Patent Grant
7506442
This application claims the benefit of Korean Patent Application No. 10-2005-0119252, filed on Dec. 8, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present general inventive concept relates to a method of fabricating an inkjet printhead, and more particularly, to a method of fabricating an inkjet printhead using a simple process.
2. Description of the Related Art
An inkjet printhead is an apparatus that ejects minute ink droplets on desired positions of recording paper in order to print predetermined color images. Inkjet printheads are categorized into two types according to the ink droplet ejection mechanism thereof. The first one is a thermal inkjet printhead that ejects ink droplets due to an expansion force of ink bubbles generated by thermal energy. The other one is a piezoelectric inkjet printhead that ejects ink droplets by a pressure applied to ink due to the deformation of a piezoelectric body.
The ink droplet ejection mechanism of the thermal inkjet printhead is as follows. When a current flows through a heater made of a heating resistor, the heater is heated and ink near the heater in an ink chamber is instantaneously heated up to about 300° C. Accordingly, ink bubbles are generated by ink evaporation, and the generated bubbles are expanded to exert a pressure on the ink filled in the ink chamber. Thereafter, an ink droplet is ejected through a nozzle out of the ink chamber.
A typical silicon substrate is used as the substrate 110. An insulating layer 12 for insulation between a heater 13 and the substrate 10 is formed on the substrate 10. The insulating layer 12 is typically made of silicon oxide. The heater 13 is formed on the insulating layer 12 to heat the ink of the ink chamber 22 and generate bubbles. An electrode 14 is formed on the heater 13 to apply current to the heater 13. A passivation layer 15 is formed on the heater 13 and the electrode 14 to protect the heater 13 and the electrode 14. The passivation layer 15 is typically made of silicon oxide or silicon nitride. An anti-cavitation layer 16 is formed on the passivation layer 15. The anti-cavitation layer 16 protects the heater 13 from a cavitation force generated when the bubbles vanish and is typically made of tantalum (Ta).
However, in the above described method of fabricating an inkjet printhead, several patterning processes are required and the thickness of the chamber layer 20 cannot be easily obtained as desired using the CMP.
The present general inventive concept provides method of fabricating an inkjet printhead using a simple process.
Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
The foregoing and/or other aspects and utilities of the present general inventive concept are achieved by providing a method of fabricating an inkjet printhead including sequentially forming an insulating layer, a heater, and an electrode on a substrate, and forming a passivation layer on the insulating layer to cover the heater and the electrode, forming a trench that exposes the substrate by sequentially etching the passivation layer and the insulating layer, forming a sacrificial layer to form an ink chamber on the passivation layer to fill the trench, forming a seed layer to provide a plating on the sacrificial layer and the passivation layer, forming a nozzle mold on the seed layer positioned over the heater, forming a plating layer on the seed layer to a predetermined thickness; forming an ink feed hole by etching a rear surface of the substrate to expose the sacrificial layer filled in the trench, forming a nozzle by sequentially removing the nozzle mold and the seed layer positioned under the nozzle mold, and forming the ink chamber by removing the sacrificial layer exposed by the nozzle and the ink feed hole.
The substrate may be made of silicon, and the insulating layer may be made of silicon oxide.
The heater may be formed by depositing a heating resistor on a top surface of the insulating layer and patterning the heating resistor. The electrode may be formed by depositing a conductive metal on a top surface of the heater and patterning the metal.
The passivation layer may be made of silicon oxide and silicon nitride.
After the forming of the passivation layer, forming an anti-cavitation layer on a top surface of the passivation layer that forms the bottom of the ink chamber may be further included. The anti-cavitation layer may be made of tantalum (Ta).
The sacrificial layer may be formed by coating a predetermined material on the passivation layer and patterning the material in a shape of the ink chamber. The sacrificial layer may be formed of a photoresist or a photosensitive polymer.
The seed layer may be made of at least one metal selected from the group consisting of copper, gold, nickel, titanium, and chrome. The plating layer may be made of at least one metal selected from the group consisting of copper, gold, and nickel.
The plating layer may be formed by electroplating.
The nozzle mold may be made of a photoresist or a photosensitive polymer. The nozzle mold may have a cross section tapering upward.
The foregoing and/or other aspects and utilities of the present general inventive concept are achieved by providing a method of fabricating an inkjet printhead comprising forming a sacrificial layer over a thermal heating device of the inkjet printhead to form an ink chamber, forming a seed layer to provide plating on the sacrificial layer and thermal heating device, forming a nozzle mold on the seed layer positioned over the thermal heating device, forming a plating layer on the seed layer to a predetermined thickness, forming an ink feed hole by etching a rear surface of the thermal heating device to expose the sacrificial layer, forming a nozzle by sequentially removing the nozzle mold and the seed layer positioned under the nozzle mold, and forming the ink chamber by removing the sacrificial layer exposed by the nozzle and the ink feed hole.
The foregoing and/or other aspects and utilities of the present general inventive concept are achieved by providing a method of fabricating an inkjet printhead, comprising forming a sacrificial layer over a thermal heating device including heaters of the inkjet printhead to form an ink chamber, forming a nozzle mold on the sacrificial layer and above each heater, forming a plating layer on the sacrificial layer and along sides of each nozzle mold to a predetermined thickness, forming an ink feed hole by etching a rear surface of the thermal heating device to expose the sacrificial layer, forming nozzles by sequentially removing each nozzle mold, and forming the ink chamber by removing the sacrificial layer exposed by the nozzles and the ink feed hole.
These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.
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As described above, the present general inventive concept can form a plating layer as a single body including a chamber layer and a nozzle layer. Thus, the inkjet printhead can be fabricated in a simple process. In addition, the thickness of the sacrificial layer and the plating layer are controlled to obtain an ink chamber and a nozzle of a desired size. Also, since the plating layer is made of a metal having good thermal conductivity, the heat generated by the heater can be efficiently dissipated to the outside.
The general inventive concept may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the inventive concept to those skilled in the art. For example, it will also be understood that when a layer is referred to as being “on” another layer or a substrate, it can be directly on the other layer or the substrate, or intervening layers may also be present. The components of the inkjet printhead according to the present general inventive concept may be made of different materials from those described in the current embodiments. Also, the sequence of stages of the method of fabricating the inkjet printhead may vary from the embodiments of the present general inventive concept. Therefore, the spirit and scope of the present general inventive concept should be defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0119252 | Dec 2005 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4894664 | Tsung Pan | Jan 1990 | A |
| 5945260 | Miyagawa et al. | Aug 1999 | A |
| 6520627 | Chen et al. | Feb 2003 | B2 |
| 6895668 | Imamura | May 2005 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20070131648 A1 | Jun 2007 | US |
