KR20010066811A - Manufacturing method of actuator for ink jet printer head - Google Patents

Abstract

PURPOSE: An actuator manufacturing method for an ink jet printer head is provided to simplify the manufacturing process by forming a structure by direct silicon joining and removing any insulation layer forming steps by using a silicon material for forming a vibration plate, thereby increasing the processing precision and the integration ratio. CONSTITUTION: An actuator manufacturing method for an ink jet printer head includes the steps of preparing a silicon wafer, forming an etching stop layer(12) at a lower part of the silicon wafer, forming a vibration plate(14) formed of a silicon material, joining the vibration plate with a lower part of the etching stop layer by thermal processing, forming a chamber plate(16) formed of silicon material, forming a chamber in the chamber plate by full-etching, joining the chamber plate formed with the chamber with a lower part of the vibration plate by thermal processing, finishing a lower structure of the actuator by removing the silicon wafer, forming a lower electrode(20) on the lower structure, forming a piezo-electric/electro-striction(22) with a uniform pattern on the lower electrode for actuating in response to power supply, and forming an upper electrode(24) on the piezo-electric/electro-striction film.

Description

Manufacturing method of actuator for ink jet printer head

TECHNICAL FIELD The present invention relates to actuators, and more particularly, to a method of manufacturing an actuator for use in an inkjet printer head.

An actuator of an inkjet printer head using a piezoelectric body generally has a lower structure composed of a diaphragm and a chamber, a piezoelectric / electric strainer which is coupled to an upper portion of the diaphragm to cause mechanical deformation when power is applied, and an electrode that transmits power to the piezoelectric / electric strainer. It consists of

The piezoelectric body of the actuator has a property of being polled when power is applied. When power is applied to the upper and lower electrodes formed on the top and bottom of the polled piezoelectric material, the piezoelectric elements located between the electrodes vibrate or deform while repeating deformation and restoration.

In the inkjet printer head, when the piezoelectric body of the actuator vibrates, the diaphragm causes mechanical deformation in the thickness direction, and ink is injected onto the recording medium.

Therefore, the substructure of the actuator composed of the chamber and the diaphragm in the inkjet printer head has become an important factor in the operation of the actuator.

In order to form the substructure of the actuator using the piezoelectric body, the chamber and the diaphragm are formed by half etching by wet etching method mainly when the metal is used as the material, and punched when the ceramic is used as the material. It is common to form a three-dimensional structure by sintering and pressing the sheet and the diaphragm sheet.

However, when forming the substructure of the actuator by half-etching metal, it is difficult to obtain a diaphragm having a desired thickness by adjusting the etching rate and time, and in the case of forming the substructure of the actuator by punching and sintering and pressing ceramics There is a problem in that precision and yield are lowered.

An object of the present invention for solving the above problems is to provide a method for manufacturing an actuator for an inkjet printer head by bonding a diaphragm and a chamber plate made of a silicon-based material by direct silicon bonding.

1 to 11 is a process diagram showing an embodiment of the method of the present invention,

12-23 is a process diagram showing another embodiment of the method of the present invention;

24 to 34 are process diagrams showing another embodiment of the method of the present invention;

35-46 are process diagrams illustrating another embodiment of the method of the present invention.

<Description of the symbols for the main parts of the drawings>

10, 30, 50, 70: silicon wafer 12, 32, 52, 72: etching stop layer

14, 34, 54, 74: diaphragm 16, 36, 56, 76: chamber plate

18, 38, 58, 78: chamber 79: euro

20, 40, 60, 80: lower electrode 22, 42, 62, 82: piezoelectric / electric strain film

24, 44, 64, 84: upper electrode

The present invention for achieving the above object comprises the steps of providing a silicon wafer; Forming an etch stop layer under the silicon wafer; Forming a diaphragm made of a silicon-based material; Bonding the diaphragm to a lower portion of the etch stop layer by a heat treatment; Forming a chamber plate made of a silicon-based material; Full etching the chamber plate to form a chamber in the chamber plate; Bonding the chamber plate on which the chamber is formed to a lower portion of the diaphragm by heat treatment; Completing the undercarriage of the actuator by removing the silicon wafer; Forming a lower electrode on the upper portion of the lower structure; Forming a piezoelectric / electric distortion film in a predetermined pattern on the lower electrode and actuating when power is applied; And forming an upper electrode on an upper portion of the piezoelectric / electric distortion film.

The present invention also provides a silicon wafer; Forming an etch stop layer under the silicon wafer; Forming a diaphragm made of a silicon-based material; Bonding the diaphragm to a lower portion of the etch stop layer by a heat treatment; Forming a chamber plate made of a silicon-based material; Etching the chamber plate to form a chamber in the chamber plate; Etching the chamber plate remaining in the lower part of the chamber to form a flow path in the lower part of the chamber; Bonding the chamber plate on which the chamber and the flow path are formed by a heat treatment to a lower portion of the diaphragm; Completing the undercarriage of the actuator by removing the silicon wafer; Forming a lower electrode on the upper portion of the lower structure; Forming a piezoelectric / electric distortion film in a predetermined pattern on the lower electrode and actuating when power is applied; And forming an upper electrode on an upper portion of the piezoelectric / electric distortion film.

EMBODIMENT OF THE INVENTION Hereinafter, the method of manufacturing the actuator for inkjet printer head of this invention is demonstrated in detail.

First, prepare a silicon wafer to bond the diaphragm. It is preferable to use a silicon wafer having a thickness of 100-500 μm, and the silicon wafer serves to fix the diaphragm in a subsequent process.

An etching stop layer is formed below the prepared silicon wafer. It is preferable to form a silicon oxide film (SiO ₂ ) or a silicon nitride film (Si ₃ N ₄ ) as the etching stop layer. The silicon oxide film is generally formed by heat treating a lower portion of a silicon wafer, and the silicon nitride film is generally formed by nitriding a lower portion of a silicon wafer. The formed silicon oxide film or silicon nitride film serves as a junction interface to be bonded to the diaphragm, and functions as an etch stop layer when etching the silicon wafer in a later step.

The diaphragm to be bonded to the silicon wafer is formed separately. As the material of the diaphragm, silicon-based materials such as silicon (Si), silicon carbide (SiC), and polysilicon (poly-Si) are used. The diaphragm is preferably formed to a thickness of 5-10 μm.

When it is difficult to form a thin thickness of the diaphragm, a thick diaphragm may be bonded to a silicon wafer and then wrapped and polished to form a diaphragm having a desired thickness.

The diaphragm and the silicon wafer on which the etching stop layer is formed are bonded. At this time, the etching stop layer formed on the lower portion of the silicon wafer is bonded to the diaphragm.

Bonding of the etch stop layer and the diaphragm is performed by heat treatment. Since the material materials are silicon-based materials, heat treatment at a high temperature of 1,000 ° C. or higher is required. In this case, pressure may be applied during heat treatment to facilitate bonding. In addition, when the heat treatment process at a high temperature is difficult, by applying a DC field of 800VDC or less to the upper and lower wafers during bonding, the heat treatment temperature can be lowered to about 400-500 ° C.

At this time, since both the etch stop layer and the diaphragm are made of a silicon-based material, they are joined by direct bonding between silicon atoms.

The chamber plate is formed separately. As the material of the chamber plate, silicon-based materials such as silicon and silicon carbide are used, and it is preferable to manufacture the wafer in a wafer form.

In this case, the chamber plate may be formed in which only the chamber is formed, but may also form a chamber plate in which the chamber and the flow path are integrally formed.

In the case of forming only the chamber, the chamber-type silicon is formed by performing a full etching of the wafer-type silicon-based material, which becomes the chamber plate, by dry or wet etching. In the case of dry etching, the cross section of the chamber has the advantage of being formed in a vertical shape. In the case of wet etching, the cross section of the chamber is formed in an inclined shape. There is an advantage that can increase the adhesive area of the. In addition, since the pressure of the ink due to the expansion and contraction of the diaphragm is pressurized in the flow direction, there is an advantage in ejecting the ink.

When the chamber and the flow path are to be integrally formed, a silicon-based material in the form of a wafer to be a chamber plate is first etched to form a chamber, and then the remaining chamber plate is etched to form a flow path at the bottom of the chamber. In this case, both wet and dry etching may be used as a method of etching the chamber, but it is preferable to form the liquid by wet etching, and the flow path is preferably formed by dry etching. As such, when the chamber and the flow path are integrally formed, arrangement errors and adhesion failures that may occur when the chamber plate and the flow path plate are separately bonded may be eliminated.

The diaphragm bonded to the silicon wafer is bonded to the chamber plate formed separately. Joining of the diaphragm and the chamber plate is performed by heat treatment. Since the material materials are silicon-based materials, heat treatment at a high temperature of 1,000 ° C. or higher is required. In this case, in order to facilitate the bonding, pressure may be applied during the heat treatment, and a heat treatment temperature may be lowered to about 400-500 ° C. by applying a DC field of 800 VDC or less to the upper and lower wafers during the bonding.

At this time, since both the diaphragm and the chamber plate are made of a silicon-based material, the diaphragm and the chamber plate are joined by direct coupling between silicon atoms.

After bonding the diaphragm and chamber plate, the silicon wafer is removed. The silicon wafer is removed by lapping or etching, or after lapping and etching. In the case of etching, since the etching is stopped in the etching stop layer formed under the silicon wafer, the degree of etching can be controlled.

By the above process, the substructure of the actuator for the inkjet printer head is completed.

A lower electrode is formed on the formed diaphragm. Conductive metals such as alloys of gold (Au), silver (Ag), platinum (Pt), aluminum (Al), nickel (Ni), copper (Cu) and silver / palladium (Pd) are used as materials for the lower electrode. It is formed using a method such as vacuum deposition, sputtering or screen printing.

An upper portion of the lower electrode is provided with a piezoelectric / electric distortion film that actuates when power is applied. Piezoelectric / electric warp film can be formed by common methods, and typical methods include piezoelectric / electric warp ceramic powder in the form of a paste and forming a film by screen printing, etc., followed by heat treatment or thin piezoelectric / And a method of etching and patterning the electrodeposited film.

The upper electrode is formed in a predetermined pattern on the piezoelectric / distortion film. The upper electrode is formed by the same material and method as the lower electrode. By forming the upper electrode, the entire actuator is completed.

The completed actuator may be used as it is, and by providing a silicon oxide film on the surface by thermally oxidizing the silicon-based material, hydrophilicity may be imparted to the surfaces of the vibrating plate and the chamber plate in contact with the ink.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following examples are intended to illustrate the invention and not to limit the scope of the invention.

1-11 illustrate the process of one embodiment of the method of the present invention.

An etching stop layer 12 is formed under the silicon wafer 10. The silicon diaphragm 14 formed separately is bonded to the lower part of the etch stop layer 12.

After the chamber plate 16 is formed of a silicon-based material, the chamber 18 is formed by full etching by wet etching. The chamber plate 16 on which the chamber 18 is formed is bonded to the lower part of the diaphragm 14. After the diaphragm 14 and the chamber plate 16 are bonded together, the silicon wafer 10 is removed by etching to complete the substructure.

An actuator is completed by forming a lower electrode 20, a piezoelectric / electric strain film 22, and an upper electrode 24 on the completed lower structure.

12-23 illustrate a process of another embodiment of the method of the present invention.

An etching stop layer 32 is formed under the silicon wafer 30. The silicon diaphragm 34 is bonded to the lower portion of the etch stop layer 32. The bonded diaphragm 34 is wrapped and polished to form a diaphragm of the desired thickness.

After the chamber plate 36 is formed of a silicon-based material, the chamber 38 is formed by full etching by wet etching. The chamber plate 36 on which the chamber 38 is formed is bonded to the lower portion of the diaphragm 34. After the diaphragm 34 and the chamber plate 36 are bonded to each other, the silicon wafer 30 is removed by etching to complete the substructure.

An actuator is completed by forming a lower electrode 40, a piezoelectric / electric strain film 42, and an upper electrode 44 on the completed lower structure.

Figures 24-34 show the process of another embodiment of the method of the present invention.

An etching stop layer 52 is formed under the silicon wafer 50. The silicon diaphragm 54 formed separately is bonded to the lower portion of the etching stop layer 52.

After the chamber plate 56 is formed of a silicon-based material, full etching is performed by dry etching to form the chamber 58. The chamber plate 56 on which the chamber 58 is formed is bonded to the lower part of the diaphragm 54. After the diaphragm 54 and the chamber plate 56 are bonded to each other, the silicon wafer 50 is removed by lapping and etching. The substructure is completed by removing the silicon wafer 50.

An actuator is completed by forming the lower electrode 60, the piezoelectric / electric strain film 62, and the upper electrode 64 on the diaphragm 54.

35-46 illustrate a process of another embodiment of the method of the present invention.

An etching stop layer 72 is formed under the silicon wafer 70. The silicon diaphragm 74 formed separately is bonded to the lower portion of the etching stop layer 72.

The chamber plate 76 is wet-etched to form the chamber 78, and the lower portion thereof is dry-etched again to form the flow path 79. The chamber plate 76 on which the chamber 78 and the flow path 79 are formed is bonded to the lower portion of the diaphragm 74. After the diaphragm 74 and the chamber plate 76 are joined, the silicon wafer 70 is removed by etching to complete the substructure.

An actuator is completed by forming a lower electrode 80, a piezoelectric / electric strain film 82, and an upper electrode 84 on the completed lower structure.

The present invention as described above forms a structure by direct silicon bonding, the process is simple, and by using a silicon-based material as a diaphragm, a separate insulating layer forming process is not necessary, the process is simplified, and the effect of hydrophilization is easy. have.

In addition, since a silicon-based material is used as the material, it can be processed at a high temperature, has excellent oxidation resistance, can increase processing accuracy, that is, increase the degree of integration, and is easy to hydrophilize.

Claims (10)

Providing a silicon wafer; Forming an etch stop layer under the silicon wafer; Forming a diaphragm made of a silicon-based material; Bonding the diaphragm to a lower portion of the etch stop layer by a heat treatment; Forming a chamber plate made of a silicon-based material; Full etching the chamber plate to form a chamber in the chamber plate; Bonding the chamber plate on which the chamber is formed to a lower portion of the diaphragm by heat treatment; Completing the undercarriage of the actuator by removing the silicon wafer; Forming a lower electrode on the upper portion of the lower structure; Forming a piezoelectric / electric distortion film in a predetermined pattern on the lower electrode and actuating when power is applied; And And forming an upper electrode on the piezoelectric / distortion film. The method of manufacturing an actuator for an ink jet printer head according to claim 1, wherein the silicon-based material as the material of the diaphragm is selected from silicon, silicon carbide, and polysilicon. The method of claim 1, wherein the diaphragm is formed to a thickness of 5-10㎛. A method of manufacturing an actuator for an ink jet printer head according to claim 1, wherein silicon or silicon carbide is used as the silicon-based material as the material of the chamber plate. The method of manufacturing an actuator for an ink jet printer head according to claim 1, further comprising performing a hydrophilic treatment on a surface in contact with the ink of the actuator. Providing a silicon wafer; Forming an etch stop layer under the silicon wafer; Forming a diaphragm made of a silicon-based material; Bonding the diaphragm to a lower portion of the etch stop layer by a heat treatment; Forming a chamber plate made of a silicon-based material; Etching the chamber plate to form a chamber in the chamber plate; Etching the chamber plate remaining in the lower part of the chamber to form a flow path in the lower part of the chamber; Bonding the chamber plate on which the chamber and the flow path are formed by a heat treatment to a lower portion of the diaphragm; Completing the undercarriage of the actuator by removing the silicon wafer; Forming a lower electrode on the upper portion of the lower structure; Forming a piezoelectric / electric distortion film in a predetermined pattern on the lower electrode and actuating when power is applied; And And forming an upper electrode on the piezoelectric / distortion film. The method of manufacturing an actuator for an ink jet printer head according to claim 6, wherein the silicon-based material as the diaphragm is selected from silicon, silicon carbide, and polysilicon. 7. The method of manufacturing an actuator for an ink jet printer head according to claim 6, wherein the diaphragm is formed to a thickness of 5-10 mu m. The method of manufacturing an actuator for an ink jet printer head according to claim 6, wherein silicon or silicon carbide is used as the silicon-based material as the material of the chamber plate. The method of manufacturing an actuator for an ink jet printer head according to claim 6, further comprising performing a hydrophilic treatment on a surface in contact with the ink of the actuator.