U.S. patent application number 12/651003 was filed with the patent office on 2011-04-21 for method for manufacturing inkjet head.
This patent application is currently assigned to SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Jae-Woo Joung, Won-Chul Sim, Chung-Mo YANG, Seuck-Young Yoo.
Application Number | 20110088262 12/651003 |
Document ID | / |
Family ID | 43878193 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110088262 |
Kind Code |
A1 |
YANG; Chung-Mo ; et
al. |
April 21, 2011 |
METHOD FOR MANUFACTURING INKJET HEAD
Abstract
A method for manufacturing an inkjet head is disclosed. The
method for manufacturing an inkjet head can include preparing a
head body including a vibrating membrane, which is located in an
upper portion of the head body, coating a lower electrode over the
vibrating membrane, patterning a resist such that an open area is
formed over the vibrating membrane, filling a piezoelectric
material in the open area, selectively coating an upper electrode
over the piezoelectric material, and removing the resist.
Inventors: |
YANG; Chung-Mo; (Ansan-si,
KR) ; Joung; Jae-Woo; (Suwon-si, KR) ; Sim;
Won-Chul; (Seongnam-si, KR) ; Yoo; Seuck-Young;
(Seoul, KR) |
Assignee: |
SAMSUNG ELECTRO-MECHANICS CO.,
LTD.
|
Family ID: |
43878193 |
Appl. No.: |
12/651003 |
Filed: |
December 31, 2009 |
Current U.S.
Class: |
29/890.1 |
Current CPC
Class: |
B41J 2/14233 20130101;
Y10T 29/49401 20150115; B41J 2/1631 20130101; B41J 2/1642 20130101;
B41J 2/1628 20130101; B41J 2/161 20130101 |
Class at
Publication: |
29/890.1 |
International
Class: |
B21D 53/76 20060101
B21D053/76 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 21, 2009 |
KR |
10-2009-0100364 |
Nov 6, 2009 |
KR |
10-2009-0107085 |
Claims
1. A method for manufacturing an inkjet head, the method
comprising: preparing a head body including a vibrating membrane,
the vibrating membrane located in an upper portion of the head
body; coating a lower electrode over the vibrating membrane;
patterning a resist such that an open area is formed on an upper
side of the vibrating membrane; filling a piezoelectric material in
the open area; selectively coating an upper electrode over the
piezoelectric material; and removing the resist.
2. The method of claim 1, wherein the resist is made of a material
including polysilicon, and the removing of the resist is carried
out by an etching process using XeF.sub.2 gas.
3. The method of claim 1, further comprising forming an inlet port
in the head body, after the removing of the resist.
4. The method of claim 1, wherein the filling of a piezoelectric
material comprises: depositing the piezoelectric material in the
open area and over the resist; and removing a portion of the
deposited piezoelectric material such that an upper surface of the
resist is exposed.
5. The method of claim 1, wherein the resist is a photo-resist, and
the selectively coating of an upper electrode comprises: coating a
conductive layer over the piezoelectric material and over the
photo-resist; and patterning the upper electrode over the
piezoelectric material by removing a portion of the conductive
layer coated over the photo-resist by etching the photo-resist.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefits of Korean Patent
Application Nos. 10-2009-0100364 and 10-2009-0107085, filed with
the Korean Intellectual Property Office on Oct. 21, 2009 and Nov.
6, 2009, respectively, the disclosure of which is incorporated
herein by reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a method for manufacturing
an inkjet head.
[0004] 2. Description of the Related Art
[0005] An inkjet head can be manufactured by processing various
parts, such as the chamber, restrictor, nozzle, etc., in a number
of layers and then attaching the layers together.
[0006] Generally, a piezoelectric device (PZT) is utilized to drive
a vibrating membrane. When some voltages are provided to both sides
of the piezoelectric device, an inner crystal structure of the
piezoelectric device is changed and a displacement can be generated
in the piezoelectric device. The operation of the vibrating
membrane utilizes the displacement.
[0007] To keep pace with an increase of nozzle density of the
inkjet head, the distance between unit cells for discharging ink
droplets needs to be narrower, and the vibrating membrane and the
piezoelectric device need to be thinner.
[0008] According to the prior art, in order to form a piezoelectric
device for each cell, a lower electrode is deposited on a head body
and a piezoelectric material is coated on the lower electrode with
epoxy resin. Then the deposited piezoelectric material is separated
in accordance with each cell by means of, for example, a blade. At
this time, the vibrating membrane may be cracked when the lower
electrode is contacted by the blade since the lower electrode is
thin. Therefore, to prevent this, the piezoelectric material is
separated into several piezoelectric devices such that a residue
layer remains in the piezoelectric material.
[0009] The residue layer causes a cross talk that delivers the
operating power of a piezoelectric device of one cell to another
cell. This causes a defective discharging of ink.
SUMMARY
[0010] An aspect of the invention provides a method for
manufacturing an inkjet head. The method in accordance with an
embodiment of the present invention can include: preparing a head
body including a vibrating membrane, which is located in an upper
portion of the head body; coating a lower electrode over the
vibrating membrane; patterning a resist such that an open area is
formed over the vibrating membrane; filling a piezoelectric
material in the open area; selectively coating an upper electrode
over the piezoelectric material; and removing the resist.
[0011] Here, the resist can be made of a material including
polysilicon, and the resist can be removed by an etching process
using XeF2 gas.
[0012] Also, the method for manufacturing an inkjet head according
to an embodiment of the invention can further include forming an
inlet port in the head body, after the resist is removed.
[0013] The piezoelectric material can be filled by: depositing the
piezoelectric material in the open area and over the resist; and
removing a portion of the deposited piezoelectric material such
that an upper surface of the resist is exposed.
[0014] Meanwhile, the resist can be a photo-resist, and the upper
electrode can be selectively coated by: coating a conductive layer
over the piezoelectric material and over the photo-resist; and
patterning the upper electrode over the piezoelectric material by
removing a portion of the conductive layer coated over the
photo-resist by etching the photo-resist.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a flowchart illustrating a method for
manufacturing an inkjet head according to an embodiment of the
invention
[0016] FIGS. 2 to 11 illustrate a respective process of a method
for manufacturing an inkjet head according to an embodiment of the
invention.
[0017] FIGS. 12 and 13 illustrate a process for coating an upper
electrode selectively according to another embodiment of the
invention.
DETAILED DESCRIPTION
[0018] A method for manufacturing the inkjet head according to
certain embodiments of the invention will be described below in
more detail with reference to the accompanying drawings. Those
components that are the same or are in correspondence are rendered
the same reference numeral regardless of the figure number, and
redundant descriptions are omitted.
[0019] FIG. 1 is a flowchart illustrating a method for
manufacturing an inkjet head according to an embodiment of the
invention, and FIGS. 2 to 10 illustrate a respective process of a
method for manufacturing an inkjet head according to an embodiment
of the invention.
[0020] First, as illustrated in FIG. 2, a head body 10, including a
vibrating membrane 16, is prepared, and a lower electrode 20 is
coated over the vibrating membrane 16 (S 110). The vibrating
membrane 16 is located in an upper portion of the head body 10. For
coating the lower electrode 20, gold can be deposited on an upper
surface of the vibrating membrane 16, but the present invention is
not limited to depositing gold.
[0021] In the head body 10, some elements such as a chamber 13, a
reservoir 11, a restrictor 13, a damper 14, and a nozzle 15 are
formed. Described below are the functions of the elements
constituting the head body 10.
[0022] The chamber 13 accommodates ink. When a piezoelectric
material (refer to reference numeral 42 in FIG. 11), which is
formed on an upper surface of the vibrating membrane, applies
pressure to the chamber 13, the chamber 13 transfers the
accommodated ink in the direction of the nozzle 15 and causes the
ink to be discharged. There can be a number of chambers, for
example, 128 chambers, 256 chambers, etc., in parallel in one
ink-jet head, and there can be an equal number of piezoelectric
devices in order to provide pressure to each chamber 13.
[0023] The reservoir 11 is supplied with the ink from the outside
through an inlet port 12 and stores the ink, and then provides the
ink to the chamber 13 described above.
[0024] The restrictor 13 links the reservoir 11 and the chamber 13
and controls the ink flow generated between the reservoir 11 and
the chamber 13. The restrictor 13 is formed to have a smaller cross
sectional area than those of the reservoir 11 and the chamber 13.
The restrictor 13 can control the amount of ink provided by the
reservoir 11 to the chamber 13 when the vibrating membrane 16 is
vibrated by a vibration generator.
[0025] The nozzle 15 is linked to the chamber 13 and is supplied
with the ink from the chamber 13. Then, the ink is ejected through
the nozzle. If the vibration generated by the vibration generator
is delivered to the chamber 13 through the vibrating membrane 16,
pressure is applied to the chamber 13, causing the ink to be
ejected through the nozzle 15.
[0026] The damper 14 is formed between the chamber 13 and the
nozzle 15. The damper 14 can carry out a function of converging the
energy generated by the chamber 13 to the nozzle 15 and dampening a
sudden change of pressure.
[0027] The head body 10 including the elements described above can
be formed by stacking one or several substrates made of silicon or
ceramic material.
[0028] Then, as shown in FIG. 3, a resist 30 is patterned such that
an open area 32 is formed over the lower electrode 20 (S120). The
open area 32 is an area in which a piezoelectric material (refer to
reference numeral 42 in FIG. 11) is to be filled. The piezoelectric
material 42 can later serve as a vibration generator. In this
embodiment, the resist 30 is patterned by depositing polysilicon by
using PECVD or LPCVD. However, the present invention is not limited
to patterning the resist by depositing polysilicon, and it shall be
evident that other materials than polysilicon can be used.
[0029] Next, the piezoelectric material 42 is filled in the open
area 32 (S130). For that, processes shown in FIGS. 4 and 5 can be
used. That is, as shown in FIG. 4, a piezoelectric material 40 can
be deposited in the open area 32 and over the resist 30 by using a
sputtering process or E-beam process, and then a portion of the
deposited piezoelectric material 40 can be removed such that an
upper surface of the resist 30 is exposed, as shown in FIG. 5. A
CMP process can be used for removing a portion of the deposited
piezoelectric material 40.
[0030] Then, an upper electrode 50 is selectively coated over the
piezoelectric material 42 (S140). For that, processes shown in
FIGS. 6 and 7 can be used. That is, a resist 52 can be formed such
that a portion of the upper surface of the piezoelectric material
42 is opened--the opened area is an area where the upper electrode
50 is to be formed--and the upper electrode 50 can be deposited in
the opened area by using, for example, a sputtering process, as
shown in FIG. 6. Then, the upper electrode 50 can be patterned by
removing the resist 52, as shown in FIG. 7.
[0031] Then, the resist 30 is removed, as shown in FIG. 8 (S150).
That is, the resist 30 utilized for selectively depositing the
piezoelectric material is removed.
[0032] If polysilicon is used for the resist 30 as described above,
the resist 30 can be removed by an etching process using XeF.sub.2
gas. In that case, the resist 30 can be selectively removed without
damaging the head body 10 or the piezoelectric material 42. If any
material other than polysilicon is used for the resist 30, an
etching process using a material that can selectively remove the
resist 30 without damaging the head body 10 or the piezoelectric
material 42 can be used.
[0033] After the resist 30 is removed, an inlet port 17 is formed
in the head body 10 (S160). For that, a process shown in FIGS. 9 to
11 can be used. That is, a resist 60 may be formed such that a
portion of the head body 10 where the inlet port 17 is to be formed
is opened, as shown in FIG. 9. And the opened portion of the head
body 10 can be etched, as shown in FIG. 10. Then, the resist 60 may
be removed, as shown in FIG. 11.
[0034] Meanwhile, processes shown in FIGS. 12 and 13 can be used
for selectively coating the upper electrode 50, in another
embodiment of the invention. That is, a conductive layer 54 can be
coated over the piezoelectric material 42 and the resist 30. Here,
the resist 30 is a photo-resist. Then, a portion of the conductive
layer 54 formed on the photo-resist 30 can be removed by etching
the photo-resist 30.
[0035] When the conductive layer 54 is coated over the upper
surface of the piezoelectric material 42 and the photo-resist 30,
and when the photo-resist 30 is etched selectively, a portion of
the conductive layer 54 coated over the photo-resist 30 can be
separated and removed. That is, the upper electrode 50 is patterned
by a lift-off process.
[0036] Here, since the reactivity of the photo-resist 30 is
different from those of the piezoelectric material 42, the lower
electrode 20 and the conductive layer 54, the photo-resist 30 can
be etched selectively without damaging the piezoelectric material
42, the lower electrode 20 or the conductive layer 54. As a result,
only a portion of the conductive layer 54 coated over the
piezoelectric material 42 can remain, and the remaining portion 50
of the conductive layer 54 can be patterned to serve as an upper
electrode.
[0037] After the upper electrode 50 is patterned, the inlet port 17
can be formed in the head body 10.
[0038] While the spirit of the invention has been described in
detail with reference to particular embodiments, the embodiments
are for illustrative purposes only and do not limit the invention.
It is to be appreciated that those skilled in the art can change or
modify the embodiments without departing from the scope and spirit
of the invention.
* * * * *