JPH08276597A - Plate-shaped substrate for recording head, recording head using plate-shaped substrate and liquid jet recording apparatus loaded with recording head - Google Patents

Abstract

PURPOSE: To enhance yield by improving a process forming tapered through- holes. CONSTITUTION: This substrate 11 has a bipolar transistor built therein and the surface thereof is covered with an insulating interlaminar film 12 and an electrothermal conversion element and the bipolar transistor are connected through the tapered through-hole 12a of the interlaminar film 12. The through- hole 12a is formed by a method wherein a photoresist 13 is applied to the interlaminar film 12 to be heated in contact with a steam atmosphere to generate a solvent moisture concn. gradient in the photoresist 13 and a tapered opening 13a is formed to the photoresist 13 by patterning and the exposed part of the interlaminar film 12 is etched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-like substrate for a recording head of a liquid jet recording apparatus used in a copying machine, a facsimile, an output printer of a word processor or a host computer, a printer for video output, etc., and a method for manufacturing the same. The present invention relates to a recording head that uses a plate-shaped substrate for a recording head and a liquid jet recording apparatus that mounts the recording head.

[0002]

2. Description of the Related Art A plate-shaped substrate for a recording head of a liquid jet recording apparatus is an electrothermal conversion element array provided on a single crystal silicon substrate, and a transistor for selectively driving each electrothermal conversion element. The drive circuit such as an array is formed on another silicon substrate and electrically connected to each electrothermal conversion element by a flexible cable or wired bonding, or inside the silicon substrate on which the electrothermal conversion element array is arranged. It is integrally formed.

In particular, a plate-like substrate for a recording head having a driving circuit, in which a driving transistor array is arranged inside a silicon substrate on which an electrothermal conversion element array is mounted, is disclosed in, for example, Japanese Patent Laid-Open No. 57-72867. As has been done
It is epoch-making in that it is very useful for prolonging the service life and improving mass productivity, and recently it is becoming the mainstream.

As shown in FIG. 17, a drive circuit-mounted plate-shaped substrate for a recording head is a single crystal silicon substrate 100.
1. An epitaxial region 10 of N-type semiconductor is provided at a predetermined portion of 1.
04, a pair of N-type collector regions 1007, a P-type semiconductor base region 1008, and a high-concentration N-type semiconductor emitter region 1010.
No. 0 array is formed, the entire surface is covered with a heat storage layer 1021, and then through holes are provided in the heat storage layer 1021 to form electrodes 1012 to 1014, and subsequently, an interlayer of silicon oxide that also serves as heat storage and electrical insulation. A film 1022 is deposited, and an array of electrothermal conversion elements including a heating resistance layer 1023 and an aluminum wiring electrode 1024 is formed thereon by lithography.

The heating resistance layer 1023 exposed from the interrupted portion of the wiring electrode 1024 is the heating portion 1020 of the electrothermal conversion element.
And the end portion of the wiring electrode 1024 is formed by the interlayer film 1
Tapered through hole 1028 provided in 022
Is connected to the collector / base common electrode 1012 and the emitter electrode 1013.

[0006] Almost the entire surface of the plate-shaped substrate 1000 including the electrothermal conversion element array and the transistor array is covered with a first protective layer 1025 mainly for electrical insulation, and a recording liquid such as ink. The second protective layer 102 is further formed on the portion requiring cavitation resistance to
6 are stacked.

The recording head includes a plate-shaped substrate 1000 for a recording head in which an array of bipolar transistors 1030 and an array of electrothermal conversion elements are formed on the same silicon substrate 100, and an ejection port (orifice) and a liquid flow on the plate-shaped substrate 1000. It is composed of a nozzle wall (not shown) that forms a passage and a top plate that closes the nozzle wall.

The wiring electrode 1024 of each electrothermal conversion element is connected to the electrodes 1012, 101 of the bipolar transistor 1030.
The reason why the through hole 1028 for connecting to No. 3 is tapered is that the thickness of the interlayer film 1022 is generally 1.0.
Since the wiring electrode 1024 has a thickness of about 0.5 μm, the step coverage in the through hole 1028 of the interlayer film 1022 having a thickness of 2 to 3 times can be improved. This is because the side surface of the through hole 1028 needs to be inclined by 35 to 55 degrees.

Conventionally, the through hole 10 of the interlayer film 1022 is used.
28 is formed by the following steps. First, as described above, the heat storage layer 1021 and each electrode 10 exposed from the heat storage layer 1021.
A portion in which a through-hole 1028 is provided after a photoresist of about 2.5 to 3.0 μm is deposited on the interlayer film 1022 of silicon oxide having a thickness of 1.0 to 1.5 μm covering the surfaces of 12 to 1014. Only the opening) is exposed, the exposed portion is removed by contacting with an alkali developing solution, and post-baking is performed at a relatively high temperature of 250 ° C. By performing the post-baking at such a high temperature, the adhesion between the interlayer film 1022 and the photoresist remaining on the surface of the interlayer film 1022 is strengthened, and the photoresist is temporarily softened so that the openings of the patterned photoresist are opened to the side surface. Deforms into a tapered hole inclined at 34 to 55 degrees.

Next, a dry etching process is performed on the interlayer film 1022 exposed from the photoresist opening by using a fluorine-based gas. At this time, Ar gas 800 SCC
M, CF ₄ gas 40SCCM, CHF ₃ gas 30SCC
M and O ₂ gas 10 SCCM are added to improve the rate of the dry etching process.

Since the side surface of the opening of the photoresist has an inclination of 35 to 55 degrees as described above, a part of the etching gas contacting the opening flows along the inclined side surface to the interlayer film 1022. Through hole formed 1028
Follows the inclination of the side surface of the opening portion of the photoresist 35-35.
It becomes a tapered through hole having an inclination of 55 degrees.

After completion of the dry etching, the photoresist is removed by irradiating O ₂ plasma for 180 seconds and using an organic solvent.

[0013]

However, according to the above-mentioned conventional technique, in the step of forming the tapered through hole in the interlayer film, if the photoresist is post-baked at a high temperature of 250 ° C. as described above. The photoresist hardens significantly and strong crosslinks occur inside it. Therefore, when removing the photoresist remaining after the dry etching, the O ₂ plasma treatment and the cleaning treatment with the organic solvent are used together, but it is difficult to completely remove the photoresist hardened by the high temperature post-baking. There is an unsolved problem that the yield of products is extremely low.

The present invention has been made in view of the above-mentioned problems of the prior art, and a step of forming a tapered through hole in an insulating layer for electrically connecting the electrothermal converting means and its driving circuit. Is extremely simple, and there is no risk of a significant reduction in yield due to the photoresist remaining in the step, a method of manufacturing the same, a recording head using the same, and a recording head using the same. An object of the present invention is to provide a liquid jet recording apparatus to be mounted.

[0015]

A plate-shaped substrate for a recording head according to the present invention is applied to a substrate having an insulating layer and a drive circuit disposed thereunder, and the surface of the insulating layer of the substrate. A plate-shaped substrate for a recording head, comprising an electrothermal converting means, wherein the electrothermal converting means is electrically connected to the drive circuit by at least one tapered through hole formed in the insulating layer. A step of depositing a photoresist on the insulating layer to generate a predetermined solvent moisture concentration gradient in the film thickness direction, and then patterning an opening in the photoresist through the through hole; and an opening in the patterned photoresist It is formed by lithography including a step of etching the insulating layer through.

The method for manufacturing a plate-shaped substrate for a recording head according to the present invention comprises a substrate having an insulating layer and a drive circuit disposed thereunder, and an electric heat applied to the surface of the insulating layer of the substrate. A method of manufacturing a plate-shaped substrate for a recording head, comprising a converting means, and the electrothermal converting means being electrically connected to the drive circuit by at least one tapered through hole formed in the insulating layer. In the step of forming the through hole, the photoresist is applied to the pre-insulating layer, and the substrate is heated in the film thickness direction of the photoresist while contacting the surface with a gas containing water or vapor of solvent. Patterning an opening in the photoresist after generating a predetermined solvent moisture concentration gradient, and etching the insulating layer through the opening in the patterned photoresist. It characterized by having a step.

The concentration of water is preferably 80 to 90%.

The concentration of the solvent vapor is preferably 50 to 90%.

The substrate may be heated on a hot plate heated to 100 to 120 ° C.

Instead of heating the substrate while contacting the surface of the photoresist with a gas containing water or solvent vapor, the substrate may be heated and then immersed in hot water.

The temperature of the hot water is preferably 60-80 ° C.

[0022]

When forming a through hole in the insulating layer, first, a photoresist is applied to the insulating layer, and the surface of the photoresist is brought into contact with a gas containing water or solvent vapor, and the substrate is placed on a hot plate at 100 to 120 ° C. After heating and pre-baking the photoresist,
A predetermined opening portion of the photoresist is exposed, and the exposed portion is removed by a developing process or the like. Since the surface of the photoresist in the heat treatment is in contact with a gas containing water or a vapor of a solvent, evaporation of water or a solvent diffused from the inside of the photoresist to the surface by heating is suppressed, and the surface of the photoresist is A solvent moisture concentration gradient occurs in which the concentration of the solvent and moisture in the photoresist increases as the concentration approaches. In the post-exposure development process, the higher the solvent moisture concentration of the photoresist, the higher the dissolution rate of the photoresist. Therefore, the opening patterned in the photoresist by the development process has a larger opening dimension as it is closer to the surface of the photoresist. It becomes tapered. By etching the insulating layer exposed from such a tapered opening at a high rate, it is possible to obtain a tapered through hole that follows the tapered shape of the photoresist opening. Since the heat treatment of the substrate is performed at a relatively low temperature as described above, the opening is tapered by patterning the opening in the photoresist and then heating the substrate to a high temperature close to 250 ° C. to temporarily soften the photoresist. There is no fear that the photoresist will be excessively hardened as compared with the method of deforming the photoresist. Therefore, it is easy to completely remove the photoresist after the etching, and there is no possibility that the yield of the product will be significantly reduced due to the remaining photoresist.

[0023]

Embodiments of the present invention will be described with reference to the drawings.

1 (a) to 1 (e) show the heat storage layer and the interlayer which is an insulating layer covering each electrode portion of the bipolar transistor which is the driving circuit in the method of manufacturing the plate-shaped substrate for the recording head according to the first embodiment. It shows a step of forming a through hole in the film.

First, as shown in FIG. 1 (a), each electrode portion is made of Al, Al--Si, Al--Cu or the like, having a bipolar transistor formed by a known method and a heat storage layer covering the bipolar transistor. Substrate 11 in a state in which the heat is exposed from the heat storage layer
A P-SiON interlayer film 12 is deposited on the surface of the above, and the interlayer film 12 is subjected to HMDS treatment, and then a positive photoresist 13 is applied to the surface by a spinner as shown in FIG. The substrate 11 is heated on the hot plate P _{1 at} 120 ° C., and the photoresist 13 is prebaked. At this time, by keeping the surroundings in a water vapor atmosphere (humidity of 80 to 90%) which is a gas containing water, the diffusion of water and solvent from the surface of the photoresist 13 is suppressed.

During the pre-baking process, the photoresist 13 is heated from below by the hot plate P ₁ .
Water and solvent of the photoresist 13 diffuse toward the surface, but as described above, since the surface of the photoresist 13 is kept in a high-humidity steam atmosphere, the photoresist 1
The diffusion of water and solvent from the surface of the photoresist 3 is suppressed, and as a result, a solvent-moisture concentration gradient in which the concentration of the solvent and moisture increases toward the surface of the photoresist 13 occurs in the film thickness direction of the photoresist 13.

Subsequently, as shown in FIG. 1C, the surface of the photoresist 13 is covered with a mask M ₁ and irradiated with ultraviolet rays to expose a predetermined portion of the photoresist 13. The exposure energy at this time is about 16 times that of Eth (natural light).

Next, as shown in FIG. 1D, an alkaline solution (TMAH 2.38%) is used to perform a developing treatment to dissolve the exposed portion of the photoresist 13 to form the opening 13.
a is formed. Photoresist 13 with alkaline solution
Has a relatively high dissolution rate, and tends to increase as the solvent water concentration of the photoresist 13 increases.

By the above-mentioned pre-baking treatment, the solvent water concentration of the photoresist 13 becomes higher as it approaches the surface, and therefore, the closer it is to the surface of the photoresist 13, the faster the dissolution rate. The opening 13a is larger than the exposed portion as a whole, and the side surface 13b has a taper shape inclined by about 35 to 55 degrees with respect to the film thickness direction of the photoresist 13 (see FIG. 2).

In this way, the opening 13a is patterned in the photoresist 13 and subsequently post-baked at 130 to 150 ° C., and then the opening 1 of the photoresist 13 is formed.
The interlayer film 12 exposed at 3a is brought into contact with etching gas to form a through hole 12a. Etching gas is F ₄ gas 30 to ₄₀ SCCM, HF ₃ gas 30 to 4
With 0 SCCM and O ₂ gas 10 SCCM added,
The etching conditions were a vacuum pressure of 1.5 to 2.0 Torr and a power supply voltage of 500W.

When O ₂ gas is added to the etching gas as described above, not only the exposed portion of the interlayer film 12 but also the photoresist 13 around it is etched, and the opening 13a is gradually enlarged. The opening 13a of the photoresist 13 is tapered as described above, and further, the through hole 12a formed in the interlayer film 12 is formed on the side surface 1 of the opening 13a of the photoresist 13 because the opening 13a expands as the etching progresses.
The taper shape has an inclination angle of approximately 30 to 50 degrees, which follows the inclination of 3b.

After the etching is completed, the photoresist 13 is removed by a known method to obtain an interlayer film 12 having a through hole 12a as shown in FIG. 1 (e).

In the above steps, the post-baking treatment after patterning the photoresist is 130 to 15
Since it is performed at a relatively low temperature of 0 ° C., there is no possibility that strong crosslinks will occur inside the photoresist and the photoresist will be over-cured. Therefore, it is possible to prevent the photoresist removal after etching from being incomplete as in the conventional example, which causes a reduction in product yield.

FIGS. 3A to 3E show a tapered through-hole forming process according to a modification of the first embodiment.
Instead of keeping the surface of the photoresist 23 in a water vapor atmosphere in the pre-baking process shown in FIG. 3B, a solvent of the same kind as the solvent of the photoresist 23, for example, E
CA (ethyl cellosolve acetate), MMP (methoxy methoxy propionate), PGMEA (propylene glycol monomethyl ether acetate), PGME
(Propylene glycol monomethyl ether), EP
(Ethylpyruvate), EL (Ethyl lactate), and the like are kept in an atmosphere of a solvent vapor that is a gas containing a vapor of a solvent, and the vapor concentration is 50 to 90%. This modification is
This has the advantage that the solvent moisture concentration gradient of the photoresist 23 after the pre-baking process can be changed depending on the type of solvent used.

4A to 4F show a through hole forming process according to the second embodiment. This is performed by prebaking using the hot plate P ₂ shown in FIG. 4B in an atmosphere of air with a humidity of about 35%, and then, as shown in FIG. The substrate 31 in which the photoresist 33 and the interlayer film 32 are laminated in warm water H ₂ is 0.5
The surface of the photoresist 33 is made to absorb moisture by immersing for 1 minute. The photoresist 33 which has absorbed the moisture in this way has a solvent moisture concentration gradient similar to that of the first embodiment, and when the developing treatment is performed following the exposure shown in FIG. ), The tapered opening 33a is formed, and the interlayer film 32 exposed from the opening 33a is formed.
Are etched to obtain through holes 32a. Since the other points are the same as those in the first embodiment, the description thereof will be omitted.

Next, the overall structure of the plate-shaped substrate 90 for the recording head according to the first and second embodiments will be described with reference to FIG. This is because an N-type epitaxial region 904 and a pair of N-type collector regions 907 are provided in a predetermined portion of the P-type silicon substrate 901.
And an array of bipolar transistors 930 composed of a P-type base region 908, a high-concentration N-type emitter region 910, and the like, and the entire surface thereof is covered with a heat storage layer 921, and then a through hole is provided in the heat storage layer 921 to form an electrode 91
2 to 914 are formed, and subsequently, an interlayer film 922 made of silicon oxide that also serves as heat storage and electrical insulation is deposited, and an electric heat conversion means is formed on the heating resistance layer 923 and the wiring electrode 924 made of aluminum. An array of heat conversion elements is formed by lithography.

The heat generating resistance layer 923 exposed from the interrupted portion of the wiring electrode 924 constitutes the heat generating portion 920 of the electrothermal conversion element, and the end portion of the wiring electrode 924 has a tapered through hole provided in the interlayer film 922. The collector / base common electrode 912 and the emitter electrode 913 are connected by a hole 928.

The entire surface on which the electrothermal transducing element array and the transistor array are arranged is mainly covered with the first protective film 925 for electrical insulation, and the cavitation resistance to the recording liquid such as ink is improved. A second protective film 926 is further stacked on a required portion.

The interlayer film 922 of the plate-shaped substrate 90 for the recording head
Are the above-mentioned interlayer films 12 and 32, and the state before the deposition is equivalent to the above-mentioned substrates 11 and 31, and the interlayer films 922
The through holes 928 provided in the above are equivalent to the through holes 12 a and 32 a of the interlayer films 12 and 32.

Next, a method of manufacturing the plate-shaped substrate 90 for the recording head of FIG. 5 will be described.

As shown in FIG. 6, a P-type silicon substrate 90 is provided.
After forming a silicon oxide film of about 8000 Å on the surface of 1 (impurity concentration of about 1 × 10 ¹² to 1 × 10 ¹⁶ cm ^-3 ), the N-type collector buried region 902 of each cell (each bipolar transistor 930) is formed. The portion of the silicon oxide film to be formed was removed by photolithography. After a new silicon oxide film is formed, N-type impurities (for example,
(P, As, etc.) is ion-implanted, and an N-type collector buried region 902 having an impurity concentration of 1 × 10 ¹⁵ cm ⁻³ or more is formed by thermal diffusion.
With a thickness of 2 to 60 μm and a sheet resistance of 30 Ω /
□ It is designed to have the following low resistance. Subsequently, the silicon oxide film in the region where the P-type isolation buried region 903 is formed is removed, a silicon oxide film of about 1000 Å is newly formed, and then P-type impurities (for example, B) are ion-implanted. Impurity concentration of 1 × 10 ¹⁵ to 1 × due to thermal diffusion
P-type isolation buried region 90 of 10 ¹⁷ cm ^-3 or more
Formed 3.

As shown in FIG. 7, after the silicon oxide film on the entire surface is removed, an N-type epitaxial region 904 (impurity concentration of about 1 × 10 ¹³ to 1 × 10 ¹⁵ cm ⁻³ ) having a thickness of 5 to 5 is formed.
Epitaxial growth of about 20 μm was performed.

As shown in FIG. 8, a 1000 Å silicon oxide film is formed on the surface of the N-type epitaxial region 904, a resist is applied, and patterning is performed to form a low-concentration P-type base region 905. Only P-type impurities were ion-implanted. After removing the resist, a low concentration P-type base region 905 (impurity concentration 1 × 10
¹⁴ to 1 × 10 ¹⁷ cm ⁻³ ) was formed to a thickness of 5 to 10 μm. After that, the silicon oxide film is entirely removed again, and a new silicon oxide film of about 8000 Å is formed.
The silicon oxide film in the portion forming the P-type isolation region 906 is removed, a BSG film is deposited on the entire surface by the CVD method, and further, it reaches the P-type isolation buried region 903 by thermal diffusion. P-type isolation region 906 (impurity concentration 1 × 10 ¹⁸ to 1 × 10 ²⁰ cm
^-3 ) was formed to a thickness of about 10 μm. At this time, BB
P-type isolation region 9 using r ₃ as a diffusion source
It is also possible to form 06.

As shown in FIG. 9, the BSG film is removed, and
After forming a silicon oxide film of about 000 Å and removing the silicon oxide film only in the portion where the N-type collector region 907 is formed, N-type solid phase diffusion and phosphorus ion implantation or thermal diffusion are performed to fill the N-type collector region. Area 9
02 and the sheet resistance is as low as 10 Ω / □ or less. N-type collector region 907 (impurity concentration 1 × 1
0 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ ) was formed to a thickness of 10 μm. Then, a silicon oxide film of about 12500Å is formed to form a heat storage layer 921 (see FIG. 10), and then the silicon oxide film in the cell region is selectively removed to obtain 2000Å
A silicon oxide film was formed to some extent. Resist patterning was performed, and P-type impurities were implanted only in the portions where the high-concentration base region 908 and the high-concentration isolation region 909 were formed. After removing the resist, the silicon oxide film in the portion forming the high-concentration N-type emitter region 910 and the high-concentration N-type collector region 911 is removed, a thermal oxide film is formed on the entire surface, and P ⁺ is implanted to remove the heat. A high concentration N-type emitter region 910 and a high concentration N-type collector region 911 were simultaneously formed by diffusion. The high concentration N-type emitter region 910 and the high concentration N-type collector region 911
Has a thickness of 1.0 μm or less and an impurity concentration of 1 × 10 ¹⁸ to 1
It was set to approximately 10 ²⁰ cm ^-3 .

Next, as shown in FIG. 10, after removing the silicon oxide film at the connection part of some electrodes, Al (aluminum) is deposited on the entire surface, and the collector / base common electrode 9 is formed.
12, Al other than the regions of the emitter electrode 913 and the isolation electrode 914 was removed.

Subsequently, as shown in FIG. 11, plasma C
By the VD method, an interlayer film 92 which also functions as a heat storage layer is formed.
A P-SiON film to be 2 was formed on the entire surface to a thickness of 1.0 to 1.5 μm. The P-SiON film may be formed by a sputtering method. Further, not only the P-SiON film but also SiO ₂
It may be a membrane. After that, in order to make electrical connection,
Emitter electrode 913 and collector / base common electrode 9
A part of the interlayer film 922 corresponding to the upper part of 12 is opened by photolithography, and a tapered through hole 928 is formed.
Was formed. At this time, according to the process shown in FIG. 1, the end face of TH is tapered by 30 to 50 ° with respect to the normal line.

Next, as shown in FIG. 12, a heating resistance layer 923 is formed on the emitter electrode 913 and the collector / base common electrode 912 and on the interlayer film 922 (P-SiON film).
As a result, HfB ₂ or TaN was deposited by about 1000Å. On the heating resistance layer 923, a pair of wiring electrodes 924 of the electrothermal conversion element (corresponding to cathode wiring electrodes of the diode)
And A as the anode wiring electrode 915 of the diode
After depositing about 1000 Å of the 1-layer, HfB ₂ or TaN and Al are partially etched, and the heat generating portion 9
20 and the wiring electrode 924 were formed.

Thereafter, as shown in FIG. 13, a first protective film 925 as a protective layer of the electrothermal conversion element and an insulating layer between Al wirings is formed by a sputtering method or a CVD method.
After depositing (SiO ₂ film or SiN film) to about 6000Å, about 2000Å was deposited on the heat generating portion 920 of the electrothermal converter as Ta as a second protective film 926 for cavitation resistance. The electrothermal conversion element thus prepared, Ta and SiO ₂ film or Si
The N film was partially removed to form a bonding pad. The second protective film 926 is made of Si in addition to SiO _2.
It may be ON or SiN.

Next, the bipolar transistor 9 which is a functional element for driving the plate-shaped substrate 90 for the recording head shown in FIG.
The basic operation of 30 will be described with reference to FIG.

In the bipolar transistor 930, the collector / base common electrode 912 corresponds to the anode electrode of the diode, and the emitter electrode 913 corresponds to the cathode electrode of the diode. That is, by applying a positive potential bias VHI to the collector / base common electrode 912, the NPN transistor in the cell is turned on,
A bias current flows out from the emitter electrode 913 as a collector current and a base current. In addition, as a result of short-circuiting the base and collector, the heat rise and fall characteristics of the electrothermal conversion element are improved, the film boiling phenomenon occurs, and the controllability of bubble growth and shrinkage accompanying it is improved and stable. The ejected ink can be discharged. this is,
In the ink jet recording head that uses thermal energy, the characteristics of the transistor and the characteristics of the film boiling are deeply linked, and the accumulation of minority carriers in the transistor is small, which results in faster switching characteristics and better start-up characteristics. It is considered to be a thing.
Further, the parasitic effect is relatively small, there is no variation between elements, and a stable drive current can be obtained. further,
By grounding the isolation electrode 914, it is possible to prevent charges from flowing into other adjacent cells, and prevent a problem of malfunction of other elements.

In such a semiconductor device, the N-type collector buried region 902 has a concentration of 1 × 10 ¹⁸ cm ⁻³ or more, and the base region 905 has a concentration of 5 × 10 ^{14 to} 5 ×.
It is desirable to set it to 10 ¹⁷ cm ^−3, and further, to make the area of the bonding surface between the high concentration base region 908 and the electrode as small as possible. By doing so, it is possible to prevent the generation of a leakage current from the NPN transistor to the ground via the P-type silicon substrate 901 and the isolation region.

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

In order to drive the electrothermal converting element RH1, the group is selected by the switching signal G1 and the electrothermal converting element 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 to the electrothermal conversion element RH1 to generate heat. This thermal energy causes the liquid (ink) to change its state, generating bubbles and ejecting the liquid from the ejection port. Similarly, when driving the electrothermal conversion element RH2, the electrothermal conversion element RH2 is selected by the switching signal G1 and the switching signal S2, and the diode cell SH2 is driven to supply a current to the electrothermal conversion body. At this time, the P-type silicon substrate 901 is grounded via the isolation region. By thus grounding the isolation region of each semiconductor element (cell), malfunction due to electrical interference between the semiconductor elements is prevented.

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

Subsequent to the substrate forming process shown in FIGS. 6 to 13, the nozzle wall 83 for forming the common liquid chamber 87 and the ejection port 88 on the plate-shaped substrate 90 for the recording head as shown in FIG. The step of providing the top plate 84 and the step of providing the connector 86 on the top plate 84 may be added.

In the ink jet recording head manufactured as described above, when the electrothermal conversion element is block-driven to record, eight semiconductor diodes are connected to one segment, and 300 mA (2.4 in total for each semiconductor diode).
Although the current of A) flows, good ejection can be performed without causing other semiconductor diodes to malfunction.

In the above description, the recording head substrate and the ink jet recording head have been described.
The recording head substrate and the recording head manufactured by the present invention can be applied to, for example, a thermal head substrate and a thermal head. Further, as a material forming the heating resistance layer 923 shown in FIG.
_{rB 2, Ti-W, Ni} -Cr, Ta-Al, Ta-S
i, Ta-Mo, Ta-W, Ta-Cu, Ta-Ni,
Ta-Ni-Al, Ta-Mo-Al, Ta-Mo-N
i, Ta-W-Ni, Ta-Si-Al, Ta-WA
1-Ni and the like. Next, the liquid jet recording apparatus shown in FIG. 16 equipped with the recording head of the present invention will be described.

A carriage 101 having a recording head unit in which a recording head 103 and an ink container, which are similar to the recording head according to the present embodiment or its modified example, are mounted is guided by a guide shaft 104 and a lead screw 105 having a spiral groove 105a. The ink container cassette 102 can be mounted on the carriage 101.

The lead screw 105 has a gear train 106a, 106b, 1 driven by a drive motor 106 that rotates in the forward and reverse directions.
Rotated forward and backward through 06c and 106d, and its spiral groove 1
The carriage 101 is reciprocally moved in the arrow direction and the counter arrow direction via a pin (not shown) provided on the carriage 101 having a tip end engaged with the reference numeral 05a. The forward / reverse rotation of the drive motor 106 is switched by detecting that the carriage 101 is at the home position by the lever 115 and the photocoupler 116 provided on the carriage 101.

On the other hand, the recording paper 109 which is the recording medium is
The platen 107 is pressed by the pressing plate 108, and is conveyed so as to face the recording head by a paper feed roller (not shown) which is a conveyance device driven by the paper feed motor 110.

The recovery unit 111 includes the recording head 103.
It is provided in order to remove the foreign matter adhering to the ejection port and the ink of high viscosity to maintain the ejection characteristic in a normal state.

The recovery unit 111 has a cap member 113 communicating with a suction means (not shown), and by capping and sucking the discharge port of the recording head 103, foreign matter and viscosity attached to the discharge port. Remove the elevated ink. Also, the recovery unit 111 and the platen 1
Between 07, a cleaning blade 114 which is guided by the guide member 112 and moves forward and backward toward the traveling path of the ejection port surface of the recording head 103 is disposed. It is configured to be able to clean foreign matter and ink droplets attached to the outlet surface.

The present invention provides excellent effects particularly in an ink jet recording type recording head and recording apparatus for recording by forming flying droplets by utilizing thermal energy in the ink jet recording system.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
No. 796, the present invention is preferably carried out using these basic principles. This recording method is applicable to both the so-called on-demand type and the continuous type.

To briefly explain this recording method, a recording liquid (ink) is recorded in correspondence with recording information on an electrothermal converter which is arranged corresponding to a sheet or a liquid path holding the recording liquid (ink). Is applied to at least one drive signal for giving a rapid temperature rise that causes a film boiling phenomenon, which exceeds the nucleate boiling phenomenon, and heat energy is generated to cause the film boiling on the heat acting surface of the recording head. Give rise to. In this way, bubbles can be formed in a one-to-one correspondence with the drive signal applied from the recording liquid (ink) to the electrothermal converter, which is particularly effective for the on-demand recording method. The recording liquid (ink) is ejected through the ejection holes by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the recording liquid (ink) with particularly excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124, which is an invention relating to the rate of temperature rise on the heat acting surface, are adopted, more excellent recording can be performed.

The structure of the recording head is a combination of a discharge port, a liquid flow path, and an electrothermal converter as disclosed in the above specifications (straight liquid flow path or right-angled liquid flow path).
In addition to the above, the present invention is also effective for those having a configuration in which the heat acting portion is arranged in the bending region as disclosed in US Pat. No. 4,558,333 and US Pat. No. 4,459,600. .

In addition, JP-A-59-123670 discloses a structure in which a common slit is used as a discharge port of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective for a device having a structure based on JP-A-59-138461, which discloses a structure in which an opening corresponds to a discharge portion.

Further, as a recording head in which the present invention is effectively used, there is a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. The full line head may be a full line configuration formed by combining a plurality of print heads as disclosed in the above specification, or may be a single full line print head integrally formed.

In addition, by being mounted on the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. The present invention is also effective when a cartridge-type recording head that is specially provided is used.

Further, it is preferable to add recovery means for the recording head or preliminary auxiliary means to the liquid jet recording apparatus of the present invention because the recording apparatus can be made more stable. Specifically, the recording head is preheated by a capping means, a cleaning means, a pressure or suction means, an electrothermal converter or a heating element other than this, or a combination thereof. It is also effective to perform stable recording by adding a preliminary discharge mode means for performing discharge different from the means and recording.

Further, the recording mode of the recording apparatus is not limited to the mode in which only the mainstream color such as black is recorded, and either the recording head may be integrally formed or a combination of plural recording heads may be used. However, the present invention is also extremely effective for an apparatus provided with at least one of a multicolor of different colors or a full color by color mixing.

In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may take the form of.

In the embodiment of the present invention described above,
Although the ink is described as a liquid, it is an ink that solidifies at room temperature or lower and becomes a liquid or a liquid at room temperature, or a temperature range for temperature adjustment that is generally performed in inkjet. ℃ or more 70 ℃
It may be softened or become liquid in the following temperature range. That is, the ink may be in a liquid state when the use recording signal is applied. In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or the ink that solidifies when left standing for the purpose of preventing the evaporation of the ink is used. In any case, the thermal energy such as the one that the ink is liquefied by applying the thermal energy according to the recording signal and ejected as an ink liquid, or the one that has already started to solidify when it reaches the recording medium. The use of an ink having the property of liquefying for the first time is also applicable to the invention. In such a case, the ink is disclosed in JP-A-54-5.
6847 or Japanese Unexamined Patent Publication No. 60-71260, a mode in which it is opposed to an electrothermal converter in a state of being held as a liquid or a solid in a recess or through hole of a porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0075]

Since the present invention is constructed as described above, it has the following effects.

The step of forming a tapered through hole in the insulating layer for electrically connecting the electrothermal converting means of the plate-shaped substrate for the recording head and its drive circuit is extremely simple, and the photoresist remaining in the step is formed. Therefore, there is no fear that the yield of products will be significantly reduced. As a result, it is possible to obtain an inexpensive and high-performance plate-shaped substrate for a recording head. By using such a plate-shaped substrate for a recording head, an inexpensive and high-performance liquid jet recording apparatus can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a step of forming a through hole in an interlayer film in the method of manufacturing a plate-shaped substrate for a recording head according to the first embodiment.

FIG. 2 is a diagram illustrating a shape of an opening of a photoresist.

FIG. 3 is a diagram showing a process of forming a through hole according to a modification of the first embodiment.

FIG. 4 is a diagram showing a process of forming a through hole according to a second embodiment.

FIG. 5 is a schematic partial cross-sectional view showing the overall structure of a plate-shaped substrate for a recording head according to the first and second examples.

6 is a first method of manufacturing the plate-shaped substrate for the recording head of FIG.
It is a figure which shows a process.

FIG. 7 is a second manufacturing method of the plate-shaped substrate for the recording head of FIG.
It is a figure which shows a process.

FIG. 8 is a third method of manufacturing the plate-shaped substrate for the recording head of FIG.
It is a figure which shows a process.

FIG. 9 is a fourth method of manufacturing the plate-shaped substrate for the recording head of FIG.
It is a figure which shows a process.

10 is a diagram showing a fifth step of the method of manufacturing the plate-shaped substrate for the recording head of FIG.

11 is a diagram showing a sixth step of the method for manufacturing the plate-shaped substrate for the recording head of FIG.

12 is a diagram showing a seventh step of the method for manufacturing the plate-shaped substrate for the recording head of FIG.

FIG. 13 is a diagram showing an eighth step of the method for manufacturing the plate-shaped substrate for the recording head of FIG.

14 is a diagram showing a ninth step of the method of manufacturing the plate-shaped substrate for the recording head of FIG.

FIG. 15 is a partial perspective view showing a part of the recording head.

FIG. 16 is a perspective view illustrating the entire liquid jet recording apparatus.

FIG. 17 is a schematic partial sectional view showing a plate-shaped substrate for a recording head according to a conventional example.

[Explanation of symbols]

 11, 31 Substrate 12, 32 Interlayer film 12a, 32a Through hole 13, 23, 33 Photoresist 13a Opening 13b Side surface 90 Recording head plate substrate 103 Recording head

Claims (12)

[Claims] 1. A substrate having an insulating layer and a drive circuit disposed thereunder, and an electrothermal converting means attached to the surface of the insulating layer of the substrate, the electrothermal converting means being formed on the insulating layer. A plate-shaped substrate for a recording head, wherein the electrothermal converting means is electrically connected to the drive circuit by at least one tapered through hole, wherein the through hole is
A step of patterning an opening in the photoresist after applying a photoresist to the insulating layer and generating a predetermined solvent-moisture concentration gradient in the film thickness direction, and forming the insulating layer through the opening of the patterned photoresist. A plate-shaped substrate for a recording head, which is formed by lithography having an etching step. 2. A predetermined solvent moisture concentration gradient in the film thickness direction of the photoresist is generated by heating the substrate while bringing the surface of the photoresist into contact with a gas containing moisture or solvent vapor. The plate-shaped substrate for a recording head according to claim 1. 3. The method according to claim 2, wherein instead of heating the substrate while contacting the surface of the photoresist with a gas containing water or a vapor of a solvent, the substrate is heated and then immersed in warm water. Plate-shaped substrate for the recording head. 4. An insulating layer and a substrate having a drive circuit disposed below the insulating layer, and an electrothermal converting means attached to the surface of the insulating layer of the substrate. The substrate is formed on the insulating layer. A method of manufacturing a plate-shaped substrate for a recording head, wherein the electrothermal converting means is electrically connected to the drive circuit by at least one tapered through hole, wherein the step of forming the through hole includes pre-insulation. The photoresist is applied to the layer, and the substrate is heated while the surface thereof is brought into contact with a gas containing water or solvent vapor to generate a predetermined solvent water concentration gradient in the film thickness direction of the photoresist, and then, A plate for a recording head, comprising a step of patterning an opening in a photoresist and a step of etching the insulating layer through the opening of the patterned photoresist. Substrate manufacturing method. 5. The method for producing a plate-shaped substrate for a recording head according to claim 4, wherein the water concentration is 80 to 90%. 6. The method for producing a plate-shaped substrate for a recording head according to claim 4, wherein the vapor concentration of the solvent is 50 to 90%. 7. The solvent is ethyl cellosolve acetate,
7. The method for manufacturing a plate-shaped substrate for a recording head according to claim 6, comprising at least one of methoxy methoxy propionate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl pyruvate and ethyl lactate. . 8. The method for producing a plate-shaped substrate for a recording head according to claim 4, wherein the substrate is heated on a hot plate heated to 100 to 120 ° C. 9. The method according to claim 4, wherein instead of heating the substrate while contacting the surface of the photoresist with a gas containing moisture or a vapor of a solvent, the substrate is heated and then immersed in hot water. 1. A method of manufacturing a plate-shaped substrate for a recording head according to claim 1. 10. The method for producing a plate-shaped substrate for a recording head according to claim 9, wherein the temperature of the hot water is 60 to 80 ° C. 11. A recording head comprising a plate-shaped substrate for a recording head according to claim 1, a nozzle wall for forming a plurality of ejection ports on the substrate, and a common liquid chamber. 12. A carriage for mounting the recording head according to claim 11, means for supplying an electric signal to a drive circuit of the recording head, and a conveyance for conveying a recording medium so as to face the recording head. Liquid jet recording apparatus equipped with a device.