Electrostatic actuator, droplet discharging head, droplet discharging apparatus, electrostatic device

Abstract

The invention provides an electrostatic actuator, etc. which is capable of miniaturizing the size, and preventing moisture, etc. from entering a gap in an effective manner. An electrostatic actuator includes an electrode substrate 10 having individual electrodes 12 as fixed electrodes, and a cavity substrate 20 having diaphragms 22 as movable electrodes which are disposed so as to be opposed to the fixed electrodes 12 with a predetermined distance, and operated due to an electrostatic force occurring between the cavity substrate 20 and the individual electrodes 12. Sealing portions 26 a are formed on one of the electrode substrate 10 and the cavity substrate 20, each of the sealing portions 26 a has a plurality of sealing layers (a TEOS layer 25 a, a moisture permeation preventing layer 25 b) laminated one another, and each of the sealing layers is made of a sealing material 25 for isolating a space formed between the individual electrode 12 and the diaphragm 22.

Description

technical field [0001] The present invention relates to electrostatic devices such as electrostatic actuators and liquid drop discharge heads in which movable parts are displaced by applied force in microfabrication elements, devices using the electrostatic devices, and methods for manufacturing them. It is particularly concerned with sealing on microfabricated components. Background technique [0002] For example, microfabrication technology (MEMS: MicroElectro Mechanical Systems), which processes silicon or the like to form tiny elements, has been rapidly developed. Examples of microfabrication elements formed by microfabrication technology include droplet ejection heads (inkjet heads), micropumps, and optical variable filters used in recording (printing) devices such as liquid droplet ejection printers. , Electrostatic drives such as motors, pressure sensors, etc. [0003] Here, as an example of a microfabrication element, a droplet ejection head as an electrostatic act...

AI Technical Summary

Problems solved by technology

[0012] Generally, epoxy resins are used to seal the gap in the electrostatic drive, including the conventional electrostatic drive type inkjet head. When epoxy resin is used as the sealing material, since the epoxy resin utilizes the Attractive force penetrates deep into the gap, so the amount of sealing must be increased so that the sealing material does not penetrate into the electrostatic actuator, and there is a problem that it is difficult to miniaturize the inkjet head

In addition, since the capillary attraction force cannot be generally controlled, there is a problem that the sealing state of each gap varies

[0013] In addition, in the conventional inkjet head and its manufacturing method (for example, refer to Patent Document 1), only one kind of oxide film is used for sealing. For example, when the oxide film is a silicon oxide film, since the silicon oxide film has relatively low water permeability Therefore, it is necessary to increase the thickness of the sealing material. As a result, there is a problem that it is difficult to realize the miniaturization of the inkjet head.

[0014] In addition, when the oxide film is an aluminum oxide film, since the water permeability of aluminum oxide is low, although the thickness of the sealing material can be reduced, it takes time to form the film, and it is easy to react with an alkaline solution. The manufacturing of the head is difficult and other problems

[0015] Furthermore, in a conventional electrostatic actuator and an inkjet head using the same (for example, refer to Patent Document 2), a polyimide-based sealing material containing silicon is used as a sealing material, but since the polyimide-based sealing material containing silicon Since the material is liquid, there is a problem that the silicon-containing polyimide sealing material penetrates into the depth of the gap due to capillary attraction like epoxy resin, and it is difficult to realize the miniaturization of the inkjet head.

Furthermore, in the manufacturing process, if it adheres to a part that does not need to be sealed originally—for example, a portion that is bonded to another substrate or a portion that becomes a terminal of an electrode that is taken out, it will hinder the connection with other substrates and the electrical connection with the power supply device. connection, so a removal process is necessary

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