TWI443023B - A structure of a piezoelectric inkjet print head - Google Patents

Description

Piezoelectric inkjet head structure

The present invention relates to an ink jet head structure, and more particularly to a piezoelectric ink jet head structure.

With the advancement of inkjet technology, inkjet technology is no longer only used in the traditional printing market. In recent years, it has been applied to the process technology of flat panel display and semiconductor industry. However, in order to reduce costs and save process time, new ones are sought. The most widely used inkjet technology is piezoelectric inkjet technology.

The piezoelectric inkjet head structure uses a piezoelectric actuator as a power source for ejecting droplets. Therefore, in addition to the specific characteristics of the piezoelectric actuator, the inkjet quality is affected, and the piezoelectric actuator is cut. It will also affect its inkjet quality and droplet size. In other words, the droplet size at the time of ink ejection is determined by the piezoelectric actuator being vibrated and displaced after receiving a voltage. Therefore, in order to conform the droplet size at the time of ink ejection to the set specification, the piezoelectric actuator is activated. The length, width and depth of the cut are an important part of the cut, so that the piezoelectric actuator after cutting can generate the maximum displacement when vibrating, so as to provide sufficient power to make the piezoelectric ink jet head structure ejectable. Set the droplet size within the specification.

The purpose of the present invention is to provide a piezoelectric ink jet head structure, which mainly utilizes a piezoelectric actuator to form an actuator unit after cutting, and by setting a depth of a cutting portion of the piezoelectric actuator to be cut, and an actuation unit The length of the first side and the second side allows the actuating unit to provide sufficient power when vibrating to cause the piezoelectric ink jet head structure to eject a droplet size within a set specification.

In order to achieve the above object, a broader aspect of the present invention provides a piezoelectric ink jet head structure comprising at least: a plurality of plates; a vibrating plate disposed on a plurality of plates; and an ink jet unit in plurality The plate member has a cavity; and the actuating unit is disposed on the vibrating plate and corresponds to the cavity of the ink jet unit, wherein the actuating unit has a first side and a second side, the first side and a second side having a length ratio of between 1:1 and 3:1; and wherein the actuating unit is formed by cutting a piezoelectric actuator, and the piezoelectric actuator has a thickness and a cut to form The actuating unit generates a displacement amount when vibrating.

In order to achieve the above object, another broad aspect of the present invention provides a piezoelectric ink jet head structure comprising at least: a plurality of plates; a vibrating plate disposed on a plurality of plates; and a plurality of ink jet units; The two ink jet units have a cavity in a plurality of plates; and the plurality of actuating units are disposed on the vibrating plate and respectively correspond to the cavities of the plurality of ink ejecting units. Each of the actuating units has a first side and a second side, and a length ratio of the first side and the second side is between 1:1 and 3:1; and wherein the plurality of actuating units are The piezoelectric actuator is formed by cutting, and the piezoelectric actuator has a thickness and a cutting portion to form a plurality of actuation units to generate a displacement amount when vibrating.

Some exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It is to be understood that the present invention is capable of various modifications in the various aspects of the present invention, and the description and drawings are intended to be illustrative and not limiting.

Please refer to FIG. 1A and FIG. 1B , wherein FIG. 1A is a schematic cross-sectional view of the ink jet head structure of the preferred embodiment of the present invention, and FIG. 1B is a plan view schematically shown in FIG. 1A . As shown in the figure, the ink jet head structure 1 of the present invention is formed by, for example, stacking a plurality of stainless steel plate members by a high temperature diffusion bonding technique, thereby forming a microstructure of the ink jet head structure 1, wherein the ink jet head structure 1 has a substrate 10, plural The plate member 11, the ink jet unit 12, the vibrating plate 13, and the actuating unit 14. The substrate 10 has an inkjet hole 101, the inkjet hole 101 is disposed relative to the inkjet unit 12, and a plurality of plates 11 are stacked on the substrate 10, so that the inkjet unit 12 includes a liquid storage chamber 121, a liquid inlet channel 122, The microstructure of the cavity 123 and the liquid outlet channel 124 and the like, and the liquid storage chamber 121, the liquid inlet flow path 122, the cavity 123, the liquid discharge flow path 124, and the ink ejection hole 101 are connected to each other such that a fluid (not shown) can flow out through the liquid storage chamber 121, the liquid inlet flow path 122, the cavity 123, the liquid discharge flow path 124, and the ink discharge port 101 to achieve the purpose of ink ejection. In some embodiments, the inkjet unit 12 and the actuation unit 14 may be one or more, but not limited thereto. The vibrating plate 13 is laid on a plurality of plate members 11. The actuating unit 14 is disposed on the vibrating plate 13 and corresponds to the cavity 123 of the ink jet unit 12, wherein the actuating unit 14 is a rectangular structure and has The first side edge L and the second side edge W, wherein the first side edge L can be a long side, and the second side edge W can be a short side, but not limited thereto.

The actuating unit 14 of the ink jet head structure 1 of the present invention can be driven by an electric field (not shown), and the actuating unit 14 generates a displacement amount h in the Z-axis direction to push the vibrating plate 13 (as shown in FIG. 1C). The volume of the cavity 123 is changed. When the fluid stored in the liquid storage chamber 121 is squeezed by the cavity 123 to generate a flow, the fluid of the liquid storage chamber 121 passes through the liquid inlet flow path 122, the cavity 123, and the liquid discharge. The flow path 124 is finally ejected by the ink ejection orifice 101 for the purpose of ink ejection.

Please refer to FIG. 1A and FIG. 1B together with FIG. 1C, wherein FIG. 1C is a schematic cross-sectional view taken along line a-a' of FIG. 1B. As shown, in the present embodiment, the actuating unit 14 is formed by cutting the piezoelectric actuator 15 and the piezoelectric actuator 15 has a thickness T and a cutting portion 151 (as shown in FIG. 1C). In this embodiment, the piezoelectric actuator 15 is correspondingly disposed above the vibration plate 13 of the cavity 123 of the inkjet unit 12, and then a wafer cutting blade (not shown) corresponds to the shape of the cavity 123. After the piezoelectric actuator 15 is linearly cut, the actuation unit 14 is formed, and the dicing depth of the wafer dicing blade can be changed according to the thickness T of the piezoelectric actuator 15 without exceeding the piezoelectricity. The thickness T of the rotor 15 is preferred, and in some embodiments, the dicing width of the wafer dicing blade is preferably 50 μm, but not limited thereto. After the cutting operation is completed, the piezoelectric actuator 15 forms a cutting portion 151 at the cutting portion, and each of the actuating units 14 is disposed correspondingly above each of the cavities 123. In some embodiments, the wafer dicing blade can be cut by water cooling or air cooling, but not limited thereto, so that the cutting process is maintained at a uniform temperature below 100 degrees.

According to the concept of the present invention, when the ratio of the depth of the cutting portion 151 of the piezoelectric actuator piece 15 and the thickness T is between 0.6 times and 1 time, the actuation unit 14 can be caused to generate the maximum displacement amount h when vibrating. Thereby, the actuating unit 14 can have sufficient power to cause the piezoelectric ink jet head structure 1 to eject in accordance with the set droplet size. In some embodiments, when the thickness T of the piezoelectric actuator piece 15 is less than or equal to 200 μm, and the ratio of the depth of the cut portion 151 of the piezoelectric actuator piece 15 to the thickness T is between 0.6 times and 1 time The droplet size ejected by the ink ejection orifice 101 of the ink jet head structure 1 can be between 1 pL and 45 pL, and preferably the droplet size can be further controlled between 30 pL and 45 pL.

According to the concept of the present invention, when the area enclosed by the first side L and the second side W of the actuating unit 14 is constant, the length of the first side L and the second side W are set to be longer than a predetermined length. The ratio of the range allows the actuation unit 14 to produce a maximum amount of displacement h. Please refer to Fig. 2, which is a graph showing the relationship between the displacement amount and the area of the actuating unit of the present invention. As shown in the figure, taking the area of the actuating unit 14 (that is, the area surrounded by the first side L and the second side W, L*W) takes five sets of data as an example, which are respectively 1296*980μm ² , 1584 *800μm ² , 1630*780μm ² , 1800*705μm ² , 2000*635μm ² , as shown in Fig. 2, when the ratio of the length of the first side edge L to the second side edge W is closer to 1:1 (that is, When the first side edge L and the second side edge W have the same length, the actuation unit 14 is caused to generate a larger displacement amount h when vibrating.

In this embodiment, the optimal length ratio of the first side edge L and the second side edge W of the actuating unit 14 of the present invention is between 1:1 and 3:1, but not limited thereto. In this way, the plurality of actuation units 14 can achieve the optimal number of cuts on the vibrating plate 13, and can also generate an optimal displacement h during vibration to provide sufficient power to cause the piezoelectric inkjet head multilayer structure 1 to Spray out the droplet size within the set specifications. In addition, in order to avoid cutting the piezoelectric actuator piece 15, the cutting quality is affected by factors such as stress and heat generation, so the length of the first side edge L and the second side edge W of the actuation unit 14 can be set to 50 μm to Between 2000 μm, wherein the length of the first side edge L can be further set to be between 1500 μm and 2000 μm, and the length of the second side edge W is set to be between 500 μm and 1000 μm, but not Limiting, the actuation unit 14 can have optimal cutting quality and size. In this way, when a voltage is applied to the plurality of actuation units 14, a displacement amount h is generated to provide sufficient actuation force to eject the droplets, and the droplet size can conform to the set specifications.

In summary, the piezoelectric inkjet head structure of the present invention mainly uses a piezoelectric actuator to be disposed on the vibration plate, and after the wafer cutting blade performs the cutting operation, the piezoelectric actuator film is cut to form a plurality of a moving unit, wherein the piezoelectric actuator has a thickness and a cutting portion, and the plurality of actuation units respectively have a first side and a second side, and the ratio of the depth to the thickness of the cutting portion of the piezoelectric actuator Between 0.6 times and 1 time, and when the length ratio of the first side and the second side of the plurality of actuating units is between 1:1 and 3:1, the plurality of actuating units receive one The voltage is post-vibrated to produce the maximum amount of displacement. In this way, the plurality of actuating units are provided with sufficient power to cause the piezoelectric ink jet head multilayer structure to eject a droplet size within a set specification.

This case has been modified by people who are familiar with the technology, but it is not intended to be protected by the scope of the patent application.

1. . . Inkjet head structure

10. . . Substrate

101. . . Ejection hole

11. . . Multiple boards

12. . . Inkjet unit

121. . . Liquid storage chamber

122. . . Liquid inlet channel

123. . . Cavity

124. . . Outlet channel

13. . . Vibrating plate

14. . . Actuating unit

15. . . Piezoelectric actuator

151. . . Cutting department

L. . . First side

W. . . Second side

T. . . thickness

h. . . Displacement

Fig. 1A is a schematic cross-sectional view showing the structure of an ink jet head of the preferred embodiment of the present invention.

Figure 1B: A schematic plan view shown in Figure 1A.

Fig. 1C is a schematic cross-sectional view taken along line a-a' of Fig. 1B.

Fig. 2 is a graph showing the relationship between the displacement amount and the area of the actuating unit of the present case.

13. . . Vibrating plate

14. . . Actuating unit

15. . . Piezoelectric actuator

151. . . Cutting department

T. . . thickness

h. . . Displacement

Claims (9)

A piezoelectric inkjet head structure comprising at least:
a plurality of boards;
a vibrating plate disposed on the plurality of plates;
An ink jet unit having a cavity in the plurality of plates; and an actuating unit disposed on the vibrating plate corresponding to the cavity of the ink jet unit, wherein the actuating unit has a first a side edge and a second side, the first side edge and the second side edge have a length ratio between 1:1 and 3:1;
The actuating unit is formed by cutting a piezoelectric actuator, and the piezoelectric actuator has a thickness and a cutting portion to form a displacement amount of the actuating unit when vibrating. The piezoelectric ink jet head structure of claim 1, further comprising a substrate having an ink ejection orifice. The piezoelectric ink jet head structure of claim 2, wherein the plurality of plates are stacked on the substrate, and the ink jet unit is formed. The piezoelectric ink jet head structure according to claim 3, wherein the ink jet unit comprises a liquid storage chamber, a liquid inlet flow path, the cavity body and an liquid outlet flow path, and the liquid inlet flow path And communicating with the cavity and the liquid storage chamber, the liquid flow channel is connected to the cavity and the ink ejection hole. The piezoelectric ink jet head structure according to claim 1, wherein the thickness of the piezoelectric actuator is less than or equal to 200 μm. The piezoelectric ink jet head structure according to claim 1, wherein a ratio of a depth of the cut portion of the piezoelectric actuator to a thickness of the piezoelectric actuator is 0.6 to 1 times The actuating unit produces an optimum amount of displacement when vibrating. The piezoelectric ink jet head structure according to claim 1, wherein the actuating unit is a rectangular structure, and the first side is a long side, and the second side is a short side. The piezoelectric ink jet head structure according to claim 1, wherein the first side and the second side have a length ranging from 50 μm to 2000 μm. A piezoelectric inkjet head structure comprising at least:
a plurality of boards;
a vibrating plate disposed on the plurality of plates;
a plurality of ink jet units arranged symmetrically with each other, and each of the ink jet units has a cavity in the plurality of plates; and a plurality of actuating units disposed on the vibrating plate and respectively The first inkjet unit has a first side and a second side, and the first side and the second side have a length ratio of 1: Between 1 and 3:1;
The plurality of actuating units are formed by cutting a piezoelectric actuator, and the piezoelectric actuator has a thickness and a cutting portion to form a plurality of actuating units to generate a displacement amount when vibrating.