JP4051238B2 - Ink jet head, printer including the ink jet head, and resistance adjustment method for ink jet head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention records an image by depositing ink droplets on a recording sheet in a predetermined pattern.Ink jet head, printer including the ink jet head, andThe present invention relates to a method for adjusting a resistance value of an inkjet head.
[0002]
[Prior art]
Conventionally, an ink jet head has been used as a recording device for forming an image on recording paper.
[0003]
Ink jet head recording systems use thermal energy generated by heating elements to eject ink droplets toward recording paper, those that use deformation of piezoelectric elements, and also occur when electromagnetic waves are irradiated. There are some that use heat, and among these, thermal ink jet type that uses the heat energy of the heating element is easy to pattern the heating element, and even a heating element with a small area is relatively large Since heat energy can be generated, it is attracting attention as being suitable for high-density recording.
[0004]
As such an ink jet head, for example, as shown in FIG. 8, a plurality of heating elements 23 arranged linearly on the upper surface of a base plate 22 made of single crystal silicon or the like, and a power supply electrically connected to the heating elements 23. On the head substrate 21 to which the wiring 24 is attached, a top plate 25 having a plurality of ink discharge holes 26 corresponding to the heating elements 23 is formed with a predetermined gap therebetween. And a structure in which the gap between the head substrate 21 and the top plate 25 is filled with ink 27 is known, and a plurality of papers are conveyed while conveying the recording paper along the outer surface of the top plate 25. The heating elements 23 are selectively joule-heated individually based on image data from the outside to generate bubbles A in the ink 27 on the heating elements 23, and with the pressure generated by the generated bubbles A. Ink 27 on the thermal element 23 pushed to the ink discharge hole 26 side, predetermined image is recorded by ejecting a part of the ink 27 toward the recording paper from the ink discharge hole 26.
[0005]
The heating element 23 and the power supply wiring 24 provided on the head substrate 21 are usually patterned by a conventionally well-known thin film forming technique. Specifically, first, a resistive thin film made of TaSiO or the like and a metal thin film made of aluminum or the like are sequentially deposited on the upper surface of the base plate 22 by sputtering or the like, and these are finely processed by photolithography, etching technique or the like, thereby generating a heating element. 23 and the power supply wiring 24 are patterned.
[0006]
The top plate 25 is made of various materials such as ceramic, resin, and metal, and the ink discharge holes 26 provided in the top plate 25 are formed by using well-known laser processing, photoetching, or the like. It was common to form.
[0007]
[Problems to be solved by the invention]
However, in the conventional inkjet head described above, when the heating element 23 is formed by a conventionally known thin film forming technique, the shape and thickness of the heating element 23 become non-uniform due to variations in manufacturing conditions and the like. Ink discharge holes may be caused by variations in processing conditions or the like when the electrical resistance values of the ink discharge holes 26 are individually different, or when the ink discharge holes 26 are formed on the top plate 25 by laser processing or photoetching, which is conventionally known. Since the sizes (areas) of the heaters 26 are individually different, the heat energy and ink discharge amount generated by the heating element 23 cannot be made uniform during the recording operation, and as a result, the ink discharge amount is reduced by the heating element. It has a defect that density unevenness of printing is formed on the recording paper.
[0008]
Therefore, in order to eliminate the above-described drawbacks, the electrical resistance values of the heating elements 23 are individually measured, and correction data is created based on the measured resistance values, and the applied power to the heating elements 23 using the correction data. It has been proposed that the heat energy generated by the heat generating element 23 is made uniform by adjusting.
[0009]
However, when adjusting the power applied to each heating element 23 using correction data, a large memory, a complicated correction circuit, a power supply circuit, etc. for storing correction data to be applied to all the heating elements 23 are separately provided. In addition, the configuration of the ink jet head and the printer body in which the ink jet head is incorporated is greatly complicated, and since such correction is performed for each printing line, the time required for the recording operation is prolonged and the recording speed is lowered. Inducing a disadvantage that leads to
[0010]
  The present invention has been devised in view of the above drawbacks, and its purpose is to form a good and clear image on recording paper, and also to increase the recording speed while maintaining a simple configuration. High performance inkjet headAnd a printer including the inkjet head, andAn object of the present invention is to provide a method for adjusting the resistance value of an inkjet head.
[0011]
[Means for Solving the Problems]
  An ink jet head according to the present invention includes a head substrate including a base plate, a plurality of heating elements arrayed on the upper surface of the base plate, and a power supply wiring electrically connected to the plurality of heating elements, an ink A top plate provided on the head substrate through a gap for filling the ink and having an ink discharge hole for discharging the ink, and discharges ink from the ink discharge hole by thermal energy. Each of the power supply wirings has a trimming pad larger than the line width of the power supply wiring, and the heating element is formed of a TaSiO-based resistance material, and the Ta content is 50 atomic% to 60%. It is characterized by being set to atomic%. In the ink jet head, it is preferable that the heating element has a resistance value adjusted using a pulse trimming method. In the present inkjet head, it is preferable that the trimming pad is located outside the edge of the top plate. In the ink jet head, the trimming pad is preferably formed by at least one of nickel plating and gold plating. In the present inkjet head, it is preferable that the trimming pads are arranged in a staggered manner along the arrangement direction of the plurality of heating elements. In the inkjet head, the head substrate further includes a protective film covering the heating element and the power supply wiring so that the trimming pad is exposed, and the oxygen content of the protective film is 2.0 mass. % To 10.0% by mass is preferable.
[0012]
  BookA printer according to the invention includes the inkjet head according to the invention.
[0013]
  The method of adjusting the resistance value of the inkjet head according to the present invention is as follows.A head substrate including a base plate, a plurality of heating elements arranged on the upper surface of the base plate, and a power supply wiring electrically connected to the plurality of heating elements, and a gap for filling ink A resistance value adjusting method for an ink jet head, wherein the ink is ejected from the ink ejection holes by thermal energy, and the top plate is provided on the head substrate and has an ink ejection hole for ejecting the ink. In the inkjet head, each of the power supply wirings has a trimming pad larger than the line width of the power supply wiring, the heating element is formed of a TaSiO-based resistance material, and the Ta content is 50 atom% to 60 atoms. %, And applying a power pulse to each of the plurality of heat generating elements, the ink is ejected from the ink ejection holes. The first step of measuring the volume of the ejected ink and the volume of the ink measured in the first step are compared with each other to obtain a volume difference between the first step and corresponding to the volume difference. A second step of selecting a trimming pulse and applying a trimming pulse selected in the second step to the corresponding heating element by bringing the probe into contact with the trimming pad to adjust the electric resistance value of the heating element And a third step.
[0014]
  BookAccording to the adjustment method of the invention, the electrical resistance value of the heat generating element can be accurately corrected by the well-known pulse trimming based on the volume of the ink actually ejected from the ink ejection hole. By optimizing the thermal energy, the volume of the ink ejected from the ink ejection holes can all be made uniform, thereby obtaining a high-performance inkjet head capable of forming a clear image with little density unevenness. It becomes like this.
[0015]
The adjustment method of the present invention is to uniformize the heat energy of the heating element by adjusting the electric resistance value of the heating element. In this case, when adjusting the applied power using the correction data, Compared to this, the memory for correction data storage, complicated correction circuits, power supply circuits, etc. are not required, the configuration of the ink jet head and the printer body in which it is incorporated can be kept simple, and correction processing during recording operation Therefore, it is possible to obtain a high-performance inkjet head that can be used for increasing the recording speed.
[0016]
Further, according to the adjustment method of the present invention, since the heating element to which the trimming pulse is applied is covered with the protective film made of an inorganic material containing silicon and oxygen, a part of the heating element reacts with oxygen in the protective film. By forming a thin oxide film on the surface of the heat generating element, the resistance value of the heat generating element can be increased, and the resistance value of the heat generating element can be corrected both vertically.
[0017]
Furthermore, according to the adjustment method of the present invention, the degree of increase in resistance when a predetermined trimming pulse is applied by setting the oxygen content in the protective film to 2.0 mass% to 10.0 mass%. There is also an advantage that the resistance becomes moderate and finer resistance value adjustment is possible.
[0018]
Furthermore, according to the adjustment method of the present invention, an ink jet head is assembled by applying a trimming pulse to the heating element through a trimming pad provided in the middle of the power supply wiring and outside the ink filling region. Even after this, trimming can be performed by making sure that the probe of the probing device used for applying the trimming pulse is brought into contact with the pad reliably and easily. There is also an advantage of being good.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view of an inkjet head obtained by an adjustment method according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the inkjet head of FIG. 1, 1 in the figure is a head substrate, 7 is a top plate, 9 is ink.
[0020]
The head substrate 1 includes a plurality of heating elements 3 arranged in a straight line on a top surface of a base plate 2 formed in a rectangular shape, and a power supply wiring 4 electrically connected to the heating elements 3. It has a structure in which it is deposited and formed and covered with a protective film 6.
[0021]
The base plate 2 is made of a semiconductor material such as single crystal silicon, or an electrically insulating material such as glazed alumina ceramics, and supports the heating element 3, the power supply wiring 4, the protective film 6 and the like on its upper surface. Functions as a support base material.
[0022]
When the base plate 2 is made of, for example, single crystal silicon, an ingot (lumps) of single crystal silicon is formed by adopting a conventionally known chocolate ski method (lifting method) or the like, and is sliced into a predetermined thickness. It is manufactured by processing the top. In this case, the surface of the base plate 2 has silicon oxide (SiO 2).₂An insulating film (not shown) made of an electrically insulating material such as 1) to 3 μm is provided, and the single crystal silicon forming the base plate 2 by such an insulating film is electrically transferred from the heating element 3 or the like. Insulated.
[0023]
The plurality of heating elements 3 provided on the upper surface of the base plate 2 are linearly arranged in the main scanning direction at a density of, for example, 600 dpi (dot per inch), each of which is TaN, TaSiO, TaSiNO, It is formed of a resistive thin film made of an electrical resistance material such as TiSiO, TiSiCO, NbSiO.
[0024]
Since the heat generating element 3 itself is made of an electric resistance material, it is necessary for generating Joule heat and generating bubbles A in the ink 9 when power is supplied through the power supply wiring 4 or the like. A predetermined heat energy is generated.
[0025]
These heating elements 3 are subjected to resistance correction by pulse trimming, which will be described later, so that a substantially constant amount of ink 9 is ejected from all the ink ejection holes 8 provided in the top plate 7 during the recording operation. In addition, the heat energy of each heating element 3 is optimized.
[0026]
Further, the power supply wiring 4 connected to the heat generating element 3 is for applying power to the heat generating element 3 described above, and one end of the power supply wiring 4 is led out to a filling area of the ink 9 described later, The lead-out unit is connected to a terminal such as a driver IC (not shown).
[0027]
In addition, the power supply wiring 4 has a trimming pad 5 having a circular or square shape larger than the line width of the wiring 4 outside the filling region of the ink 9 in the middle of each, and these pads 5 generate heat. The elements 3 are arranged in a line in a direction (main scanning direction) parallel to the arrangement direction of the elements 3.
[0028]
The pad 5 is used to contact a probe of a probing device that applies a trimming pulse when adjusting the electric resistance value of the heating element 3 by a conventionally known pulse trimming method. The top plate 7 is positioned outside the edge so that the trimming operation can be easily performed even after the operation.
[0029]
The heating element 3 and the power supply wiring 4 are performed by a conventionally well-known thin film forming technique, for example, sputtering, photolithography, etching technique or the like. Specifically, first, a resistive material such as TaSiO and a metal material such as aluminum are sequentially deposited on the upper surface of the base plate 2 by conventional well-known sputtering to form a laminate composed of a resistance thin film and a metal thin film. The heat generating element 23 and the power supply wiring 4 are patterned into a predetermined shape by fine processing using a well-known photolithography and etching (photo etching) technique, and after the assembly process of the inkjet head is completed, the electric resistance of each heat generating element 3 The value is adjusted by the adjustment method described later.
[0030]
The pad 5 of the power supply wiring 4 is deposited and formed to a thickness of, for example, 2 μm to 5 μm by applying nickel plating, gold plating, or the like to a predetermined portion of the power supply wiring 4 by a conventionally known electroless plating method or the like. .
[0031]
The protective film 6 covering the heat generating element 3 and the power supply wiring 4 etc. is corroded by alkali ions or moisture contained in the ink 9 coming into contact with the heat generating element 3 or the power supply wiring 4, or In order to effectively prevent the lump of the dye contained in the ink 9 from adhering to the surface of the heating element 3, for example, SiO 2₂(Silicon oxide), SiON, Si_ThreeN_FourFor example, it is formed to a thickness of 0.2 μm to 2.0 μm by an inorganic material such as (silicon nitride).
[0032]
The protective film 6 has its end positioned on the heat generating element 3 side of the pad 5 so that the pad 5 is exposed, and conventionally known sputtering, vacuum vapor deposition, plasma CVD (Chemical Vapor Deposition), etc. And the above-mentioned inorganic material is deposited on the surface of the heat generating element 3 and the power supply wiring 4 to a predetermined thickness.
[0033]
On the other hand, a top plate 7 is disposed on the above-described head substrate 1 so as to form a predetermined gap therebetween.
[0034]
The top plate 7 is for closing an ink flow path composed of ink 9 filled in the gap with the head substrate 1 and has a plurality of ink discharge holes 8 corresponding to the heating elements 3 on a one-to-one basis. The outer shape of the top plate 7 is such that one end of the top plate 7 is located closer to the heating element 3 than the position of the pad 5 so that the dimension in the sub-scanning direction is smaller than that of the head substrate 1. Are arranged as follows.
[0035]
The top plate 7 is positioned so that the ink discharge holes 8 are positioned immediately above the corresponding heat generating elements 3, and the ink droplets i are directed toward the recording paper from the ink discharge holes 8 during the recording operation of the inkjet head. It is designed to discharge.
[0036]
The top plate 7 is made of a metal plate made of molybdenum or the like, a ceramic plate made of alumina ceramics, a resin plate such as epoxy resin or polyimide resin, or a combination of the above materials. For example, when it is made of molybdenum, an ingot of molybdenum is formed into a plate shape by a conventionally well-known metal processing method, and conventionally well-known laser processing, photo-etching technology, etc. are adopted at a predetermined portion of the plate body. The head substrate is manufactured by punching a large number of ink ejection holes 8 having a diameter of about 10 μm to 100 μm, and the obtained top plate 7 is connected to a head substrate via a spacer, a sealing member 11 or the like (not shown). The top plate 7 is fixed at a predetermined position on the head substrate 1 by being placed on and bonded to the head substrate 1.
[0037]
As the ink 9 filled in the gap between the head substrate 1 and the top plate 7, for example, an aqueous dye ink is preferably used, and the viscosity thereof is, for example, 0.3 mPa · s to 3.0 mPa · s (25 ° C).
[0038]
Such ink 9 is supplied from an ink tank (not shown) to the gap between the head substrate 1 and the top plate 7, and bubbles A are generated in the ink 9 by the heat energy from the heating element 3 described above. Then, a part of the ink 9 is ejected to the outside as ink droplets i from the ink ejection holes 8 due to the pressure when the bubbles are generated, and the ink droplets i are conveyed along the outer surface of the top plate 7. A predetermined image is formed by adhering to the surface of the paper.
[0039]
Next, a method of adjusting the resistance value of the ink jet head described above will be described with reference to the flowchart of FIG.
[0040]
(1) First, a predetermined gap is formed between the head substrate 1 having the heating elements 3 and the like patterned by a conventionally known thin film forming technique and the top plate 7 having the ink discharge holes 8. Then, the ink 9 is filled in the gap and the ink jet head is assembled.
[0041]
(2) Next, a predetermined power pulse (rated pulse) is applied to each heating element 3 on the head substrate 1 to eject the ink 9 from the ink ejection holes 8 and the volume of the ejected ink 9 is measured. .
[0042]
For example, as shown in FIG. 4, the volume of the ink 9 is an image of ink droplets i recorded in a plurality of photographs obtained by simultaneously photographing the ink droplets i ejected from the ink ejection holes 8 using a plurality of cameras. The volume measurement is performed on the ink droplets i ejected from all the ink ejection holes 8.
[0043]
(3) Next, the volume of the ink droplet i obtained in the step (2) is compared with a predetermined reference volume to determine the volume difference between the two, and it is necessary to bring the volume of the ink droplet i closer to the reference volume. A predetermined trimming pulse, that is, a trimming pulse corresponding to the volume difference is selected.
[0044]
For example, when the reference volume is 8 pl (picoliter) and the volume of the ink droplet i obtained by measurement is 10 pl, the volume difference between the two (measured volume−reference volume) is 2 pl, and a trimming pulse corresponding to this volume difference is applied. Obtained from FIG. 5 and FIG.
[0045]
In this step, first, the resistance value correction width corresponding to the volume difference is obtained from the diagram (FIG. 5) showing the relationship between the “volume difference” and the “resistance value correction width”, and then the “resistance value correction width”. And a trimming pulse energy to be applied to the heating element 3 from the diagram (FIG. 6) showing the relationship between the “trimming pulse energy” and a plurality of types of trimmings prepared in advance with trimming pulses closest to this. Select one of the pulses.
[0046]
When the volume of the ink droplet i obtained by the measurement is smaller than the reference volume, the resistance value is corrected in the downward direction. Therefore, the diagram of FIG. 6A is used, and the ink droplet i is used. When the volume is larger than the reference volume, correction is made in the direction of increasing the resistance value, so the diagram of FIG. 6B is used.
[0047]
(4) Finally, a well-known pulse trimming method, specifically, applying the trimming pulse selected in the step (3) to the corresponding heat generating element 3 to decrease or increase the electric resistance value of the heat generating element 3 As a result, the electric resistance value of the heating element 3 is adjusted.
[0048]
The application of the trimming pulse to the heating element 3 is performed via the pad 5 of the power supply wiring 4 described above, and the probe (probe) 10 of the probing apparatus is brought into contact with the surface of the pad 5 as shown in FIG. In this state, the heating element 3 is trimmed by applying the predetermined trimming pulse selected in the step (3) from the probing device, and thereby the electric resistance value of the heating element 3 is adjusted.
[0049]
In such a pulse trimming method, for example, a resistive material for forming the heating element 3 is crystallized by applying a trimming pulse having a relatively short pulse width (energization time) and a relatively large amplitude (voltage value) to the heating element 3. In this case, the heating element 3 is annealed to cause a decrease in resistance value.
[0050]
On the other hand, when the resistance value of the heating element 3 is increased, a part of the resistance material forming the heating element 3 by applying a trimming pulse having a relatively long pulse width and a relatively small amplitude to the heating element 3. Is combined with oxygen in the protective film 6 to form a thin oxide film on the surface, thereby increasing the resistance value.
[0051]
At this time, when the protective film 6 is formed of an inorganic material containing oxygen and the oxygen content in the protective film is set to 2.0 mass% to 10.0 mass%, the resistance value is increased. There is an advantage that the amount of change in the resistance value becomes moderate, and fine adjustment of the resistance value is facilitated by the pulse trimming method.
[0052]
Here, if the oxygen content in the protective film 6 is less than 2.0% by mass, the degree of increase in the resistance value is too small, and there is a disadvantage that it takes a long time to adjust the resistance value. When the content is larger than 10.0% by mass, cracks or the like are generated in the protective film 6 or the adhesion strength of the protective film 6 tends to decrease. Therefore, the oxygen content in the protective film 6 is preferably set to 2.0 mass% to 10.0 mass%.
[0053]
Then, after performing the above-described trimming operation, the resistance value of the heat-generating element 3 that has been trimmed is measured. If the measured value is not sufficiently close to the target resistance value, the resistance value falls within the allowable range. Until the above trimming operation is repeated.
[0054]
In such a trimming operation, the resistance value adjustment may be performed only by either decreasing or increasing the resistance value, or may be performed by both decreasing and increasing the resistance value. When the resistance value of the heating element 3 is adjusted only by lowering the value, the material and thickness of the resistance thin film are selected so that all the initial resistance values are set sufficiently higher than the target resistance value.
[0055]
According to the adjustment method of the present embodiment as described above, the electrical resistance value of the heat generating element 3 is accurately corrected by the conventionally known pulse trimming based on the volume of the ink droplet i actually ejected from the ink ejection hole 8. Therefore, by optimizing the thermal energy generated by the heating element 3 by this resistance value correction, the volumes of the ink droplets i ejected from the ink ejection holes 8 can all be made uniform. As a result, a high-performance inkjet head capable of forming a clear image with little density unevenness can be obtained.
[0056]
In this case, since the heat energy generated by each heating element 3 is made uniform by adjusting the resistance value of the heating element 3, a memory for storing correction data is used compared with the case where the applied power is adjusted using the correction data. In addition, no complicated correction circuit, power supply circuit, etc. are required, and the configuration of the inkjet head and the printer body in which the inkjet head is incorporated can be maintained in a simple manner. A high-performance inkjet head that can be used for speeding up can be obtained.
[0057]
Furthermore, according to the resistance value adjusting method described above, the pad 5 of the power supply wiring 4 that contacts the probe 10 of the probing device when the trimming pulse is applied is provided outside the ink 9 filling region. Even so, there is also an advantage that trimming can be easily performed by reliably bringing the probe 10 of the probing device into contact with the pad 5 and trimming workability can be improved.
[0058]
In addition, this invention is not limited to embodiment mentioned above, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
[0059]
For example, in the above-described embodiment, a partition member for separating the adjacent heating element 3 is interposed between the head substrate 1 and the top plate 7, or such a partition member is formed integrally with the top plate 7. It doesn't matter if you do.
[0060]
In the above-described embodiment, the ink discharge holes 8 of the top plate 7 are positioned right above the corresponding heat generating elements 3. Instead, the ink discharge holes are shifted from right above the heat generating elements. The present invention may be applied to an edge shooter type inkjet head that is arranged or that ejects ink droplets from the edge of the head substrate.
[0061]
Further, in the above-described embodiment, the trimming pads 5 are arranged in a line in the main scanning direction, but instead, the trimming pads 5 are arranged in a staggered pattern in the main scanning direction. In this case, there is an advantage that a space can be provided between adjacent pads, and a short circuit between adjacent power supply lines and pads can be effectively prevented.
[0062]
Furthermore, in the above-described embodiment, the resistance value correction width is first obtained from the volume difference between the ink droplet volume and the reference volume, and then the trimming pulse is obtained from the obtained resistance value correction width. Instead of this, a table showing the relationship between the volume difference between the ink droplet volume and the reference volume and the trimming pulse is prepared in advance, and the trimming pulse is directly selected from the volume difference using such a table.・ You may decide.
[0063]
Furthermore, in the above-described embodiment, if the heating element 3 is formed of a TaSiO-based resistance material and the Ta content is set to 50 atomic% to 60 atomic%, the electrical resistance value of the heating element 3 is conventionally known. When adjusting by the pulse trimming method, there is an advantage that the resistance value fluctuation amount when the trimming pulse is applied becomes an appropriate magnitude, and finer resistance value adjustment is facilitated by the pulse trimming method.
[0064]
Here, if the Ta content in the heat generating element 3 is larger than 60 atomic%, the resistance value fluctuation of the heat generating element 3 when a trimming pulse is applied tends to increase, and fine resistance value adjustment tends to be difficult. On the other hand, if the Ta content in the heat generating element 3 is less than 50 atomic%, the resistance value fluctuation of the heat generating element 3 is small when a trimming pulse is applied, so that the electrical resistance value of the heat generating element 3 is greatly changed. In addition, it takes a long time to adjust the resistance value. Therefore, it is preferable to set the Ta content in the resistance material forming the heating element 3 to 50 atomic% to 60 atomic%.
[0065]
【The invention's effect】
According to the adjustment method of the present invention, since the electrical resistance value of the heating element can be accurately corrected by the conventionally known pulse trimming based on the volume of the ink actually ejected from the ink ejection hole, By optimizing the heat energy that is emitted, the volume of ink ejected from the ink ejection holes can all be made uniform, thereby obtaining a high-performance inkjet head capable of forming clear images with little density unevenness. Be able to.
[0066]
The adjustment method of the present invention is to uniformize the heat energy of the heating element by adjusting the electric resistance value of the heating element. In this case, when adjusting the applied power using the correction data, Compared to this, the memory for correction data storage, complicated correction circuits, power supply circuits, etc. are not required, the configuration of the ink jet head and the printer body in which it is incorporated can be kept simple, and correction processing during recording operation Therefore, it is possible to obtain a high-performance inkjet head that can be used for increasing the recording speed.
[0067]
Further, according to the adjustment method of the present invention, since the heating element to which the trimming pulse is applied is covered with the protective film made of an inorganic material containing silicon and oxygen, a part of the heating element reacts with oxygen in the protective film. By forming a thin oxide film on the surface of the heat generating element, the resistance value of the heat generating element can be increased, and the resistance value of the heat generating element can be corrected both vertically.
[0068]
Furthermore, according to the adjustment method of the present invention, the degree of increase in resistance when a predetermined trimming pulse is applied by setting the oxygen content in the protective film to 2.0 mass% to 10.0 mass%. There is also an advantage that the resistance becomes moderate and finer resistance value adjustment is possible.
[0069]
Furthermore, according to the adjustment method of the present invention, an ink jet head is assembled by applying a trimming pulse to the heating element through a trimming pad provided in the middle of the power supply wiring and outside the ink filling region. Even after this, trimming can be performed by making sure that the probe of the probing device used for applying the trimming pulse is brought into contact with the pad reliably and easily. There is also an advantage of being good.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an inkjet head obtained by an adjustment method according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the inkjet head of FIG.
FIG. 3 is a flowchart for explaining an adjustment method according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a state in which the volume of an ink droplet i is measured.
FIG. 5 is a diagram showing a relationship between “volume difference” and “resistance value correction width”;
6A is a diagram showing the relationship between “resistance value correction width” and “trimming pulse energy” when the resistance value is lowered, and FIG. 6B is “resistance value when the resistance value is raised. FIG. 6 is a diagram showing a relationship between “correction width” and “energy of trimming pulse”.
FIG. 7 is a cross-sectional view for explaining a trimming operation.
FIG. 8 is a cross-sectional view of a conventional inkjet head.
[Explanation of symbols]
1 ... Head substrate
2 ... Base plate
3. Heating element
4 ... Power supply wiring
5 ... Pad
6 ... Protective film
7 ... top plate
8: Ink discharge hole
9 ... Ink
10 ... probing probe
A ... Bubble
i ... Ink droplet

Claims (8)

A head substrate including a base plate, a plurality of heating elements arranged on the upper surface of the base plate, and a power supply wiring electrically connected to the plurality of heating elements, and a gap for filling ink An inkjet head that is provided on the head substrate and has an ink ejection hole for ejecting the ink, and ejects ink from the ink ejection hole by thermal energy,
Each of the power supply wirings has a trimming pad larger than the line width of the power supply wiring,
The ink-jet head is characterized in that the heating element is made of a TaSiO-based resistance material, and the Ta content is set to 50 atomic% to 60 atomic%. The inkjet head according to claim 1, wherein a resistance value of the heating element is adjusted using a pulse trimming method. The inkjet head according to claim 1, wherein the trimming pad is located outside an edge of the top plate. The inkjet head according to any one of claims 1 to 3, wherein the trimming pad is formed by at least one of nickel plating and gold plating. 5. The inkjet head according to claim 1, wherein the trimming pads are arranged in a zigzag pattern along an arrangement direction of the plurality of heat generating elements. The head substrate further includes a protective film covering the heating element and the power supply wiring so that the trimming pad is exposed,
6. The inkjet head according to claim 1, wherein an oxygen content of the protective film is set to 2.0 mass% to 10.0 mass%. A printer comprising the inkjet head according to claim 1. A head substrate including a base plate, a plurality of heating elements arranged on the upper surface of the base plate, and a power supply wiring electrically connected to the plurality of heating elements, and a gap for filling ink A resistance value adjusting method for an ink jet head, wherein the ink is ejected from the ink ejection holes by thermal energy. ,
In the inkjet head, each of the power supply wirings has a trimming pad larger than the line width of the power supply wiring, the heating element is formed of a TaSiO-based resistance material, and the Ta content is 50 atomic% to 60 atomic%. Adjusted to be
A first step of applying a power pulse to each of the plurality of heating elements to discharge the ink from the ink discharge holes, and measuring the volume of the discharged ink, and the ink measured in the first step A second step of comparing the volume with a reference volume to obtain a volume difference between the two and selecting a trimming pulse corresponding to the volume difference, and a probe in contact with the trimming pad is selected in the second step. And a third step of adjusting the electric resistance value of the heat generating element by applying the trimming pulse to the corresponding heat generating element, and a method for adjusting the resistance value of the ink jet head.

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