JP3122098B2 - Method for manufacturing liquid jet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention uses thermal energy to eject liquid to form ejected droplets, and attaches them to a recording material such as paper for recording. The present invention relates to a method for manufacturing a liquid jet recording head mounted on a liquid jet recording apparatus that performs the following.

[Conventional technology]

The liquid ejection recording method is a recording method in which a discharge droplet of a recording liquid such as ink is formed by various methods, and the droplet is attached to a recording material such as paper to perform recording.

Among printing apparatuses to which such a printing method is applied, as an apparatus having a structure suitable for high-density multi-ejection ports,
A liquid jet recording apparatus that uses thermal energy as energy for forming a droplet to be ejected can be used.

A liquid jet recording apparatus utilizing thermal energy as the droplet discharge energy usually has a liquid jet recording head having a droplet forming means for forming droplets of a recording liquid and a liquid heating means. The droplet forming means has a discharge port for discharging droplets and a liquid path including a portion for applying heat to the recording liquid, and the liquid heating means generates heat by applying an electric signal, It includes an electrothermal energy converter including a heating resistor (hereinafter, referred to as a heater) capable of heating the recording liquid and a pair of electrodes for applying an electric signal to the heating resistor.

The droplet forming means applies a predetermined recording signal to the heater through the electrode to cause the heater to generate heat, thereby heating the recording liquid and giving the recording liquid a pressure displacement accompanying a volume increase due to rapid foaming. Then, the recording liquid is discharged from the droplet discharge port to form a droplet of the recording liquid.

On the other hand, as a recording liquid used when recording is performed by a liquid jet recording apparatus, an aqueous recording liquid is mainly used in terms of recording characteristics, ejection stability, and the like.

The aqueous recording liquid is generally formed by a recording agent component such as a pigment or a dye and a solvent component mainly composed of water or water and a water-soluble organic solvent for dissolving or dispersing the recording agent component.

The heating limit temperature for rapidly vaporizing the recording liquid containing a solvent component consisting of water and a water-soluble organic solvent,
That is, the temperature between the heat transfer surface and the liquid is extremely thin and a stable vapor film is formed, and the temperature at which vaporization occurs at the gas-liquid interface due to the amount of heat transferred by the heat conduction is 250 ° C. to 350 ° C.

Therefore, using a recording liquid having such a temperature characteristic, the recording liquid is foamed and discharged by giving an electric signal to the heater, and in order to perform recording, the heater needs to be heated from room temperature every time the electric signal is supplied. It generates heat repeatedly from 300 ° C to 800 ° C.

The heater is, for example, a heating resistor (for example, HfB ₂ , Zr, or the like) provided on a substrate (for example, Si, glass, ceramics, or the like).
On B _2, TaN _2, heat resistance material such as TaSi), intermediate layer (Ti, Cr
And the like, and a wiring portion (electrode, for example, Al, Au, Ag, Cu, or the like) made of a metal that is a good electrical conductor is laminated so as to expose the intermediate layer. That is, the portion where the intermediate layer is exposed serves as a heater.

Further, if necessary, a protective layer (eg, Si) having excellent heat resistance and ink shielding properties to prevent electrolytic corrosion and oxidation from the recording liquid.
O ₂ , Al ₂ O ₃ , Si ₃ N _4, etc.) are provided at least on the heater and the electrode, and shield them from the recording liquid.

In a recording apparatus having a configuration in which a heater having the above-described configuration is repeatedly heated to a high temperature by an electric signal corresponding to a recording signal to heat a recording liquid and discharge droplets, recording characteristics during recording (particularly, For the purpose of improving the properties of the recording liquid, for example, viscosity, etc., conventionally, after a liquid jet recording apparatus has been sold, with a liquid jet recording head mounted on the apparatus, see, for example, US Pat. No. 4,712,172. Pre-discharge processing indicated,
Alternatively, for example, USP 4463359, USP 4296421, USP
The preheating treatment described in US Pat. No. 4,471,792 and US Pat. No. 4,712,172 was performed in the recording mode.

[Problems to be solved by the invention]

By performing the above-described processing, mainly the properties of the recording liquid at the time of recording are improved, but it cannot always be said that a method for achieving the best recording state from an early stage is necessarily sufficient.

That is, phase change, stress change, oxidation, and composition change of the heater material may be caused by repeated high-temperature heat generation of the heater material in the recording mode including the above-described preliminary discharge process and the preliminary heating process, and the resistance value of the heater material gradually increases. Was easy to change.

In addition, the resistance distribution of the heater material changes due to the interface resistance in the boundary region between the heater material and the wiring portion (electrode), and also due to the diffusion phenomenon between the two.

When the heater resistance value changes in this way, the heat energy generated by the initially set electric signal increases or decreases in accordance with the resistance change and deviates from a predetermined value. As a result, the droplet discharge speed and the discharge amount gradually become different from those initially set.

If these finally exceed a range suitable for discharging the recording liquid, the quality of a recorded image formed by discharging the recording liquid is deteriorated.

Furthermore, when the change in resistance is decreasing, the heat energy generated by the heater increases, and the heater generates heat at or above the set value. It deteriorates remarkably.

Therefore, a method of maintaining such a change in the heater resistance value within a range in which printing failure and durability deterioration of the heater material do not occur has been studied.

As one of the methods, for example, in the manufacture of a liquid jet recording apparatus, there is a method in which a change in the resistance value of the heater is reduced by performing a heat treatment on the entire recording head when the recording head is completed.

However, when the processing by such a manufacturing method is applied, portions other than the heater that do not require heat treatment are also heated. For this reason, inconveniences due to heating often occur in portions where heat treatment is unnecessary. That is, cracks and defects occur due to an increase in internal stress of the recording head due to the heat treatment, and problems such as warpage of the recording head itself and poor adhesion due to peeling between components of the recording head have occurred.

Further, problems such as poor electrical resistance and poor contact due to oxidation of a bonding portion for electrical connection between the recording head and an external device, and deterioration of adhesion at those portions also occurred.

Furthermore, in order to obtain the effect of stabilizing the resistance value of the heater in this method, it is necessary to perform the heat treatment at a high temperature of 500 ° C. or more, which limits the materials that can be used for the recording head components, thereby increasing the manufacturing cost The problem of doing so.

The present invention has been made in view of these problems,
In performing the recording, the change in the heater resistance is suppressed within a range suitable for always obtaining a good droplet discharge state from the initial stage of the recording. An object of the present invention is to provide a method of manufacturing a liquid jet recording head capable of obtaining a discharge state.

It is another object of the present invention to provide a method of manufacturing a liquid jet recording head capable of obtaining a liquid jet recording head having a high durability life with respect to repetitive heat generation for a long time in a heater of a recording apparatus.

Still another object of the present invention is to provide a method for manufacturing a liquid jet recording head which can suppress a variation in manufacturing and can easily and inexpensively manufacture a liquid jet recording head capable of obtaining a good and stable droplet discharge state. There is also.

Another object of the present invention is to suppress a change in the heater resistance within a suitable range to always obtain a good droplet discharge state, and always provide a good and stable droplet discharge state even during long-time recording. An object of the present invention is to provide a liquid jet recording head obtained.

Another object of the present invention is to provide a liquid jet recording head having a high durability life against repeated heating for a long time in a heater of a recording apparatus.

Still another object of the present invention is to provide a low-cost and easy-to-use liquid jet recording head capable of suppressing manufacturing variations and obtaining a good and stable droplet discharge state.

Still another object of the present invention is to provide a liquid jet recording apparatus equipped with a liquid jet recording head having excellent characteristics as described above.

[Means for solving the problem]

The method for manufacturing a liquid jet recording head according to the present invention is used for generating thermal energy used for ejecting ink by applying an electric signal, and comprises a heating resistor and the heating resistor. An electrothermal energy converter including a pair of electrodes for applying an electric signal to the body, and a liquid path having a portion where heat from the heating resistor is applied to the recording liquid, In a manufacturing method, in a state where the liquid path of the liquid jet recording head is filled with ink, a high frequency signal is applied from the electrode at a pulse number of 1 × 10 ⁵ or more to cause the heat generating resistor to generate heat, An aging step of stabilizing the resistance value of the heat generating resistor by the action of the heat generated by the heat is provided.

According to the manufacturing method, it is possible to obtain a liquid jet recording head and a liquid jet recording apparatus having the recording head that can achieve the above-described object.

The electric signal during the aging process in the manufacturing method is sufficient to cause the heating resistor to generate heat and to stabilize the resistance value of the heating resistor by the action of heating due to the generated heat.

Further, a liquid jet recording apparatus having a recording head obtained by the method of the present invention can have means for optimizing the ejection of ink from the recording head.

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a liquid jet recording apparatus having a liquid jet recording head manufactured by the method of the present invention, and FIG. 2 is a liquid jet recording mounted on the liquid jet recording apparatus shown in FIG. FIG. 3 is a partially enlarged developed perspective view of a main part of a head.

The liquid jet recording apparatus shown in FIGS. 1 and 2 has the following configuration. That is, reference numeral 1 denotes a main tank 9 for storing the recording liquid and a sub-tank 2 for temporarily storing the recording liquid in the recording apparatus, a supply tube for supplying the recording liquid from the main tank 9 to the sub-tank 2, and 3 a recording head. 7, a suction tube connected to a recovery pump which communicates with a cap member 10 used for a discharge recovery process and a capping process of the recording head.
Supply pipe unit for supplying a recording liquid from the liquid chamber 5 to the liquid chamber 5;
Reference numeral 6 denotes a presser for the supply pipe unit 4, reference numeral 7 denotes a recording head in which a predetermined number of droplet discharge ports 12 for discharging recording liquid are arranged in a vertical direction as shown in FIG. 2, and reference numeral 8 denotes a recording head shown in FIG. Fluid path
Heater for applying thermal energy to the recording liquid in 14
A flexible printed circuit board (hereinafter, referred to as FPC) for applying an electric signal from the ejection signal generating means 15 to the apparatus 13 or applying a signal from the preliminary ejection processing control means 16 and the preliminary heating processing means 17 to the apparatus 13. An electric wiring unit 11 is a base plate for supporting the arrangement of the supply pipe unit 4, the liquid chamber 5, the recording head 7, the supply pipe holder 6, and the FPC 8.

In this example, as shown in FIG. 2, discharged droplets are discharged from a droplet discharge port 12 and a liquid path 14 communicating with the liquid discharge port 12 and including a portion where heat from a heater 13 is applied to a recording liquid. A droplet forming means for forming the droplet is configured. Further, a liquid heating means (electric heat energy converter) is formed by the heater 13 and a pair of electrodes (not shown) for applying an electric signal to the heater 13 as necessary (this electrode receives a recording signal from the FPC 8). Is configured.

To perform recording using this apparatus, first, the recording liquid is filled from the main tank 9 into the sub tank 2, the liquid chamber 5, and the liquid path 14 via the supply tube 1 and the supply pipe unit 4. Next, a recording signal, that is, an electric signal from the ejection signal generating means 15 is applied from the FPC 8 to the heater 13 via the electrode. As a result, the heater 13 generates heat, and heat energy is applied to the recording liquid existing in the liquid path 14 near the heater 13. By applying the thermal energy to the recording liquid from the heater 13 in this manner, air bubbles are generated in the recording liquid with an instantaneous increase in the volume of the recording liquid at that portion. As a result, the recording liquid existing downstream of the heater 13 is discharged from the discharge port 12, and droplets of the recording liquid are formed. The droplets of the recording liquid are attached to a recording material such as paper sent in front of the recording head 7 to perform desired image recording.

Note that, at the time of printing by the above-described printing apparatus, a pre-ejection process, a pre-heating process, and a print head recovery process are performed for the purpose of optimizing the ejection of ink from the print head and forming a high-quality image. These processes are performed by a preliminary discharge processing control unit 16, a preliminary heating control unit 17, and a recovery processing control unit 18.
, And can be incorporated as a series of recording modes or independently of each other.

The preliminary ejection processing and the preliminary heating processing mainly adjust the viscosity and the like of the recording liquid. The recovery process is to recover the clogging of the ejection openings by pressurizing or sucking the ink in the recording head while the recording head 7 is in contact with the cap member 10.

In the method of manufacturing a liquid jet recording head according to the present invention, an electric signal is supplied to the heater 13 at any stage when the liquid jet recording head mounted on the apparatus having the above-described configuration is manufactured. In addition, an aging process for stabilizing the resistance value of the heater 13 by heating only the vicinity of the heater 13 is incorporated.

The aging process by the above-described heat treatment includes a series of liquid ejection after the formation of an electrothermal energy converter including a heater constituting a liquid ejection recording head and an electrode for applying an electric signal to the heater and a liquid path. It can be incorporated during the manufacturing process of the recording head. Alternatively, after completion of the liquid jet recording head, it is also possible to perform a heating process on the recording head before mounting it on a recording apparatus,
It is also possible to perform the above-described heating process after mounting the recording apparatus and before normal recording is performed (for example, before the recording apparatus is sold).

However, in consideration of the easiness of the heat treatment, the heat treatment is preferably performed after the recording head is completed.

In particular, it is preferable to perform the operation after the completion of the recording head capable of applying an electric signal to a plurality of recording heads at once and before mounting the recording apparatus. In this case, a separate apparatus for heat treatment for giving an electric signal to each of the plurality of recording heads is required.

On the other hand, in the case where the heat treatment is performed in a state where the recording head is mounted on the recording apparatus, a separate apparatus for the heat treatment is unnecessary. In addition, when the recording head is mounted on the recording apparatus, the recording head can be filled with the recording liquid, and the recording liquid is filled with the recording liquid to perform a heating process, whereby the recording liquid and the heat generation resistance are reduced. Improves the wettability between the body or the recording liquid and the liquid path, and enables more stable ejection of the recording liquid. Then, it is also preferable to perform the above-mentioned heat treatment in a state in which discharge is possible.

Further, in the above two examples of the heat treatment, even when the former is performed before the recording head is mounted on the recording apparatus, the latter is performed by filling the recording head with the recording liquid. Similar effects can be obtained.

The steps other than the heating process of the heater in the method of manufacturing a liquid jet recording head according to the present invention are the same as those of a normal method of manufacturing a liquid jet recording apparatus.

The heater heat treatment signal applied in the manufacturing method of the present invention is, for example, a signal in which heat energy generated by the heater when applied is larger than an electric signal applied for ejection, and a discharge electric signal. It is possible to apply an electric signal that can cause the heater 13 to generate heat to a temperature at which the resistance change due to the heat history of the heater 13 falls within a range where stable ejection can be maintained. This heater heat treatment signal can be applied via an FPC 8 from an external heating signal generation means (not shown).

A high frequency signal is used as a signal applied as the heater heat treatment signal, and the number of pulses is at least 1 × 10 ⁵ . A desired heating process can be performed by changing the applied voltage, applied pulse width, frequency, or the like of the high-frequency signal individually or in combination.

In addition, it is preferable that the heat treatment time of the heater 13 which generates heat by the application of the electric signal for heating be applied under such a condition that the heat treatment time is as short as possible within a range in which the above-mentioned effect can be obtained.

This is because by applying the treatment for a short heating time, the heater 13 and the members constituting the heater
This is because the influence of heat causing deterioration and the like can be minimized, the life of these components can be extended, and the diffusion of heat around the heater can be suppressed.

Hereinafter, specific examples and reference examples of a method of manufacturing a liquid jet recording head in which an aging process by a heating process is performed by changing an applied voltage, an applied pulse width, an applied pulse number, or a DC current of a high-frequency signal to be applied. Will be described.

In the embodiment and the reference example described below, a recording head in which the direction of ink discharge as shown in FIG. 2 and the direction of ink supply to a liquid path provided with a heater are substantially parallel. However, the present invention is not limited to this, and can also be applied to a recording head in which the two directions are different, for example, orthogonal.

〔Example〕

Example 1 A large number of recording heads having the configuration shown in FIG. 2 were prototyped, and the recording liquid was discharged from all the discharge ports before being mounted on the liquid jet recording apparatus and filled with the recording liquid, thereby heating the heater. The effect of the treatment was investigated.

Configuration of recording head Substrate Si (with SiO ₂ thermal oxide film) 1 mm Heating resistor HfB ₂ (sputter film) 0.1 μm Electrode Al 0.5 μm Protective layer SiO ₂ 2 μm Electric signal application conditions for heater heat treatment Pulse width: 7 μs, frequency: 2 kHz, 10 ⁶ pulses (the heat treatment time is equivalent to 8 minutes and 20 seconds) Voltage: 20 to 26 V When the change in print quality according to the number of prints was evaluated, the results shown in FIG. 3 were obtained.

That is, where the recording liquid was evaluated the relationship between K value is the ratio of the applied voltage V with respect to the foaming start voltage V ₀ to start foaming and (= V / V ₀₎ and print quality, the magnitude of the applied voltage at the time of heat treatment There was a difference in the change in print quality depending on the value (K value), and especially in the case of no processing, the print quality greatly deteriorated.

Further, as shown in FIG. 4, the higher the K value during the heat treatment, the more effective.

As is apparent from FIGS. 3 and 4, the high K
By performing the heat treatment depending on the value, it is possible to obtain a stable and good print / image with little deterioration of the resistance value of the heater.

The print quality obtained by measuring the amount of deviation from the least-square line of each vertical / horizontal line in a printed matter with respect to all dots by a microscope is an average value obtained by performing a 5-point impact point error measurement for 10 devices under each condition. In this case, the heating conditions of the heater are constant except for the K value as described above.

Next, the relationship between the heat treatment time (expressed as the number of pulses) and the rate of change in the heater resistance after the treatment was examined.
The results shown in the figure were obtained. That is, K at the time of heat treatment
As the value is higher, the heater resistance value can be stabilized with a smaller number of pulses. Note [Delta] R / R is the average of the change in value of the resistance value R of the heater after use 10 ⁸ characters.

On the other hand, when the relationship between the heater life and the K value was examined,
As shown in FIG. 6, the life of the heater tended to be opposite, and the K value during the heat treatment was higher, and the longer the heat treatment time, the shorter the life.

From the above results, when the appropriate heating treatment condition of the heater is selected, in this embodiment, the wettability between the recording liquid and the heater or between the recording liquid and the liquid path is improved and the initial characteristics are improved. In order to realize a print head that maintains and has a long life, the K value at the time of heat treatment is 1.15 to 1.25. The number of pulses is 1 × 10 ^{5 to} 1 × 10 ⁷ , particularly 1 × 10 ⁶ to 1 × 10 ^7. Turned out to be the most desirable.

Example 2 The effect of the heat treatment was examined using a recording head having the same configuration as in Example 1. In this embodiment, the pulse width is 2 to 12
The landing point error was measured in the same manner as in Example 1 while varying the application conditions while changing the conditions in the range of μs, and the optimal heat treatment conditions were determined.

As a result, when the change in print quality depending on the number of prints was evaluated, the results shown in FIG. 7 were obtained.

That is, the relationship with the applied pulse width P ₁ when the voltage value is the foaming start voltage for the pulse width 7 μs (P ₀ ) However, when a pulse width in the range of P = 1.30 to 1.55 was applied, an effective heat treatment could be performed.

Reference Example 1 Using the recording head of Example 1, heating was performed using DC current instead of pulse current, and the heater was heated as follows.

A current is applied between the common electrode of the recording head and each segment electrode (parallel) by a DC power supply for 60 seconds. Current value from 1mA to 1
The effect was changed between 00 mA and the effect was examined in the same manner as in Examples 1 and 2.

As a result, as shown in FIG.
By setting it to mA or more, the effect of the heating treatment of the heater became remarkable. In the case of Reference Example 1, even when the recording head was filled with ink, the foaming and ejection of the ink were not performed, but the effect of the surface treatment of the heater was the same as in Examples 1 and 2.

Example 3 A heat treatment was performed under the conditions a to f shown in Table 1 below using a recording head having the same configuration as the recording head shown in Example 1.

Under any of the processing conditions, the obtained liquid jet recording head was such that the change in heater resistance was suppressed within a range suitable for always obtaining a good droplet discharge state from the initial stage of recording.

As is clear from the above results, the heat treatment was performed using the K value =
1.15 to 1.25. Number of pulses 1 × 10 ⁵ to 1 × 10 ⁷ , pulse width 5-1
The heat treatment is preferably performed in a range of 0 μs, a frequency of 1.0 to 4.0 kHz, and a heat treatment time of about 2 to 15 minutes. However, a numerical value exceeding these ranges may be set as long as the initial purpose is achieved.

Table 2 shows an example of ink discharge conditions, pre-discharge processing conditions, and pre-heat processing conditions at the time of recording by the recording head described in the first embodiment.

As shown in Table 2, the ink discharge conditions, the pre-discharge processing conditions, and the pre-heat processing conditions are all completely different from the heater heat processing conditions in the present invention. Therefore, it is difficult to improve the characteristics of the heater by these processes, for example, the preliminary ejection process and the preliminary heating process.

〔The invention's effect〕

As described above, according to the present invention, a change in the heater resistance is suppressed within a range suitable for always obtaining a good droplet discharge state from the initial stage of recording, and particularly for recording over a long time, It is possible to provide a method of manufacturing a liquid jet recording head that can always obtain a good and stable droplet discharge state.

Further, it is possible to provide a method of manufacturing a liquid jet recording head capable of obtaining a liquid jet recording head having a high durability life with respect to repeated heat generation for a long time in a heater of a recording apparatus.

In addition, it suppresses manufacturing variations, improves the wettability between the recording liquid and the heater, or between the recording liquid and the liquid path, and reduces the cost of the liquid jet recording head, which can provide a good and stable droplet discharge state. And a method for manufacturing a liquid jet recording head which can be easily manufactured.

Furthermore, a change in the heater resistance is suppressed within a range suitable for always obtaining a good droplet ejection state, and especially in a long-time recording, a liquid ejection recording capable of always obtaining a good and stable droplet ejection state. A head can be provided.

Further, it is possible to provide a liquid jet recording head having a long durability life with respect to repeated heating for a long time in a heater of a recording apparatus.

Furthermore, it is possible to provide a low-cost and easy-to-use liquid jet recording head capable of suppressing manufacturing variations and obtaining a good and stable droplet discharge state.

Furthermore, it is possible to provide a liquid jet recording apparatus equipped with a liquid jet recording head having excellent characteristics as described above.

[Brief description of the drawings]

FIG. 1 is a schematic view of a liquid jet recording apparatus according to the present invention, and FIG.
The figure is an enlarged exploded perspective view of the main part of the liquid jet recording head according to the present invention mounted on the apparatus of FIG. 3 to 8 are characteristic diagrams showing characteristics of the recording heads manufactured in Examples 1 to 3 and Reference Example 1. FIG. 3 shows the relationship between the print quality and the number of prints using the K value as a parameter. FIG. 4 is a characteristic diagram showing the relationship between print quality and K value, FIG. 5 is a characteristic diagram showing the relationship between ΔR / R and the number of pulses using the K value as a parameter, and FIG. Is a characteristic diagram showing the relationship between the life and the number of pulses using the K value as a parameter, FIG. 7 is a characteristic diagram showing the relationship between the print quality and the pulse width, and FIG. 8 is a graph showing the relationship between the print quality and the DC current value. FIG. 1: Supply tube 2: Sub tank 3: Suction tube 4: Supply tube unit 5: Liquid chamber 6: Holding part of supply tube unit 4 7: Recording head 8: Electric wiring unit 9: Main tank 10: Cap member 11: Base plate 12 : Discharge port 13: Heater 14: Liquid path 15: Discharge signal generation means 16: Pre-discharge processing control means 17: Pre-heat processing control means 18: Recovery processing control means

Claims (9)

(57) [Claims] An electric signal is applied to generate heat energy used for ejecting ink. The electric signal is applied to the heating resistor and the heating resistor. A method for manufacturing a liquid jet recording head, comprising: an electrothermal energy conversion body including a pair of electrodes for; and a liquid path having a portion where heat from the heating resistor is applied to the recording liquid. In a state in which ink is filled in the liquid path of the liquid jet recording head, a high frequency signal is applied from the electrode at a pulse number of 1 × 10 ⁵ or more to cause the heat generating resistor to generate heat. A method for manufacturing a liquid jet recording head, comprising an aging step of stabilizing the resistance value of the heating resistor. 2. The method according to claim 1, wherein the high-frequency signal is applied with a pulse number of 1 × 10 ⁷ or less. 3. The method for manufacturing a liquid jet recording head according to claim 1, further comprising a protective layer that covers the electrothermal energy converter and protects the electrothermal energy converter from the ink. 4. The high-frequency signal applied during the aging step has a larger pulse width and / or voltage value than the high-frequency signal applied to discharge the ink. 3. The method for manufacturing a liquid jet recording head according to item 1. 5. The high-frequency signal applied in the aging step is a ratio of K value (= V / V / V) when the foaming start voltage is V ₀ and the voltage applied in the aging step is V.
5. The method according to claim 4, wherein (V ₀ ) applies a voltage in the range of 1.15 to 1.25. 6. The high-frequency signal applied in the aging step is a ratio of P value (= P), where P _{0 is} the pulse width at the start of foaming and P ₁ is the pulse width applied in the aging step. ₁ / P ₀₎ is a method for manufacturing a liquid jet recording head according to claim 4 in which applying a pulse width in the range of 1.30 to 1.55. 7. The method according to claim 6, wherein the application of the high-frequency signal includes a foaming start voltage.
V ₀ , where the voltage applied during the aging step is V, the voltage is a voltage having a K value (= V / V ₀ ) of at least 1.15 and a width of at least 5 μs for at least 2 minutes. 4. The method for manufacturing a liquid jet recording head according to any one of 1 to 3 above. 8. The method for manufacturing a liquid jet recording head according to claim 1, wherein the aging step is performed after the completion of the liquid jet recording head and before mounting the liquid jet recording apparatus. 9. The method for manufacturing a liquid jet recording head according to claim 1, wherein the aging step is performed after the liquid jet recording head is completed and after the liquid jet recording head is mounted on the liquid jet recording apparatus.