, the coating layer on the electrode layer refers to a coating layer on the opposite side of the electrode layer from the substrate. The thickness means an average thickness in the direction perpendicular to the substrate surface at 10 points of the coating layer on the electrode layer. Moreover, these temperatures are the average of these 10 temperatures.

  Thereafter, as shown in FIG. 2C, a protective layer 10 made of Ta or the like is formed on the heating resistor as necessary.

  Next, as shown in FIG. 2D, the liquid supply path 11 is formed on the substrate 1, and the flow path member 12 and the discharge port 13 are formed on the substrate 1. In this way, the liquid discharge head is manufactured.

  Although the temperature of the coating layer on the heating resistor is set higher than the temperature of the coating layer on the electrode layer, the method is not limited to the method of heating the heating resistor as described above. For example, the coating layer on the heating resistor may be heated using an electrode layer separately connected to the coating layer on the heating resistor.

  When etching the coating layer on the heating resistor, the temperature of the coating layer on the heating resistor may be higher than the temperature of the coating layer on the electrode layer. In this etching, the coating layer on the electrode layer may be heated or may not be heated. If the coating layer on the electrode layer is heated, etching of the coating layer on the electrode layer can be facilitated. Therefore, it is effective when the coating layer on the electrode layer is to be etched. On the other hand, when the coating layer on the electrode layer is not heated, it is easy to make a temperature difference between the coating layer on the heating resistor and the coating layer on the electrode layer, and it is easy to make a difference between the etch rates of both.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1
First, a substrate shown in FIG. The substrate 1 is made of silicon. The thermal oxidation layer 2 and the heat storage layer 4 are both made of SiO ₂ and having a thickness of 1000 nm. On the heat storage layer 4, a resistor layer 5 having a sheet resistance of 300Ω / □ made of TaSiN and an electrode layer 6 made of an aluminum alloy (Al—Cu, thickness 1000 nm) having a resistance lower than that of the resistor layer 5 are formed. ing. The portion of the resistor layer 5 not covered with the electrode layer 6 is a heating resistor 8, and the heating resistor 8 and the electrode layer 6 are covered with a coating layer 7 made of SiN. The coating layer 7 has a thickness of 400 nm and is formed by a plasma chemical vapor deposition method.

  Next, as shown in FIG. 2B, the coating layer 7 was etched to remove a part of the coating layer 7. First, the coating layer 7 on the pad portion on the right side of FIG. 2B was removed by dry etching to expose the pad portion 9 made of aluminum.

  Next, a voltage was applied by applying a pulse to the pad portion 9 and applying pulses continuously by a pulse generator as shown in FIG. As a result, the heating resistor 8 was heated, and the temperature of the coating layer on the heating resistor 8 was higher than that of the coating layer on the electrode layer 6.

Then, the coating layer 7 was etched while the temperature of the coating layer on the heating resistor was higher than the temperature of the coating layer on the electrode layer. Etching conditions are as follows.
Etching gas: CF ₄ (flow rate: 50 sccm), O ₂ (flow rate: 20 sccm)
・ Chamber pressure: 50Pa
・ RF power: 500W
・ Stage temperature: 20 ℃
-Temperature of heating resistor: 70 ° C
Under this condition, the etching rate of the coating layer on the heating resistor was 7.3 nm / sec. Moreover, the etching rate of the coating layer on the electrode layer was 4.8 nm / sec. The stage temperature and the temperature of the coating layer on the electrode layer are substantially the same. Also, the temperature of the heating resistor and the temperature of the coating layer on the heating resistor are substantially the same.

  The thickness of the coating layer on the heating resistor was set to 300 nm by etching. The thickness of the coating layer on the electrode layer was 335 nm.

  Thereafter, a protective layer 10 made of Ta having a thickness of 300 nm was formed by sputtering, and was patterned by dry etching as shown in FIG.

  As described above, 10,000 liquid discharge heads were manufactured. Thereafter, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate at which breakage or the like considered to be caused by electrostatic discharge occurred was confirmed. The results are shown in Table 1.

(Example 2)
The temperature of the heating resistor was 120 ° C., and the thickness of the coating layer on the heating resistor was 300 nm and the thickness of the coating layer on the electrode layer was 355 nm by etching. The etching rate of the coating layer on the electrode layer was 9.8 nm / sec. Except this, it was carried out similarly to Example 1, and manufactured 10,000 liquid discharge heads. Thereafter, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate at which breakage or the like considered to be caused by electrostatic discharge occurred was confirmed. The results are shown in Table 1.

(Example 3)
The temperature of the heating resistor was 320 ° C., and the thickness of the coating layer on the heating resistor was 300 nm and the thickness of the coating layer on the electrode layer was 380 nm by etching. The etching rate of the coating layer on the electrode layer was 19.8 nm / sec. Except this, it was carried out similarly to Example 1, and manufactured 10,000 liquid discharge heads. Thereafter, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate at which breakage or the like considered to be caused by electrostatic discharge occurred was confirmed. The results are shown in Table 1.

(Comparative Example 1)
The temperature of the heating resistor and the stage temperature were the same at 50 ° C. That is, the temperature of the coating layer on the heating resistor and the temperature of the coating layer on the electrode layer were both set to 50 ° C., and the coating layer made of SiN having a thickness of 400 nm was etched in this state. The etching conditions for the coating layer are as follows.
Etching gas: CF ₄ (flow rate: 50 sccm), O ₂ (flow rate: 20 sccm)
・ Chamber pressure: 50Pa
・ RF power: 500W
・ Stage temperature: 50 ℃
-Temperature of heating resistor: 50 ° C
Under these conditions, the etching rate of the coating layer on the heating resistor and the etching rate of the coating layer on the electrode layer were both 6.3 nm / sec. The thickness of the coating layer after etching was the same on the heating resistor and on the electrode layer, both 300 nm.

  Thereafter, a protective layer 10 made of Ta having a thickness of 300 nm was formed by sputtering, and was patterned by dry etching as shown in FIG.

  Except for the above points, 10,000 liquid discharge heads were manufactured in the same manner as in Example 1. Moreover, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate of occurrence of breakage or the like considered to be derived from electrostatic discharge was confirmed. The results are shown in Table 1.

  By making the temperature of the coating layer on the heating resistor higher than the temperature of the coating layer on the electrode layer, the thickness of the coating layer on the heating resistor is changed by etching so that the thickness of the coating layer on the electrode layer is reduced. It can be made relatively thinner than the thickness. Further, as the temperature difference is increased, the difference in thickness is also increased. The damage of the coating layer on the electrode layer is suppressed as the thickness of the coating layer on the electrode layer increases.

  It can also be seen that when the temperature of the coating layer on the heating resistor is the same as the temperature of the coating layer on the electrode layer and the coating layer is etched, there is no difference in the thickness of the coating layer.

Example 4
In Examples 1 to 3, the stage temperature (the temperature of the coating layer on the electrode layer) was the same, and the temperature of the heating resistor (the temperature of the coating layer on the heating resistor) was varied. In contrast, in Examples 4 and 5, the temperature of the heating resistor (the temperature of the coating layer on the heating resistor) was the same, and the stage temperature (the temperature of the coating layer on the electrode layer) was varied.

In Example 4, the thickness of the coating layer 7 made of SiN was 500 nm, and etching was performed under the following conditions.
Etching gas: CF ₄ (flow rate: 50 sccm), O ₂ (flow rate: 20 sccm)
・ Chamber pressure: 50Pa
・ RF power: 500W
・ Stage temperature: 20 ℃
-Temperature of heating resistor: 250 ° C
Under these conditions, the etching rate of the coating layer on the heating resistor was 16.5 nm / sec. Moreover, the etching rate of the coating layer on the electrode layer was 4.8 nm / sec.

  The thickness of the coating layer on the heating resistor was set to 400 nm by etching. The thickness of the coating layer on the electrode layer was 470 nm.

  Thereafter, a protective layer 10 made of Ta having a thickness of 300 nm was formed by sputtering, and was patterned by dry etching as shown in FIG.

  Except for the above points, 10,000 liquid discharge heads were manufactured in the same manner as in Example 1. Moreover, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate of occurrence of breakage or the like considered to be derived from electrostatic discharge was confirmed. The results are shown in Table 2.

(Example 5)
The stage temperature (the temperature of the coating layer on the electrode layer) was 150 ° C., and the thickness of the coating layer on the heating resistor was 400 nm and the thickness of the coating layer on the electrode layer was 430 nm by etching. The etching rate of the coating layer on the electrode layer was 11.5 nm / sec. Except for this, the same procedure as in Example 4 was carried out to produce 10,000 liquid discharge heads. Thereafter, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate at which breakage or the like considered to be caused by electrostatic discharge occurred was confirmed. The results are shown in Table 2.

(Comparative Example 2)
The temperature of the heating resistor and the stage temperature were the same at 50 ° C. That is, the temperature of the coating layer on the heating resistor and the temperature of the coating layer on the electrode layer were both 50 ° C., and the coating layer made of SiN having a thickness of 500 nm was etched in this state. The etching conditions for the coating layer are as follows.
Etching gas: CF ₄ (flow rate: 50 sccm), O ₂ (flow rate: 20 sccm)
・ Chamber pressure: 50Pa
・ RF power: 500W
・ Stage temperature: 50 ℃
-Temperature of heating resistor: 50 ° C
Under these conditions, the etching rate of the coating layer on the heating resistor and the etching rate of the coating layer on the electrode layer were both 6.3 nm / sec. The thickness of the coating layer after etching was the same on the heating resistor and on the electrode layer, and both were 400 nm.

  Thereafter, a protective layer 10 made of Ta having a thickness of 300 nm was formed by sputtering, and was patterned by dry etching as shown in FIG.

  Except for the above points, 10,000 liquid discharge heads were manufactured in the same manner as in Example 1. Moreover, the state of the coating layer on the electrode layer was observed with an electron microscope, and the rate of occurrence of breakage or the like considered to be derived from electrostatic discharge was confirmed. The results are shown in Table 2.

  By making the temperature of the coating layer on the heating resistor higher than the temperature of the coating layer on the electrode layer, the thickness of the coating layer on the heating resistor is changed by etching so that the thickness of the coating layer on the electrode layer is reduced. It can be made relatively thinner than the thickness. Further, as the temperature difference is increased, the difference in thickness is also increased. The damage of the coating layer on the electrode layer is suppressed as the thickness of the coating layer on the electrode layer increases.

(Example 6)
The stage temperature (the temperature of the coating layer on the electrode layer) and the temperature of the heating resistor (the temperature of the coating layer on the heating resistor) were made higher than in Example 1. Specifically, the temperature of the coating layer on the electrode layer was 50 ° C., and the temperature of the coating layer on the heating resistor was 300 ° C. The etching rate of the coating layer on the electrode layer was 6.3 nm / sec. The etching rate of the coating layer on the heating resistor was 18.8 nm / sec. The thickness of the coating layer on the heating resistor was 300 nm, and the thickness of the coating layer on the electrode layer was 367 nm. Except for this, a liquid discharge head was manufactured in the same manner as in Example 1. Thereafter, the manufactured liquid discharge head was filled with ink (trade name; BCI-7eM, manufactured by Canon), and a drive pulse having a voltage of 24 V and a width of 0.8 microsecond was applied to the heating resistor at a frequency of 15 kHz. Ink was discharged up to ⁹ pulses, and an image was recorded. The recorded image was visually observed and evaluated according to the following criteria.
A: No decrease in image quality was confirmed even with 1.0 × 10 ⁹ pulses.
B: Decrease in image quality was confirmed between pulse application of 5.0 × 10 ⁸ or more and less than 1.0 × 10 ⁹ .
C: Decrease in image quality was confirmed between pulse application of 1.0 × 10 ⁸ or more and less than 5.0 × 10 ⁸ .
D: Deterioration in image quality was confirmed between pulse application of 5.0 × 10 ⁷ or more and less than 1.0 × 10 ⁸ .

  The above results are shown in Table 3.

(Example 7)
The temperature of the heating resistor was 400 ° C., and the thickness of the coating layer on the heating resistor was 300 nm and the thickness of the coating layer on the electrode layer was 374 nm by etching. The etching rate of the coating layer on the heating resistor was 23.8 nm / sec. Except for this, a liquid discharge head was manufactured in the same manner as in Example 6. Thereafter, the recorded image was visually observed and evaluated according to the same criteria as in Example 6. The above results are shown in Table 3.

(Example 8)
The temperature of the heating resistor was 500 ° C., and the thickness of the coating layer on the heating resistor was 300 nm and the thickness of the coating layer on the electrode layer was 378 nm by etching. The etching rate of the coating layer on the heating resistor was 28.8 nm / sec. Except for this, a liquid discharge head was manufactured in the same manner as in Example 6. Thereafter, the recorded image was visually observed and evaluated according to the same criteria as in Example 6. The above results are shown in Table 3.

Example 9
The temperature of the heating resistor was 550 ° C., and the thickness of the coating layer on the heating resistor was 300 nm and the thickness of the coating layer on the electrode layer was 380 nm by etching. The etching rate of the coating layer on the heating resistor was 31.2 nm / sec. Except for this, a liquid discharge head was manufactured in the same manner as in Example 6. Thereafter, the recorded image was visually observed and evaluated according to the same criteria as in Example 6. The above results are shown in Table 3.

  As shown in Table 3, as the temperature of the heating resistor during etching decreased, the quality of the recorded image was improved. The cause is considered as follows. At the time of etching, the coating layer made of SiN is placed in a high temperature environment, so that hydrogen in the layer is desorbed, a dangling bond is formed, and the insulating property is lowered. When the insulating property of the coating layer is lowered, Ta of the protective layer is easily anodized during ejection, so that the oxidized layer of the protective layer is eluted into the ink. As a result, the heating resistor may be affected, and the quality of the image is lowered. Therefore, it is preferable that the temperature of the heating resistor during etching is low.

Claims (10)

A substrate, a heating resistor, an electrode layer electrically connected to the heating resistor, and a coating layer covering the heating resistor and the electrode layer, the coating on the heating resistor A method for manufacturing a liquid discharge head, wherein the thickness of the layer is thinner than the thickness of the coating layer on the electrode layer,
Preparing a substrate having a heating resistor, an electrode layer electrically connected to the heating resistor, and a coating layer covering the heating resistor and the electrode layer;
The temperature of the coating layer on the heating resistor is made higher than the temperature of the coating layer on the electrode layer, the coating layer on the heating resistor is etched, and the coating layer on the heating resistor is etched. Making the thickness thinner than the thickness of the coating layer on the electrode layer;
A method of manufacturing a liquid discharge head, comprising:   The method of manufacturing a liquid ejection head according to claim 1, wherein the temperature of the coating layer on the heating resistor is set higher than the temperature of the coating layer on the electrode layer by heating the heating resistor.   The method for manufacturing a liquid discharge head according to claim 1, wherein the coating layer on the electrode layer is heated when the coating layer on the heating resistor is etched.   The method for manufacturing a liquid ejection head according to claim 1, wherein when the coating layer on the heating resistor is etched, the coating layer on the electrode layer is not heated.   When the thickness of the coating layer after etching of the coating layer on the heating resistor is A and the thickness of the coating layer on the electrode layer is B, B / A is larger than 1.0 and 1.5. The method for manufacturing a liquid discharge head according to claim 1, wherein:   6. The liquid ejection head according to claim 1, wherein the temperature of the coating layer on the heating resistor is set to 60 ° C. or higher when the coating layer on the heating resistor is etched. Method.   7. The liquid ejection head according to claim 1, wherein the temperature of the coating layer on the heating resistor is set to 500 ° C. or less when the coating layer on the heating resistor is etched. Method.   8. The liquid ejection head according to claim 1, wherein when the coating layer on the heating resistor is etched, a temperature of the coating layer on the heating resistor is set to 400 ° C. or less. Method.   8. The liquid ejection head according to claim 1, wherein the temperature of the coating layer on the heating resistor is set to 300 ° C. or lower when the coating layer on the heating resistor is etched. Method.   10. The etching method according to claim 1, wherein when the coating layer on the heating resistor is etched, the temperature of the coating layer on the heating resistor is set to 50 ° C. or more higher than the temperature of the coating layer on the electrode layer. A method for manufacturing a liquid discharge head according to any one of the preceding claims.

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