JPH11300951A - Ink jet recording head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recording head having ink resistance, good in ink emitting and filling efficiency and capable of being produced by a simple process. SOLUTION: In a method for producing an ink jet recording head constituting nozzles by bonding a top plate 13 having grooves and a substrate having emission energy generating elements arranged to nozzles partially in order to constitute the nozzles provided corresponding to a large number of respective emitting orifices, a resin 34 is mixed with air to be sprayed the bonding surface of the top plate 13 prior to bonding the top plate 13 and the substrate to curve the cross-sectional shape of the nozzles constituted by bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording head for ejecting and flying a recording liquid generally called ink from a fine ejection port, and a method of manufacturing the same.

[0002] The present invention also relates to a facsimile having a printer, a copying machine, a communication system, and a printer for performing recording on a recording medium such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics and the like. The present invention can be applied to an apparatus such as a word processor having a section, and further to an industrial recording apparatus combined with various processing apparatuses.

In the present invention, "recording" means not only giving an image having a meaning such as a character or a figure to a recording medium, but also giving an image having no meaning such as a pattern. means.

[0004]

2. Description of the Related Art As a conventional ink jet recording apparatus, recording head and recording unit integrated with an ink tank, a recording unit utilizing thermal energy or an electromechanical transducer is known.

In particular, an ink jet recording head that discharges a recording liquid by using thermal energy can perform high-resolution recording because discharge ports for discharging ink can be arranged at a high density. It has advantages such as easy downsizing as a whole, and has already been widely used.

[0006] The ink jet recording head is provided with a liquid chamber for storing ink, an ink discharge nozzle (liquid flow path), and an ink discharge port so as to communicate with the ink discharge nozzle.

Conventionally, various types of ink discharge nozzles have been proposed for the ink jet recording head. One known method is to form a groove by performing anisotropic etching on a silicon substrate.

For example, there is a method of forming a rectangular groove by performing anisotropic etching on a silicon substrate having a (110) plane on the surface.

FIG. 1 is a schematic drawing of an example of an ink jet recording head using a member having these grooves formed thereon (hereinafter referred to as a top plate).

Reference numeral 11 denotes a silicon chip on which a number of heating elements (heaters) 12 are arranged, which will be hereinafter referred to as a heater board.

The top plate 13 and the heater board 11 are adhered, joined or adhered in the direction shown in FIG. 1 to form an elongated nozzle on the groove 14 and the surface of the heater board 11, and at this time, the heater 12 is provided inside the nozzle. Are precisely aligned to include

The ink is supplied from an ink tank (not shown) and guided to the ink liquid chamber 15, and then reaches the inside of the nozzle 14.

The heater board 11 is controlled by a control circuit (not shown), and energizes each of the heaters 12 according to print data.

The control circuit may be either on the heater board or on a separate substrate, and is not related to the gist of the present invention.

Heater 1 energized according to print data
2 generates heat and heats the ink in the nozzle.

[0016] The heated ink boils above a certain critical temperature, generating bubbles.

The generated bubble grows in a short time of several μs and gives an impact force to the ink, so that a part of the ink is vigorously pushed out from the ejection port by the impact, and lands on a printed matter, for example, paper. I do.

When this operation is repeated, a print image is completed.

Japanese Unexamined Patent Publication (Kokai) No. 6-31918 proposes a groove generally called a V-shaped groove formed from a silicon wafer cut and polished so that the upper surface is a (100) plane of a crystal.

FIG. 2 is a schematic drawing of an example of an ink jet recording head in which ink discharge nozzles are formed using a top plate on which the V-shaped groove is formed.

[0021]

However, the following problems have been pointed out from the properties and shapes of the silicon grooves formed by the anisotropic etching.

First, the silicon groove has no ink resistance.

The silicon has a property of dissolving in an alkaline solution, and is eluted when it comes into contact with an alkaline ink for a recent ink jet printer, and the nozzle is deformed.

Second, a curved surface cannot be formed by anisotropic etching.

A rectangular shape in a rectangular nozzle, and a corner shape such as a vertex of a triangle in a V-shaped groove become flow resistance, which deteriorates ink ejection and filling efficiency.

In addition, a bonding member is required to adhere, bond, or bond the top plate to the heater board as described above, and patterning of an adhesive corresponding to the nozzle wall is required on the heater board. The production process was complicated.

The present invention has been made in view of the above problems, has an ink resistance, has good ink discharge and filling efficiency, and can be manufactured in a simple process. An object of the present invention is to provide a method for manufacturing an ink jet recording head.

[0028]

In order to achieve the above object, a method of manufacturing an ink jet recording head according to the present invention is directed to a method of manufacturing a head having a groove for forming a nozzle provided for each of a plurality of discharge ports. In a method of manufacturing an ink jet recording head in which a nozzle is formed by joining a plate and a substrate having an ejection energy generating element provided in a part of the nozzle, prior to joining the top plate and the substrate, The resin is mixed with a gas and sprayed onto the joint surface side of the top plate, so that the cross-sectional shape of the nozzle formed by joining is curved.

Further, in the ink jet recording head of the present invention, the nozzle provided for each of the plurality of discharge ports includes a top plate having a groove, and a discharge energy generating element provided in a part of the nozzle. In the ink jet recording head formed by joining the substrate having the resin, a resin layer is formed on the surface on the joint surface side of the top plate, and the cross-sectional shape of the nozzle is curved by the resin layer. It is characterized by the following.

In each of the above-described embodiments of the present invention, the ink jet recording head may be an ink jet recording head that discharges liquid by generating bubbles based on the energy generated by the discharge energy generating element.

By configuring the present invention as described above, the ink jet recording head of the present invention has an excellent effect that it is resistant to ink, has good ink discharge and filling efficiency, and can be manufactured by a simple process. Having.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the ink jet recording head and the method of manufacturing the same according to the present invention, it is preferable that a silicon wafer is used as a material of a top plate and grooves are formed by anisotropic etching. A resin, a mineral, a metal, or a glass material may be used as the material, and a laser beam may be applied to these members to form grooves.

As the resin to be sprayed on the bonding surface side of the top plate after the groove is formed, an adhesive resin is preferable, and as the adhesive resin, a thermoplastic resin, particularly a polyether amide resin is excellent in ink resistance. However, as long as it has ink resistance, a chemically reactive adhesive resin such as a thermosetting resin or a photocurable resin can also be used, and the effects of the invention can be similarly achieved.

[0034]

The present invention will be described in more detail with reference to the following examples.

Embodiment 1 FIG. 3 shows the structure of an ink jet recording head according to the present invention.
(A) shows a cross section of a rectangular groove 14 formed by anisotropic etching of a silicon substrate, and various methods of manufacturing the rectangular groove have already been proposed. Therefore, detailed description here is omitted.

First, a resin is applied to the rectangular grooves.

The coating was performed using a spray coating device (microspray: manufactured by Nordson) under a compressed air pressure of 3.0 kgf /
In cm ^2, it was sprayed as a mist by mixing a resin solution and air,
It was sprayed on the bonding surface side of the top plate so as to have a thickness of several μm.

After the application, the diluent was cured on a hot plate at 100 ° C. for 2 minutes.

In this embodiment, a polyetheramide resin (HIMAL:
Hitachi Chemical Co., Ltd.) was used.

In the spray coating device, the resin is not sprayed when the viscosity of the resin solution is high.

Therefore, it is necessary to adjust the viscosity of the resin.

In this embodiment, the diluent is N-methyl-2-
The resin was diluted with a mixed solution of pyrrolidone and butyl cellosolve acetate to reduce the viscosity, thereby obtaining a resin solution.

When the resin solution is sprayed into the rectangular grooves by the spray coating device, the resin solution applied to the portion 33 on the wall flows down to the ceiling 32.

This is because the viscosity of the resin solution droplet is low as described above.

Therefore, the sprayed droplets can enter the inside of the groove, and the shape of the inside of the groove after application becomes a smooth curved surface due to the adhered resin.

Thereafter, the diluent is dried, and the adhesive resin is thinned while maintaining the curved shape inside the groove.

In this embodiment, the curing is performed to shorten the drying time. However, the resin becomes thin even at room temperature.

As a result, as shown in FIG. 3B, the resin 34 is applied with a thickness of 1 μm on the side wall 31, 3 μm on the ceiling 32, and 1 μm on the portion 33 above the wall to form a silicon ink-resistant protective film. .

Next, as shown in FIG. 3C, the heater board 11 was adjusted in position and superposed.

At this time, a load was applied vertically to the surface where the top plate and the heater board were joined, and the top plate was heated to 250 ° C. Then, the resin softens due to the thermoplastic adhesive and assumes a shape as shown in FIG.

When the top plate was returned to room temperature, the resin was cured again, and the top plate and the heater board were joined.

The inside of the nozzle formed by the above steps has a curved shape because it is coated on the resin as shown in FIG.

Since the resin is thermoplastic, it is softened when heated above the glass transition point.
If heated to a temperature that deforms under the load but does not deform under its own weight, only the upper part of the wall, that is, the resin on the bonding surface between the heater board and the top plate, deforms and contributes to the bonding, and the inside of the nozzle The resin can maintain a curved shape without being deformed.

Further, since the resin coated inside the nozzle is deformed, the silicon is not exposed,
There is no hindrance to the effect as a protective film for ink.

Further, at a temperature lower than the glass transition point, the resin solidifies into a thin film and does not have tackiness, so that the top plate can be easily handled in mass production, and the adhesive property in the nozzle when the printer is used. And exert no adverse effects.

In this embodiment, rectangular grooves are used.
Similar effects can be obtained with nozzles of other shapes such as V-shaped grooves.

Also, even if the nozzle is made of a material other than silicon, if the nozzle has no ink resistance, if the nozzle has a shape with corners or is not smooth, the top plate and the heater board are connected via a joining member. The present invention is effective if any of the cases such as joining is applied.

For example, there is a method in which a member made of resin, mineral, metal or glass is irradiated with laser light to form a rectangular groove, but the cross-sectional shape of the groove is not a curved shape.

Therefore, the present invention is effective.

Although a thermoplastic adhesive is used as the resin in this embodiment, a chemically reactive adhesive resin such as a thermosetting resin or a photocurable resin may be used as long as the resin has ink resistance.

Embodiment 2 Next, another embodiment of the present invention will be described.

First, the top plate (FIG. 4A) having the grooves was fixed on a hot plate and heated to 80.degree.

In the same state as in Example 1, the resin solution was sprayed on the bonding surface side of the top plate, that is, the nozzle, using a spray coating device, while keeping the temperature.

The resin used was the same as that used in Example 1 except that a strong thermoplastic adhesive was diluted with a diluent.

FIG. 4B shows a state after curing at 100 ° C. for 2 minutes on a hot plate in order to dry the diluent after application, and FIG.
μm, 1 μm on the ceiling 32 and 3 μm on the part 33 above the wall.
m to form a silicon ink-resistant protective film.

In this embodiment, the diluent is easily dried because the top plate is heated while the resin solution is sprayed.

That is, as soon as the spray droplets adhered to the grooves, they were dried and the resin was solidified.

Therefore, even when the width of the wall is very small, for example, several tens of μm or less, the liquid droplets that have once adhered to the upper portion of the wall do not fall into the inside of the groove.

Accordingly, as shown in FIG. 4B, the resin could be applied thickly on the wall.

Further, since a part of the applied resin solution enters the inside of the groove as in Example 1, a smooth resin layer could be formed inside the groove. However, all of the resin solution that enters the inside of the groove does not adhere to the ceiling and solidify, but also adheres to the side surface of the wall as shown in FIG. For this reason, the adhesion amount (thickness) of the ceiling portion was smaller than the adhesion amount of the portion above the wall.

Next, as in the first embodiment, the top plate 13 and the heater board 11 were overlaid and weighted as shown in FIG. 4C, and the top plate was heated to 250 ° C.

Then, the thermoplastic adhesive softens and takes a shape as shown in (d).

When the top plate was returned to room temperature, the resin was cured again, and the top plate and the heater board were joined.

The shape of the inside of the nozzle formed by the above steps was a smooth curved surface shape as shown in FIG.

By heating the object to be coated during coating as in this embodiment, it becomes possible to apply a thick adhesive to the upper part of the wall, that is, the bonding area, and to obtain a sufficient bonding strength. I got it.

Although a rectangular groove is used in this embodiment,
Similar effects can be obtained with nozzles of other shapes such as V-shaped grooves.

Also, even if the nozzle is made of a material other than silicon, if the nozzle has no ink resistance, if the nozzle has a shape with corners or is not smooth, the top plate and the heater board are connected via a joining member. The present invention is effective if any of the cases of joining are applicable.

Although a thermoplastic adhesive is used as the adhesive resin in this embodiment, a chemically reactive adhesive resin such as a thermosetting resin or a photocurable resin may be used as long as it has ink resistance.

Embodiment 3 Next, another embodiment of the present invention will be described. In this example, FIG.
As shown in above, a method of spraying a resin solution using a spray coating device using a top plate 13 in which a ceiling 32 portion of a rectangular groove 14 formed by anisotropic etching is not smooth and a convex portion 51 is formed. State.

When a rectangular groove is formed by anisotropic etching, a wafer having a crystal orientation of the <110> plane of Si is used, and patterning is performed so that the nozzle wall becomes the <111> plane. Then, the part of the nozzle wall is <11
Although a smooth surface can be obtained due to the etching resistance of the 1> surface, the top portion is a <110> surface that is more easily etched. Therefore, the ceiling portion is etched sequentially from a portion having a weak silicon bond, and the surface becomes rough.

When anisotropic etching is performed, a projection may be generated due to a thermal oxide film of a mask material or a residue of carbon in a resist.

Further, the surface may be rough due to crystal defects of Si.

Even if a resin solution is sprayed on the projections 51 using a spray coating device, the projections 51 are not sufficiently covered by a usual method and are dissolved in alkaline ink.

The present invention describes a method of manufacturing an ink jet head which sufficiently covers the convex portion 51 and is resistant to alkaline ink.

The adhesive resin used was the same as that used in Example 1 except that a strong thermoplastic resin was diluted with a diluent.

FIG. 5B shows a state after curing at 100 ° C. for 2 minutes on a hot plate in order to dry the diluent after the application, and FIG.
μm, 3 μm on the ceiling 32 and 1 μm on the wall 33.

Since the top plate was not heated in the first application, the ceiling could be coated with a thick and sufficient adhesive resin.

Therefore, as shown in FIG. 5 (b), the convex portion which was initially on the ceiling was covered with the resin, and the shape in the groove became smooth.

Next, the adhesive resin was applied again by a spray device while heating the top plate in the same manner as in Example 2.

FIG. 5 shows the state of the top plate after re-application.
As shown in (c), the thickness of the adhesive resin in the portion above the wall is increased by heating and re-application.

Next, as in the first embodiment, the top plate 13 and the heater board 11 were overlapped with each other as shown in FIG. 5D, a weight was applied, and the top plate 13 was heated to 250 ° C.

As a result, the thermoplastic resin softens, as shown in FIG.
It is shaped like

When the top plate was returned to room temperature, the resin was cured again, and the top plate and the heater board were joined.

By the re-coating, the thickness of the adhesive resin layer on the wall, that is, the adhesive area in the adhesive area could be increased, and sufficient adhesive strength could be obtained.

In the present embodiment, by changing the first and second application temperatures, it was possible to apply a thick resin to both the ceiling portion of the groove and the portion above the wall.

That is, according to the present invention, both a smooth inner shape of the nozzle covering the convex portion inside the nozzle and a sufficient adhesive strength between the top plate and the heater board were obtained.

Further, the resin inside the nozzle was thickly applied, so that the ink resistance was further enhanced.

In this embodiment, rectangular grooves are used.
Similar effects can be obtained with nozzles of other shapes such as V-shaped grooves.

[0099] Even if the nozzle is made of a material other than silicon, if the nozzle has no ink resistance, or if the nozzle has a shape with corners or is not smooth, the top plate and the heater board are connected via a joining member. The present invention is effective if any of the cases of joining are applicable.

Although a thermoplastic adhesive is used as the adhesive resin in this embodiment, a chemically reactive adhesive resin such as a thermosetting resin or a photocurable resin may be used as long as the resin has ink resistance.

Embodiment 4 Next, another embodiment of the present invention will be described.

In a liquid discharge head, as a method for improving the liquid discharge efficiency, the discharge force, the discharge speed, and the landing accuracy on a recording medium, a method in which a movable member having a valve function is provided in the head is special. It is disclosed in Japanese Unexamined Patent Publication No. Hei 9-11471.

FIG. 6 shows an example of the movable member provided inside the groove.

In the present embodiment, the present invention is applied to a head on which the movable member is provided. This embodiment will be described below with reference to FIG. First, the top plate with the groove formed (Fig. 7
(A)) is fixed on a hot plate and heated to 80 ° C. In the state of being heated, as in Example 2,
That is, the resin solution is sprayed on the nozzle using a spray coating device.

The resin used was the same as that used in Example 2, except that a strong thermoplastic adhesive was diluted with a diluent.

FIG. 7B shows a state after curing at 100 ° C. for 2 minutes on a hot plate in order to dry the diluent after application, and FIG.
μm, 1 μm on the ceiling 32 and 3 μm on the part 33 above the wall.
m to form a silicon ink-resistant protective film.

Next, as in the second embodiment, the top plate 13 and the heater board 11 are overlaid as shown in FIG.

However, in this embodiment, a heater board on which the movable member 61 is already provided is used.

Next, when a load is applied to the top plate and the top plate is heated to 250 ° C., the thermoplastic adhesive softens and assumes a shape as shown in FIG. 7D.

Here, when the top plate is returned to room temperature, the resin is cured again and the top plate and the heater board are joined.

The inside of the nozzle formed by the above steps had a smooth curved surface as shown in FIG. 7D.

In the present invention, at the time of joining, that is, in FIG. 7 (c), the resin on the wall is not heated yet, so it is not softened or deformed.

Accordingly, the movable member does not come into contact with the resin, and the movable member is not damaged. In addition, contact between the resin and the movable member does not cause poor adhesion between the top plate and the heater board.

Further, since a thick adhesive was applied to the portion above the wall, that is, to the bonding area, sufficient bonding strength could be obtained.

Observation of the ejection state and recording on recording paper were performed using an ink jet recording head manufactured by the above-described method. As a result, ink ejection and filling efficiency were good, and good results were obtained for printing. Was.

[0116]

As described above, according to the present invention, ink resistance can be imparted by providing a protective film on an ink jet nozzle.

In addition, a rectangular groove for a rectangular groove and a vertex of a triangle for a V-shaped groove, which are ink flow resistances, are eliminated, and the inside of the nozzle is formed into a smooth curved surface to improve the ink discharge and filling efficiency. Can be improved.

Further, at the same time, an adhesive for joining the top plate and the heater board can be easily applied in a small amount to a small bonding area in an amount necessary and sufficient to satisfy the bonding strength.

In particular, an effective point of the present invention is that an ink jet recording head which can simultaneously satisfy all of the above effects can be realized.

Therefore, it was possible to provide an ink jet printer having high reliability for a long time and high discharge and filling efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic sketch drawing of an example of an ink jet recording head using a top plate on which a groove is formed.

FIG. 2 is a schematic plan view of an example of an inkjet recording head using a top plate having a V-shaped groove.

3A to 3D are schematic cross-sectional views illustrating Embodiment 1 of the inkjet recording head according to the present invention.
The production procedure is shown below.

FIGS. 4A to 4D are schematic cross-sectional views illustrating an ink jet recording head according to a second embodiment of the present invention.
The production procedure is shown below.

FIGS. 5A to 5E are schematic cross-sectional views illustrating Embodiment 3 of the inkjet recording head according to the present invention, wherein FIGS.
The production procedure is shown below.

FIG. 6 is a schematic diagram for explaining a fourth embodiment of the ink jet recording head according to the present invention.

FIGS. 7A to 7D are schematic cross-sectional views illustrating an ink jet recording head according to a fourth embodiment of the present invention.
The production procedure is shown below.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Heater board 12 Heating element 13 Top plate 14 Groove 15 Liquid chamber 21 V-shaped groove 22 Nozzle member 31 Wall side 32 Ceiling 33 Part on wall 34 Resin 51 Convex part

Claims (24)

[Claims] 1. A top plate having a groove for forming a nozzle provided corresponding to each of a plurality of discharge ports, and a substrate having a discharge energy generating element provided in a part of the nozzle. In the method of manufacturing an ink jet recording head that forms a nozzle by joining, prior to joining the top plate and the substrate, by mixing a resin with a gas and spraying the mixture onto the joining surface side of the top plate, A method for manufacturing an ink jet recording head, characterized in that a cross-sectional shape of the nozzle formed by bonding is a curved surface. 2. The method of manufacturing an ink jet recording head according to claim 1, wherein the step of mixing the resin with a gas and spraying the mixed resin on a joint surface side of the top plate is performed while heating the top plate to room temperature or higher. . 3. The step of mixing the resin with a gas and spraying the mixture on the bonding surface side of the top plate is divided into two or more times. 2. The method for manufacturing an ink jet recording head according to claim 1, wherein the temperature is higher than the temperature of the top plate when applying the ink to the ink jet recording head. 4. The top plate is made of a silicon wafer,
The method for manufacturing an ink jet recording head according to claim 1. 5. The method according to claim 4, wherein the groove is formed by anisotropic etching. 6. The method according to claim 1, wherein the groove is formed by irradiating a member serving as a top plate with laser light. 7. The method according to claim 6, wherein the member is any one of a resin, a mineral, a metal, and a glass material. 8. The method for manufacturing an ink jet recording head according to claim 1, wherein the resin is an adhesive resin. 9. The adhesive resin is a thermoplastic resin,
A method for manufacturing an ink jet recording head according to claim 8. 10. The method according to claim 8, wherein the adhesive resin is a polyether amide resin. 11. The method according to claim 8, wherein the adhesive resin is a chemically reactive adhesive resin. 12. A nozzle provided corresponding to each of a plurality of discharge ports is formed by joining a top plate having a groove and a substrate having a discharge energy generating element provided in a part of the nozzle. In the formed ink jet recording head, a resin layer is formed on a surface on a bonding surface side of the top plate, and the cross-sectional shape of the nozzle is curved by the resin layer. . 13. The ink jet recording head according to claim 12, wherein said top plate is made of a silicon wafer. 14. The ink jet recording head according to claim 13, wherein said groove is formed by anisotropic etching. 15. The device according to claim 1, wherein the groove is formed by irradiating a member serving as a top plate with laser light.
3. The inkjet recording head according to 2. 16. The ink jet recording head according to claim 15, wherein said member is any one of a resin, a mineral, a metal, and a glass material. 17. The ink jet recording head according to claim 12, wherein the resin is an adhesive resin. 18. The ink jet recording head according to claim 17, wherein the adhesive resin is a thermoplastic resin. 19. The ink jet recording head according to claim 17, wherein the adhesive resin is a polyether amide resin. 20. The ink jet recording head according to claim 17, wherein the adhesive resin is a chemically reactive adhesive resin. 21. A liquid jet recording apparatus comprising the ink jet recording head according to claim 12. 22. The ink jet recording head according to claim 1, wherein said ink jet recording head is an ink jet recording head which discharges a liquid by generating bubbles based on energy generated by said discharge energy generating element. Head manufacturing method. 23. The ink-jet recording head according to claim 12, wherein said ink-jet recording head is an ink-jet recording head that discharges a liquid by generating bubbles based on energy generated by said discharge energy generating element. head. 24. The liquid jet recording apparatus according to claim 21, wherein said ink jet recording head is an ink jet recording head which discharges a liquid by generating bubbles based on energy generated by said discharge energy generating element.