JPH02158344A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To obtain a liquid jet recording head particularly suitable and easily applicable for a high-density alignment by a method wherein a heat-accumulation layer is formed on an area over a plurality of thermal energy acting parts on a substrate, and the heat-accumulation layer is provided with a release structure for alleviating a distortion due to heat. CONSTITUTION:In a recording head production process, at least one slit (or round) omission pattern or end cutout omission pattern is formed on a heat- accumulation layer as a release structure for reducing a thermal distortion. On an Si substrate, the heat-accumulation layer (SiO2) 10 is formed, and thereon the patterns as a release structure are provided. Both the slit patterns and the cutout patterns are passed through the heat-accumulation layer down to the Si substrate. If the exposure of the Si in the pattern parts is not preferable in succeeding processes, a thin SiO2 can be formed thereon. As a result, the durability of the heating substrate can be improved.

Description

[Detailed Description of the Invention] The present invention relates to a liquid jet recording head, and more specifically,
The present invention relates to a heating element substrate for a recording head of a thermal inkjet printer.

Conventional non-impact recording methods have recently attracted attention because the noise generated during recording is so small that it can be ignored. Among them, high-speed recording is possible,
However, the so-called inkjet recording method, which allows recording on plain paper without the need for special fixing treatment, is an extremely powerful recording method, and various methods have been proposed, improved, and commercialized. Some have been developed, and efforts are still being made to put them into practical use.

In this type of inkjet recording method, recording is performed by causing droplets of a recording liquid called ink to fly and adhere to a recording member. There are several types of methods depending on the control method used to control the flight direction of the generated recording liquid droplets.

First, the first method is the one (TClc type method) disclosed in, for example, U.S. Pat. Recording is performed by controlling the droplets with an electric field in accordance with a recording signal to selectively attach recording liquid droplets to a recording member.

To explain this in more detail, an electric field is applied between the nozzle and the accelerating electrode to eject a negatively charged recording liquid droplet from the nozzle, and the ejected recording liquid droplet is converted into a recording signal. Accordingly, the droplet is caused to fly between x and y deflection electrodes configured to be electrically controllable, and the droplet is selectively deposited on the recording member by changing the intensity of the electric field to perform recording.

The second method is a method (Sweet method) disclosed in, for example, U.S. Pat. No. 3,596,275, U.S. Pat. Recording is performed on a recording member by generating droplets with a controlled amount of charge and flying the generated droplets between deflection electrodes to which a negative electric field is applied.

Specifically, the orifice (discharge port) of a nozzle, which is a part of the recording head to which the piezo vibrating element is attached.
A charged electrode configured to have a recording signal applied thereto is arranged at a predetermined distance in front of the piezo vibrating element, and an electric signal of a constant frequency is applied to the piezo vibrating element to mechanically vibrate the piezo vibrating element, A small droplet of recording liquid is ejected from the ejection port. At this time, charges are electrostatically induced in the recording liquid droplet discharged by the charging electrode, and the droplet is charged with an amount of charge corresponding to the recording signal. When a droplet of recording liquid with a controlled amount of charge flies between deflection electrodes to which a constant electric field is uniformly applied, it is deflected according to the amount of charge applied.
Only the droplets carrying the recording signal are allowed to deposit on the recording member.

The third method is the method (Hertz method) disclosed in, for example, US Pat. No. 3,416,153,
In this method, an electric field is applied between a nozzle and a ring-shaped charged electrode, and small droplets of recording liquid are generated and atomized using a continuous vibration generation method to perform recording. That is, in this method, the atomization state of droplets is controlled by modulating the electric field intensity applied between the nozzle and the charging electrode in accordance with the recording signal, and the gradation of the recorded image is produced.

The fourth method is, for example, the method disclosed in US Pat. No. 3,747,120 (StBmme method), and this method is fundamentally different in principle from the above three methods.

That is, in all three methods, the droplets of recording liquid ejected from the nozzle are electrically controlled while they are in flight, and the droplets carrying the recording signal are selectively attached to the recording member. In contrast, this Stemme method
Recording is performed by ejecting small droplets of recording liquid from an ejection port in response to a recording signal.

In other words, the + Stemme method applies an electrical recording signal to a piezo vibrating element attached to a recording head that has an ejection port for discharging recording liquid, and converts this electrical recording signal into mechanical vibration of the piezo vibrating element. Instead, recording is performed by ejecting small droplets of recording liquid from the ejection port according to the mechanical vibrations and adhering them to the recording member.

These four conventional methods each have their own advantages, but there are also points that can be solved in the other method.

That is, in the first to third methods, the direct energy for generating droplets of the recording liquid is electrical energy, and the deflection control of the droplets is also electric field control.

Therefore, although the first method is simple in structure, it requires a high voltage to generate droplets, and it is difficult to use a multi-nozzle recording head, making it unsuitable for high-speed recording.

The second method allows the recording head to have multiple nozzles and is suitable for high-speed recording, but it has a complicated structure, and the electrical control of the recording liquid droplets is sophisticated and difficult. There are problems such as the tendency to generate dots.

The third method has the advantage of being able to record images with excellent gradation by atomizing recording liquid droplets, but on the other hand, it is difficult to control the atomization state and fog occurs in the recorded image. In addition, it is difficult to create a multi-nozzle recording head.
There are various problems such as being unsuitable for high-speed recording.

The fourth method has relatively many advantages compared to the first to third methods. In other words, the structure is simple, and since recording is performed by ejecting recording liquid from the ejection opening of the nozzle on-demand, it is possible to reduce the number of small droplets that fly as in the first to third methods. Second, it is not necessary to collect droplets that are not needed to record an image, and unlike the first and second methods, there is no need to use a conductive recording liquid, and the material of the recording liquid is It has great advantages such as a high degree of freedom. However, on the other hand, it is difficult to make the recording head multi-nozzle because there are problems in processing the recording head, and it is extremely difficult to make a piezo vibrating element having a desired resonance number into a E-shape. Furthermore, since the recording liquid droplets are ejected and ejected in flight using the mechanical energy of the mechanical vibration of the piezo vibrating element, it has the disadvantage that it is not suitable for high-speed recording.

Furthermore, Japanese Patent Application Laid-Open No. 48-9622 (corresponding to the above-mentioned US Pat. No. 3,747,120) discloses, as a modification,
It is described that thermal energy is used instead of using mechanical vibration energy by means such as the piezo vibration element described above.

That is, the above-mentioned publication describes a so-called bubble jet liquid jet recording device that uses a heating coil that directly heats liquid as a pressure increasing means instead of a piezo vibrating element to generate steam that causes a pressure increase. There is.

However, in the above publication, the liquid ink in the bag-shaped ink chamber (liquid chamber), which has only one opening through which liquid ink can go in and out, is directly heated and vaporized by energizing the heating coil as a pressure increasing means. However, when discharging liquid continuously and repeatedly, it is not clear how to heat it.
There is nothing to suggest. In addition, the heating coil is located at the deepest part of the bag-shaped liquid chamber far from the liquid ink supply path, which makes the head structure complicated and requires continuous high-speed printing. For repeated use,
It is not suitable.

Moreover, with the technical content described in the above-mentioned publication, it is not possible to quickly prepare for the next liquid discharge after discharging the liquid using the generated heat, which is of paramount importance in practical use.

As described above, the conventional method has advantages and disadvantages in terms of structure, high-speed recording, multi-nozzle recording head, generation of satellite 1 to I cuts, and fogging of recorded images. There was a restriction that it could only be applied to uses that benefit the public.

Also, "bubble jet recording element" (Makoto Shibata).

Akira Asai, 1986 National Institute of Electrical Engineers of Japan Conference S, 7-35~S
, 7-38) describes the heater board process.
It is disclosed that a thermal oxide film (SiO2) is formed on a silicon wafer. This 5in2 film functions as a heat storage layer. Japanese Unexamined Patent Application Publication No. 1986-59060 discloses a technique for continuously forming a protective layer in a band shape on a heating resistance layer. Japanese Patent Publication No. 63-26708 and Japanese Patent Application Laid-Open No. 60-116454 disclose techniques for protecting electrodes with organic materials. Japanese Patent Publication No. 55-1322
No. 52 discloses a head structure provided with an insulating layer.

Both of the above two prior art techniques relate to various layers formed on a heating element substrate of a thermal head, and are formed in a planar shape in a certain area. In thermal inkjet, as is well known, a heating element provided on a substrate is energized and generates heat depending on image information. Therefore, thermal distortion occurs locally or on the entire substrate, causing damage to the substrate. There are problems such as peeling and cracking due to deformation or thermal strain of each J. However, the above-mentioned prior art does not describe how to deal with these problems. Furthermore, Japanese Patent Publication No. 63-26708 states that in consideration of heat resistance, it is preferable that the organic material protective layer not be present in the heat generating part.
Publication No. 4 states that from the aspects of heat resistance and thermal conductivity,
Although it is stated that it is preferable not to have an organic material protective film in the heat generating part, the problem of thermal distortion is not mentioned.

Purpose The present invention was made in view of the above-mentioned circumstances.
This was done to solve the problem of distortion caused by heat and improve the durability of the heating element board (and by extension, the head).The heating element board has a cutout in the protective layer pattern, and the electrode is This was done with the purpose of providing a liquid jet recording head that is particularly suitable for high-density arrays (16 lines/mm or more), which could not be achieved with the conventional method of repositioning the liquids one by one, and which can be easily applied.

In order to achieve the second object, the present invention contains a recording liquid that is introduced, generates bubbles in the recording liquid by heat, and generates an action force as the volume of the bubbles increases. a flow path provided with an energy acting portion; an orifice connected to the flow path for causing the recording liquid to be ejected as droplets by the acting force; A liquid jet recording head comprising a liquid chamber for introducing the recording liquid and an introduction means for introducing the recording liquid into the liquid chamber, has a plurality of thermal energy acting parts on one substrate, has a heat storage layer formed in a plurality of regions of the thermal energy acting part,
The heat storage layer may have a relief structure for alleviating distortion due to heat, or the liquid jet recording head may have a plurality of thermal energy acting portions on one substrate, and the substrate may A heat generating element protective layer is formed in a plurality of areas of the thermal energy acting part, and the heat generating element protection layer is
R4 has a relief structure for alleviating distortion caused by heat, or, in the liquid jet recording spatula 1-, a plurality of thermal energy acting parts and a plurality of thermal energy acting parts on one substrate. [4] The substrate has an electrode protective layer formed in a region covering the plurality of electrodes, and the electrode protective layer has a plurality of electrodes connected to the electrodes. 7, or corresponds to a plurality of thermal energy application parts on one substrate and the plurality of thermal energy application parts at the liquid jet recording/\foot, The substrate has a plurality of electrodes connected thereto, and the substrate includes: 1) an insulating layer formed in a region covering a thermal energy acting portion and/or a plurality of the electrodes; The layer is characterized by having a relief structure that alleviates distortion caused by heat.

First, the principle of ink ejection using a bubble jet will be explained based on FIG. In the figure, 21 is a lid substrate, 2
2 is a heating element substrate, 27 is a selective (independent) electrode, 28 is a common electrode, 29 is a heating element, 30 is ink, 31 is a bubble, 32
is a flying ink droplet.

(a) is a steady state, in which the surface tension of the ink 30 and the external pressure are in equilibrium on the orifice surface.

In (b), the heater 29 is heated until the surface temperature of the heater 29 rises rapidly and boiling development occurs in the adjacent ink layer, and microbubbles 31 are scattered.

((2) is a state in which the adjacent ink layer that is rapidly heated on the entire surface of the heater 29 instantly vaporizes, forming a boiling film, and the bubbles 31 grow. At this time, the pressure inside the nozzle is It rises by the amount of growth, and the balance with the external pressure on the orifice surface is lost, and the ink column begins to grow from the orifice.

(,,I) is a state in which the bubble has grown to its maximum, and ink 30 corresponding to the volume of the bubble is pushed out from the orifice surface. At this time, no current is flowing through heater 29, and the surface temperature of heater 2.9 is decreasing. The maximum value of the volume of the bubble 31 is slightly delayed from the timing of electric pulse application.

(e) shows a state in which the bubbles 31 are cooled by ink or the like and begin to contract. At the tip of the ink column, it moves forward while maintaining the extruded speed, and at the rear end, the ink flows backward from the orifice surface into the nozzle due to the decrease in nozzle internal pressure as the bubbles contract, creating a constriction in the ink column. .

In (f), the air bubbles 31 are further contracted, the ink comes into contact with the heater surface, and the heater surface is cooled even more rapidly. At the orifice surface, the external pressure is higher than the nozzle internal pressure, so the meniscus is largely moving into the nozzle. The tip of the ink column becomes a droplet and drops 5 to 1 droplets toward the recording paper.
It is flying at a speed of 0m/sec.

In (g), the air bubbles have completely disappeared in the process of refilling the orifice with ink by capillary action and returning to the state of (a).

FIG. 3 is a perspective view of the recording head, FIG. 4 is an exploded perspective view of the lid substrate (a) and heating element substrate (b) that constitute the recording head, and FIG. 5 is a perspective view of the lid substrate seen from the back side. In the figure, 23 is a recording liquid inlet, 24 is an orifice, 25 is a flow path, and 26 is a region for forming a liquid chamber.

Next, a conventional method of manufacturing a heat generating substrate will be explained with reference to FIG. Note that FIG. 7 shows a cross-sectional view of the heat generating section. (a) Thermal oxidation of a silicon wafer and SiC on the surface
(b) H
The fB2 resistor and AI are subjected to M)W, and a heating element 29 and electrodes 27 and 28 are formed by photolithography. (c) Next, as an insulating layer and an anti-cavitation layer,
S]02, Ta is sequentially laminated on the portion of the AI electrode excluding the wire bonding portion, and then only Ta is patterned in a band shape around the heating element by photolithography. Then, a resin layer (protective layer) 1] is patterned on the 5102M which is not coated with Ta to complete the heating element substrate.

The purpose of this resin layer 11 is to improve the isolation between the ink and the electrodes, and is not laminated on the heating element portion.

The above description is a conventional example, and for example, it is also possible to use an alumina substrate with a glaze layer, which is often used in technologies such as thermal heads, as the substrate material. Both the SiC2 film on the silicon substrate and the glaze layer (composition is the same as the glass) on the alumina substrate function as a heat storage layer.

In addition to thermal oxidation, the 5in2 film can also be formed by CVD, sputtering, or other methods. The present invention has been developed in view of the conventional problem that the heat storage layer is subjected to thermal distortion, resulting in deformation, peeling from the substrate, or cracking, resulting in low durability of the recording head. Usually, as shown in FIG. 6(,), the heat storage layer is formed on the entire surface of the substrate. However, with such a configuration, the heat generated by the heating element brings heat locally or to the entire heating element substrate, and due to the difference in thermal expansion coefficient between the substrate and the heat storage layer, thermal distortion occurs as described above. Occurs and causes problems.

Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a diagram for explaining the manufacturing process of an embodiment of the recording head according to the present invention, in which a slit-shaped punching pattern (or a round pattern is also available) is used as a relief structure for alleviating thermal strain in at least one place in the heat storage layer. ) Alternatively, a cutout pattern is provided at the end. (,)
is a diagram showing a Si substrate, (d) is a sectional view taken along line A-A in (a),
(b) shows the heat storage Jff (S ) on the Si substrate, 02
) 10 is formed, (e) is a BB sectional view of (b), (c) is a diagram where a pattern as a relief structure is formed in the heat storage layer, (f) is a C-C sectional view of (c) It is a diagram. In addition,
The pattern shown in FIG. 1(,') is formed by photolithography and etching techniques, but the explanation of the method will be omitted here. In addition, in Fig. 1, both the Surino I~-shaped pattern and the cutout-shaped pattern are passed through to J'9 (plate (S)), and Si is exposed in the pattern part. Although,
If it is inconvenient for S'' to be exposed in a later process, you can stop this process midway through etching 5102.
It is sufficient to form a step pattern as shown in FIG. 8. Alternatively, as shown in FIG. 9, after etching up to I-], a thinner layer <Si◯ may be formed (hereinafter, L corresponds to claim 1).

Next, the 5 heating resistor will be explained.

Useful materials for forming the heating resistor include, for example, tantalum-SO2 mixtures, tantalum nitride, nichrome, silver-palladium alloys, silicon semiconductors, or hafnium and lanthanum.

Zirconium, titanium, tantalum, tungsten.

Examples include borides of metals such as molybdenum, niobium, chromium, and vanadium.

Among the materials constituting these heating resistors, metal borides are particularly excellent, and among these, hafnium boride has the best properties.
Next, zirconium boride, lanthanum boride, tantalum boride, and vanadium boride.

Niobium boride follows in this order.

The heating resistor can be formed using the above-mentioned materials by techniques such as electron beam evaporation and sputtering. The film thickness of the heating resistor is determined by its area so that the amount of heat generated per unit time is as desired.

It is determined according to the material, the shape and size of the heat-acting part, and the actual power consumption, etc., but it is usually 0.001 to 5 μm, preferably 0.01 to 1 μm.
It is said that

Next, the heating element protective layer of the present invention will be explained.

The protective layer is required to have two characteristics: to protect the heat generating resistor from the recording liquid without hindering the effective transfer of heat generated by the heat generating resistor to the recording liquid. Materials useful as materials constituting the protective layer include the above-mentioned 8102.
．． In addition to Ta, silicon nitride, magnesium oxide, and aluminum oxide.

Examples include tantalum oxide and zirconium heptoxide, and these can be formed using methods such as electron beam evaporation and sputtering. The thickness of the protective layer is usually 0.0
1-10 μm, preferably 0.1-5 μm, optimally 0.
It is desirable that the thickness be 1 to 3 μm.

In FIG. 10, 29a and 29b are heating resistance layers, 13
．． 14 are the 1st. As is clear from the figure, the second (heat generating element) protective layer is formed into a band shape or a continuous planar shape. A case in which the present invention is applied to the second protective layer 14 in FIG. 10 is shown in FIG. This is only the second protective layer in Figure 10,
In the present invention, a notch=21 is provided in the protective layer pattern in order to alleviate thermal distortion. FIG. 12 shows yet another embodiment. In this case, a slit-shaped opening is provided. Needless to say, the slit-like opening or cutout pattern of the present invention is provided at a position away from the heating element. The embodiments shown in FIGS. 11 and 12 are examples in which a cutout pattern or an open pattern in the form of a sulin 1 is removed from the protective layer pattern, but as an example applied to a heat storage layer, the embodiment shown in FIG. As explained in FIG. 9, the pattern may not go all the way to the bottom, but may stop in the middle. Such an example is shown in Figure 13(a).
Shown in (b). FIG. 13(b) is a cross-sectional view taken along the line DD of (,), and in such a case, since it is a half-open pattern, the position of the pattern may coincide with the heating element below. Note that patterns that completely go all the way to the bottom or patterns that stop midway, as shown in Figures 11 to 13, can be easily formed using photolithography and etching techniques, and these techniques are already widely known, so they will not be discussed here. The explanation will be omitted. Although the second protective layer 14 in FIG. 10 has been described here, the present invention is also applicable to the first protective layer 13. In short, in order to prevent the heating element protective layer from deforming due to thermal strain and causing pattern peeling or cracking, a relief structure is provided to alleviate the thermal strain.
It is formed by providing a notch-like pattern or a slit-like pattern opening (the above corresponds to claim 2).

Next, the electrode of the present invention will be explained.

As the material constituting the electrode, many commonly used electrode materials can be effectively used, and specific examples include Afl, Ag, Au, Pt, Cu, etc.
Using these materials, they are provided in a predetermined position with a predetermined size, shape, and thickness by a method such as vapor deposition.

In the present invention, an electrode protective layer is further provided to protect the electrode from ink. Below is the protective layer (coating)
I will explain about it.

In the present invention, the material for forming the film on the lead electrode is: 1) has good film formability, 2) has a dense structure with few pinholes, 2) does not expand or dissolve in the ink used, and 2) It is desirable to have physical properties such as good adhesion with lower layers such as electrode layers, and in some cases, high heat resistance (taking into account that it is installed near the heat generating part of the heating element). For example, silicone resin, fluororesin,
Aromatic polyamide, addition polymerization polyimide, polybenzimidazole, metal chelate polymer, titanate ester, epoxy resin, phthalate resin, thermosetting phenol resin, P-vinylphenol resin, Zyrock resin, triazine resin, BT resin ( Resins such as triazine resin and bismaleimide addition polymer resin are used. In order to form a film using these resins, the resin may be diluted with a solvent, applied onto the lead electrode by spin coating, spray coating, dip coating, or the like, and then dried and cured.

In addition to this, it is also desirable to form a film using a polyxin rylene resin or a derivative thereof by vapor deposition.

Furthermore, various organic compound monomers such as thiourea,
Thioacetamide, vinylfurocene, 1°3.5-trichlorobenzene, chlorobenzene, styrene, ferrocene, picoline, naphthalene, pentamethylbenzene, nitrotoluene, acrylonitrile, diphenylselenide, P-toluidine, P-xylene, N,N-dimethyl- P-toluidine, l-luene, aniline, diphenylmercury, hexamethylbenzene, malononitrile, tetracyanoethylene, thiophene, benzeneselenol, tetrafluoroethylene, ethylene, N-2I-
Rosodiphenylamine, acetylene, 1.2.4-)-
Lichlorobenzene and propane are produced using plasma polymerization method.
A film may be formed on the lead electrode.

The thickness of the film mentioned above is the film thickness after drying, and is usually 0°01μ.
m-10 μm, preferably 0.1 μm-5 pm, optimally 0.1 μm to 3 μm.

However, if a high-density multi-orifice type recording head is to be manufactured, it is desirable to use an organic material that is extremely easy to process using fine photolithography, in addition to the above-mentioned organic material. Specifically, such organic materials include, for example, polyimidoisointroquinasolinedione (trade name: PIQ, manufactured by Hitachi Chemical), polyimide resin (trade name: PYRALIN, manufactured by DuPont), and cyclized polybutadiene (trade name: :JSR-CBR
, CBR-M 901. Preferable examples include Nippon Synthetic Rubber Co., Ltd.), Photoneese (trade name: Square Co., Ltd.), and other photosensitive polyimide resins.

In the present invention, in order to prevent the electrode protective layer formed using the above-mentioned materials from being deformed and peeled off, cracking, etc. due to thermal strain, the method disclosed in Japanese Patent Publication No. 63-26708 and Japanese Patent Application Laid-Open No. 60-116454 is used. It goes without saying that the protective layer is not provided in the heat-generating part as described in 2007, and since it is not sufficient on its own, it is necessary to provide a relief structure under the electrode protective layer to further alleviate thermal distortion. A slit-like opening or a notched chisel pattern is provided in the area where there is no electrode pattern.

FIG. 14 shows a conventional example of a heating element substrate having an electrode protection layer. In the figure, the hatched portion is the electrode protective layer formed using the above material. In this example, since the common electrode part does not come into contact with ink, no electrode protective layer is provided. In contrast, in the present invention, as shown in FIGS. 15 and 16, a chisel-shaped open or notched chisel pattern is provided to alleviate thermal distortion. Note that this pattern completely omits up to ]2.

Therefore, these patterns are provided at positions away from the lower electrode patterns. FIGS. 17 and 18 show patterns formed for the same purpose, but the pattern does not go all the way to the bottom. This can be seen from Figure (b), which is a sectional view taken along line E-E in (a).

This case is also effective in alleviating thermal strain. In addition, in the case of this half-cutting pattern, it is not necessarily necessary to form it while avoiding the lower electrode pattern (hereinafter, corresponds to δI\requirement 3).

Next, the electrodes as shown in FIG. 19 are made into a product-no structure, and M! A recording head having a heating element substrate having an A-edge layer will be described. The details of a recording head having such a structure have already been filed by the present applicant (Japanese Patent Application No. 1983).
No. 2-274910, Japanese Patent Application No. 1987-87963). It should be noted that the materials for each jv shown in FIG. 19 are just examples, and it goes without saying that the materials listed in the other embodiments described above can be applied to these. In the present invention, a slit-like opening or a notch-like pattern is provided in the insulating layer shown in FIG. 19 as a relief structure for alleviating thermal strain without impairing the insulation between upper and lower electrodes or between adjacent electrodes. It is. FIGS. 20 and 21 show examples of slit-like openings and notch-like patterns provided in the insulating layer, respectively. In addition, in the present invention, as in the other embodiments described above, each pattern is cut out to the bottom as shown in FIG. 22(a).

As shown in FIG. 23 and FIG. 23, which is a sectional view taken along line FF' in FIG.

In addition, in all of the above-mentioned inventions, although the figures for explaining the embodiments have been explained using a chisel-like opening and a notch-like pattern, the pattern shape is not limited to these, and other shapes can be used. As shown in FIG. 24, it can take various shapes, and may be appropriately selected depending on the shape of the flow path, various patterns (heating elements, electrodes, etc.), or their positional relationships.

Although the embodiments of the present invention have been explained separately for a heat storage layer, a heating element protective layer, an electrode protective layer, and an insulating layer, combining some or all of these inventions can be even more effective. It is true.

Table 1 shows the results of durability tests in which the present invention was actually applied and in which the present invention was not used as in the past.

The common conditions for the test results shown here are as follows.

・Orifice J″ method opening 21μm ・Continuous excitation frequency fo=4.2KHz ・Aqueous ink (pH=9.8) ・Substrate charge Si ・Heat storage layer monthly charge 5in2 (thermal oxide film) ・Heating element material HfB2 ・Heating element retention %) C': Si○2 (sputtering film), electrode material 80, electrode protective layer Boliimi I, channel material DuPont dry film Resis 1
~・Thermal strain relaxation pattern shape Surin 1~ As is clear from the above, the product to which the present invention is applied has a remarkable effect in terms of the number of discharges, that is, the continuous durability, compared to the product to which the present invention is not applied. . In addition, when the sample was examined after the experiment without applying the present invention, cracks were found in each layer.

As is clear from the explanation of effects □--Effects--H, according to the present invention, notches are made in the protective layer pattern of the heating element substrate, which could not be achieved with the conventional method of folding back the electrodes one by one. It is particularly suitable for high-density arrays (16 lines/mm or more), which previously did not exist, and improves the durability of the recording head by alleviating thermal distortion.

[Brief explanation of the drawing]

1(,) to (f) are diagrams for explaining the manufacturing process of the heat storage layer of the heat generating substrate in the liquid jet recording head according to the present invention, and FIG. 2 is a diagram showing the ejection of bubble jet ink of the recording head and A diagram to explain the principle of bubble generation and disappearance,
FIG. 3 is a perspective view of the recording head, FIG. 4 is an exploded configuration diagram of the recording head, where (a) shows the lid substrate, (b) shows the heating element substrate, and FIG. 5 shows the recording head. A back view of the lid substrate, FIG. 6 is a diagram for explaining the conventional manufacturing method of the heat generating body substrate, FIG. 7 is a cross-sectional view of the heat generating part, and FIG. 8 shows the step pattern of the heat storage layer. Figures 9 and 9 are diagrams showing the structure of the step pattern of Figure 8 by another manufacturing method, and Figure 10 is
FIG. 11 is a diagram for explaining the conventional heating element protection layer, and FIG.
Figure 2 is a diagram showing another protective layer pattern, and Figure 13 is a diagram showing another pattern in which the protective layer is not completely removed.
a) is the overall view, (b) is the DD sectional view of (a), 1st-
Fig. 4 shows a conventional heating element substrate having an electrode protection layer, Fig. 15 shows a heating element substrate with a slit-like opening according to the present invention, and Fig. 15 shows a heating element substrate with a cutout open pattern. Figure 17 is a diagram showing a heating element board with a slit-shaped half-cut pattern, (a) is an overall configuration diagram, (b)
is a cross-sectional view taken along line E-E in (a), Figure 18 is a diagram showing a heating element substrate with a notch-shaped half-cut pattern, and Figures 1-9 are diagrams in which the electrodes have a laminated structure with an insulating layer between them. A diagram showing a heating element board,
Fig. 20 shows an example in which the insulating layer is provided with a pattern in which slit-like openings extend all the way to the bottom, and Fig. 21 shows an example in which the insulating layer is provided with a pattern in which notch-like openings extend all the way to the bottom. The figure which shows another Example. FIG. 22 is a diagram showing another embodiment in which a pattern in which the slit-shaped opening does not go all the way to the bottom is provided, in which (a) is an overall view, and (b) is a cross-sectional view taken along line FF in (a). , FIG. 23 is a diagram showing another embodiment in which a pattern in which the notch shape does not go all the way to the bottom is provided, and FIG. 24 is a diagram showing examples of various pattern shapes. 10... Heat storage layer, 11... Electrode protective layer, 12...
insulation layer. 13... First heating element protective layer, 14. Second heating element protective layer, 21... Lid substrate, 22... Heat generating element substrate, 23.
...Recording liquid inlet, 24. Orifice, 25.. Channel. 27... Selection (independent) electrode, 28... Common electrode, 29
... Heating element (resistance WJ), 30... Ink. Patent applicant Ricoh Co., Ltd.

Claims (1)

[Scope of Claims] 1. A flow path that accommodates the recording liquid introduced and is provided with a thermal energy acting section that generates bubbles in the recording liquid using heat and generates an acting force as the volume of the bubbles increases. an orifice that communicates with the flow path and causes the recording liquid to be ejected as droplets by the acting force; and a liquid chamber that communicates with the flow path and introduces the recording liquid into the flow path. In a liquid jet recording head comprising an introduction means for introducing the recording liquid into the liquid chamber, a plurality of thermal energy acting parts are provided on one substrate, and the substrate has a plurality of thermal energy acting parts. 1. A liquid jet recording head comprising a heat storage layer formed in a region extending over the entire area, the heat storage layer having a relief structure for relieving distortion caused by heat. 2. A flow channel that accommodates the recording liquid to be introduced and is provided with a thermal energy acting section that generates bubbles in the recording liquid using heat and generates an acting force as the volume of the bubbles increases; an orifice that communicates with the flow path to eject the recording liquid as a droplet by the acting force; a liquid chamber that communicates with the flow path and introduces the recording liquid into the flow path; A liquid jet recording head comprising an introduction means for introducing liquid, which has a plurality of thermal energy acting parts on one substrate, and the substrate is formed in an area spanning the plurality of thermal energy acting parts. 1. A liquid jet recording head comprising a heat generating element protective layer, the heat generating element protective layer having a relief structure for alleviating distortion due to heat. 3. A flow path that accommodates the recording liquid to be introduced and is provided with a thermal energy acting section that generates bubbles in the recording liquid using heat and generates an acting force as the volume of the bubbles increases; an orifice that communicates with the flow path to eject the recording liquid as a droplet by the acting force; a liquid chamber that communicates with the flow path and introduces the recording liquid into the flow path; In a liquid jet recording head comprising an introduction means for introducing liquid, a plurality of thermal energy acting parts and a plurality of electrodes corresponding to and connected to the plurality of thermal energy acting parts are arranged on one substrate. A liquid jetting method characterized in that the substrate has an electrode protective layer formed in a region covering a plurality of the electrodes, and the electrode protective layer has a relief structure for mitigating distortion due to heat. recording head. 4. A flow path that accommodates the recording liquid to be introduced and is provided with a thermal energy acting section that generates bubbles in the recording liquid using heat and generates an acting force as the volume of the bubbles increases; an orifice that communicates with the flow path to eject the recording liquid as a droplet by the acting force; a liquid chamber that communicates with the flow path and introduces the recording liquid into the flow path; In a liquid jet recording head comprising an introduction means for introducing liquid, a plurality of thermal energy acting parts and a plurality of electrodes corresponding to and connected to the plurality of thermal energy acting parts are arranged on one substrate. The substrate has an insulating layer formed in a region covering a plurality of the thermal energy acting parts and/or the electrodes, and the insulating layer has a relief structure for mitigating distortion due to heat. A liquid jet recording head characterized by: