JP2839964B2 - Printhead substrate and printhead manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a recording head substrate and a method for manufacturing a recording head.

[0002]

2. Description of the Background Art In recent years, ink jet recording apparatuses have
It has begun to be used for copying machines, facsimile machines, word processors, host printer output printers and video output printers.

FIG. 17 is a schematic configuration diagram showing the configuration of an ink jet recording head used in an ink jet recording apparatus.

An ink jet recording head 800 includes a substrate 801 made of silicon or the like, a plurality of electrothermal transducers 802 forming an electrothermal transducer array, and an electrothermal transducer 80.
2 and a wiring electrode 803 for connecting the functional element for driving the electrothermal transducer 802 (not shown);
2 and a top plate 804 provided so as to face the substrate 801 via the nozzle wall 803.
The drive function element supplies electricity to the electrothermal conversion element 802 via the wiring electrode 803 and heats the ink on the electrothermal conversion element 802, thereby utilizing the energy of foaming generated by the ink liquid. The droplet is discharged from the discharge port 808. The ink is supplied to the supply pipe 805 and the connector 8.
The ink is supplied to the common liquid chamber 807 from an ink tank (not shown) through the nozzles 06 and the nozzles (substrate 801 and nozzle wall) by capillary action.
803 and the top plate 804).

However, this ink jet recording head 80
0, the driving functional element is disposed outside the substrate 801, and the connection between the electrothermal conversion element 802 and the driving functional element is performed by connecting the wiring electrode 803 and the driving functional element with a flexible cable or wired bonding. Therefore, there are some problems with simplification of the structure of the ink jet recording head, reduction of defects occurring in the manufacturing process, uniformization of characteristics of each element, and improvement of reproducibility. In order to solve this problem, the present applicant has proposed an ink jet recording head in which an electrothermal transducer and a driving functional element are provided on the same substrate in Japanese Patent Laid-Open No. 57-72867.

FIG. 18 is a schematic view showing a vertical structure of a part of a substrate for an ink jet recording head having a configuration proposed in Japanese Patent Application Laid-Open No. 57-72867.

This ink jet recording head substrate 900
In this example, a heating section 920 as an electrothermal conversion element and a bipolar transistor 930 as a driving functional element are formed on a P-type silicon substrate 901.

Here, the bipolar transistor 930 is
N type collector buried region 902 and N type collector buried region
Two high-concentration N-type collector regions 911 formed on the P-type silicon substrate 901 via the 902, and inside the high-concentration N-type collector region 911 via the N-type collector buried region 902 and the P-type base region 905. And a high-concentration N-type emitter formed between the high-concentration P-type base region 908 via the N-type collector buried region 902 and the P-type base region 905. The region 910 has the structure of an NPN transistor, but operates as a diode when the high-concentration N-type collector region 911 and the high-concentration P-type base region 908 are connected by the collector / base common electrode 912. Also, bipolar transistors
Adjacent to 930, a P-type isolation buried region 903, a P-type isolation region 906, and a high-concentration P-type isolation region 909 are sequentially formed as element isolation regions. In addition, a heating resistor layer 923 is formed on the P-type silicon substrate 901 via the N-type epitaxial region 904, the heat storage layer 921, and the interlayer film 922.
By cutting the wiring electrode 924 formed above,
A heating section 920 is configured. The upper surface of the ink jet recording head substrate 900 is covered with a first protective film 925, and the high concentration N of the bipolar transistor 930 is high.
Protective film 92 on the side of the heat generating portion 920 from the mold emitter region 910
5 is covered with a second protective film 926. The substrate 900 for an ink jet recording head having such a structure can be manufactured by a known semiconductor manufacturing process by photolithography.

FIGS. 19 (A) to 19 (E) are schematic views showing the steps of etching the material layer 824 of the wiring electrode in the heating section 920 by photolithography. A wiring electrode material layer 824 (for example, aluminum) is deposited on the entire surface of the heating resistor layer 923, and the wiring electrode material layer 82 is deposited.
4 Apply a photoresist 1000 for the mask to the entire upper surface, expose the photoresist 1000 for the mask using the mask, and then develop the photoresist 1000 for the mask, thereby masking the portion of the wiring electrode material layer 824 to be etched. The photoresist 1000 is removed (FIG. 1A). Then, a wiring electrode material layer 824 is formed with a wiring electrode etching solution.
By etching the photoresist for the mask
The wiring electrode material layer 824 in the portion where 1000 is removed is gradually etched, and the wiring electrode material layer 824 is cut to form the wiring electrode 924 (FIG. 9B).
(D)). After the wiring electrodes 924 are formed, the remaining photoresist for mask 1000 is removed (FIG. 10E).

[0010]

However, the above-described ink jet recording head substrate 900 has a heating section 920.
In the edge portion 924 ₁ of the wiring electrode 924 is formed, because it has almost nearly vertical shape, as shown in FIG. 19 (E), resulting the following problems.

(1) In order to generate thermal energy in the heat generating portion 920, the high-concentration N-type emitter region 910 is connected to the wiring electrode 92.
When an electric current is applied to the 4, the flow of current from the wiring electrode 924 in the heat generating portion 920 to the heating resistor layer 923, as shown by the arrows in FIG. 20, to focus on the lower edge portion 924 _1. That is,
According to an experimental result, the current density at the lower edge portion 924 ₁ reaches ^{8.2 × 10 7 A / cm 2} , the wiring electrode 924
The current density of 1.7 × 10 ⁶ A / cm ² and the heating section 92
At 0, the current density is abnormally large compared to the current density of 1.03 × 10 ⁷ A / cm ² at the center of the heating resistance layer 923. As a result, the concentration of the current density at the lower edge portion 924 ₁ determines the lifetime of the ink jet recording head leads to some cleavage of the heat generating resistor layer 923 was found.

(2) In order to improve the step coverage in the heat generating portion 920, the thickness of the first protective film 925 needs to be, for example, about 1.0 μm.
925 is interposed as thermal resistance when the thermal energy generated in the heat generating portion 920 is transmitted to the ink, so that the driving power of the heat generating resistive layer 923 must be increased, and the frequency characteristic is deteriorated due to a delay in heat conduction. This has been one of the factors that hinder low power consumption and high performance of the ink jet recording head.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording head substrate and a method of manufacturing a recording head which are excellent in durability and can achieve low power consumption and high performance.

[0014]

According to a method of manufacturing a recording head substrate of the present invention, a plurality of electrothermal transducers and a plurality of drive functional elements for driving the respective electrothermal transducers are formed by photolithography. A method for manufacturing a substrate for a recording head in which a plurality of wiring electrodes respectively connecting the respective driving functional elements and the respective electrothermal converting elements are formed on a substrate, wherein tetramethylammonium hydroxide is used as a main component. Then, the material layer of the wiring electrode is etched by using an alkaline solution having a liquid temperature of 30 to 55 ° C. while the photoresist for a mask of the material layer of the wiring electrode is etched and set back to form the wiring electrode.

Here, tetramethylammonium.
The liquid temperature is 30 to 55, mainly containing hydroxide.
The development of the mask photoresist may be performed using an alkaline solution at a temperature of ° C., or the material layer of the wiring electrode may be an aluminum layer.

According to a method of manufacturing a recording head of the present invention, a plurality of electrothermal transducers, a plurality of driving functional elements for driving each of the electrothermal transducers by photolithography,
A substrate forming step of forming a plurality of wiring electrodes respectively connecting the respective driving functional elements and the respective electrothermal converting elements on the substrate to form a substrate for a recording head; and forming a plurality of discharge electrodes for discharging ink. An ink ejection portion forming step of forming an ink ejection portion having an outlet on the recording head base, wherein the base formation step includes tetramethylammonium hydroxide as a main component. And etching the wiring electrode material layer using an alkaline solution having a liquid temperature of 30 to 55 [deg.] C. while etching back the mask photoresist of the wiring electrode material layer to form the wiring electrode. Process. Here, the substrate forming step may include a developing step of developing a photoresist for a mask using an alkaline solution having a liquid temperature of 30 to 55 ° C. and having tetramethylammonium hydroxide as a main component. Alternatively, the material layer of the wiring electrode may be an aluminum layer.

[0017]

According to the method of manufacturing a substrate for a recording head of the present invention, a mask for a material layer of a wiring electrode is formed by using an alkaline solution containing tetramethylammonium hydroxide as a main component and having a liquid temperature of 30 to 55 ° C. By etching the material layer of the wiring electrode while the photoresist for etching is recessed, the amount of etching of the material layer of the wiring electrode in the region where the photoresist for mask is recessed can be changed substantially linearly. The shape of the edge portion of the wiring electrode thus formed can be a linear taper.

Further, a method of manufacturing a recording head according to the present invention comprises:
In the substrate forming step, a wiring electrode is formed by etching back a photoresist for a mask of a material layer of the wiring electrode by using an alkaline solution containing tetramethylammonium hydroxide as a main component and having a liquid temperature of 30 to 55 ° C. By including a wiring electrode etching step of forming a wiring electrode by etching a material layer of the above, a recording head having excellent durability can be manufactured.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below, and may be any as long as the object of the present invention can be achieved.

FIGS. 1A to 1E are schematic diagrams showing a process of etching a material layer 34 of a wiring electrode for describing a first embodiment of a method of manufacturing a recording head substrate according to the present invention. FIG.

A wiring electrode material layer 34 made of aluminum is deposited on the entire surface of the heating resistor layer 23, and a photoresist 100 (positive type) for mask is applied to the entire surface of the wiring electrode material layer 34 to a thickness of 1.2 μm. After exposing the photoresist 100 for a mask using a mask, the photoresist 100 for a mask is developed, so that the material layer 34 of the wiring electrode is formed.
The portion of the photoresist 100 for the mask which is to be etched is removed (FIG. 3A). Then, the wiring electrode material layer 3
Baking is performed at 125 ° C. for 225 seconds in order to improve the adhesion between the substrate 4 and the photoresist 100 for the mask and to remove the solvent and the like in the photoresist 100 for the mask, and then the etching operation of the material layer 34 of the wiring electrode is started. . Here, the etching solution for the wiring electrode (aluminum) used for etching the wiring electrode material layer 34 made of aluminum is a mixture of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ) and acetic acid (CH ₃ COOH). Although a liquid is generally known, the mask photoresist 100 cannot be etched with this mixed liquid. Therefore, aluminum is an amphoteric metal and is alkali-soluble.Also, a positive mask photoresist 100 represented by a mixture of an alkali-soluble phenol resin and naphthoquinonediazide is basically soluble in a strong alkaline aqueous solution. Therefore, in the present embodiment, the material layer 34 of the wiring electrode is formed using an alkaline solution containing tetramethylammonium hydroxide (hereinafter referred to as “TMAH”) as a main component and having a liquid temperature of 34 ° C. Perform etching. When the etching of the wiring electrode material layer 34 is started using the alkaline solution, only the wiring electrode material layer 34 is mainly etched (FIG. 2B), but as time passes, the mask photo Since the resist 100 is also etched, the material layer 34 of the wiring electrode is etched while the photoresist 100 for the mask is retreated (FIG. 10C). Therefore, the amount of etching of the wiring electrode material layer 34 in the region where the mask photoresist 100 has receded changes almost linearly.
When the etching operation of _No. 4 is completed and the wiring electrode 24 is formed, the shape of the edge portion 241 of the wiring electrode 24 becomes a linear taper as shown in FIG. When the formation of the wiring electrode 24 is completed as described above, the remaining photoresist 100 for the mask is removed (FIG. 10E). The solution temperature was 34 ° C. and the TMAH concentration was 2.3.
According to one experimental result in which the material layer 34 of the wiring electrode was etched for 10 minutes using the 8% alkaline solution, the etching retreat amount (pattern size shift amount) of the mask photoresist 100 was about 1.3 μm. Figure 2 (angle relative to the normal of the surface of the wiring electrode 24) edge portions 24 ₁ of the angle of the taper of the wiring electrodes 24 shown in (a) theta is about 60 degrees.

When the material layer 34 of the wiring electrode is etched as shown in FIG.
Both sides (toward the front and the surface of the rear-side) 24 ₂ in the form of well, as shown in FIG. 2 (B), a linear taper.

FIG. 3 is a schematic view showing a vertical structure of a part of the substrate 40 for an ink jet recording head manufactured by the manufacturing method shown in FIG.

This ink jet recording head substrate 40
Is the substrate 900 for an ink jet recording head shown in FIG.
Is different from, and that the shape of the edge portion 24 ₁ and the both side surfaces 24 _{and second} wiring electrode 24 is a linear taper, the collector-base common electrode 12, the emitter electrode 13
Also, the shape of the edge portion and both side surfaces of the isolation electrode 14 is a linear taper as shown in FIGS. 4 (A) and 4 (B).

Therefore, in the ink jet recording head substrate 40, the current flow in the heat generating portion 20 is as follows.
As shown in FIG. 5, it is not concentrated to the lower edge portion 24 ₁ of the wiring electrode 24. For example, one experiment according to the results, when the current density at the lower edge portion 24 ₁ of the wiring electrode 24 is substantially vertical shape of the edge portion 24 ₁ 8.2
It can be reduced from × 10 ⁷ A / cm ² to 2.6 × 10 ⁷ A / cm ² . As a result, it is possible to prevent the heating resistor layer 23 from being partially cut. Therefore, according to one experimental result in which the inkjet recording head is configured using the inkjet recording head base 40, for example, the durability of the inkjet recording head is 7 ×. 1 × 1 from 10 ⁷ pulses
It was able to be extended significantly to ⁰⁹ pulses.

Further, since it is possible to step coverage property also very good in the first protective layer 25 (see FIG. 3), is substantially vertical thickness profile of the edge portion 24 ₁ of the first protective film 25 Thinner than usual (for example, 1.0μ
m to 0.6 μm). As a result, the thermal energy generated in the heat generating section 20 can be efficiently and quickly transmitted to the ink, and the first protective film 2
5, the throughput of the apparatus for forming 5 could be approximately doubled.

Next, a process of manufacturing the ink jet recording head substrate 40 shown in FIG. 3 will be described.

As shown in FIG. 6, a P-type silicon substrate 1
Formed (an impurity concentration ^{1 × 10 12 ~1 × 10 16} cm ^-3 or so) the surface of, after forming the silicon oxide film of about 8000 Å, the N-type collector buried region 2 of each cell (each of the bipolar transistor 30) The portion of the silicon oxide film to be removed was removed by photolithography. After forming a silicon oxide film, N-type impurities (for example, P, As, etc.)
Is implanted, and the impurity concentration is 1 × 10 ¹⁸ c by thermal diffusion.
An n-type collector buried region 2 of m ^-3 or more is formed to a thickness of about 2 to 6 [mu] m so that the sheet resistance is as low as 30 Ω / □ or less. Subsequently, the P-type isolation buried region 3
The silicon oxide film in the region where the silicon oxide film is to be formed is
After the formation of a silicon oxide film of about the same size, a P-type impurity (for example, B) is ion-implanted, and a P-type isolation buried region having an impurity concentration of 1 × 10 ¹⁵ to 1 × 10 ¹⁷ cm ⁻³ or more is formed by thermal diffusion. 3 was formed.

As shown in FIG. 7, after removing the silicon oxide film over the entire surface, the thickness of the N-type epitaxial region 4 (impurity concentration 1 × 10 ¹³ ~1 × 10 approximately ¹⁵ cm ^-3) of 5-20
It was epitaxially grown by about μm.

As shown in FIG. 8, a silicon oxide film of about 1000 ° is formed on the surface of the N-type epitaxial region 4, a resist is applied, patterning is performed, and a portion where the low-concentration P-type base region 5 is formed is formed. Only a P-type impurity was ion-implanted. After the resist is removed, the low-concentration P-type base region 5 (impurity concentration 5 × 10 ^{14 to} 5 × 10
¹⁷ cm ^-3 ) in a thickness of about 5 to 10 [mu] m. Thereafter, the entire silicon oxide film is removed again to form a silicon oxide film of about 8000 °, and then the silicon oxide film in the portion where the P-type isolation region 6 is to be formed is removed.
An SG film is deposited on the entire surface by using the CVD method, and is further spread by thermal diffusion so as to reach the P-type isolation buried region 3 (impurity concentration 1 × 1).
0 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ ) with a thickness of about 10 μm. At this time, it is also possible to form the P-type isolation region 6 using BBr ₃ as a diffusion source.

As shown in FIG. 9, the BSG film was removed and 8
After forming a silicon oxide film of about 2,000 ° and removing the silicon oxide film only in the portion where the N-type collector region 7 is to be formed, the N-type collector is implanted by implanting N-type solid phase diffusion and phosphorus ions or thermal diffusion. Collector region 7 (impurity concentration 1 × 10 ¹⁸ to 1 × 1) so as to reach embedded region 2 and have a low sheet resistance of 10 Ω / □ or less.
(Approximately 0 ²⁰ cm ⁻³ ) to a thickness of about 10 μm. Subsequently, after forming a silicon oxide film of about 12,500 ° and forming a heat storage layer 21 (see FIG. 10), the silicon oxide film in the cell region was selectively removed to form a silicon oxide film of about 2000 °. After performing resist patterning, the high concentration base region 8 and the high concentration isolation region 9 are formed.
P-type impurities were implanted only into the portions where After removing the resist, the silicon oxide film at the portion where the high-concentration N-type emitter region 10 and the high-concentration N-type collect region 11 are formed is removed, a thermal oxide film is formed on the entire surface, and N-type impurities are implanted. High concentration N-type emitter region 1 by thermal diffusion
Zero and high-concentration N-type collect regions 11 were simultaneously formed.
The high-concentration N-type emitter region 10 and the high-concentration N-type collect region 11 have a thickness of 1.0 μm or less and an impurity concentration of 1 μm.
It was set to about × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ .

Next, as shown in FIG. 10, after removing the silicon oxide film at the connection part of the electrodes, Al (aluminum) is deposited on the entire surface to form a collector / base common electrode 1.
2, emitter electrode 13 and isolation electrode 14
Al other than the region was removed. At this time, the shapes of the edge portions and both side surfaces of the collector / base common electrode 12, the emitter electrode 13, and the isolation electrode 14 are not vertical, but are at an angle of 30 to 75 degrees with respect to the normal line.
As shown in FIG. 1, Al was etched while the resist was recessed.

Subsequently, as shown in FIG. 11, an SiO ₂ film serving as an interlayer film 22 having a function as a heat storage layer was formed to a thickness of about 0.6 to 1.0 μm on the entire surface by a sputtering method. The SiO ₂ film may be formed by a CVD method.
Further, the film is not limited to the SiO ₂ film, and may be a SiO film or a SiON film. Thereafter, in order to make electrical connection, a part of the interlayer film 22 corresponding to the upper part of the emitter electrode 13 and the collector / base common electrode 12 was opened by photolithography to form a through hole TH.

Next, as shown in FIG. 12, the interlayer film 2 is formed on the emitter electrode 13 and the collector / base common electrode 12.
HfB ₂ was deposited at about 1000 ° on the second (SiO ₂ film) through the through hole TH as the heat generating resistance layer 23. An Al layer, which is a material layer of a wiring electrode for forming a pair of wiring electrodes 24 (corresponding to a cathode wiring electrode of a diode) and an anode wiring electrode 15 of a diode, is formed on the heating resistance layer 23 by about 5000 Å. After depositing about, rather than the shape of the edge portion 24 ₁ and the both side surfaces of the wiring electrode 24 is vertical, so that an angle of 30 degrees to 75 degrees with respect to the normal, the photo mask as shown in FIG. 1 Al was etched while the resist was set back by etching.

Thereafter, as shown in FIG. 13, a first protective film 25 (S) serving as a protective layer of the electrothermal transducer and an insulating layer between Al layers is formed by sputtering or CVD.
After depositing about 6000 ° of an iO ₂ film, about 2000 ° of Ta was deposited on the heating section 20 of the electrothermal converter as a second protective film 26 for cavitation resistance. The electrothermal transducer, the Ta and the SiO ₂ film thus formed were partially removed to form a bonding pad P. The first protective film 25 is made of SiO ₂
Alternatively, SiON or SiN may be used.

Next, the basic operation of the bipolar transistor 30, which is a functional element for driving the ink jet recording head substrate 40 shown in FIG. 3, will be described with reference to FIG.

In the bipolar transistor 30, the collector / base common electrode 12 corresponds to the anode electrode of the diode, and the emitter electrode 13 corresponds to the cathode electrode of the diode. That is, by applying a positive potential bias V _H1 to the collector / base common electrode 12, the NPN transistor in the cell is turned on, and the bias current flows out of the emitter electrode 13 as a collector current and a base current. In addition, as a result of the configuration in which the base and the collector are short-circuited, the rise and fall characteristics of the heat of the electrothermal conversion element are improved, the film boiling phenomenon occurs, and the controllability of the growth and shrinkage of the air bubbles is improved. Can be discharged. This is because, in an ink jet recording head that uses thermal energy, the characteristics of the transistor and the film boiling characteristics are deeply linked, and the switching characteristics are faster and the start-up characteristics are better because the accumulation of minority carriers in the transistors is smaller. It is thought that it is doing. In addition, there is relatively little parasitic effect, there is no variation between elements, and a stable driving current can be obtained. Further, by grounding the isolation electrode 14, it is possible to prevent charge from flowing into another adjacent cell, and to prevent a problem of malfunction of another element.

In such a semiconductor device, the concentration of the N-type collector buried region 2 is set to 1 × 10 ¹⁸ cm ⁻³ or more, and the concentration of the base region 5 is set to 5 × 10 ^{14 to} 5 × 10 ¹⁷ c.
m ^−3, and furthermore, it is desirable to minimize the area of the joint surface between the high-concentration base region 8 and the electrode. In this way, it is possible to prevent the occurrence of a leakage current from the NPN transistor to the ground via the P-type silicon substrate 1 and the isolation region.

FIG. 14 shows two diode cells SH.
1 and SH2 are only shown, but in actuality, such drive functional elements are arranged at equal intervals corresponding to, for example, 128 electrothermal conversion elements, so that block drive is possible. Are electrically connected in a matrix.
Here, for the sake of simplicity, the driving of the electrothermal transducers RH1 and RH2 as two segments in the same group will be described.

In order to drive the electrothermal transducer RH1, a group is first selected by the switching signal G1, and the electrothermal transducer RH1 is selected by the switching signal S1. Then, the diode cell SH1 having the transistor configuration is positively biased, and a current is supplied, so that the electrothermal conversion element RH1 generates heat. This thermal energy causes a state change in the liquid (ink) to generate bubbles, and the liquid is discharged from the discharge port. Similarly, when the electrothermal transducer RH2 is driven, the electrothermal transducer RH2 is selected based on the switching signal G1 and the switching signal S2, and the diode cell SH2 is driven to supply a current to the electrothermal transducer RH2. . At this time, P
The silicon substrate 1 is grounded via an isolation region. Since the isolation region of each semiconductor element (cell) is grounded in this way, malfunction due to electrical interference between the semiconductor elements is prevented.

Next, an embodiment of the method of manufacturing a recording head according to the present invention will be described.

In order to manufacture an ink jet recording head having the structure shown in FIG. 17 having the ink jet recording head substrate 40 shown in FIG. 3, the photoresist 100 for the mask of the material layer 34 of the wiring electrode is formed. Following the base electrode forming step shown in FIGS. 6 to 13 including the wiring electrode etching step shown in FIG. 1 for etching the wiring electrode material layer 34 to form the wiring electrode 24 while retreating, ink is ejected. For forming an ink discharge section having a plurality of discharge ports on the substrate 40 for ink jet recording head (as shown in FIG. 15, forming the discharge port 208 on the substrate 40 for ink jet recording head). A step of providing a plurality of nozzle walls (see FIG. 17) and a top plate 204) and a connector (see FIG. 17) on the top plate 204. That process or the like may be added to.

With respect to the ink jet recording head manufactured as described above, the electrothermal transducer is driven by a block.
Recording and operation tests were performed. In the operation test, eight semiconductor diodes were connected to one segment, and a current of 300 mA (total 2.4 A) was applied to each semiconductor diode.
The other semiconductor diodes did not malfunction and could perform good ejection. Further, since the above-mentioned ink jet recording head has a good heat transfer efficiency, it requires only 80% of the conventional driving power and has excellent high-frequency response. further,
Excellent characteristics were also obtained in terms of life and uniformity.

[0044] Table 1 shows an example of the evaluation result when subjected to a durability test of the ink jet recording head by changing the angle θ of the straight tapered edge portions 24 ₁ of the wiring electrode 24.

[0045]

[Table 1] From the results of the evaluation, by the angle θ of the linear taper of the edge portions 24 ₁ of the wiring electrode 24 between 75 ° to 30 °, the durability of the ink jet recording head was improved.

Table 2 shows the temperature of the alkaline solution containing TMAH as a main component and the edge portion 24 _{1 of the} wiring electrode 24.
Shows the results of an experiment for examining the relationship between the taper angle and the angle θ.

[0047]

[Table 2] From the experimental results shown in Table 2, by changing the temperature of the alkaline solution containing TMAH as the main component, the wiring electrode 24
Together with the edge portions 24 ₁ and the angle θ of the taper can be set to a desired angle by the liquid temperature of the alkaline solution mainly containing TMAH and 30 to 55 ° C., the wiring electrode 24 edge portion 24 ₁ taper angle θ
Has been found to be between 30 and 75 degrees.

Next, a description will be given of a second embodiment of the method for manufacturing a recording head substrate according to the present invention.

The method of manufacturing a recording head substrate of this embodiment focuses on the fact that an alkaline solution containing TMAH as a main component can be used as a developer for a positive resist, and develops a photoresist 100 for a mask. Photoresist for a mask in a portion for etching the material layer 34 of the wiring electrode
When TMAH is removed as shown in FIG.
The difference from the one shown in FIG. 1 is that an alkaline solution having a temperature of 30 to 55 ° C. and containing as a main component is used as a developer. Therefore, in the present embodiment, the process of developing the mask photoresist 100 and the process of etching the wiring electrode can be performed continuously, so that the process of forming the base can be shortened and the throughput can be improved.

It should be noted that a liquid temperature of 4 containing TMAH as a main component
After developing the photoresist 100 for a mask using an alkaline solution at 0 ° C., the material layer 34 of the wiring electrode was etched while the photoresist 100 for the mask was continuously etched back. could be the angle of the straight tapered edge portions 24 ₁ theta at approximately 75 degrees.

Next, a description will be given of a third embodiment of the method for manufacturing a recording head substrate according to the present invention.

In the embodiment shown in FIG. 1, the shape of both side surfaces 24 ₂ (see FIG. 2B) of the wiring electrode 24 is also a linear taper, but only the reduction of the current density in the heating part 20 is achieved. to the both side surfaces 24 _{and second} shape of the wiring electrode 24, FIG. 16 (B), the may remain vertically substantially as shown respectively in (C).

In this case, the etching of the wiring electrode material layer 34 for forming the wiring electrode 24 and the wiring electrode 2
4 of the edge portion 24 ₁ of the shape may be performed separately and linear etching of the edge portion 24 ₁ of the wiring electrode 24 for a tapered. That is, first, the wiring electrode material layer 3
4 A resist is applied on the entire surface, and the wiring electrode 24 is formed by etching the material layer 34 of the wiring electrode using a conventional wet etching method or a dry etching method such as RIE using a Cl-based gas. At this time, the shape of both side surfaces of the wiring electrode 24 becomes substantially vertical as in the related art. Thereafter, as shown in FIG. 16A, after covering the portions other than the heat generating portion 20 with a photoresist 50 for a mask,
By etching the wiring electrodes 24 by the method shown in FIG. 1, FIG. (B), it is possible to linear taper only (C), the shape of the edge portion 24 ₁ of the wiring electrode 24 .

In the above description, the substrate for an ink jet recording head and the ink jet recording head have been described. However, the substrate for a recording head and the recording head manufactured according to the present invention can be applied to, for example, a substrate for a thermal head and a thermal head. You can do it. In addition, as a material constituting the heating resistance layer 23 shown in FIG. 3, Ta, ZrB ₂ , Ti—W, Ni—Cr, and Ta—A
1, Ta-Si, Ta-Mo, Ta-W, Ta-Cu,
Ta-Ni, Ta-Ni-Al, Ta-Mo-Al, T
a-Mo-Ni, Ta-W-Ni, Ta-Si-Al,
Ta-W-Al-Ni and the like.

FIG. 21 is a schematic diagram showing an example of the configuration of an ink jet recording apparatus 700 equipped with an ink jet recording head (hereinafter, referred to as a “recording head”) 510 manufactured by the method of manufacturing a recording head according to the present invention. It is.

The recording head 510 is mounted on a carriage 720 which engages with a spiral groove 721 of a lead screw 704 which rotates via driving force transmitting gears 702 and 703 in conjunction with forward and reverse rotation of a driving motor 701. Drive motor 701
Is reciprocated in the directions of arrows a and b along the guide 719 together with the carriage 720 by the power of. A paper holding plate 705 for the recording paper P conveyed onto the platen 706 by a recording medium feeding device (not shown) presses the recording paper P against the platen 706 in the carriage movement direction.

The photocouplers 707 and 708 are connected to a carriage 720
The presence of the lever 709 in this area is confirmed by the drive motor 70.
1 is a home position detecting means for performing the switching of the rotation direction. The support member 710 is provided with the recording head 510 described above.
A cap member 711 for capping the entire surface of the device is supported. The suction means 712 sucks the inside of the cap member 711 and recovers the suction of the recording head 510 via the opening 713 in the cap. The moving member 715 allows the cleaning blade 714 to move in the front-rear direction. The moving member 715 and the cleaning blade 714 are supported by a main body support plate 716. It goes without saying that the cleaning blade 714 is not limited to this form, and a known cleaning blade can be applied to the present embodiment. Further, the lever 717 for starting the suction for the suction recovery is provided with the cam 71 engaged with the carriage 720.
8, the driving force from the driving motor 701 is controlled by a known transmission means such as clutch switching. A print control unit for giving a signal to a heat generating unit provided in the recording head 510 and controlling the driving of each mechanism described above is provided on the apparatus main body side (not shown).

In the ink jet recording apparatus 700 having the above-described structure, the platen 706 is provided by the recording medium feeding apparatus.
The recording head 510 performs recording on the recording paper P conveyed upward while reciprocating over the entire width of the recording paper P, and the recording head 510 manufactured by the method described above is used. Therefore, high-precision and high-speed recording is possible.

The present invention particularly relates to an ink jet recording head (hereinafter, referred to as a "recording head") of the type which ejects ink using thermal energy, which is proposed by Canon Inc. among the ink jet recording methods. This provides an excellent effect in an apparatus (hereinafter, referred to as a “recording apparatus”).

Regarding the typical structure and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both on-demand type and continuous type.
In the case of the on-demand type, a rapid temperature rise exceeding the nucleate boiling corresponding to the recorded information is applied to the electrothermal transducer disposed corresponding to the sheet holding the liquid (ink) or the liquid path. By applying at least one drive signal to the recording medium, heat energy is generated in the electrothermal transducer, and the film is boiled on the heat acting surface of the recording head. As a result, the liquid (ink) This is effective because bubbles in the parentheses) can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. In addition,
U.S. Pat.
By adopting the conditions described in the specification of 313,124,
Further excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat.No. 4,558,333 and U.S. Pat.
The configuration using the specification of Japanese Patent No. 9,600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. Japanese Unexamined Patent Publication (Kokai) discloses a configuration corresponding to the discharge section
The present invention is also effective as a configuration based on Japanese Patent Publication No. 138461/59.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above specification is used. Either a configuration that satisfies the length or a configuration as a single recording head that is integrally formed may be used, but the present invention can more effectively exert the above-described effects.

In addition, an exchangeable chip-type recording head, which is electrically mounted to the apparatus main body and can supply ink from the apparatus main body when attached to the apparatus main body, or integrated with the recording head itself. The present invention is also effective when a cartridge-type recording head provided in a fixed manner is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like provided as components of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. . Specifically, for the recording head, a capping unit, a cleaning unit, a pressurizing or suctioning unit, a preheating unit using an electrothermal transducer or another heating element or a combination thereof, and a recording unit It is also effective to perform a preliminary ejection mode for performing another ejection in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, and may be a single recording head or a combination of plural recording heads. The present invention is also very effective for an apparatus provided with at least one of full colors by color mixture.

In the embodiments of the present invention described above, the ink is described as a liquid. However, the ink is a solidified ink at room temperature or lower, and is softened or liquid at room temperature. Generally, the temperature is controlled within a range of not less than 70 ° C. and not more than 70 ° C., and the temperature is controlled so that the viscosity of the ink is in a stable ejection range. Good. In addition, positively prevent the temperature rise due to thermal energy by allowing the ink to change its state from the solid state to the liquid state as energy, or
In order to prevent evaporation of the ink, ink that solidifies in a standing state is used, and in any case, the ink is liquefied by application of a heat energy according to the recording signal, and the ink is discharged as a liquid ink or reaches a recording medium. The use of inks that liquefy for the first time with thermal energy, such as those that already begin to solidify at that point, is also applicable to the present invention. In such a case, as described in JP-A-54-56847 or JP-A-60-71260, the ink is held as a liquid or solid in a porous sheet recess or through hole, It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0067]

As described above, the present invention has the following effects.

According to the first to third aspects of the present invention, the wiring electrode is formed by etching the material layer of the wiring electrode while the photoresist for the mask of the material layer of the wiring electrode is etched back. Since the shape of the edge portion can be made to be a linear taper, it is possible to prevent the current density from being concentrated in the heat generating portion and to improve the step coverage in the heat generating portion.

According to a fourth aspect of the present invention, in the substrate forming step, the wiring electrode is formed by etching the wiring electrode material layer while etching away the mask photoresist of the wiring electrode material layer. By including the wiring electrode etching step, it is possible to manufacture a recording head which is excellent in durability, low in power consumption and high in performance.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a process of etching a material layer of a wiring electrode for explaining a first embodiment of a method of manufacturing a substrate for a recording head according to the present invention, and FIG. Diagrams showing the state before the layer is etched, (B)-
(D) is a diagram illustrating a state in which the material layer of the wiring electrode is being etched, and (E) is a diagram illustrating a state in which the etching of the material layer of the wiring electrode is completed.

FIG. 2 is a view showing a shape of a formed wiring electrode;
(A) is a sectional view taken along line AA of (B), and (B) is a plan view.

FIG. 3 is a schematic view showing a vertical structure of a part of a substrate for an ink jet recording head manufactured by the manufacturing method shown in FIG.

4A and 4B are diagrams showing the shapes of the edges and both side surfaces of the collector / base common electrode, the emitter electrode, and the isolation electrode shown in FIG. 3, and FIG. 4A is a cross section taken along line AA of FIG. FIG. 2B is a plan view.

FIG. 5 is a diagram showing a flow of current in a heat generating part shown in FIG. 3;

FIG. 6 is a diagram showing a manufacturing process of the ink jet recording head substrate shown in FIG.

FIG. 7 is a diagram showing a process of manufacturing the ink jet recording head base shown in FIG.

FIG. 8 is a view showing a process of manufacturing the ink jet recording head base shown in FIG. 3;

FIG. 9 is a diagram showing a manufacturing process of the inkjet recording head substrate shown in FIG.

FIG. 10 is a diagram showing a manufacturing process of the inkjet recording head base shown in FIG.

FIG. 11 is a diagram showing a process of manufacturing the ink jet recording head base shown in FIG.

FIG. 12 is a diagram showing a manufacturing process of the ink jet recording head base shown in FIG. 3;

FIG. 13 is a diagram illustrating a process of manufacturing the ink jet recording head substrate illustrated in FIG. 3;

14 is a diagram for explaining a basic operation of a bipolar transistor which is a functional element for driving the inkjet recording head substrate shown in FIG. 3;

FIG. 15 is a schematic cross-sectional view for explaining the method for manufacturing a recording head according to the present invention.

FIG. 16 shows a third example of the method for producing a recording head substrate of the present invention.
FIGS. 4A and 4B are diagrams showing an example of the present invention, in which FIG. 4A shows a state before the material layer of the wiring electrode is etched, and FIG. 4B shows a state after the material layer of the wiring electrode is etched; FIG. 2C is a cross-sectional view taken along line A, and FIG. 2C is a plan view showing a state after the material layer of the wiring electrode is etched.

FIG. 17 is a schematic configuration diagram illustrating a configuration of an inkjet recording head used in an inkjet recording apparatus.

FIG. 18 is a schematic view showing a vertical structure of a part of a substrate for an ink jet recording head having a configuration proposed in Japanese Patent Application Laid-Open No. 57-72867.

FIGS. 19A and 19B are schematic diagrams illustrating a process of etching a material layer of a wiring electrode in a heat generating portion by photolithography, and FIG. 19A is a diagram illustrating a state before the material layer of the wiring electrode is etched; FIGS. 6A to 6D are views showing a state in which the material layer of the wiring electrode is being etched, and FIGS. 6E to 6D are views showing a state in which the etching of the material layer of the wiring electrode is completed.

FIG. 20 is a view for explaining a problem of the ink jet recording head base shown in FIG. 18;

FIG. 21 is a schematic configuration diagram showing an example of a configuration of an ink jet recording apparatus equipped with an ink jet recording head manufactured by the method for manufacturing a recording head of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 P-type silicon substrate 2 N-type collector buried region 3 P-type isolation buried region 4 N-type epitaxial region 5 P-type base region 6 P-type isolation region 7 N-type collector region 8 High-concentration P-type base region 9 high Concentration P-type isolation region 10 High-concentration N-type emitter region 11 High-concentration N-type collector region 12 Collector / base common electrode 13 Emitter electrode 14 Isolation electrode 15 Anode wiring electrode 20 Heat generation part 21 Heat storage layer 22 Interlayer film 23 Heat generation resistance layer DESCRIPTION OF SYMBOLS 24 Wiring electrode 24 ₁ edge part 24 ₂ side surface 25 1st protective film 26 2nd protective film 30 Bipolar transistor 34 Wiring electrode material layer 40 Ink jet recording head base 50, 100 Photoresist for mask 204 Top plate 208 Discharge port TH through hole P pad RH1 RH2 electrothermal transducer SH1, SH2 diode cells S1, S2 switch signals G1 switching signal V _H1 bias

Claims (6)

(57) [Claims] 1. A plurality of electrothermal transducers, a plurality of drive functional elements for driving each of the electrothermal transducers, and each of the drive functional elements and each of the electrothermal transducers are formed by photolithography. In a method of manufacturing a substrate for a recording head in which a plurality of wiring electrodes to be connected to each other are formed on a substrate, an alkaline solution having a liquid temperature of 30 to 55 ° C. containing tetra-methyl-ammonium hydroxide as a main component, A method for manufacturing a substrate for a recording head, comprising: forming a wiring electrode by etching a material layer of the wiring electrode while etching back a photoresist for a mask of the material layer of the wiring electrode. 2. The recording head substrate according to claim 1, wherein the mask photoresist is also developed using an alkaline solution containing tetramethylammonium hydroxide as a main component and having a liquid temperature of 30 to 55 ° C. Manufacturing method. 3. The method according to claim 1, wherein the material layer of the wiring electrode is an aluminum layer. 4. A plurality of electrothermal transducers, a plurality of drive functional elements for driving each of the electrothermal transducers, and each of the drive functional elements and each of the electrothermal transducers by photolithography. A substrate forming step of forming a plurality of wiring electrodes to be connected on a substrate to form a substrate for a printhead, and an ink forming an ink discharge section having a plurality of discharge ports for discharging ink on the substrate for a printhead. In the method of manufacturing a recording head including the step of forming a discharge part, the step of forming a base mainly includes tetra-methyl-ammonium-hydroxide, and the liquid temperature is 30 to
A wiring electrode etching step of forming the wiring electrode by etching the material layer of the wiring electrode while etching back the mask photoresist of the material layer of the wiring electrode using an alkaline solution at 55 ° C. Manufacturing method of a recording head. 5. The step of preparing a substrate includes a step of developing a photoresist for a mask using an alkaline solution containing tetramethylammonium hydroxide as a main component and having a liquid temperature of 30 to 55 ° C. A method for manufacturing a recording head according to claim 4. 6. The method according to claim 4, wherein the material layer of the wiring electrode is an aluminum layer.