JPS60204373A - Liquid jet recording head - Google Patents

Abstract

PURPOSE:To provide a liquid jet recording head low in cost and easy to manufacturae, wherein electrodes connected to an energy generator constitute a liquid passage communicated with an orifice for forming a flying liquid droplet. CONSTITUTION:First, Ta is deposited on a base 1 formed of a non-alkali glass or the like by HF bipolar sputtering to provide a heating resistor layer 3, and a Cu film is deposited thereon with Ta as an electrode. Then, Au is deposited on the pattern of the Cu electrode exclusive of the part of the resistor layer 3 to provide counter electrodes 14. Subsequently, SiO2 is deposited on the electrodes 14 to provide an ink-shielding layer 15, and ink liquid passages 18 are defined. Further, a top plate 7 is placed on the layer 15 to form closed liquid passages 18, and orifices 18A are provided at the tip of the top plate 7 to constitute the desired recording head.

Description

Detailed Description of the Invention [Technical Field] The present invention is characterized in that a liquid subjected to the action of thermal energy undergoes a state change accompanied by a rapid increase in volume, and the acting force based on the state change causes an orifice at the tip of a recording head to open. The present invention relates to a droplet jetting recording head in which a flying droplet is formed by ejecting a droplet, and the droplet adheres to a recording member to perform recording.

[Prior Art] An outline of a conventionally used droplet jet recording head will be explained with reference to FIGS. 1(a), (b) and FIGS. 2(a), (b), and (C).

FIGS. 1(a) and 1(b) show a substrate used in a conventional head of this kind, in which a Si crystal is used as l. Insulating oxide @2 is formed on the surface of this Si crystal by thermal oxidation, and this is used as a heat storage layer. The thickness of the heat storage layer 2 may be determined from the response frequency of the recording head.

A heating resistor layer 3 as an energy generator for droplet ejection is deposited over the entire surface of the heat storage layer 2 of this support l by high frequency bipolar sputtering.Next, the heating resistor layer 3 is deposited by electron beam evaporation. At least one pair of opposing electrodes 4 made of Al or the like are attached thereon. Here, the heating resistor layer 3 and the electrode 4 are formed by photolithography.
For example, it is assumed that a desired pattern shape is formed as shown in FIG. 1(a). Further, on the patterned heating resistor layer 3 and electrode 4, a two-part layer 5 in the form of a SiO□ film or the like is formed by high-frequency bipolar sputtering, and the substrate is thus constructed.

The process of forming a liquid flow path on the substrate configured as described above will be described with reference to FIGS. 2(a) to 2(C). First, a dry film 6 is laminated on the surface of the upper layer 5 of the substrate, and the dry film 6 is coated on the surface of the upper layer 5 of the substrate as shown in FIG. 2(a).
, (b), patterning is performed by photolithography into a desired pattern shape. Next, the patterned dry film 6 is covered with a top plate 7 to form a closed liquid flow path 8. Reference numeral 8 indicates a heat generation portion by the patterned heating resistor layer 3, and reference numeral 10 indicates a liquid flow path 8.
Shows the heat acting part inside.

In the liquid flow path 8, due to the heat from the heat generating section 8, the volume of the ink in the heat acting section 10 rapidly increases.
The acting force associated with the state change causes the liquid to be ejected as flying droplets from the orifice 8A provided at the tip of the flow path 8.

Here, in order to improve the adhesion between the top plate 7 and the wall of the liquid flow path 8, it is preferable to arrange an adhesion direction 1 and layer 11 in the form of a dry film between them, as shown in the illustrated example. It is.

Next, although not shown, an ink storage tank is formed on the outer surface of the top plate 7 at a position opposite to the orifice 8A, and this tank and the liquid jXf path 8 are connected to each other through an opening made in the top plate 7 ( (not shown).

Furthermore, a lead wire of a flexible cable is connected to the electrode 4 by wire bonding, and an electrical connection is made to the circuit of the JA section via this flexible cable. The recording head constructed as described above is extremely useful when it is desired to obtain high-density dots or to realize high-speed response, even at the expense of a slight increase in cost.

On the other hand, when creating the liquid flow path of the head, the dry film is patterned to form the liquid flow path wall, and the environment is always in contact with liquid (ink) containing organic solvents, etc., which is a harsh condition. Therefore, close attention had to be paid to the adhesion between the substrate and the dry film. For this reason, the dry film process was complicated, and assembly, etc., was often done manually.

Furthermore, it is not a good idea from the standpoint of manufacturing a low-cost, disposable recording head that does not require high dot density or high speed response.

[Objective] In view of the above-mentioned points, an object of the present invention is to provide a droplet jet recording head that meets the demand for low cost and can be easily manufactured.

[Example] The present invention will be described in detail below with reference to the drawings.

3(a), (b) and FIG. 4 show a first embodiment of the present invention, where FIGS. 1(a), (b) and FIGS. 2(a) to (C) Similar parts will be given the same reference numerals.

In this example, non-alkali glass (for example, Corning's 70511) is used as the support 1, and Ta is deposited on the support 1 to a thickness of 500 mm by high-frequency bipolar sputtering to form the heating resistor layer 3. A thick Cu film with a thickness of 3 is deposited on top of the film by electrolytic plating using Ta as an electrode.
5gtn, and the third layer is attached to this Cu film.
Desired liquid flow path 16 as shown in FIG.
The patterned Cu electrode is patterned by photolithography to form a pattern of
By attaching only 4, at least one pair of opposing electrodes 14
form. 'Subsequently, ink was applied to the electrode 4-H to a thickness of 5,000 mm using the CVD method to form a layer 15.
form. This ink layer layer 15 is omitted in FIG. 4, but in reality, as shown in FIG. 3(b),
The ink liquid flow path 1 is formed by an ink blocking layer 15 having an uneven structure corresponding to the pattern of the electrode 14.
8 is limited.

A top plate 7 on which the adhesion improving layer 11 is laminated is placed on the ink blocking layer 15 to form a closed liquid flow path 18. In this example, an opening is provided in the top plate 7 and the adhesion improving layer ll at a position corresponding to the position of the heating resistor layer 3, and an orifice 18A is formed at the tip of the top plate 7.

Place the liquid storage tank (not shown) on top plate 7 and orifice 1.
8A, and further, a lead wire of a flexible cable for electrical connection with an external circuit is connected to the electrode 14 by wire bonding.

The recording head constructed in this manner does not require the provision of a patterned dry film 6 as in the conventional example described above, and only the electrodes can be patterned, so that manufacturing costs can be significantly reduced.

The second embodiment of the present invention is shown in FIGS. 5(a), (b) and 6.
As shown in the figure. In this example, a polyimide film is used as the support 1, and a heating resistor layer 3 is formed on the film 1 by splicing Ta 2 N to a thickness of 500^ by reactive sputtering. A desired pattern is formed on this film 3 by photolithography. A dry film is laminated on this patterned heating resistor layer 3, a pattern is formed on this dry film, and electrolytic plating is performed to form Cu to a thickness of 20 pm and then Au to a thickness of Ig+n. . Next, the dry film is peeled off to obtain at least one pair of opposing electrodes 24 in a desired pattern. In this example, the pattern of the electrode 24 is the fifth
As shown in FIG. 6(a) or FIG. 6, a desired pattern is formed in which an orifice 18A is formed at one end and parallel liquid flow paths 28 are formed.

Subsequently, electrode 4" was coated with 5" by high frequency sputtering.
Ink-blocking layer 2 by attaching i02 to a thickness of 3000A
form 5. Therefore, the actual liquid flow path 18 and orifice 18A are limited by this ink-tight layer 25. However, in FIG. 6, this inked conflict layer 25 is omitted for simplicity of illustration.

A top plate 7 laminated with dry film II is attached to the inked layer 25. As a result, a closed liquid flow path 18 is formed, and an orifice 18A is formed at the opening on the heating resistor layer 3 side.

As shown in FIG. 6, a liquid storage tank 43 is placed adjacent to the top plate 7 on the laminate film ll.

44 is an ink liquid supply tube for the tank 43.

In this example, the end of the electrode 24 opposite to the orifice 28A can be formed as it is as an electrical connection part with an external circuit, and this end can be directly inserted into the connector. , Wire bonding of the lead wire of the flex cable as shown above is no longer necessary, which simplifies the manufacturing process.

FIGS. 7(a) and 7(b) show a third embodiment of the present invention, in which an orifice 38A is formed in the support l.

A polyimide film is used as the support l, and a rolled Cu foil (thickness: 35 #Lm) is adhered onto the support l.

A pattern forming mutually parallel liquid channels 38 is formed on this Cu foil by photolithography as shown in FIG. 7(a), and then electroplated on the pattern to a thickness of
At least one pair of opposing electrodes 34 are formed by pricking Au of #LII.
form. A hole 3θ is formed in the support l in accordance with the pattern of the electrodes 34 so that the orifice 38A is disposed between at least one pair of opposing electrodes.

On the other hand, a heat generating resistor layer 3 is formed by depositing Ta to a thickness of 500 Å on the glass top plate 7 by high frequency reactive sputtering, and this heat generating resistor layer 3 is attached to the opposing electrode 34 on the polyimide film l. The polyimide film 1 and the glass top plate 7 are fixed with an adhesive after being crimped onto the electrode 34 so that an electrical connection is made between them.

A liquid storage tank is arranged on the top plate 7 at a position opposite to the orifice 38A, and the end of the electrode 34 on the opposite side to the orifice 38A is directly connected to the external circuit as in Example 1-1. The end can be connected directly to the connector.

Therefore, also in this example, since wire bonding of the flexible cable is not necessary, the manufacturing process can be simplified.

Note that in each of the above embodiments, the electrodes are formed using plating technology, but such electrodes can also be formed by screen printing.

Next, a fourth embodiment of the present invention is shown in FIGS. 8 and 9(a).
, (b) and (c). In this example, a piezo element (for example, Bimorph (trade name)) 53 is used as an energy generator for ejecting droplets. Here, the electrode 51 of the electrodes 51 and 52 connected to the piezo element 53 forms a liquid flow path 55 together with the partition 54 .

Note that 56 is an insulating layer that electrically insulates the electrodes 51 and 52.

[Effects] According to the present invention, the liquid flow path wall can be formed of an inorganic material, and the liquid flow path wall can be formed at the same time as the electrodes are formed, so that the manufacturing process can be greatly simplified. Moreover, a dry film is sometimes used as an adhesion-improving layer, but in this case, there is no need to permanently use a finely patterned layer like in the past, and it is sufficient to form a dry film on the entire surface. There is no need to be very careful about adhesion, and the process is not complicated.

Thus, the recording head according to the present invention can significantly reduce the time and labor and material costs required for manufacturing.

Furthermore, when the droplet jet head according to the present invention was driven at a frequency of 500 Hz, the print quality was almost the same as that of the conventional head.

[Brief explanation of the drawing]

FIG. 1(a) is a front view showing an example of a substrate in a conventional recording head, FIG. 1(b) is a cross-sectional view taken along line A-A, and FIG. 2(a) is the overall configuration of a conventional recording head. 2(b) is a top view thereof, FIG. 2(c) is a sectional view taken along line A-A of FIG. 2(a), and FIG. 3(a) is a front view showing an example of the present invention. 3(b) is a sectional view taken along line A-A, FIG. 4 is a perspective view thereof, and FIG. 5(a) is a front view showing a second embodiment of the present invention. , 5th
Figure (b) is a top view thereof, Figure 6 is a perspective view thereof, Figure 7 (a) is a front view showing the third embodiment of the present invention,
Figure (b) is a sectional view taken along the line A-A, Figure 8 is a perspective view showing the fourth embodiment of the present invention, Figure 8 (^
) is a sectional view taken along the line xx', and FIG. 9(b) is a sectional view taken along the line Y-Y.
Fig. 8(C) is a sectional view taken along the line zz'. 1...Support, 2...Heat storage layer, 3...Heating resistor. 7... Top plate, 9... Heat generating part, lO... Heat acting part, 11... Adhesion improving layer, 14.24.34... Electrode, 15.25... Ink blocking layer , 18.28.38...liquid flow path, 18A, 28A, 38A...orifice, 43...
Liquid storage tank, 44...Liquid supply tube 51, 52...Electrode, 53...Piezo element, 54...Partition wall, 55...Liquid channel, 56...Insulating layer. Patent applicant Canon Co., Ltd. Representative Patent attorney Yoshi Tani- 359- 360- 361- 362-

Claims (1)

[Scope of Claims] A liquid ejecting head comprising an orifice for forming flying droplets, and an energy generator for generating energy used to eject the droplets from the orifice, comprising: A liquid jet recording head characterized in that an electrode connected to the generator constitutes a liquid flow path communicating with the orifice.