TW568837B - Piezo-electrical ink-jetting nozzle head and its production method - Google Patents

Abstract

The ink-jetting nozzle head of this invention includes: a first laminar structure, a second laminar structure and a piezo-electrical component. The first and second laminar structures made by erosion or adherence are sealed to form a nozzle head, including: an ink-jetting aperture, an ink chamber, an ink channel, a vibrating membrane and a protrusion block. The piezo-electrical component is secured to a protruding block and has an affixing base extending along its both sides to be affixed to a sidewall of the second laminar structure, with a polarization direction along the planar orientation and extending towards the opposing sides from a center. Under the influences of the electrical field along a thickness direction, the piezo-electrical component moves in a cutting manner, such that the center portion that is connected to the protruding block may urge against the vibrating membrane, thereby subjecting ink contained in the ink chamber to be sprayed from the ink-jetting aperture due to compression.

Description

568837 V. Description of the Invention (1) Technical Field The present invention relates to a driving principle and a manufacturing method of a shear-type piezoelectric inkjet head, and particularly to a driving method and a manufacturing method of a piezoelectric actuator. BACKGROUND OF THE INVENTION In addition to being used in black and color printers, facsimiles, and plotters, inkjet printheads can also be used in the electronics, biochip, pharmaceutical, and chemical industries for microdroplet applications. At present, the inkjet print heads suitable for computer peripherals are mainly divided into thermal bubble inkjet print heads and piezoelectric inkjet print heads. The thermal bubble type uses a heater to instantly vaporize the ink and generate high-pressure bubbles. The ink is ejected from the nozzle, and the piezoelectric type works by using piezoelectric ceramics to deform due to applied voltage, squeezing the liquid to generate high pressure to eject the liquid, and according to the mechanism of different piezoelectric deformation, various piezoelectric inkjet printing The head can be divided into a bend type (Bend mode), a push type (Push mode), a shear type (Shear mode), and a shrink tube type (Squeeze tube mode). The direction of the electric field and the direction of polarization of a shear-type piezoelectric actuator are perpendicular to each other, and its moving mode is a shearing mode. As shown in Fig. 1, it is a structural diagram of a typical piezoelectric inkjet head, which is composed of a partition plate 104, a piezoelectric element plate 101 and a nozzle plate 102. The compartment board 1 0 4 has an ink chamber 105 and an ink channel 103, and the ink passes through the ink storage tank.

568837

V. Description of the invention (2) Circulation from the ink channel 103 to the ink chamber 105. When an electric field is applied to the piezoelectric element 101, the piezoelectric element 101 is moved to generate a thrust, and the ink in the ink chamber 105 is ejected from the nozzle holes 106 of the nozzle plate 102.

Fig. 2 shows the inkjet driving method of the piezoelectric element 101 of the inkjet head, which can be shown by the A-A sectional view of Fig. 1. As shown in FIG. 2, the polarization direction of the dust electric element 101 is the thickness direction, and the piezoelectric element 1 0 1 at the center of the ink chamber 105 has positive electrodes 1 7 on the upper and lower sides, and the compartment plate 1 0 There are negative electrodes 108 on the upper and lower sides of the piezoelectric element 1 0 1 on the side walls 1 0 9 on both sides of 4. When a voltage is applied to the positive and negative electrodes on both sides of the piezoelectric element 101, since the direction of the electric field and the polarization direction are perpendicular to each other, the piezoelectric element 101 is moved in a shearing manner toward the ink chamber 105. Push the ink to the nozzle hole 106 to eject. This type of inkjet head has a piezoelectric element with a polarization design of 10, and its displacement can be expressed as: X-Vd15

Where X is the displacement, V is the applied voltage, and d! Is the piezoelectric coefficient. This displacement is the center maximum displacement when the piezoelectric element 101 is fixed on both sides. When the piezoelectric element 101 is fixed on all four sides, its displacement will be less than this value. This type of inkjet head is designed so that its piezoelectric element 101 acts as the diaphragm of the ink chamber 105 in addition to its actuator. Therefore, the lower electrode of the piezoelectric element 101 will directly contact the ink, so the choice of ink will be greatly limited. Fig. 3 is another inkjet driving method of the piezoelectric element 201 of the inkjet head, which can be shown by the A-A sectional view of Fig. 1. As shown in Figure 3, the polarization direction of the piezoelectric element 201 is from the center of the ink chamber 2 05 to the thickness direction compartment.

Page 5 568837 V. Description of the invention (3) The side walls 2 0 9 of the plate 2 0 4 have a negative electrode 2 7 on the upper side of the piezoelectric element 2 0 and a positive electrode 2 8 on the lower side. When a voltage is applied to the positive and negative electrodes on both sides of the piezoelectric element 201, since the direction of the electric field and the direction of polarization are perpendicular to each other, the piezoelectric element 201 is moved in a shearing manner to the direction of the ink chamber 250. Push the ink to the nozzle hole 206 and eject. This type of inkjet head has a piezoelectric element with a polarization design of 201, and its displacement can be expressed as: X-LVd15 / 2t where X is the displacement, V is the applied voltage, di is the piezoelectric coefficient, and t Is the thickness of the piezoelectric element 201, and L is the distance between the side walls 209 on both sides of the partition plate 204. This displacement is the maximum displacement of the center of the piezoelectric element when both sides are fixed. When the piezoelectric element is fixed on all four sides, the displacement will be smaller than this value. Due to the different polarization methods of piezoelectric elements, the actuation displacement of this type of inkjet head is relatively large. The larger the value of L, the greater the actuation displacement. Therefore, the longer the length, the better, and the thinner the thickness. it is good. The thickness t of the piezoelectric element 201 should not be too thin, and it must be thick enough to generate a large thrust force to eject the ink. It should not be too long, because the larger the distance between the two nozzle holes 206, the higher the resolution of the inkjet head will be. The piezoelectric elements of the two inkjet heads described above are not divided, but are entirely covered under the pressure chamber. Only the positive and negative electrodes are coated on the area of each pressure chamber, so that the ink in each pressure chamber can be controlled independently. ejection. Since the piezoelectric element is not separated, two adjacent pressure chambers will have

568837 V. Description of the invention (4) The effect of interaction, the smaller the distance between the nozzle holes, the more obvious it will affect the inkjet quality. All four sides of the piezoelectric element on the pressure chamber are fixed on the side wall of the compartment plate. Therefore, a large voltage is required to generate a sufficient displacement, but a large voltage is easy to short-circuit and cause danger. In addition to the piezoelectric element acting as an actuator, the piezoelectric element also acts as the diaphragm of the ink chamber, so the lower electrode of the piezoelectric element will directly contact the ink, so the ink cannot have conductivity and corrosion components, so the choice of ink will be very Big restrictions. Summary of invention

The main purpose of the present invention is to improve the disadvantages of the previous inkjet head structure and the polarization method of the piezoelectric element, which can not only reduce the operating voltage of the inkjet head, but also simplify its manufacturing process and reduce the manufacturing cost. Another object of the present invention is that the piezoelectric element is not in direct contact with the ink, so the choice of the ink is not greatly limited.

In order to achieve the above object, the structure of the inkjet head of the present invention is characterized in that the nozzle hole, the ink chamber, the ink channel and the diaphragm of the inkjet head are composed of two structural plates, and the element driving the inkjet is sheared. In the case of a piezoelectric material acting in a mode, the so-called shear mode is that the direction of the electric field acting on the piezoelectric material and the polarization direction of the material are perpendicular to each other. According to the current invention, the first structural plate of the inkjet head has array-type nozzle holes and corresponding portions of the ink chamber space, ink passages, and partition side walls. The second structural plate of the ink head of the nozzle has a part of the space of the ink chamber, a side wall of the compartment, a diaphragm and a bump connected to the piezoelectric element. The piezoelectric element is fixed at

Page 7 568837 V. Description of the invention (5) On the bump, the two sides of the bump are fixed to the fixing seat on the side wall of the second structure plate, and the polarization direction is from the center to the two sides, and the signal electrode is in the piezoelectric On the upper side of the element thickness direction, the ground electrode is on its lower side. When an electric field acts between the electrodes, the piezoelectric element moves in a shearing manner because the direction of the electric field and the direction of polarization of its material are perpendicular to each other. Because both sides of the piezoelectric element are fixed to the fixing seat on the side wall of the second structure plate, the diaphragm is connected to the middle portion of the projection to push the diaphragm, so that the ink in the ink chamber is squeezed and ejected from the nozzle hole. . In order to improve the resolution of the inkjet head, the smaller the nozzle hole spacing is, the better. Therefore, the shape of the ink chamber is mostly rectangular, and generally the aspect ratio is large. The smaller the width of the ink chamber, the smaller the nozzle hole pitch, and the higher the resolution of the inkjet head. Because the piezoelectric element of the present invention is a fixed seat that is exaggerated on the side wall of the compartment in the length direction of the ink chamber, the larger the length of the ink chamber, the larger the displacement of the piezoelectric element under the action of a fixed voltage. Therefore, the operating voltage of the inkjet head can be reduced. The main purpose of the diaphragm bump of the present invention is to connect the diaphragm and the piezoelectric element, which can transmit the thrust generated by the piezoelectric element to the diaphragm and push the ink to be ejected from the nozzle hole. The design with this bump allows the piezoelectric element to be less constrained by the boundary, so it can generate a larger amount of displacement and reduce the operating voltage of the inkjet head. In order to increase the effective length of the bump, the bump can be designed to be convex, that is, the length on the side of the contact diaphragm is larger than the length of the contact on the piezoelectric element. In order to make the purpose, features, and advantages of the present invention more comprehensible, a detailed example is given below with reference to the accompanying drawings.

Page 8 568837 V. Description of the invention (6) Figure 1 shows the cross-sectional structure of the previous inkjet head. FIG. 2 is a sectional view of the inkjet head taken along the line A-A in FIG. FIG. 3 is a cross-sectional view of another ink jet head taken along the line A-A in FIG. 1. FIG. 4 is a cross-sectional structural view showing an inkjet head of the present invention. FIG. 5 is a sectional view of the inkjet head taken along the line B-B in FIG. FIG. 6 shows how the inkjet head of FIG. 4 ejects ink. Fig. 7 is a schematic diagram showing the manufacturing process of the first structural plate of the ink jet head of the present invention.

Fig. 8 is a schematic diagram showing the manufacturing process of the second structural plate of the ink jet head of the present invention. FIG. 9 is a schematic diagram showing a manufacturing process of a piezoelectric element of the inkjet head of the present invention. FIG. 10 is a cross-sectional structural view showing another ink jet head according to the present invention. FIG. 11 shows how the inkjet head of FIG. 10 ejects ink. Figure number description:

1 0 first structural plate 1 1 second structural plate 1 2 piezoelectric element 1 3 ink chamber 1 4 nozzle hole 15 ink channel 1 6 diaphragm 1 7 bump

Page 9 568837 V. Description of the invention (7) 1 8 Fixed base 1 9 Compartment side wall 2 0 Signal electrode 2 1 Ground electrode 22 Ink drop 2 3 Hard substrate 2 4 Photoresist layer 2 5 Piezo substrate 2 6 Positive electrode 2 7 Negative electrode 28 convex convex block embodiment: Fig. 4 shows a cross-sectional structural view of the inkjet head of the present invention, and Fig. 5 shows a cross-sectional view of the inkjet head along the line B-B of Fig. 4. The structure of the ink jet head of the present invention is composed of a first structural plate 10, a second structural plate 11 and a piezoelectric element 12. The first structure plate 10 and the second structure plate 11 constitute the nozzle holes 14 of the main structure of the inkjet head, the ink chamber 1 3, the ink channel 15, the diaphragm 16 and the bump 17. The first structural plate 10 has array-type nozzle holes 14 and a corresponding space of the ink chamber 13, an ink channel 15 and a compartment side wall 19. The second structural plate 11 has a space of a part of the ink chamber 13, a partition side wall 19, a diaphragm 16, and a bump 17 and a fixing base 18 connected to the piezoelectric element 12. The element driving the inkjet is a piezoelectric element 12 acting in a shearing manner. The so-called shearing manner is that the direction of the electric field acting on the piezoelectric material and the polarization direction of the material are perpendicular to each other. From

Page 10 568837 V. Description of the invention (8) Fig. 4 shows that the piezoelectric element 12 is fixed on the bump 17 and the two sides thereof are fixed to the fixing base 1 1 on the side wall of the second structural plate 1 1 'While the polarization direction is from the center position to both sides, the signal electrode 20 is on the upper side of the piezoelectric element 12 in the thickness direction, and the ground electrode 21 is on its lower side. When an electric field acts between the electrodes, the piezoelectric element moves in a shearing manner because the direction of the electric field and the polarization direction of its material are perpendicular to each other. Since both sides of the piezoelectric element are fixed to the side wall fixing base 18 of the second structural plate 11, the middle portion of the piezoelectric element connected to the bump 17 can push the diaphragm 16 to make the inside of the ink chamber 13 The ink is squeezed and ejected from the nozzle holes 14. The polarization direction of the piezoelectric element 12 is in the plane direction of the piezoelectric plate and along one side of the longer side of the space of the ink chamber 13. Under the same operating conditions, this type of polarization method will be better than that of the inkjet head in the previous invention. Side) is more efficient. Figures 4 and 5 show that the ink is enclosed in the ink chamber 13 by the first structural plate 10 and the second structural plate 11. The electrodes of the piezoelectric element 12 are not in direct contact with the ink, so there is no circuit. Short circuit and electrode corrosion by ink occur. The piezoelectric element 12 of the present invention is not one of the structures for enclosing the ink in the ink chamber 13, so it is not necessary that all four sides are fixed and sealed. As shown in FIG. 4, only the two sides of the longer side are fixed to the side. The wall mount 18 is free, and there are no restrictions on the free ends of the other short sides, as shown in Figure 5. This type of actuator is designed to generate a large displacement amount under a fixed voltage operation, so that the applied voltage of the inkjet head can be reduced. In addition, from Figure 5, it can be shown that the piezoelectric elements 12 of each inkjet mechanism are independently connected and separated, that is, the actuators adjacent to each other can work independently without interfering with each other.

568837 V. Description of the invention (9) Disturbance, therefore, two adjacent pressure chambers 13 will have less interaction with each other. Even if the distance between the nozzle holes 14 is smaller, the inkjet quality will be less affected.

The main purpose of the bump 17 of the present invention is to connect the diaphragm 16 and the piezoelectric element 12, which can transmit the thrust generated by the piezoelectric element 12 to the diaphragm 16 and push the ink to be ejected from the nozzle hole 14 Out. It can be seen from FIG. 5 that the design with the bump 17 can increase the width of the piezoelectric element 12 without affecting its actuating displacement. Increasing the width of the piezoelectric element 12 can increase the thrust generated by the piezoelectric element 12. The design with this bump 17 allows the piezoelectric element 12 to be less restricted by the boundary, so that a larger amount of displacement can be generated, and the operating voltage of the inkjet head can be reduced. In addition, it can generate the non-uniform displacement amount of the piezoelectric element 12 (decreasing from the maximum displacement amount at the center position to the end points of both sides in turn). The uniform displacement amount is transferred to the Vibration membrane 1 6. In order to achieve this, the thickness of the bump 17 needs to be much larger than the thickness of the diaphragm 16, and it is preferably much larger than 10 times. As a matter of fact, the thinner the thickness of the diaphragm 16 is, the better, it is about several micrometers, and the thickness of the bump 17 is about tens of micrometers to 100 micrometers. In order to increase the volume change of the diaphragm 16, the design of the length and width of the bump 17 is as large as possible. However, when the width of the bump 17 is wider, the diaphragm 16 is less likely to be deformed. When the length of the bump 17 is longer, the displacement amount generated by the piezoelectric element 12 is transferred to the diaphragm 16 Relatively reduced. Therefore, the bump 17 needs to have a proper design to obtain the optimal displacement and volume change of the diaphragm 16. The working principle of the piezoelectric inkjet print head of the present invention is that when the power supply device gives the piezoelectric element 12 a micro-actuator with a sufficient pulse voltage to generate a small up-and-down swing deformation, the micro-actuator quickly expands and pushes. Diaphragm 1 6 compressed ink chamber

Page 12 568837 V. Description of the invention (ίο) 1 3 ink, and the ink is sprayed on the paper surface. The piezo element 1 2 ^: actuator continuously prints ink droplets through a continuous pulse voltage. Fig. 6 shows how the ink jet head of the present invention shown in Fig. 4 ejects ink and the deformation state of the piezoelectric element 12 pushing the diaphragm 16 through the bump 17. The lower electrode of the piezoelectric element 12 is a ground electrode 2 1 ', and the upper electrode thereof is a signal electrode 20. When a pulse is applied to the signal electrode 20, the direction of the electric field and the polarization direction of the material are perpendicular to each other ', so the piezoelectric element 12 moves in a stinking manner. Figure 6 (a) shows the situation where the signal electrode 20 is at zero potential, that is, there is no electric field effect, so the piezoelectric element 12 is not deformed, so the ink in the ink chamber 13 is in a static state without external force. Figure 6 (b) shows that when the signal electrode 20 is connected to a negative voltage, the piezoelectric element 12 has an electric field in the thickness direction. Since the direction of the electric field and the polarization direction of the material are perpendicular to each other, the piezoelectric element 12 is moved downward in a shearing manner. Through the transmission of the bumps 17, the diaphragm 16 is also deformed downward, which causes the volume of the ink chamber 13 to increase and the pressure to decrease, which promotes the ink tank (Figure (Not shown) flows into the ink chamber 1 3 through the ink channel 15. Figure 6 (c) shows that when the signal electrode 20 is connected to a positive voltage, the piezoelectric element 12 has a downward electric field in the thickness direction. Since the direction of the electric field and the polarization direction of its material are perpendicular to each other, the piezoelectric element is The shearing mode moves upwards, and through the transmission of the bumps 17, the diaphragm 16 is also squeezed upward to deform, so that the ink in the ink chamber 13 is squeezed and the ink droplets 2 are ejected from the nozzle holes 1 4 2. The manufacturing process of the piezoelectric inkjet head of the present invention generally includes three parts, such as a first structure plate 10, a second structure plate 11 and a piezoelectric element 12, and the manufacturing processes are described below. Silicon wafer etching technology has been identified in semiconductor manufacturing technology

页 Page 13 568837 V. Description of the invention (11) High-precision etching can be performed, so the material of the first structure plate 丨 〇 and the second structure plate ii is based on silicon wafers. Figure 7 shows the inkjet head of the present invention. Schematic diagram of the manufacturing process of the first structural plate 10. First, as shown in FIG. 7 (a), a photoresist layer 24 is spin-coated on a silicon substrate 23 of an appropriate thickness to uniformly use the photoresist layer 24 as a protective layer. Then use the photomask to develop the photoresist layer 2 4 into the ink channel 15 (shown in this view butterfly method) and part of the ink chamber 1 3 by exposure and development. Then dry-etch the non-photoresist The silicon substrate 23 protected by the layer 24 etches the space of the ink channel 15 and a part of the ink chamber 3, as shown in FIG. 7 (b). Next, as shown in FIG. 7 (c), another uniform photoresist layer 24 is spin-coated. Similarly, the photoresist layer 2 4 is developed by using the same mask to develop the ink. 1 3 Close to the nozzle hole 1 4 Small space, and then dry-etch the silicon substrate 2 3 protected by the photoresist layer 2 4 to a part of the ink chamber 1 3. Next, as shown in FIG. 7 (d), a uniform photoresist layer 2 4 ′ is spin-coated on the back surface of the silicon substrate 23 and the size of the nozzle holes 14 is developed by exposure and development. As shown in FIG. 7 (e), the shape of the nozzle hole 14 is etched in the Shi Xi substrate 2 3 protected by the photoresist-free layer 2 4 in a dry etching manner. Finally, as shown in FIG. 7 (f), after removing all the photoresist layers 24, the complete engineering drawing of the first structural board 10 can be displayed. The first structure plate 10 has array-type nozzle holes 14 and a corresponding space of the ink chamber 13, an ink channel 15 and a partition side wall 19 therein. Among them, the ink channel 15 and the compartment side wall 19 cannot be displayed in this view. Fig. 8 is a schematic diagram showing the manufacturing process of the second structural plate 11 of the ink jet head of the present invention. The process of the first structural plate 10 is still based on a silicon wafer. Firstly, as shown in FIG. 8 (a), a silicon substrate 2 with a suitable thickness is rotated. 568837 V. Description of the invention (12) A uniform photoresist layer 24 is coated, and the photoresist layer 24 is used as a protective layer. Then, the photoresist layer 2 4 is developed by a photomask to develop a space of a part of the ink chamber 13 as shown in FIG. 8 (b). Next, as shown in Fig. 8 (c), the silicon substrate 2 3 protected by the photoresist layer 2 4 is etched in a dry manner to etch out part of the groove wall space of the ink chamber 1 3 and the partition side wall 19 (this view cannot be used) show),. Then, as shown in FIG. 8 (d), a uniform photoresist layer 24 is further spin-coated on the back surface of the Shixi substrate 23. Next, as shown in FIG. 8 (e), the photoresist layer 2 4 is developed into the shape of the diaphragm 16 by using different photomasks in an exposure and development manner, and then the silicon without the photoresist layer 24 protection by dry etching is used. The substrate 2 3 etches the shapes of the diaphragm 16 and the bump 17. Finally, as shown in Fig. 8 (f), after removing all the photoresist layers 2 4, a complete engineering drawing of the second structural plate 11 can be displayed. This second structural plate 11 has a part of the space of the ink chamber 13, a partition side wall 19, a diaphragm 16, and a bump 17 and a fixing base 18 connected to the piezoelectric element 12. Wall 19 cannot be displayed in this view. The current manufacturing process of the first structural board 10 and the second structural board 11 is based on a silicon wafer as a substrate and is etched. In addition to the silicon wafer as a substrate, resin, metal, and ceramic substrates can also be used. To replace. The above-mentioned manufacturing process of the first structural plate 10 and the second structural plate 11 is to etch the substrate out of the microstructure of the inkjet head by means of the erasing method. In addition, the materials can be successively attached to the substrate by the adhesion method. In order to form the microstructure of the inkjet head. The method of the adhesion method can be a thin film process such as sputtering, vapor deposition, and CVD, or an electroforming method. In order to obtain thick microstructures, electroforming is generally used, and the plating solution is mainly nickel sulfamate with low internal stress. In terms of the manufacturing process of the piezoelectric element 12, zirconate titanate

Page 15 568837 V. Description of the invention (13) Lead (PZT) series piezoelectric powder is used to manufacture piezoelectric substrates. The manufacturing process is shown in Figure 9. First, the piezoelectric powder is press-formed with a suitable jig, and then the piezoelectric powder is made into a dense piezoelectric substrate by a high-temperature sintering method. This substrate is processed to a suitable thickness and surface smoothness by a double-side grinding machine. Nine (a) is the processed piezoelectric substrate 25. Next, as shown in FIG. 9 (b), a layer of polarizing positive electrode 26 and negative electrode 27 is covered on the upper and lower sides of the piezoelectric substrate 25 in the thickness direction. This electrode can be screen-printed or coated. the way. The coating method can be made by using a metal mask, etching or lift-off (1 ift 〇f 〇) manufacturing method. The electrode material for screen printing can be gold, silver, palladium, silver palladium, etc., and The coated electrode materials can be gold, silver, princess, silver, nickel, platinum, etc. Then, as shown in FIG. 9 (c), the positive electrode 26 and the negative electrode 2 on the upper and lower sides of the piezoelectric substrate 25 are shown in the thickness direction. A surface polarized electric field is given between 7 and the direction of polarization is the same as the direction of the arrow in the figure. Finally, as shown in FIG. 9 (d), the positive electrodes 26 and negative electrodes on the upper and lower sides of the piezoelectric substrate 25 in the thickness direction are shown. The electrode 27 is removed, and then a layer of the signal electrode 20 is covered on the upper side, and a layer of the ground electrode 21 is covered on the lower side, so that the fabrication of the piezoelectric element 12 can be completed. Fig. 10 shows another spray nozzle of the present invention. A cross-sectional structural diagram of the ink head. The main structure and driving method of the piezoelectric actuator of this inkjet head are similar to those of the previous inkjet head of the present invention, and the difference is in the shape of the bumps. This inkjet head The shape of the bump on the head is convex, as shown in the figure The length of the convex bump 2 8 contacting the diaphragm 16 is larger than the length of the piezoelectric element 12. The convex bump 2 8 has a smaller area to contact the piezoelectric element 12. The main purpose is to make the piezoelectric element 12 is less restricted, causing it to generate a larger actuating displacement.

Page 16 568837 V. Description of the invention (14) Because the piezoelectric element 12 is deformed in a shearing manner, the maximum displacement from the center position decreases in order to the fixed ends of the two end points. The main purpose of the larger area on the side of the diaphragm 16 is to make the equivalent volume change of the diaphragm 16 larger. Fig. 11 shows how the ink jet head of the present invention shown in Fig. 10 ejects ink and the shape of the piezoelectric element 12 pushing the diaphragm 16 through the convex projection 28. As shown in the figure, the design of this convex bump 28 is shown. The displacement of the piezoelectric element 12 pushing the diaphragm 16 is large, so the driving voltage can be reduced under the same operating conditions.

The above descriptions are merely preferred embodiments of the present invention, but they are not intended to limit the present invention. Any modification made by anyone skilled in the art in the field of the present invention and having the same effect are included. Covered within the scope of patent application of the present invention.

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Claims (1)

568837 Case No. 91136784 Amendment VI. Patent application scope The device does not directly contact the diaphragm, but pushes the diaphragm by the bumps on the die, so that the ink in the ink chamber is squeezed out from the nozzle hole. 5. The inkjet head according to item 1 of the scope of the patent application, wherein each inkjet unit has an independent signal-controlled piezoelectric actuator, and each piezoelectric actuator is separated from each other And not connected together. 6 · — The first and second molds, and the piezoelectric and ink compartments, which are pressed together to form a convex shape, and from the seed spray structure, the water chamber is actuated on the side of the vibration chamber with an electro-structural sheet on its side. The nozzle head plate of the block, which has a square wall on its mold, and the device and the vibration mold are sprayed with an ink film from the side polarized middle hole of the vibrator on the first side; Out. The composition includes: a lot of nozzle holes of the same pitch; a lot of the same pitch of the ink inlet channel and the ink chamber corresponding to the nozzle holes are provided with a fixed seat for fixing the piezoelectric actuator and a convex bump connected thereto The closed empty water inlet channel formed by the structural plate and the second structural plate, with nozzle holes on the upper side, and fixed on the convex block, the two sides of which are fixed to the first fixed seat, the electric field of the piezoelectric actuator The direction of action is perpendicular to each other. Under the action of the electric field, it is connected to the convex can push the diaphragm, so that the ink in the ink chamber is squeezed. 7. The inkjet head according to item 6 of the patent application scope, wherein the second structure plate The shape of the bump under the vibration mode is convex, and the bump and the piezoelectric actuator Page 20 2003.10.17. 020 568837 _ Case No. 91136784_ year month__ Sixth, the scope of patent application The area of contact is smaller than the area of contact with the vibration mold. 8. The inkjet head according to item 6 of the scope of patent application, wherein the two ends of the longer side of the piezoelectric actuator are fixed bases fixed to the side wall of the second structure plate, and the shorter side The sides are free ends without any restrictions. 9. The inkjet head according to item 6 of the scope of the patent application, wherein the piezoelectric actuator does not directly contact the diaphragm, but pushes the diaphragm by a convex bump on the die to make the ink in the ink chamber Squeezed and ejected from the nozzle hole. 10. The inkjet head according to item 6 of the scope of patent application, wherein the polarization direction of the piezoelectric actuator is from the center position to both sides of the longer end. 1 1. The inkjet head according to item 6 of the scope of patent application, wherein the electrodes of the piezoelectric actuator are on the upper and lower sides in the thickness direction. 1 2. —A method for manufacturing an inkjet head, including: manufacturing a plurality of nozzle holes of the same pitch and corresponding ink outlet channels, a part of the ink chamber space and a partition wall by means of erasing or attaching. The first structural plate of the method; by the method of erasing or attaching, manufacturing a lot of vibrating dies with the same pitch, there are corresponding ink inlet channels above the vibrating dies, part of the space of the ink chamber and the side wall of the compartment, fixed below it The second structure plate of the seat and the bump; the first structure plate and the second structure are interposed or directly connected Page 21 2003.10.17. 021 568837 _ Case No. 91136784_ year month__ VI. The patent application board is combined together; a piezoelectric substrate is made so that the polarization direction and the thickness direction are perpendicular to each other and from the center Position to both sides, and the working electrode is above and below the thickness direction; after the piezoelectric substrate is adhered to the second structure plate, the piezoelectric substrate is processed into an array of piezoelectric actuators by dry etching, laser processing or cutting. Actuator. 1 3. According to the manufacturing method described in Item 12 of the scope of the patent application, the first structure plate and the second structure plate manufactured by the elimination method are manufactured by using a silicon wafer as a substrate by etching; except for silicon crystal In addition to the circle, substrates such as resin, metal, and ceramic can be used instead. 14. According to the manufacturing method described in Item 12 of the scope of the patent application, the first structural plate and the second structural plate produced by the adhesion method are produced by electroforming, and the plating solution is made of amine with low internal stress. Based on nickel sulfonate. 15. According to the manufacturing method described in item 12 of the scope of the patent application, the working electrode of the piezoelectric actuator can be manufactured by screen printing or coating. 16. According to the manufacturing method described in item 15 of the scope of the patent application, the material of the electrode may be gold, silver, handle, I, nickel, platinum, etc. 1 7. According to the manufacturing method described in Item 12 of the scope of patent application, the piezoelectric substrate Page 22 2003.10.17. 022 568837 _ Case No. 91136784_ year month amendment _ six, the scope of the patent application for dry etching process into an array of piezoelectric actuators, the processing method is to use ICP ° 1 8. According to the application In the manufacturing method described in item 12 of the patent scope, the piezoelectric substrate is processed into an array-type piezoelectric actuator by laser, and the processing method is an excimer laser. 19. According to the manufacturing method described in item 12 of the scope of the patent application, the piezoelectric substrate is processed into an array-type piezoelectric actuator by a cutting method, and the processing method is a wafer dicing machine. Page 23 2003.10.17. 023