JPS60208249A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To enable the densification of a heat generation part and to reduce possibility for generating shortcircuit between electrodes by arranging a common electrode and a selection electrode to the upper and under surfaces of a substrate, by providing a heat generation part to a support having the substrate and a support member so as to arrange the same to the end surface of the substrate. CONSTITUTION:A selection electrode 308 is laminated to the upper surface of a substrate 303 possessed by a liquid jet recording head 301 and a common electrode 309 is furthr laminated to the under surface thereof and a heat generation part 301 comprising a heat generating resistance layer 313 connected to the terminal parts of said electrodes is arranged to the side surface of said substrate 301. The heat generating resistance layer 313 and the selection electrode 308 are respectively patterned at desired positions in such a shape and size that the heat generation part 302 is arranged between the common electrode 309 and the selection electrode 308. The substrate 303 having the above-mentioned constitution provided to the surfaces thereof is connected between a support member 306-1 and a support member 306-2 through the upper and under surfaces thereof to be integrated with both support members to constitute a support 317.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording head installed in a liquid jet recording device that jets a liquid as a recording liquid as flying droplets and performs recording using the droplets, and in particular, a recording head that utilizes thermal energy. The present invention relates to a recording head used in a liquid jet recording device that jets liquid.

The inkjet recording method (liquid jet recording method) has the advantage that the noise generated during recording is extremely small to the extent that it can be ignored, that it is capable of 0-speed recording, and that it requires a special process of fixing on so-called plain paper. Recently, various types have been actively researched due to their ability to perform recording without the need for recording.

Among them, there is a method in which thermal energy is applied to a static body to obtain the motive force for discharging liquid, that is, the liquid subjected to the action of thermal energy undergoes a sudden change in volume, causing a change in volume. Due to the acting force based on the state change, liquid is ejected from the orifice (liquid ejection hole) at the tip of the recording hent, forming flying droplets, and the droplets are made to land on a recording material such as paper. The recording method is the so-called drop-on
Not only can it be applied very effectively to de+5 and tlj ill, but it can also be used to
This method is attracting attention as a method that can obtain high-resolution, high-quality images at high speed because it can easily realize a high-density multi-orifice recording head.

The recording head section of the apparatus used in the recording method applying such a method communicates with an orifice provided for ejecting liquid, and thermal energy for ejecting the liquid acts on the liquid. The device includes a liquid discharge section that forms a liquid flow path that includes a heat acting section as a part, and an electrothermal converter as one stage that generates thermal energy.

This electrothermal converter includes a pair of electrodes and a heat generating resistance layer connected to these -7tt poles and having a heat generating region (heat generating portion) between these electrodes.

A typical example of the structure of such a liquid jet recording head is shown in FIGS. 1(a) and 1(b).

Figure 1 (&) is a partial front view of the liquid jet recording head seen from the orifice side, and Figure 11 (b) is Figure 1 (a).
FIG. 2 is a partial cross-sectional view taken along a line indicated by a dashed line X-Y.

The recording head 101 shown in these figures has a substrate 103 on which an electrothermal transducer 102 is provided.
It has a structure in which the liquid discharge part 106 is formed by joining so as to cover a grooved plate 104 in which a predetermined number of grooves of a predetermined depth and a predetermined linear density are provided. The liquid discharge part 106 has an orifice 10 for discharging liquid.
5, and a heat acting part 107 where the thermal energy generated by the electrothermal converter 102 acts on the liquid to generate bubbles, causing a rapid change in state due to expansion and contraction of the volume.

The heat acting part +07 is the heat generating part +0 of the electrothermal converter 102
The heat acting part 108, which is located on the upper part of the heat generating part +08 and comes into contact with the liquid of the heat generating part +08, is its lower face.

The heating resistance layer I11 includes a layer Il for generating heat.
Electrodes 113 and 114 for supplying current to l are provided on the surface thereof, and a heat generating portion 108 is formed by a heat generating resistive layer between these electrodes.

The electrode 113 is a common electrode for the heat generating section of each liquid discharging section, and the electrode 114 is a selection electrode for selecting the heat generating section of each liquid discharging section to generate heat. It is provided along the liquid flow path of the section.

In the heat generating section 108, the layer 112 is a heat generating resistor layer 112 for chemically and physically protecting the heat generating resistor layer I11 from the liquid used. It has a protective function of isolating the liquid filling the liquid flow path of the liquid discharge part 106 and preventing a short circuit between the electrodes 113 and 114 through the liquid, and also has a protective function of preventing a short circuit between the electrodes 113 and 114 through the liquid. It also has the role of preventing electrical leakage [1].

The liquid flow paths provided in each liquid discharge section are communicated with each other via a common liquid chamber (not shown) that constitutes a part of the liquid flow path. The electrode connected to the heating resistance layer I11 provided in each liquid discharge part! 13 and 114 are provided so as to pass under the common liquid chamber on the upstream side of the heat acting section while being protected by the protective layer due to their design considerations.

In such a liquid jet recording head, as shown in FIG. An electrode layer having a shape of -4 electrode (common electrode 11
3. The heat generating section 108 made of the heat generating resistor layer connected between the selection electrodes +14) was laminated and formed so as to be placed at a predetermined position on the substrate -F. Therefore, the common electrode +13 has a folded shape, and since the common electrode 113 and the selection electrode +14 are arranged alternately, the plurality of heat generating parts +08 are arranged so as to sandwich the common electrode.

When such electrode wiring is applied, since the electrodes 113 and 114 are arranged next to each other in an overcurrent manner, the protective layer 112 can effectively have the protective function as described above. Furthermore, short circuits between the electrodes 113 and 114 or electrical leakage to the liquid that is in contact with the protective layer 112 often occur. The protective layer 112 has a structure that is susceptible to the shock that occurs.
This causes a decrease in the long-term durability of the heat generating section 108, which causes problems such as a decrease in the functionality of the recording head and a shortened lifespan.

Furthermore, by providing a large number of electrodes +13.114,
In particular, there are many bonding points in the common electrode wiring.
Furthermore, since the density increases, there is a high possibility that a connection failure will occur at the bonding point, which causes a decrease in reliability.

On the other hand, when increasing the density of a plurality of orifices, generally the distance between the heat generating parts corresponding to each of these orifices is narrowed so that the desired orifice density is achieved11), that is, the distance between each electrode is reduced. The density of the orifice has been increased by narrowing the filtrate or by making the fil of each electrode thinner.

However, if the spacing between the electrodes is made too narrow, the i+1 possibility of short circuits or electrical leaks between the electrodes 113 and 114 as described above will increase, and if the width of each electrode is made thinner than necessary. There are limits to the structure of reducing the spacing between each electrode or reducing the rfJ of each electrode, that is, further increasing the density, as this may cause a decline in the function of the electrode. Ta.

The present invention has been developed in view of these problems, and has a structure that prevents short-circuits between adjacent electrodes as described above, and prevents deterioration of the function and reliability of the recording head, as well as conventional The purpose of IJ is to provide a liquid jet recording head that can further increase the density of orifices, which has been a limit in liquid jet recording heads that utilize thermal energy.

The above object can be achieved by the following invention.

That is, the present invention provides liquid jet recording, and (g) includes an orifice provided for ejecting liquid to form flying droplets, and a thermal energy communicating with the orifice for forming the droplets. At least one pair of opposing electrodes is electrically connected to a liquid flow path formed on a support body having a heat acting part, which is a part that acts on the liquid, and a heating resistance layer provided on the support body. and an electrothermal transducer in which a heat generating part for generating the thermal energy is formed between these electrodes. A heat generating part is formed on one surface F of the base, and the electrodes 4 are separated and wired on both the left and right sides adjacent to the one surface of the base, and the base and the support member are integrally connected. The support body is characterized in that the support body is formed by:

Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Part 31 (a) to (d) are schematic diagrams for explaining examples of the liquid jet recording vent of the present invention.

No. 31N(a) is an example of the liquid jet recording head of the present invention.
FIG. 3(b) is a schematic perspective view of the main part of the base body provided with the air-thermal converter, and FIG. FIG. 3(C) is a schematic cross-sectional partial view of the main part of a liquid jet recording head having a support in which the substrate shown in FIG.
) is a partial front view of the main part of the recording head shown in FIG. 3(C), viewed from the orifice side.

Stone base 303 of liquid jet recording head 3o+ of the present invention
As shown in FIGS. 3(a) and 3(b), selections 1g, M! Further, a common electrode 308 is laminated on the lower surface of the common electrode 308, and a heat generating section 302 consisting of a heat generating resistor layer 313 connected to the ends of these electrodes is arranged on the side surface thereof.

The heat generating resistive layer 313 and the selection electrode 308 are patterned in such a shape and size that the heat generating portion 302 is placed between the common electrode 308 and the selection electrode 308 at a desired position, respectively.

Note that it is preferable that the common electrode 309 is provided integrally with the lower surface of the base 303. This is because by providing the common electrode Mii 309 in an integrated manner, the number of bonding points of the 7E electrode can be reduced. Port I that causes poor connection etc.
This is because lowering the saturation provides +jf performance and improves the reliability of the recording head.

By wiring the selection electrode 308 and the common electrode 308 separately in this way, the heat generating section 302 can be connected to a portion of the heat generating section 302 that is separated from the common electrode +13 in the conventional example shown in FIG. The plurality of selection electrodes 308 arranged next to each other are arranged corresponding to the selection electrodes 114.
It is now possible to arrange multiple heat generating parts 30 according to
Narrowing the distance between each of the 2's resulted in 7 functions.

In this way, the installation density of these heat generating parts 302 is reduced to 1'.
It is now possible to increase the density of fi from the conventional 12 pieces/layer to about 32 pieces/■, and the heat generation part 302
It has become possible to increase the density of the orifices provided correspondingly.

Furthermore, since the common electrode and the selection electrode are wired separately, the recording head of the present invention has a structure in which short circuits between these electrodes are less likely to occur.

The base 303 having such a configuration on its surface has a third
As shown in Figure (C) and Figure 3 (d), the support member 30B-1 and the support member 306-
2 and are integrated with these, thus forming the support body 317. Furthermore, the support body is a jig 3
11, and the top plate 304 and the groove side wall 312 are joined to the heat generating part 3.
An orifice 305 corresponding to 02, and a liquid flow path 31 communicating with the orifice and having a heat acting part 315 as a part of the structure.
6, and a common liquid chamber 310 for supplying liquid to the liquid flow path.
are provided to form a liquid jet recording head of the present invention.

The support member 30B-2 has a supply hole 307 for supplying the liquid to the heat acting part 315 that constitutes a part of the liquid flow path 31B.
is provided. Therefore, i1g! Each liquid flow path 31B divided by the side wall 312 is connected to the supply hole 307.
and is communicated with each other via a common liquid chamber 310.

In the example of the present invention shown in FIGS. 3(C) and 3(d), as described above, the base 303 on which the electrothermal converter is provided is connected to the two supporting members 30B. -1 and 3
08-2, one of these support members (306-1) may be integrated with the jig 311.

Although not shown in the figure, a protective layer may be provided on the base body on which the heat generating section 302 is arranged.

This protective layer covers the electrodes 30B, 309 and the heat generating part 302.
It chemically and physically protects the heat-generating resistor layer constituting the heating resistor layer from the liquid on top of the layer, and prevents short circuits between the electrodes (1) caused by the contact of the energized electrode with the liquid, which occurs through the liquid. The main purpose is to prevent electrolytic corrosion of the electrodes and to efficiently transfer the thermal energy generated in the heat generating part to the liquid. Note that when a liquid-resistant material such as a Ta alloy is used for the heat generating resistor layer 1, it is not necessary to provide a protective layer as described in 12 above.

In the liquid jet recording head of the present invention having such a structure, the support body has a structure in which the base body provided with the electrothermal transducer is sandwiched between the support members, so that there is no radiation other than the heat generation line. The structure has no part where the electrode comes into direct contact with the liquid, and there is no need to provide a protective layer on this part as in conventional recording heads, which prevents peeling of the protective layer and contact between the electrode and liquid. Defects such as electrolytic corrosion caused by contact no longer occur. In addition, the structure is resistant to shocks caused by cavitation when discharging liquid.
The durability of the recording hand has been improved.

The substrate 303 of the liquid jet recording head of the present invention is the surface of a plate made of silicon, glass, ceramics, etc., or a metal plate made of aluminum, etc.

Insulating materials, such as those in which an insulating layer made of saponified metal such as aluminum oxide, zirconia 11, tantalum chloride, etc. is provided by vapor deposition, sputtering, or oxidation treatment of a predetermined surface of the metal. can be used.

The support member 30B, the groove side wall 312, and the top plate 304 can be formed from a material such as silicon, glass, ceramics, or resin, and have excellent liquid resistance in the parts that come into direct contact with the liquid. This is desirable.

Heat generating section 302 included in the liquid jet recording head of the present invention
The heating resistor layer 313 can be formed from almost any material that can generate the desired heat when energized.

Such materials include, for example, tantalum nitride, nichrome, silver-palladium alloys and silicon oxide conductors, as well as hafnium, lanthanum, zirconium, titanium, tantalum,
Preferred materials include metals such as tungsten, molybdenum, niobium, chromium, and henadium, their alloys, and their borides.

Among these materials that can form the heating resistance layer 313, the most preferable materials having excellent characteristics as a heating resistance layer are Ta-based alloys, Nb-based alloys, and Nl alloys.
Examples include alloys.

The heat generating resistance layer 313 can be formed using the above-mentioned materials by a vapor deposition method, a sputtering method, or the like.

The layer thickness of the heating resistor Ji1313 is determined according to various conditions such as its area, material, shape and size of the heat acting part, and actual power consumption so that the heating value per unit time is the desired value. Although determined as appropriate, it is preferably 0.001 to 5-1, more preferably 0.01 to 1-1.

The materials that can form the electrodes 308 and 309 include most of the commonly used electrode materials, including metals such as Al, Ag, Au, Pt, and Cu. It can be formed using a vapor deposition method or the like.

When providing a protective layer on the electrodes 308 and 309 and the heat generating portion 3021, the protective layer may be selected from inorganic materials such as metal oxides, metal nitrides, and metal carbides, and organic materials such as resin depending on the location where the protective layer is provided. It can be formed from a single piece of material appropriately selected to satisfy the characteristics described above.

In the recording head of the present invention shown in FIGS. 3(a) to 3(d), the orifices were arranged in horizontal rows, but the recording head of the present invention is An example of the recording head of the present invention having such a configuration, which may be formed by stacking two or more bodies 317 and having orifices arranged in two or more rows in one direction, is shown in FIG. 4(a). ) and Figure 4(b)
).

In this example, orifices 405-1, 405-
2 corresponds to the heat generating portions 402-1 and 402-2, respectively, and
These base bodies are placed between the jig 4 and 17-2.
111.4+1-2, 411-3 are arranged and positioned on the left and right at a predetermined interval, and the top plate 404 is provided with orifices 405-1 and 405-2.
and a groove side plate 4 that serves the liquid flow paths 418-1 and 416-2.
12-1 and 412-2 are joined to form a recording head.

When recording using this recording head, the recording liquid supplied from the common liquid chamber 410 to the liquid flow paths 416-1 and 416-2 is affected by the thermal effects that form part of these liquid flow paths. In the sections 415-1 and 415-2, the heat generating section 402-1
, 402-2, the orifices 405-1, 40
It is discharged from 5-2.

The orifices provided at predetermined positions on the top plate 404 are orifices 405-1, !, on the left and right sides, respectively. The niorifices 405-2 are arranged in one row, and the orifices 405-2
5-1 and orifice 405-2 are arranged so as not to overlap each other in the direction perpendicular to the direction in which the orifices are arranged.

In this case, two rows of orifices are arranged.

By shifting the arrangement of orifice 405-1 and orifice 405-2 on the left and right, 32 dots/1 ml.
High-density dot printing up to a certain level is a II skill.

Note that the jig 4+11 and the 1h jig 411-2 may be integrated with the support members 40B-] and 406-2, respectively. In addition, in this example, the base 417-1.41
A common liquid chamber 410 was provided between 7-2.

A jig 411+ and a jig 4+12 are arranged (separate common liquid chambers communicating with the liquid flow paths 41B-1 and 418-2 may be provided at Place the jig at position 410 and open the supply hole 407-1.

407-2 may be provided respectively on the support member located on the side of the common liquid chamber.Furthermore, the record of the present invention in which three or more supports are stacked and a plurality of oriswises are arranged in three or more rows. It is also possible to form a head.

In the liquid jet recording head of the present invention having the structure as described above, the heat generating portion is provided on the side surface of the base of the support body having the base body and the support member, so that the common electrode and the selection electrode By wiring these electrodes in this way, we have created a structure that is suitable for wiring the electrodes separately on the top and F sides of the substrate, and by wiring these electrodes in this way, we can eliminate the heat generation area that was the limit of the conventional folded electrode pattern. In addition, the recording head of the present invention has a structure in which short circuits between these electrodes are less likely to occur.

Furthermore, the structure of the recording head of the present invention is suitable for constructing a recording head in which orifices are arranged in two to seven rows on the left and right sides, and the orifice arrangement of 2 Au By shifting F toward -, higher density dot printing became possible.

On the other hand, the structure is such that there is no part of the electrode that comes into direct contact with the liquid other than the heat generating part, so there is no need to provide a protective layer in this part as in conventional recording heads. In addition, the structure is resistant to shocks caused by cavitation during liquid ejection, improving the durability of the recording head.

Furthermore, since the common electrode is integrated as one electrode, the number of electrode bonding points is reduced, and the possibility of connection failures at bonding points is lowered, resulting in high reliability of recording. became.

The liquid recording jet recording head of the present invention will be explained in more detail according to Examples.

Example 1 A liquid jet recording head of unreleased J shown in FIGS. 3(a) to 3(d) was prepared in the following manner.

First, one side surface of the alumina substrate 303 (35!l@X3? amount mXO, 5 mm) was polished flat, and the corners formed by the side surface and the upper surface of the substrate and the top surface were rounded.

Next, a Ta-Al alloy is deposited on the side surface of the base body 303 from a direction perpendicular to the side surface as a heat generating resistor layer 313 by a mask vapor deposition method using a pattern mask having a predetermined shape, so that a heat generating resistor M313 ( thickness 0.2μs)
has been established.

Next, 0.5% Au is deposited on both sides of the base 303 by vapor deposition.
The Au layer on the upper surface of the substrate 303 is etched using a pattern mask with a predetermined shape to form a predetermined shape and number of Au layers as shown in FIG. 3(a). The electrode 30B is provided corresponding to the heat generating resistance layer 313, and the heat generating part 302 (30 μx
150u) was formed. The arrangement density of the formed heat generating portions 302 was 16/111.

In this manner, a support member 30 ft-1 is placed on the top surface of the base 303 with the heat generating part 302 provided at a predetermined position, and a support member 30ft-1 is provided with the supply hole 307 at a position corresponding to the heat generating part 302 on the F side. The members 30B-2 were adhered to each other using an adhesive to form a support 317.

Separately, add a 20u photosensitive dry film to the top plate 3.
04, and exposed and developed using a predetermined pattern mask to form groove side walls 312.
An orifice 305 was provided at a predetermined position on a top plate 304 partitioned by.

After finishing, the groove side walls 312 thus created and the top plate 304 are bonded to the supports 31 previously created using epoxy adhesive. Then, the recording head of the present invention was completed by bonding so that the orifice 305 was located at a position corresponding to the heat generating section 302.

The liquid jet recording head of the present invention has two IBs/ll.
This resulted in a high-density multi-orifice recording head in which orifices were arranged at a density of 11 l.

When recording was performed using this unreleased IJI liquid jet recording head, high-resolution, high-quality images were obtained at high speed, and it was also highly reliable for long-term use.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic partial view of a stop surface of a surface provided with an orifice of an example of a conventional liquid jet recording head, and FIG. 1(b)
) is a partial cross-sectional view taken at point tCJIIX-Y in FIG. 1(a), FIG. Figure 3 (
a) is a schematic perspective view of the main part of the base body provided with the electrothermal converter of an example of the liquid jet recording head of the present invention, and FIG.
b) is a schematic partial cross-sectional view of the main part of the substrate shown in FIG. 3(a), and FIG. 3(e) is a support body having the substrate shown in FIG. 3(a) as a part of its structure. FIG. 3(d) is a schematic cross-sectional partial view of the main part of the liquid jet recording head, and FIG. 4(a) is a front partial view of the main part of the recording head shown in FIG. 3(a) is a schematic cross-sectional view of the main part of the liquid jet recording head of the present invention having two hollow supports, and ffi41m(b) is wS41'14(
FIG. 4 is a partial front view of the main parts of the recording head shown in FIG. 101.301, 401: Recording head 102: Electrothermal converter 103: Substrate + 04 grooved plate 105.105-1.105-2, 105-3, 305
, 405 + orifice 106: liquid discharge section 107. 315, 415-1, 415-2: heat action section 1
178.302, 402-1, 402-2: Heat generating part 1
09: Netsaku Kawamen 111.111-1, 111-2, 111-3, 313
:Heating resistance layer 112:Protective layer 113.309,409-1,409-228ate1
14.308,408-1.408-2: Selection electrode 30
3: Base 304.404: Top plate 30B-1, 306-2, 408-1, 408-2: Support member 307.407-1, 407-2: Supply hole 310
．． 410: Common liquid chamber 311.411-1, 411-2, 411-3: Jig 3
12.412-1, 412-2: Groove side wall 31G: Liquid flow path 317. 417-1, 417-2 + support body NS 1 Figure (a) Figure 1 (b) 11) 4 Figure 2 Figure 3 ( a 1) 3 Figure (b) 3rd shiQ (c Figure 3 (d)

Claims (1)

[Claims] (1) A sunken orifice to eject a liquid to form a flying droplet, and a thermal effect that is a part communicating with the orifice and where thermal energy acts on the liquid to form the droplet. At least a pair of opposing electrodes are provided, electrically connected to a liquid flow path formed in the support body 1- having an area of and an electrothermal transducer in which a heat generating part is formed, in which the electrothermal converter forms the heat generating part on one surface of the base and Liquid jetting characterized in that electrodes are separated and wired on both left and right sides adjacent to one surface of the base, and the base and the support member are joined and integrated to constitute the support body. Record hend.