JPS60157869A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To provide the titled recording head having excellent durability in frequent repeated use or long-time continuous use, wherein an intermediate layer is provided between a heat-generating part and at least a part of a pair of electrodes. CONSTITUTION:A base board 202 for liquid jet recording provided with an electro-thermal converter 201 and a grooved plate 203 are provided as an essential part. The base board 202 comprises a support 206, a lower layer 207, a heating resistor layer 208 and an intermediate layer 211 covering a common electrode 209, a selecting electrode 210 and the electro-thermal converter 201. The surface (heating surface 215) of the first protective layer 213 makes contact with a liquid filling a liquid passage 204. The stability in jetting the liquid is more excellent than that in the construction wherein an upper layer comprising the second protective layer 216 is provided also on the upper side of the common electrode 209.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid jet recording head that performs recording by jetting liquid and forming flying droplets.

The inkjet recording method (liquid jet recording method) is capable of high-speed recording, in that the noise generated during recording is extremely small and can be ignored, and can be recorded without the need for special processing such as fixing on so-called plain paper. Recently, there has been a lot of interest in how it can be carried out.

Among them, for example, the liquid jet recording method described in Japanese Patent Application Laid-Open No. 54-51837 and German Opening Publication (DOLS) No. 2843064 applies thermal energy to a liquid to obtain the motive force for ejecting droplets. In this respect, it has different characteristics from other liquid jet recording methods.

That is, in the recording method disclosed in the above-mentioned publication, the liquid subjected to the action of thermal energy undergoes a state change accompanied by a sharp increase in volume, and the acting force based on this state change causes the orifice at the tip of the recording head to The liquid is ejected to form flying droplets, and the droplets adhere to the recording member to perform recording.

In particular, the liquid jet recording method disclosed in DOLS 2843064 is a so-called drop-and-man
Not only is it extremely effective32 applied to the d recording method, but
Since the recording head section can be easily implemented as a full 1ine type recording head with high density multi-orifices, it has the feature that high resolution and high quality images can be obtained at high speed.

The recording head section of the apparatus applied to the above recording method is a part that communicates with an orifice provided for ejecting liquid and where thermal energy acts on the liquid in order to eject droplets. The apparatus includes a liquid discharge part having a liquid flow path in which a heat acting part is a part of the structure, and an electrothermal converter as a means for generating thermal energy.

This electrothermal converter includes a pair of electrodes, and a heat generating resistance layer connected to these electrodes and having a heat generating region (heat generating portion) between these electrodes.

Typical examples of the structure of such a liquid jet recording head are shown in FIGS. 1(a) and 1(b).

FIG. 1(a) is a partial front view of the liquid jet recording head seen from the orifice side, and FIG.
FIG. 1 is a partial cross-sectional view taken along a portion indicated by a dashed line XY.

The recording head 100 includes a grooved plate 103 in which a predetermined number of grooves of a predetermined width and depth are provided at a predetermined linear density on the surface of a substrate 102 on which an electrothermal transducer 101 is provided.
By joining so as to cover the orifice 104
It has a structure in which a liquid discharge part 105 is formed. In the case of the recording head shown in the figure, C2 is shown as having a plurality of orifices 104, but of course the present invention is not limited to this type of recording head, and a recording head with a single orifice may also be used. This is within the scope of the present invention.

The liquid discharge part 105 has an orifice 104 at its terminal end for discharging the liquid, and thermal energy generated by the electrothermal converter 101 acts on the liquid to generate bubbles, which rapidly expands depending on the volume expansion and yield. It has a heat acting part 106 which is a tube place that causes a change in state.

The heat acting part 106 is the heat generating part 10 of the electrothermal converter 101.
The bottom surface thereof is a heat acting surface 10B which is located at the upper part of the heat generating section 7 and comes into contact with the liquid of the heat generating section 107.

The heat generating section 107 is a lower layer 1 provided on the substrate 102.
09. Heat generating resistance layer 110 provided on the lower layer 109
, and an upper layer 111 provided on the heating resistance layer 110. The heating resistor layer 110 is provided with electrodes 112 and 113 on its surface for supplying electricity to the layer 110 in order to generate heat. The electrode 112 is a common electrode for the heat generating section of each liquid discharging section, and the electrode 113 is a selection electrode for selectively generating heat in the heat generating section of each liquid discharging section. It is provided along the flow path.

In the heat generation section 107, the upper layer 111 fills the heat generation resistance layer 110 and the liquid flow path of the liquid discharge section 105 in order to chemically and physically protect the heat generation resistance layer 110 from the liquid used. The heating resistor layer 110 has a protective function of isolating the electrodes 112 and 113 from the liquid and preventing a short circuit between the electrodes 112 and 113 through the liquid.

The upper layer 111 also has the role of preventing electrical leakage between adjacent electrodes. In particular, it is necessary to prevent electrical leakage between each selected electrode, or to prevent electrical leakage of the electrodes caused by contact between the electrode and the liquid under each liquid flow path for some reason and applying current to the electrode. Preventing corrosion is important, and for this purpose, the upper layer has the function of a protective layer. 1J111 is provided at least on the electrode located below the liquid flow path.

Furthermore, the liquid flow path provided in each liquid discharge section has a common liquid chamber (
However, due to design considerations, the electrodes connected to the electrothermal converters provided in each liquid discharge section are connected to the common liquid chamber on the upstream side of the heat acting section. It is generally installed so that it passes underneath. Therefore, the above-mentioned upper layer is generally provided in this portion as well to prevent the electrode from coming into contact with the liquid.

By the way, the above-mentioned upper layer 111 has different characteristics required depending on the location where it is provided. That is, for example, the heat generating portion 107 has excellent (1) heat resistance, (2) liquid resistance, (3) liquid permeation prevention property, (2) thermal conductivity, (2) oxidation prevention property, (2) insulation property, and (3) rupture resistance. In areas other than the heat-generating portion 107, it is required to have sufficiently excellent liquid penetration prevention properties, liquid resistance, and abrasion superiority, although they can be alleviated by thermal conditions.

However, there is currently no material constituting the upper layer that fully satisfies all of the above characteristics (■~■) as desired.
Currently, some of the characteristics of (2) are relaxed. That is, for the heat generating section 107, priority is given to ■, ■, and ■ when selecting the material;
For example, in the electrode part other than 1, ■, ■, and ■1:
Priorities are made to select materials, and upper layers are formed with each suitable material on each relevant area surface.

On the other hand, in the case of a multi-orifice type liquid jet recording head, in order to simultaneously form a large number of fine electrothermal transducers on the substrate, in the manufacturing process,
Formation of each layer and removal of a portion of the formed layer are repeated on the substrate, and at the stage where the upper layer is formed, the surface on which the upper layer is formed forms a slab wedge portion (stepped portion).
Because it has a certain fine unevenness, the upper layer has good coverage at this step (5tep coverage).
has become important. In other words, if the coverage of this stepped portion is poor, liquid will penetrate into that portion, causing electrolytic corrosion or electrical breakdown. In addition, if the upper layer to be formed is less likely to have defects due to its manufacturing method, liquid may penetrate through the defects.
This is a factor that significantly reduces the lifespan of electrothermal converters.

For these reasons, the upper layer must have good coverage at the stepped portion, and the probability that defects such as pinholes will occur in the formed layer is low, and even if they occur, they can be ignored in practical terms. Or more (less than 1 is required).

However, in the past, no liquid jet recording head has been proposed that satisfies all of these requirements and has excellent overall usage durability.

The present invention has been developed in view of the above points, and has excellent overall durability in frequent repeated use and long-term continuous use, and maintains good initial droplet formation characteristics over a long period of time. The main object of the present invention is to provide a liquid jet recording head that can be maintained stably.

Another object of the present invention is to provide a liquid jet recording head that is highly reliable in manufacturing and processing.

Furthermore, it is also an object to provide a liquid jet recording device with high manufacturing yield even when multi-orifice is used.

The liquid jet recording head of the present invention includes an orifice provided for ejecting liquid to form flying droplets, and communicating with the orifice, so that thermal energy for forming the droplets acts on the liquid. At least one pair of opposing electrodes are provided electrically connected to the liquid discharge part having a liquid flow path having a heat acting part as a part thereof, and the heat generating resistor layer provided on the substrate. In a liquid jet recording head comprising an electrothermal transducer having a heat generating section formed between these electrodes, an intermediate layer is provided on the heat generating section and at least a part of the electrode. It is characterized by having.

Hereinafter, the liquid jet recording head of the present invention will be specifically explained with reference to the drawings.

FIG. 2 (all= is a partial front view seen from the orifice side for explaining the main part of the structure of a preferred embodiment of the liquid jet recording head of the present invention. 2
Figure (a) shows a partial cross-sectional view when cut at the part indicated by the dashed line AN, and Figure 2 (a) corresponds to Figure 1 (a) (2) explained earlier. , Figure 2(b) is the first
This is similar to Figure (b).

The liquid jet recording head 200 shown in the figure includes a substrate 202 for liquid jet recording (abbreviated as BJ) that utilizes heat for liquid ejection, on which a desired number of electrothermal transducers 201 are provided, and The main part thereof is constituted by a grooved plate 203 that distributes grooves provided corresponding to the heat exchanger 201 as desired.

The BJ board 202 and the grooved plate 203 are joined at predetermined locations with an adhesive or the like, so that the electrothermal converter 2 of the BJ board 202
A liquid flow path 204 is formed by the portion where 01 is provided and the groove portion of the grooved plate 203, and the liquid flow path 20
4 has a heat acting part 205 as a part of its structure. 2. The BJ substrate 202 includes a support 206 made of silicon, glass, ceramics, etc., and a support 206 made of Sin, etc. on the support ZOe. lower layer 207 and heating resistance layer 2
08, and liquid flow channels 20 on both sides of the upper surface of the heating resistance layer 208.
4 along the common electrode 2J09 and the selection electrode 210, the common electrode 209, the selection electrode 210 and the electrothermal converter 20
1, and an intermediate layer 211 covering the top layer 1.

The electrothermal converter 201 has a heat generating section 21 as its main part.
4, the heat generating section 214 has a lower layer 207, a heat generating resistance layer 208,
The intermediate layer 211 and the first protective layer 218 are laminated, and the surface of the first protective layer 2.18 (thermal action surface 2
15) is in direct contact with the liquid filling the liquid flow path 204.

On the other hand, a selection electrode 21 partially covered with an intermediate layer 211
0 is provided with an upper layer in which a first protective layer 218 and a second protective layer 216 are laminated in order from the electrode side. It may also be provided at the bottom portion of the common liquid chamber provided upstream.

In the case of the liquid jet recording head 200 shown in FIG. 2, the upper layer of the common magnetic pole 209 has a structure in which an upper layer without the second protection layer 216 is provided. However, the present invention is not limited to this, and an upper layer having a second protective layer similar to the upper layer of the selection electrode 210 may be provided.However, in the case of the liquid jet recording head having the structure shown in FIG. As shown in a partial plan view of the BJ board in FIG. 2(C), on the orifice side of the heat acting surface 215 of the liquid flow path in each liquid discharge part, the second protective layer 21
6 is not provided. Therefore, as shown in the cross section 1 of FIG. 2(b), the surface position of the upper layer 213 on the common electrode 209 and the heat action surface are located before and after the heat action surface 215 in the liquid flow path direction. Since the difference in level between the surface position and the common electrode 215 is only the difference caused by providing the common electrode 209 and the intermediate layer 211 that covers the electrode, an upper layer having a second protective layer is also provided on the common electrode 209. Compared to the case,
The stability of liquid discharge is excellent at °C.

That is, in the case of the liquid jet recording head 200 shown in FIG. 2, from the heat acting surface 215 to the orifice side,
Since the bottom surface of the liquid flow path has few irregularities and is relatively smooth, the liquid flows smoothly and the droplets are formed stably. However, the step difference Δd formed between the surface position of the upper layer on the common electrode 209 and the surface position of the heat action surface 215 is substantially smaller than the distance d between the upper surface of the liquid flow path 204 and the heat action surface 215. If it is negligibly small, it will not significantly affect the stability of droplet formation. Therefore, within this range, there is no problem in providing an upper layer having the second protective layer on the common electrode 209 as well.

Further, in the case of the liquid jet recording head 200 shown in FIG. 2, the first protective layer 213 has a two-layer structure in order to further increase the mechanical strength of the protective layer. The lower layer of the first protective layer 213 is made of, for example, Sin.

The lower layer of the first protective layer 213 is sticky and has relatively excellent mechanical strength. For example, when the lower layer of the first protective layer is formed of 5i01, it is made of a metal material such as Ta, which has adhesiveness and adhesion to the lower layer and the second protective layer 216. In this way, by disposing a layer made of an inorganic material such as a metal that is relatively sticky and has mechanical strength on the upper layer of the first protective layer, it is possible to prevent the liquid from being discharged, especially on the heat acting surface 215. The shock from the cavitation action that occurs during this process can be sufficiently absorbed, and the life of the electrothermal converter 201 can be significantly extended.

However, in the liquid jet recording head shown in FIG. 2, the layer formed as the upper layer of the first protective layer does not have the above-mentioned effect even if it is provided as the third protective layer on the outermost layer of the upper layer. There is.

As the material constituting the lower layer of the first protective layer 213, an inorganic insulating material with relatively excellent thermal conductivity and heat resistance is suitable. For example, inorganic oxides such as 5iO1, transition metal oxides such as titanium oxide, vanadium oxide, niobium oxide, molybdenum oxide, tantalum oxide, tungsten oxide, chromium oxide, zirconium oxide, hafnylum oxide, lanthanum oxide, yttrium oxide, manganese oxide, etc. metal oxides such as aluminum oxide, calcium oxide, strontium oxide, barium oxide, silicon oxide, and their composites, high-resistance nitrides such as silicon nitride, aluminum nitride, boron nitride, tantalum nitride, and these oxides, Even if semiconductor bulk materials such as nitride composites, amorphous silicon, and amorphous selenium have low resistance, their resistance increases during manufacturing processes such as sputtering, CVD, vapor deposition, gas phase reaction, and liquid coating. The thin film materials obtained can be mentioned.

In addition to the above-mentioned Ta, materials that can form the upper layer of the first protective layer and the third protective layer include s*, y
Elements of group 1a of the periodic table such as, elements of group ffa such as Ti, Zr, Hf, elements of group Va such as v, Nb,
Group VIa elements such as Cr, Mo, W, Fe*Co,
N1yzWhich Group 1 elements: Ti-Ni, Ta
-W, Ta-Mo-Ni, Ni-Cr,
Fe-Co, Ti-W, Fe-7%, Fe
-Ni, Fe-Cr, Fe-Ni-Cr7 and any of the above metal alloys; TI-B, Ta-B pH
f-B, W-871-borides of any of the above metals; Ti-
C, Zr-C.

Carbides of the above metals such as VC, Ta-C, Mo-C, N1-C71; Mo-8i, W-8i, Ta-
9t 'fZ Silicides of any of the above metals: Ti -N
Examples include nitrides of the above metals such as mNb-N and Ta-N. The upper layer of the first protective layer and the third protective layer are
Using these materials, vapor deposition method, sputtering method, CV
It can be formed by a method such as the D method. The upper layer of the first protective layer and the third protective layer may be the above-mentioned layers alone, but of course some of them can also be combined. In addition, the third protective layer is not just the above-mentioned one alone,
It is also possible to use it in combination with the material of the protective layer of Ml, like the first protective layer shown in FIG.

The second protective layer 216 is made of an organic insulating material that has excellent liquid penetration prevention and liquid resistance properties, and has the following characteristics: ■ good film formability, ■ dense structure with few pinholes, and ■ use. It is desirable that the material has physical properties such as not swelling or dissolving in ink, (1) having good insulation properties when formed into a film, and (2) having high heat resistance. Such organic materials include the following resins, such as silicone resins, fluororesins,
Aromatic polyamide, additive type polyimide, polybenzimidazono ν, metal chelate polymer, titanate ester, epoxy resin, phthalate resin, thermosetting phenol resin, P-vinylphenol resin, Zylock resin,
Examples include triazine resin, BT resin (triazine resin and bismaleimide addition polymer resin), and the like. Also, in addition to this,
The second protection #218 can also be formed by vapor deposition of polyxylylene resin and its derivatives.

Furthermore, various organic compound monomers such as thiourea,
Thioacetamide, vinylferrocene 1.3.5-)
Lichlorobenzene, chlorobenzene styrene, ferrocene, viroline, naphthalene, pentamethylbenzene, nitrotoluene, ac-90 nitrile, diphenylselenide, p-toluidine, ゛P-xylene, N,N-dimethyl-P-toluidine, toluene, aniline, diphenyl Marquis, :L Li-1 to +4)/Tylbenzene, Malononitrile, Tetracyanoethylene, Thiophene, Benzeneselenol, Tetrafluoroethylene, Ethylene, N
-Nitrosodiphenylamine, acetylene, 1°2.4
-) The second protective layer 21B can also be formed by forming a film by a plasma polymerization method using dichlorobenzene, propane, or the like.

However, if a high-density multi-orifice type recording head is to be manufactured, an organic material that is extremely easy to process using fine photolithography is used as the material for forming the second protective layer 21B, in addition to the above-mentioned organic materials. is desirable.

Specifically, such an organic material includes, for example, polyimide isoindoquinazolinedione (trade name: P
IQ, manufactured by Hitachi Chemical), Boliimide resin (product name: P
Preferred examples include YRALIN, DuPont M), cyclized polybutadiene (product name: JSR-CBR, CBR-M2O3, manufactured by Japan Synthetic Rubber Co., Ltd.), Photonice (product name Square M), and other photosensitive polyimide resins. .

The lower layer 207 is provided as a layer that mainly controls the flow of heat generated from the heat generating section 214 toward the support body 206, and when applying thermal energy to the liquid in the heat acting section 205, , so that more heat generated from the heat generating section 214 flows to the heat acting section 205 side, and when the electricity to the electrothermal converter 201 is turned off, the heat generating section 214
The constituent materials are selected and the layer thickness is designed so that the heat remaining in the support 14 quickly flows to the support 206 side. Materials constituting the lower layer 207 include, in addition to the above-mentioned SiO2, inorganic materials typified by metal oxides such as zirconium oxide, tantalum oxide, and magnesium oxide.

The material constituting the heat generating resistor layer 208 can be almost any material as long as it generates the desired amount of heat when energized.

Specific examples of such materials include tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor,
Alternatively, metals such as hafnium, lanthanum, i) ruconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, vanadium, alloys thereof, and borides thereof, and the like are preferred.

Among these materials constituting the heating resistance layer 208, metal borides are particularly excellent, and among them, hafnium boride has the most excellent properties.
This is followed by zirconium boride, lanthanum boride, tantalum boride, vanadium boride, and niobium boride.

The heat generating resistor layer 208 can be formed using the above-mentioned materials using techniques such as electron beam evaporation and sputtering.

The material constituting the electrodes 209 and 210 is selected from among many electrode materials, taking into consideration cost and electrical conductivity. Specifically, metals such as AI and Cu are used, and these are used to provide a predetermined size, shape, and thickness at a predetermined position by a method such as vapor deposition.

The materials constituting the intermediate layer 211 include: (1) Even if there is a defect in the upper layer, it can prevent the electrode from coming into contact with the liquid in the liquid flow path.

■ It is stable to the liquid.

■ Improving the adhesion between the first protective layer and the electrode.

■ Stable for frequent repeated use and long-term continuous use.

Materials with excellent environmental resistance that meet the following conditions are suitable. Therefore, materials that easily form a stable and dense passive film on one surface, such as Ti, Hf, Zr, La*Nb, and W.

Examples include metals such as Mo and Si, and mixtures thereof with carbides, nitrides, and oxides; examples of materials stable in the liquid include metals such as Au, Pt, Pd, and mixtures thereof. . Using these materials, it is formed into a predetermined size and shape at a predetermined location using methods such as vapor deposition, sputtering, CVD, and plating.

Provided in thickness.

If the thickness of the intermediate layer 211 is too thick than necessary, the coverage with the first protective layer will be poor, and if it is too thin, the effect of providing the intermediate layer will be reduced. Therefore, the thickness of the electrode is 21-4
Double thickness is suitable.

In addition, the electrical resistance value of the intermediate layer is greater than the electrical resistance value of the heat generating resistive layer between the electrodes, so that the forming material and forming conditions are different from those of the heat generating resistive layer. Set.

The materials constituting the grooved plate 208 and the components of the common liquid chamber provided upstream of the heat acting section 205 are materials whose shape is not affected by thermal effects during the manufacturing or use environment of the recording head. They do not undergo any susceptibility, or hardly any susceptibility, and can be easily applied with micro-precision machining, and can easily achieve the desired surface precision. Most materials are effective as long as they can be processed to allow liquid to flow smoothly.

Typical examples of such materials include ceramics, glass, metal, plastic, and silicone. In particular, glass and silicone are suitable materials because they are easy to process and have appropriate heat resistance, thermal expansion coefficient, and thermal conductivity.

The outer surface around the orifice 217 is treated with an oil-repellent treatment if the liquid is aqueous, or an oil-repellent treatment if the liquid is non-aqueous, to prevent the liquid from leaking and getting around to the outside of the orifice 217. It's better to do so.

The orifice 217 may be formed by attaching a photosensitive resin to the substrate 202, forming a pattern using photolithography, and then attaching a top plate.

FIG. 8 shows another embodiment of the invention. Figure 8 shows the second
This corresponds to figure (b). Its characteristics are as described above.

The liquid jet recording head of the present invention will be specifically explained below with reference to Examples.

EXAMPLE The liquid jet recording head shown in FIG. 2 was manufactured as follows.

A 5 μm thick Si film was formed by thermal oxidation on the SI sea urchin and used as a substrate. Heat generating resistor @z08 Toshite HfB on the board by sputtering! A 150 OA thick mini-layer is formed, followed by a Ti layer of 50 Å and an AI layer by electron beam evaporation. layer 5000A
were successively deposited to form electrodes 209 and 210.

As a result of forming a pattern as shown in FIG. 2(C) by a photolithography process, the size of the heat-active surface is 80 mm wide and 15 mm wide.
At a length of 0 μm, the resistance was 80 ohms including the resistance of the M electrode.

Next, amorphous silicon was deposited at 200O by plasma CVD.
After being deposited to a thickness of A over the entire surface of the substrate, an intermediate layer 1!211 was formed in a pattern shown in FIG.

Next, as the lower layer of the first protective layer 218, 2.5 in.
It was deposited to a thickness of .mu.m over the entire surface of the substrate by magnetron type high rate sputtering, and then Ta was deposited to a thickness of 0.6 .mu.m over the entire surface of the substrate by the same sputtering method as the upper layer of the first protective layer 21B.

Next, PIQ is formed as a second protective layer 216 to a thickness of zOμm on the shaded area in FIG. 2(c) according to the following steps,
I created a BJ board.

That is, after washing and drying the support on which the first protective layer was formed, the PIQ solution was coated on the first protective layer using a spinner (the spinner rotation conditions in the coating conditions were 500 rpm in the first step).

10 sec, 2nd step 4000 rpm, 40 sec
c). Next, one leaf was left at 8ff'C, and after the solvent was dried, it was baked at 22σC for 60 minutes. A photoresist OMR-88 (Tokyo Ohka Bag) was applied thereon using a spinner, and after drying, it was exposed using a mask aligner and developed to obtain a desired PIQ layer pattern. Next, P.I.
The PIQ layer was etched at room temperature using a Q etchant. After washing with water and drying, the stripping solution for OMR was removed.After the resist was removed, it was baked at 850°C for 60 minutes to complete the process of forming the PIQ layer pattern. ) As shown in Ic, the size is 50 #l x 250 μm.

Next, a grooved glass plate was adhered to the BJ substrate in a predetermined manner. That is, as shown in FIG. 2(b), BJ
A grooved glass plate (groove width: 50 .mu.m x depth: 50 mm x length'l, w) for forming an ink introduction channel and a heat acting section is adhered to the substrate.

The liquid jet recording head produced as described above and the liquid jet recording head similar to the liquid jet recording head shown in Fig. 2 except that no intermediate layer was provided was heated to cause the wiring to deteriorate. After 10 days in an accelerated state, 1
The wiring residual rate after 00 days was measured. For comparison, a conventional liquid jet recording head having the configuration shown in FIG. 1 was also tested at the same time.

The results are shown in FIG. In the figure, A is this embodiment,
B shows a configuration example in which the intermediate layer is removed from this example, and C shows the results of a conventional example. The vertical axis shows the wiring survival rate (ch), and the horizontal axis shows the immersion time in days. The wiring remaining rate at the start is Loom.

As is clear from the figure, the liquid jet recording head of the present invention (
A and B) exhibit superior wiring survival rates and excellent durability compared to the conventional liquid jet recording head (C).

Furthermore, in order to test the failure rate of liquid jet recording heads A, B, and C, we applied 30 V of 10μs to the core air heat converter of each head.
A rectangular voltage of 8 KHz was applied.

The results are shown in FIG. In the figure, the vertical axis shows the failure rate (@), and the horizontal axis shows the number of drive pulses.

The increase in the failure rate of the conventional liquid jet recording head (C) observed near the lXl0' pulse is due to the via holes and coverage problems in the protective layer. ), this failure has almost been overcome, and the failure rate remains unchanged up to 1X108 pulses, resulting in excellent durability.

Further, the liquid jet recording head of the present invention was able to stably maintain the initial good droplet formation characteristics over a long period of time. Furthermore, the reliability in manufacturing and processing was high (and the manufacturing yield was also high when multi-orifices were used).

[Brief explanation of drawings]

1(a) and 1(b) are for explaining the configuration of a conventional liquid jet recording head, respectively. FIG. 1(a) is a schematic front partial view, and FIG. 1(b) is a partial front view. Partial cross-sectional view taken along dashed-dotted line XY in Fig. 1 (a), Fig. 2 (a), (b)
, (cl are for explaining the structure of the liquid jet recording head of the present invention, FIG. 2(a) is a schematic front partial view, and FIG. 2(b) is shown in FIG. 2(a). Dot-dashed line AA
Figure 2 (C) is a plan view of the board, Figure 8 is a partial cross-sectional view at
The figure shows the test results for the wiring survival rate, and FIG. 4 is a graph showing the test results for the failure rate. 100.200...Liquid jet recording head 101
．． 201... Electrothermal converter 102.202...
...Plates 108, 208... Grooved plates 104, 217... Orifice 105...
...Liquid discharge part 106.205...Heat action part 107.214...Heat generation part 108.215...Heat action surface 109.207...・Lower layer 110, 208...Heating resistance layer 111...
...Top layer 112.209... (Common) electrode 118.21
0... (selection)'Magnetic pole 204...Liquid flow path 206...Support 211...Intermediate layer 218...Pa...first Protective layer 216... Second protective layer section 1 Figure (a) Figure 1 (b) Figure 2 (b) Figure 2 (C)

Claims (1)

[Claims] It comprises an orifice provided for ejecting liquid to form flying droplets, and a heat acting part that communicates with the orifice and is a part where thermal energy acts on the liquid to form the droplets. A liquid discharge part having a liquid flow path as a part thereof is electrically connected to a heating resistance layer provided on the substrate,
In a liquid jet recording head comprising at least a pair of opposing electrodes, and an electrothermal converter having a heat generating section formed between these electrodes, the heat generating section and at least one of the electrodes are provided with a heat generating section. A liquid jet recording head characterized in that an intermediate layer is provided on top of the liquid jet recording head.