JPH11188886A - Production of basic body for ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a heating element film for the basic body of an ink jet head in which the resistance is stabilized by suppressing fluctuation. SOLUTION: A heating element layer is formed by DC or RF sputtering, for example, while detecting the resistance by means of a resistance detecting element 4012, or the like. When a desired resistance is reached, formation of film is ended by stopping a power supply 4006 through a power controller 4013.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink jet substrate having a plurality of heating resistors for generating thermal energy for discharging ink onto a substrate.

[0002]

2. Description of the Related Art Ink jet recording systems have attracted attention in recent years because they enable high-speed, high-density, high-precision, high-quality recording and are suitable for colorization and compactness (US Pat. No. 4,723,129, US Pat. 4740796
issue).

As shown in FIG. 1, a head used for this ink jet recording is provided with a plurality of ejection ports 1001, and an electrothermal converter for generating thermal energy used for ejecting ink from each ejection port. Element 10
02 is provided on the substrate 1004 for each ink flow path 1003. The electrothermal conversion element 1002 is mainly composed of a heating resistor 1005 and an electrode wiring 1 for supplying power thereto.
006 and an insulating film 1007 for protecting them. Further, each ink flow path 1003 is formed by a top plate on which a plurality of flow path walls 1008 are integrally formed, and a substrate 1004.
It is formed by joining while positioning the relative position with the upper electrothermal conversion element or the like by means of image processing or the like.

[0004] Each ink flow path 1003 has a discharge port 10
The end opposite to 01 is in communication with the common liquid chamber 1009, and ink supplied from an ink tank (not shown) is stored in the common liquid chamber 1009. Common liquid chamber 10
09 is supplied to each of the ink flow paths 10 from here.
The liquid is guided to 03, and a meniscus is formed and held near the discharge port 1001. Here, by selectively driving the electrothermal conversion element 1002, the ink on the heat acting surface is rapidly heated by utilizing the generated thermal energy to cause film boiling, thereby discharging the ink.

FIG. 2 shows a portion of the ink jet recording head substrate 2000 corresponding to an ink path,
FIG. 4 is a schematic partial cross-sectional view taken along a dashed-dotted line XX ′ shown in FIG. In FIG. 2, 2
001 is a silicon substrate, and 2002 is a heat storage layer made of a thermal oxide film. 2003 is a SiO film or SiN that also serves as heat storage.
An interlayer film made of a film or the like;
Is a metal wiring of Al, Al-Si, Al-Cu, etc., 200
Reference numeral 6 denotes a protective layer made of a SiO film, a SiN film, or the like. 20
Reference numeral 07 denotes a cavitation-resistant film for protecting the protective film 2006 from chemical and physical impacts caused by heat generation of the heat-generating resistance layer 2004. Reference numeral 2008 denotes a heat acting portion of the heating resistance layer 2004.

At present, a TaN film or the like is generally used as the heating resistor layer 2004 used in such an ink jet head. The characteristic stability of the TaN film, particularly the rate of change in resistance during long-term repeated recording, has a strong correlation with the composition of the TaN film. Among them, it is known that a heating resistor composed of tantalum nitride containing 0.8 hex of TaN has a small resistance change rate during long-term repetitive recording and is excellent in ejection stability (Japanese Patent Application Laid-Open No. 7-125218).

On the other hand, various types of thin-film heating resistors have been proposed for high-speed thermal recording in a thermal print head which performs recording by directly contacting a thermal paper or an ink ribbon. For example, as described in JP-A-53-25442, the first element is Ti, Zr, Hf, V, Nb, T
a, W and Mo, at least one selected from the group consisting of N, the second element is Si, the third element is Si, the first element is 5 to 40 atomic%, and the second element is Is 30 ~
When the composition is 60 atomic% and the third element is 30 to 60%, a heating resistor excellent in life characteristics can be obtained even when heat is generated at a high temperature.

At present, a multi-orifice (multiple nozzles) type ink jet recording head in which a plurality of heating resistors are formed on a substrate is mainly used. For example, 6
There are 4 nozzles and 128 nozzles.

[0009]

The above-mentioned multi-nozzle type ink jet recording head has the following problems.

For example, since a heating resistor used for a large number of recording heads is formed at a time, the resistance value of the formed heating resistor depends on various conditions during film formation when the heating resistor is formed. Variation sometimes occurred.

Factors that may cause fluctuations in the formation of the heating resistor include fluctuations in the power supplied to the target, the introduced gas, the substrate heating temperature, and the like. In order to suppress these fluctuations, studies on equipment and processes have been made, but they have not been sufficient. If the resistance value of the heating resistor varies, the ejection amount fluctuates and stable recording cannot be performed. Therefore, various attempts have been made to perform stable recording.

For example, when the resistance value of the completed heating resistor varies, there is a method of adjusting the driving voltage applied to each recording head. In this method,
When forming the heating resistance layer, a resistance layer that is not used for ink ejection is simultaneously formed near the heating resistance layer. Then, by measuring the resistance value of the heating resistance layer from the printer main body side, the ink ejection is actually estimated to estimate the resistance value of the heating resistance layer, and the driving voltage according to the estimated resistance value is set to the recording head. Is applied. However, the resistance value estimated in this manner includes a slight error between the resistance value of the actual heating resistance layer and the like due to variations in the resistance value of the electrodes, resistance reading errors on the printer body side, and the like. . Also,
Since the communication with the printer main body is required, a situation such as complication of the apparatus is caused.

Further, for example, there is a method of adjusting the discharge amount by making the voltage applied to the heating resistor a double pulse drive. As shown in FIG. 3, the double pulse drive means that the main pulse P2 and the sub-pulse P1 and the pause time P
By adjusting the sub-pulse length and the pause time in the pulse composed of No. 3, the ink ejection amount and the substrate temperature are adjusted. Each drive pulse is applied to the drive means 300
4 and the heating resistor layer 3 via the shift register 3005
006, whereby a bubble 3002 is generated in the ink 3003 in the discharge port 3007, and the ink droplet 3001 is discharged. Here, when the substrate temperature is relatively low, such as about 10 ° C., the ejection amount decreases because the viscosity of the ink is increased. In that case, the ejection amount can be increased by setting the sub pulse width to be long. On the other hand, when the substrate temperature rises to about 50 ° C., the applied energy may be small, so that the sub-pulse width is set short to reduce the ejection amount.

[0014] However, these attempts to stabilize the ejection amount for stable printing have complicated the driving method and have not always been satisfactory. Therefore, it is required to form a stable heating resistor by minimizing the variation in the resistance value of the heating resistor in the stage of manufacturing the inkjet base.
Further, in the future, higher image quality and higher speed of printing will be required, and in order to increase the number of nozzles, it is urgently necessary to suppress the variation in the resistance value of the heating resistor.

A main object of the present invention is to solve the above-mentioned problems relating to the heating resistor of the conventional ink jet recording head, and to make it possible to easily obtain a heating resistor having a stable resistance value with little variation. It is an object of the present invention to provide a method for manufacturing a substrate for use.

Another object of the present invention is to make it possible to easily obtain a heat-generating resistor with stable ejection even in the case of small dots corresponding to high definition of a recorded image and multiple nozzles corresponding to high speed recording. It is an object of the present invention to provide a method for manufacturing an ink jet substrate.

Another object of the present invention is to provide a method of manufacturing a substrate for ink jet which can simplify a driving method and realize a low-cost apparatus by forming a heating resistor having a stable and stable resistance value. To provide.

[0018]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have achieved the above object by providing the following manufacturing method.

That is, the present invention relates to a method of manufacturing a substrate for an ink jet head having a plurality of heating resistors for generating thermal energy for ejecting ink on a substrate. A method of manufacturing a substrate for an ink jet head, comprising: forming the heating resistor; and, when the resistance value reaches a desired value, terminating the formation of the heating resistor.

By performing such a process, it is possible to suppress the variation in the resistance value of the heating resistor of the ink jet head substrate, and as a result, it is possible to obtain a high-quality recorded image and to simplify the driving method. Thus, it is possible to provide a low-cost liquid ejection device.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

According to the manufacturing method of the present invention, an ink jet head substrate having the structure shown in FIGS. 1 and 2 and an ink jet head using the same can be manufactured. In the present invention, as a film forming method of the heating resistor 2004, various film forming methods such as a DC or RF sputtering method using a direct current (DC) power supply and a high frequency (RF) power supply, a vapor deposition method, and an ion plating method are used. But generally DC
Alternatively, an RF sputtering method is used.

FIG. 4 shows an outline of a sputtering apparatus for forming a heating resistance layer 2004. In FIG.
1 is a target prepared in advance with a predetermined composition,
002 is a plate magnet, 4011 is a shutter for controlling film formation on a substrate, 4003 is a substrate holder,
Reference numeral 4004 denotes a substrate, and 4006 denotes a power supply connected to the target 4001 and the substrate holder 4003. Reference numeral 4012 denotes a resistance detection element for monitoring the resistance of the heating resistor,
Reference numeral 013 denotes a power supply 4 according to a signal from the resistance value detecting element 4012.
006 is a controller that controls the power.

Further, in FIG. 4, reference numeral 4008 denotes an external heater provided around the outer peripheral wall of the film forming chamber 4009. The external heater 4008 is used for adjusting the ambient temperature of the film formation chamber 4009. Substrate holder 4003
Is provided with an internal heater 4005 for controlling the temperature of the substrate. It is preferable to control the temperature of the substrate by using an external heater 4008 in combination.

The film formation using the apparatus shown in FIG. 4 is performed, for example, as follows. First, the deposition chamber 4009 is evacuated to 1 × 10 ⁻⁵ to 1 × 10 ⁻⁶ Pa using the exhaust pump 4007.
Next, a mixed gas composed of argon gas and nitrogen gas is
The gas is introduced from the gas inlet 4010 into the film forming chamber 4009 via a mass flow controller (not shown). At this time, the internal heater 4005 and the external heater 4008 are adjusted so that the substrate temperature and the ambient temperature become predetermined temperatures.
Next, the power of the power supply 4006 is controlled to a predetermined value by the controller 4013, and the sputtering is performed by applying the power to the target 4001. When the heating resistor sputtered from the target is deposited on the substrate, the resistance value R at that time is expressed by the following equation.

R = ρ · l / w · t [Ω] (ρ: specific resistance of the resistor [Ω · cm], l: length of the resistor [cm], w: width of the resistor [cm], t: thickness [cm] of the resistor.

The sputtered particles sputtered from this target accumulate on the substrate 4004 over time (curve A in FIG. 5) and also accumulate on the resistance detecting element 4012 (curve B in FIG. 5). Resistance value detection element 401
2, the resistance value of the heating resistor deposited with time can be monitored. Here, the substrate 40 as shown in FIG.
04 and the resistance value of the resistance value detection element 4012 are checked in advance, and the value of the resistance value R ′ monitored by the resistance value detection element 4012 when the heating resistor reaches the target resistance value R is obtained in advance. Then, in the step of forming the heating resistor, when the resistance value R ′ is monitored by the resistance value detecting element 4012,
The power of the power supply 4006 is controlled or stopped by the controller 4013. Further, the start / end of the film formation can be controlled by using the shutter 4011 together.

FIG. 6 is a flowchart showing a film forming process of the heating resistor using the apparatus of FIG. That is, by following such a flowchart, it is possible to form a good heat-generating resistor.

In the example shown in FIG. 4, the resistance value detecting elements 4012 are provided in places other than the substrate, but they may be formed on the substrate. Further, in the above example, the method of forming the heating resistor by a reactive sputtering method using an alloy target was described.However, the present invention is not limited to this. It is also possible to form by multi-source simultaneous reactive sputtering in which film formation is performed by controlling the power of a plurality of power supplies connected to the power source. In this case, it is possible to independently control the power applied to each target.

The substrate for an ink-jet head manufactured by forming a heating resistor by the method described above is used for a recording medium including paper, plastic sheet, cloth, article, etc. with ink, functional liquid or the like. Is used as a base for forming an ink jet head for recording, printing, etc. of characters, symbols, images, and the like by discharging ink, and an ink jet head configured using this base is supplied to the ink jet head. It is used for an ink-jet pen including an ink storage section for storing ink and an ink-jet device to which an ink-jet head is mounted.

The ink-jet pen mentioned here includes both a cartridge form in which the ink-jet head and the ink storage section are integrated and a form in which they are detachably assembled separately from each other. This ink-jet pen is detachable from mounting means such as a carriage on the apparatus main body side. In addition, the ink jet device referred to here is a word processor, an output terminal of an information processing device such as a computer, which is integrally or separately provided, as well as a copying device combined with an information reading device and the like, and has an information transmitting / receiving function. Facsimile machines, machines that print on fabric, etc.

[0032]

Embodiments of the present invention will be described below. However, the present invention is not limited to the following examples.

<Embodiment 1> In this embodiment, a Si substrate or a Si substrate in which a driving IC has already been fabricated is used. Thermal oxidation, sputtering, CV
1.2 μm thick SiO ₂ heat storage layer 2 by D method or the like
002 was formed, and a heat storage layer of SiO ₂ was also formed during the manufacturing process of the Si substrate in which the IC was formed.

Next, a 1.2 μm-thick interlayer insulating film 2003 made of SiN or SiO ₂ was formed by a sputtering method, a CVD method, or the like. Next, the heating resistance layer 200
4 was formed using the apparatus of FIG. 4 according to the flowchart of FIG.

First, a mixed gas of Ar gas 80 ccm and N ₂ gas 20 ccm was introduced from a gas inlet 4010 using an alloy target made of Ta-Si. At this time, the substrate temperature was set at 200 ° C.
A control signal was sent from 013 to a power supply 4006, power was applied to the target 4001, the shutter 4011 was opened when the discharge was stabilized, and the formation of the heating resistor layer 2004 on the substrate 4004 was started. On the other hand, the shutter 4011
Was opened, film formation was started on the resistance value detecting element 4012 provided near the substrate 4004.

As the resistance value detecting element 4012, as shown in FIG. 7, an element having a pattern of a heater size actually used and sandwiched between electrodes on both sides was used. Of course, the size of the heater formed in a pattern on the resistance value detecting element 4012 is not necessarily limited as long as it corresponds to the heater size actually used.

This electrode is connected to a resistance value measuring device, and when a thin film is formed on the pattern, the resistance value between both electrodes is measured. Therefore, the resistance value when the film formation is in progress by opening the shutter 4011 can be constantly monitored, and the data is input to the controller 4013. Then, when the resistance value reaches a predetermined value, a control signal is sent from the controller 4013 to the power supply 4006, the power supplied to the target is stopped, the shutter is closed, and the formation of the heating resistance layer 2004 is completed.

After the formation of the heating resistor layer 2004 is completed,
An Al film having a thickness of 5500 Å was formed as the electrode wiring 2005 by a sputtering method. Next, a pattern was formed using a photolithography method, and a 22 μm × 45 μm heat acting portion 2008 from which the Al film had been removed was formed.
Next, a 1 μm-thick insulator made of SiN was formed as a protective film 2006 by a plasma CVD method. Next, a Ta film having a thickness of 2300 Å was formed as the anti-cavitation layer 2007 by a sputtering method, and a substrate for an ink jet head as shown in FIG. 1 was produced by a photolithography method.

Using the substrate thus produced,
The resistance value of the heating resistor was measured. Target resistance value 45
The resistance value actually manufactured was 455 Ω with respect to the resistance value of 600 Ω set to obtain 0 Ω, and a resistance value with a small error was obtained.

Next, using this substrate, the foaming start voltage _Vth of the ink was examined. The foaming start voltage V _th is obtained by applying a driving frequency of 10 kHz and a driving pulse width of 5 μs to the heating resistor.
c. And a voltage at which the ink starts foaming while increasing the applied voltage. The foaming start voltage _Vth is the same for each head, and it is preferable that the variation is small because stable ejection independent of the head is performed. The foaming start voltage V _th of this substrate was about 16 V.

In this embodiment, ten substrates are successively formed, and the resistance value of the heating resistor and V
_th was measured. The results are shown by the solid lines in FIGS. As shown in these figures, in the present embodiment, variations in the resistance value and _Vth were small.

Comparative Example 1 In the same manner as in the conventional method, the inkjet head was manufactured in the same manner as in Example 1 except that the resistance value detecting element 4012 was not used and the film formation was performed in accordance with preset uniform film forming conditions. Ten substrates were continuously manufactured, and the resistance value and V _th of the heating resistor were measured in the same manner. The results are shown by the broken lines in FIGS. From the results shown in these figures, in Example 1 (solid line) using the manufacturing method of the present invention, there is less variation in both the resistance value and _Vth than in Comparative Example 1 (dashed line) using the conventional manufacturing method. You can see that.

<Embodiment 2> The film forming conditions were as follows: Ta target power: 400 W, Si target power: 200 W
(Binary sputtering method), Ar gas: 78 ccm, N
₂ gas: changed to 22 cm, and 10 ink-jet head bases were continuously produced in the same manner as in Example 1 except that the heater size (heat acting portion 2008) was changed to 23 × 30 μm, and heat was similarly generated. Resistance value of resistor and V _th
Was measured. The results are shown by the solid lines in FIG. 10 and FIG. As shown in these figures, also in the present example, the variation in the resistance value and _Vth was small.

Comparative Example 2 In the same manner as in the conventional method, the inkjet head was manufactured in the same manner as in Example 1 except that the resistance value sensing element 4012 was not used and the film formation was performed in accordance with preset uniform film forming conditions. Ten substrates were continuously manufactured, and the resistance value and V _th of the heating resistor were measured in the same manner. The results are shown by broken lines in FIGS. From the results shown in these figures, in Example 2 (solid line) using the manufacturing method of the present invention, the resistance value and V _th were similarly compared with Comparative Example 2 (dashed line) using the conventional manufacturing method. It can be seen that both have little variation.

[0045]

As described above, according to the present invention,
A heating resistor having a small resistance and a stable resistance value can be easily obtained.

Further, even in the case of a small dot corresponding to high definition of a recorded image and a large number of nozzles corresponding to high speed recording, a heating resistor with stable ejection can be easily obtained. It is possible to provide a discharge head base, a liquid discharge head including the base, and a liquid discharge apparatus including the liquid head.

Further, by forming a heating resistor having a stable resistance value with a small variation, the driving method conventionally required for stabilizing the ejection is simplified, and a low-cost apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a substrate of an inkjet head according to the present invention.

FIG. 2 is a cross-sectional view of the substrate when FIG. 1 is cut perpendicularly by a dashed line XX ′.

FIG. 3 is a schematic cross-sectional view of double pulse driving foaming of a substrate for an ink jet recording head.

FIG. 4 is a film forming apparatus for forming each layer of a substrate for an ink jet recording head according to the present invention.

FIG. 5 is a diagram showing a resistance value of a heating resistor that changes with the lapse of a film forming time.

FIG. 6 is a flowchart showing a film forming method according to the present invention.

FIG. 7 is a view showing a resistance value detecting element used in the manufacturing method of the present invention.

FIG. 8 is a diagram showing the results of the resistance values of the heating resistors in Example 1 and Comparative Example 1.

FIG. 9 shows a foaming start voltage V in Example 1 and Comparative Example 1.
It is a figure showing a result of _th .

FIG. 10 is a diagram showing the results of the resistance values of the heating resistors in Example 2 and Comparative Example 2.

FIG. 11 is a diagram showing the results of foaming start voltage V _th in Example 2 and Comparative Example 2.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1001 discharge port 1002 electrothermal conversion element 1003 ink flow path 1004 substrate 1005 heating resistor 1006 electrode wiring 1007 insulating film 1008 flow path wall 1009 common liquid chamber 2000 base 2001 silicon substrate 2002 heat storage layer 2003 interlayer film 2004 heating resistance layer 2005 metal wiring 2006 Protective film 2007 Anti-cavitation film 2008 Heat acting part 3001 Ink droplet 3002 Bubbles 3003 Ink 3004 Driving means 3005 Shift register 3006 Heating resistance layer 3007 Discharge port 4001 Target 4002 Plate magnet 4003 Substrate holder 4004 Substrate 4005 Internal heater 4006 Power supply 4007 Pump External heater 4009 Deposition chamber 4010 Gas inlet 4011 Shutter 4012 Resistance detection Element 4013 Controller

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiko Ogawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (5)

[Claims] 1. A method of manufacturing a substrate for an inkjet head having a plurality of heating resistors for generating thermal energy for discharging ink on a substrate, wherein the heating resistor is detected while detecting a resistance value of the heating resistor. Forming a heating element and terminating the formation of the heating resistor when the resistance value reaches a desired value. 2. A power supply for supplying power for forming the heating resistor, a power controller for controlling the power of the power supply, and a resistance detecting means for monitoring a resistance value of the heating resistor. The heating resistor is formed while detecting the resistance value of the heating resistor by the resistance value detecting means, and when the resistance value reaches a desired value, the power of the power supply is stopped via the power controller. The formation of the heating resistor is terminated by causing the heating resistor to be formed.
A method for producing a substrate for an inkjet head as described above. 3. The heating resistor is formed by a DC or RF sputtering method, and when the resistance value of the heating resistor reaches a desired value, DC or RF is applied to a target.
3. The method for manufacturing a substrate for an ink jet head according to claim 2, wherein the formation of the heating resistor is terminated by stopping the power of the power supply. 4. The method according to claim 2, wherein the heating resistor is formed by reactive sputtering in a mixed gas atmosphere of Ar and N ₂ using an alloy target made of Ta—Si. 5. using two types of targets made of Ta and Si, 2 in a mixed gas atmosphere consisting of Ar and N ₂
3. The method for manufacturing a substrate for an ink jet head according to claim 2, wherein the heat generating resistor is formed by primary reactive sputtering.