Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Making named article
Reexamination Certificate
2000-06-21
2002-06-18
McPherson, John A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Making named article
Reexamination Certificate
active
06406835
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a printhead of an ink jet printing apparatus and its manufacturing method and, more particularly, to a printhead and its manufacturing method of forming ink orifices on a photosensitive film by photolithography (exposure and development).
BACKGROUND OF THE INVENTION
In a conventional thermal bubble printhead, a high temperature is generated by a heating element so that a bubble is generated in the ink within the ink chamber on the heating element. The ink is ejected through an ink orifice by the pressure of the bubble and a dot of ink is printed onto a substrate (such as a sheet of paper). However, to let the bubbles generated by heating adequately eject the ink and form a dot of ink, the ink has to be confined in the ink chamber of the printhead and has to be ejected through a predetermined ink orifice.
A piezoelectric printhead utilizes a piezoelectric material to eject the ink by deforming a film through changing the voltage of an electrode so that the ink is ejected by the film and a dot of ink is printed onto a predetermined substrate through an ink orifice.
The print cartridge of a conventional bubble-type ink jet printing apparatus is shown in FIG.
1
. It comprises an ink reservoir
10
and a printhead
12
. The ink in the ink reservoir
10
flows through the printhead
12
and is ejected by the printhead
12
onto a substrate.
FIG. 2
illustrates the structure of the printhead
12
. The printhead
12
comprises a micro-control apparatus
16
formed with a plurality of ejecting elements (i.e. heating elements
14
in accordance with the preferred embodiment of the invention). A photosensitive film (dry film photoresist)
18
is formed on the micro-control apparatus
16
. The photosensitive film
18
is used to form ink chambers
20
at locations in alignment with the heating elements
14
by photolithography (exposure and development) so that the ink can flow into the ink chambers
20
. The ink orifices
22
is formed in a nozzle plate
24
by electrical forming and the nozzle plate
24
is applied to the dry film photoresist
18
by a way of precision alignment. Therefore, in the assembling process, the ink orifices
22
in the nozzle plate
24
must be in precision alignment with the ink chambers
20
in the photosensitive film
18
respectively so that the ink heated by the heating elements
14
can be ejected through the ink orifices
22
. It can be known that this manufacturing process incurs high costs including the tool cost for precision alignment and low quality alignment, assembling, or application of the nozzle plate
24
to the dry film photoresist
18
reduces the yield rate.
Another printhead of a bubble-type ink jet printing apparatus is disclosed in U.S. Pat. No. 5,537,133 and is illustrated in FIG.
3
. The printhead
30
comprises a micro-control apparatus
34
formed with a plurality of ejecting elements (i.e. heating elements
32
in accordance with the preferred embodiment of the invention). A photosensitive film (dry film photoresist)
35
is formed on the micro-control apparatus
34
. An ink chamber
36
is formed on each of the heating elements
32
by photolithography (exposure and development). Ink orifices
39
are formed in a tape (flexible circuit board)
38
, which is attached to the printhead
30
by Tape Automated Bonding (TAB), by laser ablating and the tape
38
is applied to the micro-control apparatus
34
in a way of precision alignment so that each ink orifice
39
and a corresponding ink chamber
36
cooperatively form an ink reservoir for the ink. However, forming ink orifices
39
in tape
38
by laser ablating incurs a high equipment cost that significantly increases the manufacturing cost of the printhead. In addition, low quality alignment and assembling may also reduce the yield rate.
SUMMARY OF THE INVENTION
A primary object of the invention is to provide a printhead and the manufacturing method therefor to thereby prevent ink channels and ink chambers provided in a first layer of film from adhering to a nozzle plate formed by photolithography when the nozzle plate is applied to the first layer of film.
Another object of the invention is to provide a printhead and the manufacturing method therefor to thereby make an electrical connection between signal input means and a micro-control apparatus.
Still another object of the invention is to provide a printhead and the manufacturing method therefor that features the efficacy of precision alignment and high quality assembling so that the yield can be increased and the manufacturing process can be simplified.
Further still another object of the invention is to provide a printhead and the manufacturing method therefor so that the process of manufacturing a printhead can be simplified, the equipment cost can be reduced, and the yield can be increased.
A printhead of an ink jet printing apparatus according to the present invention comprises a micro-control apparatus formed with a plurality of ejecting elements; a first layer of film, formed over said micro-control apparatus, with a plurality of ink chambers formed at positions respectively corresponding to said plurality of ejecting elements, a plurality of ink channels connected with said plurality of ink chambers, and a plurality of supporting cylinders located within said plurality of ink channels; a photosensitive film, formed over said first layer of film, with a plurality of ink orifices formed at positions respectively corresponding to said plurality of ink chambers by photolithography; and a signal input means connected to connected to said micro-control apparatus.
Therefore, the manufacturing process of the printhead in accordance with the present invention is relatively simple. Using this process, the application of a nozzle plate to a photoresist film and the precision alignment between ink orifices and ink chambers in manufacturing a conventional printhead can be avoided so that the throughput and yield rate can be increased.
REFERENCES:
patent: 4558333 (1985-12-01), Sugitani et al.
patent: 5537133 (1996-07-01), Marler et al.
Kang Hung-Chou
Lin Chen-Hua
Wu Ji-Chen
Chang, Esq. Ya-Chiao
McPherson John A.
Wisertek International Corporation
LandOfFree
Method for manufacturing a printhead of ink jet printing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for manufacturing a printhead of ink jet printing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for manufacturing a printhead of ink jet printing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2938752