KR100771967B1 - Piezoelectric ink jet printer head manufacturing process - Google Patents

Abstract

Piezoelectric inkjet printer head manufacturing method according to the present invention comprises the steps of manufacturing an elastic plate using laminating; Machining a hole in one side of the elastic plate by a punching operation; Forming a spacer, a channel plate and a nozzle plate on the side and the bottom of the chamber by laminating, the through hole and the chamber portion to be supplied ink to the spacer by a punching operation, the chamber portion and the ink passage in the channel plate, the nozzle Forming a tapered portion and a nozzle on the plate; Aligning the elastic plate, the spacer, the channel plate, and the nozzle plate using an alignment mark, and then performing stacking; Performing sintering; Forming a lower electrode on the elastic plate; Forming a piezoelectric plate on the lower electrode; Forming an upper electrode on the piezoelectric plate; And forming a protective layer on the upper electrode.

Accordingly, the piezoelectric inkjet printer head manufacturing method according to the present invention can easily implement a shape (not connected to the TOP or Bottom, forming a blank space in the center, cantilever, etc.) that is difficult to manufacture by the MEMS process than conventional.

In addition, the present invention can prevent the increase in the size of the product, the complexity of the process and the increase in cost caused by laminating several conventional plates.

Inkjet Printer Heads, Laminating, Sintering, Piezoelectric Plates

Description

Piezoelectric ink jet printer head manufacturing process

1 is a plan view and a cross-sectional view showing an inkjet printer head according to the prior art.

2 is a flowchart illustrating a method of manufacturing an inkjet printer head according to the prior art.

3 is a view briefly showing an elastic plate, a spacer, a channel plate, and a nozzle plate according to an embodiment of the present invention.

4 is a flowchart illustrating a method of manufacturing an inkjet printer head according to an embodiment of the present invention.

5A to 5C are diagrams for explaining stacking, pressurization, and isostatic molding according to an embodiment of the present invention, and FIG. 5D is a view showing a state after the process.

6A and 6B are graphs for explaining a structure of sintering (sintering) and a temperature control method during sintering according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

52: nozzle plate 56: channel plate

58: ink passage 60: lower electrode

62: piezoelectric plate 64: through hole

66: protective layer 68: upper electrode

70: elastic plate 72: spacer

74: electrode pad 78: chamber

The present invention relates to a method for manufacturing a piezoelectric inkjet printer head, and more particularly, to simplify the number of processes and products, and to reduce the cost, and to further reduce the size of the finished product, compared to the method manufactured using a conventional MEMS process. And it relates to a piezoelectric inkjet printer head manufacturing method that can be optimized.

The present invention is a patent in which the applicant has further improved a patent registered on March 31, 2005 (registration number: 10-481996, name: piezoelectric inkjet printer head and manufacturing method).

The registered patent will be described in more detail with reference to FIGS. 1 and 2.

1 is a plan view and a cross-sectional view of an inkjet printer head according to the prior art, and FIG. 2 is a flowchart for explaining a method of manufacturing the inkjet printer head according to the prior art.

Referring to FIG. 1, in the inkjet printer head conventionally configured by stacking a plurality of plates, the upper and lower electrodes 68 and 60 and a piezoelectric plate 62 inserted therebetween, and the upper electrode 68 An actuator part including a protective layer 66 positioned on the upper side of the upper side of the panel) and an elastic plate 70 disposed below the lower electrode 60; A spacer 72 disposed below the elastic plate 70 to form a side portion of the chamber 78 and a chamber 78 disposed below the spacer 72 to extend the chamber 78; A channel plate 56 for forming an ink passage on one side of the channel plate, and a nozzle 52a disposed below the channel plate 56 to form a lower side of the chamber 56 and connected to the chamber 56. An ink flow unit configured of the nozzle plate 52; And an ink supply portion formed by a through hole penetrating through the actuator portion and the spacer 72 and reaching the ink passage of the channel plate 56.

In addition, referring to Figure 2, in the manufacturing method of the inkjet printer head conventionally configured by stacking a plurality of plates such as an elastic plate having elasticity and a nozzle plate provided with a nozzle,

Arranging the elastic plate 70 (S101), printing the lower electrode 60 on the elastic plate 70 (S102), and spacers 72 below the elastic plate 70. Printing (S103), and printing the channel plate 56 on the lower side of the spacer 72 (S104), the elastic plate 70, the lower electrode 60 and the spacer 72 and the channel plate ( Sintering the combination of 56 (S105), step S106 of forming a piezoelectric plate 62 above the lower electrode 60, and an upper electrode 68 above the piezoelectric plate 62; Step (S107), forming a protective layer 66 on the upper electrode 68 (S108), and through-hole processing from the protective layer 66 to the spacer 72 Step (S109), step (S110) of processing the tapered portion 54 on the nozzle plate 52, step (S111) of processing the fine spray hole at the apex of the tapered portion 54 of the nozzle plate, The nozzle plate 52 and the channel plate 56 And a summing step (S112).

However, since the conventional technology uses a MEMS process to produce a laminated method, it is impossible to produce a shape (that is, it is not connected to a top or bottom, and an empty space is formed in the center, a cantilever, etc.). Even if this is possible, manufacturing costs increased because a number of additional additional processes were required. In addition, conventionally, in order to realize any shape, even a minute portion must be manufactured on a substrate (Substrate) that is basically supported, so that a multi-layer stack or a package after finishing pattern production to realize a complicated shape of the final product Increasing thickness makes product miniaturization and optimization difficult.

In addition, as mentioned above, the conventional technology uses the MEMS process to manufacture the inkjet printer head, so the designer needs to increase the size of the chamber or the entire print head or change the design by the substrate, whether or not he / she wants to. Is generated.

The present invention has been made to solve the above problems, the purpose of the laminating method of the components (elastic plate, spacer, channel plate and nozzle plate, etc.) forming the upper, side and lower side of the chamber of the inkjet printer head. The present invention provides a method of manufacturing an inkjet print head that can simplify the product process, reduce manufacturing costs, and minimize and optimize finished products.

Piezoelectric inkjet printer head manufacturing method according to the present invention for achieving the above object comprises the steps of producing an elastic plate using laminating; Machining a hole in one side of the elastic plate by a punching operation; Forming a spacer, a channel plate and a nozzle plate to form the side and the bottom of the chamber by laminating, and through the punching operation through the through hole and the chamber portion, the chamber portion and the ink passage to the channel plate, Forming a tapered portion and a nozzle on the nozzle plate; Aligning the elastic plate, the spacer, the channel plate, and the nozzle plate using an alignment mark, and then performing stacking; Performing sintering; Forming a lower electrode on the elastic plate; Forming a piezoelectric plate on the lower electrode; Forming an upper electrode on the piezoelectric plate; And forming a protective layer on the upper electrode.

Temperature control during the sintering step of increasing by 1 ~ 10 ℃ per minute (min) until the sintering temperature is 100 ~ 300 ℃; Maintaining the sintering temperature for 100 to 300 ° C. for 1 to 2 hours; Raising 1 to 10 ° C. per minute until the sintering temperature is 1050 to 1200 ° C .; Maintaining the sintering temperature at 1050 to 1200 ° C. for 2 to 3 hours; And it characterized in that it comprises the step of lowering the sintering temperature by 1 ~ 10 ℃ per minute (min).

The nozzle is preferably tapered on its upper side so that the cross-sectional area of the chamber gradually changes from the chamber to the beginning of the nozzle.

The material of the elastic plate is preferably ZrO ₂ or BaTiO ₃ or Al ₂ O ₃ .

In addition, the material of the spacer, the channel plate and the nozzle plate is preferably ZrO ₂ or BaTiO ₃ or Al ₂ O ₃ .

The height of the elastic plate is 3 ~ 10㎛, the height of the spacer is 100 ~ 200㎛, the height of the channel plate and the nozzle is preferably 20 ~ 40㎛.

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Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the inkjet printer head manufacturing method according to the present invention.

The ink jet printer head used in the present invention is similar in structure to the ink jet printer head used in the prior art.

That is, referring to Figure 1, the inkjet printer head according to the present invention is a nozzle plate 52, channel plate 56, spacer 72, elastic plate 70, lower electrode 60, The piezoelectric plate 62, the upper electrode 68, and the protective layer 66 are formed in this order.

A nozzle 52a penetrating in the vertical direction is formed in the nozzle plate 52, and a tapered portion 54 is formed at an upper portion of the nozzle 52a.

The nozzle 52a preferably changes gradually in cross-sectional area of the chamber 78 from chamber 78 to the beginning of the nozzle.

The channel plate 56 is connected to the spacer 72 at the upper side thereof, and is connected to the tapered portion 54 at the bottom thereof to extend an inner space of the chamber 78, and an ink passage 58 is formed at one side thereof.

The spacer 72 and the elastic plate 70 are coupled to each other, and the elastic plate 70 has an upper side, the spacer 72 and the channel plate 56 have side portions, and the nozzle plate 52 is formed therein. The chamber 78 constituting the lower side is formed.

In the present invention, an upper ink supply cylinder (not shown) for supplying ink to the chamber 78, a protective layer 66, upper and lower electrodes 68, 60, and a piezoelectric plate 62 from the ink supply cylinder. ), A through hole 64 penetrating the elastic plate 70 and the spacer 72 to reach the ink passage 58 is formed.

Meanwhile, an electrode pad 74 is formed at one side of the protective layer 66 to be electrically connected to an external control circuit (not shown).

In the present invention, the elastic plate 70, the spacer 72, the channel plate 56 and the nozzle plate 52 are manufactured by laminating.

In the present invention, any one of ZrO ₂ , BaTiO ₃ , and Al ₂ O ₃ may be used as the material of the elastic plate 70, the spacer 72, the channel plate 56, and the nozzle plate 52.

Here, laminating refers to bonding between the layers by isostatically forming a plurality of sheets and the like and then laminating them together.

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3 is a view briefly showing an elastic plate, a spacer, a channel plate, and a nozzle plate according to an embodiment of the present invention.

Referring to FIG. 3, an elastic plate 70 is positioned at an upper portion, a spacer 72 is positioned at a lower portion of the elastic plate 70, a channel plate 56 is positioned at a lower portion of the spacer 72. The nozzle plate 52 is positioned below the channel plate 56.

Preferably the height b of the said elastic plate 70 is 3-10 micrometers, More preferably, it is 3 micrometers.

The height c of the spacer 72 is preferably 100 to 200 µm, more preferably 160 µm.

The height d (e) of the channel plate 56 or the nozzle plate 52 is preferably 20 to 40 µm, more preferably 30 µm.

4 is a flowchart illustrating a method of manufacturing an inkjet head according to an embodiment of the present invention.

Referring to FIGS. 1 and 4, in the present invention, an elastic plate 70 is first manufactured by laminating. (S201) After laminating the stacked sheets of BaTiO ₃ sheets, the stacked sheets are laminated. Isostatic pressing (see FIG. 5C) is carried out to bond a plurality of sheets of BaTiO _{3 to} each other.

The elastic plate 70 has a thickness of 10 to 20 μm, and the material is ZrO _2. , BaTiO ₃ Any of, Al ₂ O ₃ may be used.

After manufacturing the elastic plate 70 as described above, in the present invention to form a shape of the elastic plate by the punching operation (S202), that is, a hole (hole) on one side of the elastic plate 70. Here, the hole is a through hole 64 to which ink is supplied.

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Then, in the present invention, the spacer 72, the channel plate 56 and the nozzle plate 52 constituting the side and bottom of the chamber 78 are manufactured by the laminating method used when manufacturing the elastic plate. (S203)

Then, in the present invention, the through hole and the chamber portion 78 to supply ink to the spacer 72 in the punching operation, the chamber portion 78 and the ink passage 58 to the channel plate 56, the nozzle plate 52 The tapered part 54 and the nozzle 52a are formed in (S204). It is preferable that the said nozzle plate 52 is a ceramic material. Further, the nozzle 52a is formed by processing a fine spray hole at the apex of the tapered portion.

After the tapered portion 54 and the nozzle 52a are formed on the nozzle plate 52 as described above, in the present invention, the elastic plate 70, the spacer 72, the channel plate 56 and the nozzle plate 52 are After aligning using the alignment mark, staking is performed (see FIG. 5A). (S205)

Then, in the present invention, sintering (see FIG. 6A and FIG. 6B) is performed (S206) so that the structure is firm and the adhesive force between the layers is secured.

Then, in the present invention, the lower electrode 60 to supply the driving power of the piezoelectric element is formed on the elastic plate 70 (S207).

As the method of forming the lower electrode 60 and the upper electrode 68, which will be described later, a method such as sputtering, MOCVD, and evaporation may be used. On the other hand, the upper electrode 68 and the lower electrode 60 is formed by the appropriate patterning (for example, lithography, lift-off process) each of the elastic plate 70, upper and lower electrodes (constituting one inkjet printer head) 68 and 60, the piezoelectric plate 62, and the protective layer 66 may be included and include a pad 74 for electrically connecting with an external control circuit (not shown).

As described above, after the lower electrode 60 is formed on the elastic plate 70, the piezoelectric plate 62 is deposited on the lower electrode 60 (S208), and the lower electrode 60 thereon. The upper electrode 68 is formed so as to be insulated from each other. (S209) Here, in order to avoid contact between the upper electrode and the lower electrode, an insulating film is deposited in advance at a point where the lower electrode and the upper electrode are expected to contact, or by appropriate arrangement. Make sure there is no point where the top and bottom electrodes touch.

The piezoelectric plate 62 has a thickness of 1.5 to 6 mu m, and the material is preferably PZT.

After forming the upper electrode 68, the piezoelectric plate 62 and the lower electrode 60 as described above, in the present invention, the protective layer 66 is formed on the upper side of the upper electrode 68. (S210) This is possible by the method of depositing SiO ₂ by CVD. Thereafter, the piezoelectric plate may be heat treated to compensate for the degradation of the piezoelectric plate due to hydrogen.

When the protective layer forming process is completed, the manufacturing process of the inkjet printer head is completed.

The protective layer 66 may etch a portion necessary to expose the pad portion of the upper electrode 68. The protective layer 66 serves to electrically and chemically protect the elastic plate 70, the upper and lower electrodes 68 and 60, the piezoelectric plate 62, and the like from the ink solution. Not shown) will be installed. At this time, it is preferable to insert an appropriate sealing means, for example, an O-ring having corrosion resistance to ink in the fastening part or to use an adhesive such as epoxy.

Meanwhile, the ink supply container (not shown) may already contain ink in itself, or may have a form in which a port for connecting an ink container separately from the outside is provided while having its own internal space.

The protective layer 66, the elastic plate 70, the lower electrode 60, the spacer 72 is preferably processed so that the through-hole 64 is formed in a funnel shape as shown in FIG.

It is preferable that the diameter of the processing hole 64 is 30 micrometers, and the depth of a hole is 150 micrometers or less.

As described above, by manufacturing the elastic plate 70, the spacer 72, the channel plate 56 and the nozzle plate 52 using laminating, the manufacturing process can be simplified and the cost can be reduced. Alternatively, the size of the chamber 78 can be changed by the manufacturer (freely).

5A to 5C are diagrams for explaining stacking, pressurization, and isostatic molding according to an embodiment of the present invention, and FIG. 5D is a view showing a state after the process.

Referring to FIG. 5A, a stacking operation refers to stacking 15 BaTiO ₃ sheets having a thickness of 20 μm, and the width and length of the sheet are preferably about 180 mm.

Referring to FIG. 5B, the stacked 15 sheets are pressed. The thickness is then 300 μm.

Referring to FIG. 5C, the pressurized sheets are isostatic pressed. The isostatic molding method includes cold isostatic pressing (CIP) and hot isostatic pressing (HIP). In the present invention, it is preferable to use cold isostatic pressing (CIP).

The CIP refers to a method of compression molding using hydrostatic pressure of the same size acting in all directions.

As a result, as shown in FIG. 5D, one molded body having a different width, length, and height than before is formed. That is, the horizontal and vertical length of the molded body is reduced to about 160mm, the height is also reduced to 270 ~ 280㎛.

6A and 6B are graphs for explaining a structure of sintering (sintering) and a temperature control method during sintering according to an embodiment of the present invention.

6A, in the present invention, Al ₂ O ₃ powder (powder) 20 is uniformly and uniformly distributed between BaTiO ₃ specimens 10 subjected to isostatic molding, and an Al ₂ O ₃ plate (upper and lower) After the 30) is installed, sintering is performed by applying the sintering temperature according to the time shown in FIG. 6B.

The Al ₂ O ₃ plate 30 is installed to apply the same pressure to implement the shape of the correct ink printer head, it is preferable that the size is larger than the BaTiO ₃ specimen (10).

The height l of the BaTiO ₃ specimen 10 is approximately 270-280 μm. In addition, the horizontal and vertical length (n) (o) of the Al ₂ O ₃ plate 30 is preferably about 180㎛, the height (m) is preferably about 10㎛.

The Al ₂ O ₃ plate 30 preferably has a higher sintering temperature than the BaTiO ₃ specimen 10. The reason is that Al ₂ O ₃ to have when applied to less than the sintering temperature of Al ₂ O ₃ plate 30 is BaTiO ₃ attached sample 10 is different problem of the sintering temperature BaTiO ₃ specimen (10) generated in the plate 30 Because.

For reference, in the section B of FIG. 6B, the dispersant, the binder, and the plasticizer included in the specimen are blown into the air, and the two steps (B, C) as described above to sinter only the particles (pointing to BaTiO ₃ pure particles) are performed. Hold through. As a result, the uniformity of the BaTiO ₃ test piece 10 is increased to improve the quality of the final product (finished product).

Referring to Figure 6b, the temperature control during sintering according to the present invention goes through the following steps. That is, initially, the sintering temperature is increased by 1 to 10 ° C. per minute (min) until the sintering temperature is 100 to 300 ° C. (corresponding to section A). Hold for a period of time (corresponding to section B) and then raise it by 1 to 10 ° C per minute (corresponding to section C) until the sintering temperature reaches 1050-1200 ° C, then the sintering temperature is 1050-1200 It is maintained for 2 to 3 hours in the state of ℃ (corresponding to the D section), and finally lowering the sintering temperature by 1 ~ 10 ℃ per minute (corresponding to the E section).

It looks at the operation of the inkjet printer head according to an embodiment of the present invention having the configuration as described above.

First, when ink is injected through the through hole 64 formed on the upper side, the ink falls downward by gravity and collects in the chamber 78 via the ink passage 58.

The ink collected in the chamber 78 is not discharged to the nozzle 52a unless an external force is applied because mutual forces exist between molecules.

Here, when current is supplied to the upper and lower electrodes 68 and 60, the piezoelectric plate 62 is contracted, and the elastic plate 70 attached to the piezoelectric plate 62 is convex downward, and the chamber inside the head. Pressure is applied.

By this pressure, the ink stored in the chamber 78 is discharged to the outside through the nozzle 52a to enable the spraying operation.

As described above, the piezoelectric inkjet printer head manufacturing method according to the present invention can easily implement a shape (not connected to the top or bottom, can be formed in the center, cantilever, etc.) difficult to manufacture by the MEMS process than conventional. .

In addition, the present invention can prevent the increase in the size of the product, the complexity of the process and the increase in cost caused by laminating several conventional plates.

In addition, the manufacturing process of the present invention can be applied to various fields such as an inkjet printer head as well as a sensor, an actuator manufactured using the MEMS process.

In the detailed description of the present invention as described above, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

Claims (7)

Manufacturing an elastic plate using laminating; Machining a hole in one side of the elastic plate by a punching operation; Forming a spacer, a channel plate and a nozzle plate to form the side and the bottom of the chamber by laminating, and through the punching operation through the through hole and the chamber portion, the chamber portion and the ink passage in the channel plate, Forming a tapered portion and a nozzle on the nozzle plate; Aligning the elastic plate, the spacer, the channel plate, and the nozzle plate using an alignment mark, and then performing stacking; Performing sintering; Forming a lower electrode on the elastic plate; Forming a piezoelectric plate on the lower electrode; Forming an upper electrode on the piezoelectric plate; And Piezoelectric inkjet printer head manufacturing method comprising the step of forming a protective layer on the upper electrode. The method of claim 1 wherein the temperature control during sintering is Raising 1 to 10 ° C. per minute until the sintering temperature is 100 to 300 ° C .; Maintaining the sintering temperature for 100 to 300 ° C. for 1 to 2 hours; Raising 1 to 10 ° C. per minute until the sintering temperature is 1050 to 1200 ° C .; Maintaining the sintering temperature at 1050 to 1200 ° C. for 2 to 3 hours; And Piezoelectric inkjet printer head manufacturing method comprising the step of lowering the sintering temperature by 1 ~ 10 ℃ per minute (min). The piezoelectric inkjet printer head manufacturing method of claim 1, wherein the nozzle is tapered at an upper side thereof so that the cross-sectional area of the chamber gradually changes from the chamber to the beginning of the nozzle. The piezoelectric inkjet printer head manufacturing method of claim 1, wherein the elastic plate is made of ZrO ₂ or BaTiO ₃ or Al ₂ O ₃ . The piezoelectric inkjet printer head manufacturing method of claim 1 or 2, wherein the spacer, the channel plate, and the nozzle plate are made of ZrO ₂ or BaTiO ₃ or Al ₂ O ₃ . The piezoelectric inkjet of claim 1 or 2, wherein the height of the elastic plate is 3 to 10 µm, the height of the spacer is 100 to 200 µm, and the height of the channel plate and the nozzle is 20 to 40 µm. How to make a print head. delete

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