JP2008221712A - Manufacturing method for liquid jet recording head, liquid jet recording head manufactured by the method, and liquid jet recorder equipped with the liquid jet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress change in resistance of a heater when a head is used in the liquid jet recording head which uses a TaXN (X=Si, B) thin film as the heater. <P>SOLUTION: In any of phases before the liquid jet recording head is completed by forming the TaXN (X=Si, B) thin film, a treatment for stabilizing Ta-N coupling in the thin film is carried out. Specifically, a vacuum annealing treatment is carried out after the TaXN thin film is formed into a film, and a protecting film is fabricated on it, thereby determining an optimum annealing condition while observing a change of Ta-N coupling by the X-ray diffraction method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid jet recording head, a liquid jet recording head manufactured by the method, and a liquid jet recording apparatus equipped with the liquid jet recording head.

  The liquid jet recording method is a method in which flying droplets are formed by a recording liquid such as ink, and this is attached to a recording material such as paper, and recording is performed. A liquid jet recording apparatus employing such a recording method is High-speed printing and high-density recording with low noise, and because it does not require processing such as development and fixing for plain paper, the device itself can be miniaturized and in mass production It is particularly attracting attention as a product that can be manufactured at low cost and with low production costs.

  In particular, the on-demand type liquid jet recording apparatus does not require a high voltage generator and an unnecessary ink collecting apparatus required for the continuous type liquid jet recording apparatus, and can be miniaturized. Yes. Among them, the one described in Japanese Examined Patent Publication No. 61-59914 is a method in which a part of a liquid path filled with a liquid is heated to give the liquid a pressure displacement accompanying a volume increase due to foaming. As a liquid jet recording apparatus, a liquid jet recording head that records liquid droplets by ejecting liquid from ejection ports that communicate with the path and depositing such liquid droplets on a recording material is used. Particular attention has been paid. In addition, since the above-described liquid jet recording head has the feature that the nozzles are easily densified and multi-purpose, the printing speed can be improved and a high-quality image can be obtained by lengthening the head. There is a special feature.

  In the liquid jet recording head that uses thermal energy to form this flying droplet, the means for heating the recording liquid is a heating resistor that can generate heat by applying an electrical signal to heat the recording liquid. (Hereinafter referred to as a heater) and a pair of electrodes for applying an electrical signal to the heating resistor. The recording liquid used here is generally formed of a recording component such as a pigment or dye and water for dissolving or dispersing the recording component or a solvent component composed of water and a water-soluble organic solvent.

  By the way, the heating limit temperature for rapid vaporization in such an aqueous recording liquid, that is, the heat conduction is transmitted through a very thin and stable vapor film between the surface of the heater and the liquid. The temperature at which steam is generated by the amount of heat is 250 ° C to 350 ° C. Therefore, in order to record the recording liquid on the recording material by foaming the recording liquid by applying an electric signal to the heater by using the recording liquid having such temperature characteristics, and recording the recording material on the recording material, the heater Is given repeatedly at a temperature from the ambient temperature to 300 ° C to 800 ° C.

The heater, the electrode, and the like are formed by a semiconductor process. For example, a heating resistor (for example, HfB ₂ , ZrB ₂ , TaN ₂ , TaSi, etc.) provided on the substrate (for example, Si, glass, ceramics, etc.) The intermediate layer has a wiring portion (electrode, for example, Al, Au, Ag, Cu, etc.) made of a metal that is a good electrical conductor via an intermediate layer (for example, Ti, Cr, etc.) on the intermediate layer. It is formed by being laminated so as to be exposed, and the exposed portion becomes a heater. Further, a protective film excellent in heat resistance and recording liquid blocking property for preventing electrolytic corrosion and oxidation from the recording liquid is formed on the heater and the electrode as necessary.

In addition to the heat resistant resistors listed above as the heat generating resistors, cermet thin films (TaXN thin films: X = Si, B) in which Si or B is added as a third component to tantalum nitride can be cited. TaXN thin film can achieve high resistance, and its temperature coefficient of resistance (TCR) is small compared to other high resistance thin films, and its calorific value is stable even if the temperature of the environment changes. It is one of the most excellent materials for heating resistors used in the heaters of equipment.
Japanese Examined Patent Publication No. 61-59914

  However, the liquid discharge recording head using the TaXN thin film as a heater can obtain stable discharge for a short time use, but if the liquid discharge recording head is used for a long time, There was a problem that the discharge characteristics were not stable due to the change in the resistance R. Currently, many liquid jet recording devices are being developed in order to extend the life of the head in order to reduce the cost burden on consumers, and the resistance change of the TaXN thin film heater develops the liquid jet recording device. It was a big hindrance above.

  The present invention is used for generating thermal energy used for ejecting ink by applying an electrical signal, and for applying an electrical signal to the heating resistor and the heating resistor. A cermet thin film (TaXN thin film: N) having a liquid jet recording head having an electrothermal energy conversion body including a pair of electrodes, and adding Si or B as a third component to nitrogen (N) and tantalum (Ta) = Si, B) in a method for manufacturing a liquid jet recording head using a heating resistor, the method includes a process of stabilizing Ta-N bonds in the heating resistor.

  In a liquid jet recording head using a cermet thin film having Ta and N and a third component X as a constituent element for increasing the resistivity as the heating resistor, the change in the heater resistivity described above is Ta- It was found through detailed examination that the cause is a change in the binding state of N. That is, according to the present invention, the heating resistor is subjected to a treatment for stabilizing the Ta—N bond, thereby suppressing the above-described change in resistivity and stabilizing the ejection characteristics of the liquid ejection recording apparatus over a long period of time. It makes it possible.

  As described above, according to the present invention, the change in the resistance of the heater can be suppressed within a suitable range in order to always obtain a good droplet discharge state from the initial stage of recording, especially in recording over a long time. Therefore, 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 for manufacturing a liquid jet recording head that can obtain a liquid jet recording head having a high durability against repeated long-term heat generation in the heater of the recording apparatus.

  Furthermore, the change in the heater resistance is suppressed within a suitable range for always obtaining a good droplet discharge state, and liquid jet recording that can always obtain a good and stable droplet discharge state even in recording over a long period of time. The head is provided.

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

  FIG. 1 shows an example of a liquid jet recording apparatus equipped with a liquid jet recording head manufactured by the method of the present invention. FIG. 2 shows the configuration of the main part of the liquid jet recording head shown in FIG. FIG. 2 shows an example of a cross section of a heater of the liquid jet recording head shown in FIG. 2 and a CMOS transistor used for driving the heater.

  In FIG. 1, 1 is a liquid jet recording head, 2 is mounted with a recording head 1 and a sub ink tank 3, and reciprocally moves along a guide shaft 4, and 5 is a recording material (recording) at a position opposite to the recording head 1. Sheet) 6 is a platen holding the sheet. The sub tank 3 is supplied with the recording liquid from the main tank 7 for storing the recording liquid through the supply tube 8 and is further led to the liquid chamber 10 (see FIG. 2) of the recording head 1 through the supply pipe unit 9. . Note that the above-described configuration is a unit in which the recording head 1, the sub ink tank 3, the main tank 7, the supply tube 8, and the supply pipe unit 9 are combined into one unit, or all the above functions. It may be a recording head with a built-in recording head. Reference numeral 11 denotes a flexible printed circuit board (hereinafter referred to as FPC). By this FPC 11, various kinds of discharge signals such as discharge signals from the discharge signal generating means 12, preliminary discharge processing control means 13, and preheating processing control means 14 of the recording apparatus are provided. A control signal is supplied to the recording head 1. A pressing member 15 holds the supply pipe unit 9 and the end of the FPC 11, and the recording head 1 and the like between the base plate 16.

  On the other hand, for the recording head 1 that performs recording, the recovery pump 17 and the cap member 18 are in contact with the recording head 1 in the vicinity of the home position outside the recording area to perform the discharge recovery operation and the capping process, and suction between them. A tube 19 is provided and is controlled by the recovery process control means 20. Thus, in combination with the control on the recording head 1 side by the preliminary discharge processing control means 13 and the preliminary heating processing control means 14, in order to obtain high-quality recording, operations corresponding to each other or in a series of modes are performed. .

  Next, the configuration of the recording head 1 will be described with reference to FIG. Here, 1A is a head substrate. On the head substrate 1A, a common liquid chamber 10, a liquid path 21 communicating therewith, a discharge port 22 for discharging recording liquid (hereinafter referred to as ink), and each liquid path 21 are provided. Each of the heaters 23 to be provided is provided, and the recording head 1 is configured in such a manner that a top plate 24 is overlapped thereon.

  Further, the heater unit that applies thermal energy to the ink of the recording head 1 will be further described with reference to FIG. Reference numeral 1A denotes a substrate, on which a thermal oxide film 25 for forming a CMOS is provided. Reference numerals 26 to 27 denote elements of the CMOS transistor for supplying power sufficient to cause the heating resistor 30 to foam through the electrodes 28 and 29. Between the heat generating resistor 30 and the ink, an insulating film 31 for insulating the ink and the heat generating resistor, and bubbles in the ink generated by the application of heat energy from the heat generating resistor 30 include the heat energy. A protective film 32 is formed to protect the heating resistor 30 and the insulating film 31 from an impact that occurs when the application of the metal is interrupted and disappears.

  In order to perform recording using the recording apparatus configured as described above, ink is first filled from the main tank 7 into the sub tank 2, the liquid chamber 10, and the liquid path 21 through the supply tube 8 and the supply pipe unit 9. . Next, an electrical signal, that is, an electrical signal from the ejection signal generating means 12 is applied to the heater 23 of the recording head 1 by the FPC 11. By causing the heater 23 to generate heat, heat energy is applied to the ink existing in the liquid path 21 near the heater 23. Thus, when thermal energy is applied to the ink from the heater 23, bubbles accompanied by an increase in the volume of the ink are instantaneously generated at that portion, and the ink existing downstream (discharge port 22 side) from the heater 23 is discharged. The ink droplets are ejected from the outlet 22 to form flying ink droplets. Therefore, the ink droplets are attached to a recording material such as paper at the opposite position, and desired image recording is performed. During the recording, preliminary ejection processing, preliminary heating processing, and recording head recovery processing are performed for the purpose of optimizing the ejection of ink from the recording head 1 and forming a high-quality image. These processes are controlled by the preliminary discharge processing control means 13, the preliminary heating processing means 14, and the like.

  The preliminary ejection process and the preliminary heating process mainly adjust the viscosity of the ink. The recovery process recovers clogging of the discharge ports 22 by pressurizing or sucking ink in the recording head 1 with the recording head 1 in contact with the cap member 18.

  The manufacturing method of the liquid jet recording head according to the present invention is a Ta—N bond in the heating resistor 30 in FIG. 3 at any stage when manufacturing the liquid jet recording head mounted on the apparatus having the above-described configuration. It is characterized in that a processing process for stabilizing the is incorporated.

  As a process for stabilizing the Ta—N bond inside the heating resistor, there is a method in which the Ta—N bond is sufficiently changed to stabilize against heat. Specifically, after the film formation of TaXN which is a heating resistor, it is sufficient for the Ta-N bond to be thermally stabilized at any stage when manufacturing the liquid jet recording head having the above-described configuration. There is a method of giving a heat energy to the heating resistor.

  Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

  In the process of manufacturing the head having the structure shown in FIG. 2, the vacuum overheat treatment is performed after the basic structures 26 and 27, the wirings 28 and 29, the heating resistor film 30 and the insulating film 31 in FIG. I did it. The configuration of the head and the conditions of the vacuum heat treatment are as shown below.

Recording head configuration Substrate Si (with SiO ₂ thermal oxide film) 1mm
Heating resistor TaSiN (Sputtered film) 0.1μm
Electrode Cu 0.5μm
Protective layer SiO ₂ 2μm
Vacuum heat treatment conditions Vacuum degree: 1 × 10 ⁻⁵ Pa
Heat holding time: 30 minutes The heating temperature was controlled between 100 ° C. and 800 ° C. by a heating system connected to a thermocouple, and a plurality of recording heads processed at different heating temperatures were prepared. The state of the Ta—N bond change before and after the vacuum heat treatment was observed using an X-ray diffractometer. The effect of stabilizing the Ta-N bond on the recording head is that the rate of change in the heater resistivity when the recording liquid is ejected from the ejection port before being installed in the liquid jet recording apparatus and filled with the recording liquid. Evaluation was made by measuring ΔR / R.

4 and 5 are X-ray diffraction patterns of the heating resistor before the vacuum heat treatment and after the vacuum heat treatment at 800 ° C. The peak indicated by the arrow 2A is a signal from the Si substrate. Before the vacuum heat treatment, a gentle signal can be confirmed in the vicinity of 2θ = 37 °, but it can be said that the structure is in an amorphous state. On the other hand, a steep peak is confirmed in FIG. 5 after the vacuum heat treatment. These peaks are consistent with those arising from the Ta ₂ N crystal structure. FIG. 6 shows the size of the X-ray diffraction peak when the vacuum overheat treatment is performed while changing the heating temperature. From FIG. 6, it can be seen that the bonding state of Ta—N varies depending on the processing temperature and is almost stabilized at 600 ° C. or higher.

  Further, when the relationship between the size of the X-ray diffraction peak and the rate of change in the heater resistance value was examined, the result shown in FIG. 7 was obtained. From FIG. 7, after the count number of X-ray diffraction exceeds 25000 and the Ta-N bond is stabilized, the heater resistance change rate ΔR / R is small, and the recording head is mounted on a liquid jet recording apparatus and used. Even in recording over a long time, a good and stable droplet discharge state can always be obtained.

  ΔR / R is an average of the rate of change of the resistivity R of the heater after using 108 characters.

  Furthermore, the treatment for stabilizing the Ta—N bond described above does not necessarily need to be the heat treatment after film formation described in the above embodiment. That is, the Ta—N bond stabilization process may be a process performed during film formation, for example, substrate heating during film formation.

  Furthermore, the method for evaluating the state of the Ta—N bond described above does not need to be the X-ray diffraction described above. For example, infrared spectroscopy, electron magnetic resonance (EMR) nuclear magnetic resonance (NMR), or Mossbauer spectroscopy may be used.

  The stabilization process of the Ta-N bond of the heater in the method of manufacturing a liquid jet recording head of the present invention is the same as the method of manufacturing a conventional liquid jet recording head and a liquid jet recording apparatus equipped with the same. Detailed description is omitted.

1 is a configuration diagram of a liquid jet recording apparatus according to the present invention. FIG. 2 is a perspective view illustrating an example of a configuration of a liquid jet recording head according to the present invention mounted on the apparatus of FIG. 1. FIG. 3 is a cross-sectional view of a heater and a substrate of the liquid jet recording head shown in FIG. 2. It is the result of having measured the heating resistor thin film by the X ray diffraction method immediately after film-forming. It is the result of measuring the heating resistor thin film by X-ray diffractometry after stabilizing the Ta-N bond. FIG. 6 is a characteristic curve diagram showing the relationship between the heat treatment temperature of the heating resistor thin film and the peak value of the X-ray diffraction signal in FIG. 5. FIG. 6 is a characteristic curve diagram showing the relationship between the peak value of the X-ray diffraction signal in FIG. 5 and the change in resistance change rate ΔR / R when a durability test is performed by applying a pulse to the head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 1A Board | substrate 2 Carriage 3 Sub tank 11 Flexible printed wiring board 12 Discharge signal generation means 13 Preliminary discharge process control means 14 Preheating process control means 21 Liquid path 22 Discharge port 23 Heater 23A, 23B Electrode 25 Thermal oxide film of Si substrate 26, 27 CMOS transistor 28, 29 Electrode wiring 30 Heating resistor thin film 31 Insulating film 32 Protective film 2A X-ray line signal by Si substrate

Claims (4)

  A heating resistor and a pair of electrodes for applying an electrical signal to the heating resistor are used to generate thermal energy used for ejecting ink by applying an electrical signal. In the method of manufacturing a liquid jet recording head using a cermet thin film in which a third component is added to nitrogen (N) and tantalum (Ta) as a heating resistor. A method of manufacturing a liquid jet recording head, comprising a processing step of stabilizing Ta-N bonds in a resistor.   3. The liquid jet recording head according to claim 1, wherein the third component is Si or B, and the heating resistor is a cermet thin film represented by a TaXN thin film (X = Si or B). Manufacturing method.   2. The method of manufacturing a liquid jet recording head according to claim 1, wherein the processing step of stabilizing the Ta-N bond is a step of applying thermal energy to the heating resistor.   A heating resistor and a pair of electrodes for applying an electrical signal to the heating resistor are used to generate thermal energy used for ejecting ink by applying an electrical signal. In a liquid jet recording head using a cermet thin film in which a third component is added to nitrogen (N) and tantalum (Ta) as a heating resistor. A liquid jet recording head manufactured by including a processing step for stabilizing Ta-N bonds.

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