Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2000-12-13
2003-08-05
Vo, Anh T. N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06601947
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a connector for a narrow pitch and also to an electrostatic actuator, a piezoelectric actuator, a micro machine, a liquid crystal panel, an ink jet head using these electrostatic actuator and piezoelectric actuator, an ink jet printer mounted with these ink jet heads, and an electronic appliance, each of which includes the connector for a narrow pitch.
BACKGROUND ART
In the recent years, electronic appliances have been configured acceleratedly more compact and lighter in weight. Along with this compact configuration of the electronic appliances, there have been stronger demands for parts to be used for the electronic appliances which are configured more compact and manufactured at lower costs. A micro working technology referred to as micro machining has been developed to cope with these demands and micro machines which are compact and have advanced functions have been manufactured. As an example of the micro machines, there is a printer head (hereinafter referred to as a printer engine) which has a built-in piezoelectric element and ejects ink by oscillating the built-in piezoelectric element.
An LCD cell of a liquid crystal panel is another example of part for which compact configuration is demanded.
To connect such a compact part to an external substrate, there as been used, for example, a method which interposes a connector composed of a flexible substrate, a method which uses wire bonding or a method which solders a wire cable.
FIG. 28
is an enlarged view showing main parts of a connection object and a connector composed of a flexible substrate. On a surface of a connection object
1
such as a printer engine an LCD cell of a liquid crystal panel, a plurality of wires
2
connected to an element are arranged and terminal electrodes
3
are formed at an end as shown in FIG.
28
.
Used as a connector
4
which connects the connection object
1
to an external substrate is a flexible substrate which is made of a material of polyimide. Terminal electrodes
5
which can be overlapped with the terminal electrodes
3
formed at the end of connection object
1
are formed at an end of the substrate and terminal electrodes
6
which have a width greater than that of the terminal electrodes
5
are formed at a wider pitch at an end on a side opposite to the side at which the terminal electrodes
5
are formed. Wires
6
A are arranged to connect the terminal electrodes
5
to the terminal electrodes
6
, and the width and the pitch are changed in the course of the wires
6
A.
FIG. 29
is a diagram descriptive of procedures for connecting the connection object
1
to the connector
4
and
FIG. 30
is a sectional view taken along a C—C line in FIG.
29
.
In a case where the above described connection object
1
is to be connected to the connector
4
as shown in
FIGS. 29 and 30
, the connection object
1
is first placed on a bonding stage
7
so that the terminal electrodes
3
are set upside. Then, the terminal electrodes
5
arranged on the connector
4
are positioned to the terminal electrodes
3
and these terminals are overlapped with each other. An adhesive containing electrically conductive particles is applied between the terminal electrodes
3
and the terminal electrodes
5
so that the electrodes are electrically conductive by way of the electrically conductive particles.
A bonding tool
8
which can be raised and lowered is disposed over the overlapped electrodes, that is, over the terminal electrodes
5
of the connector
4
. A heater
9
is built in the bonding tool
8
so that a tip of the bonding tool
8
can be heated by operating the heater
9
.
At a bonding step, the electrodes are connected by lowering the bonding tool
8
and pressing the connector
4
with the bonding tool
8
so as to bring the electrically conductive particles into close contact with the electrodes and shorten a drying time of the adhesive by heating.
However, it is conventionally necessary to arrange connecting terminals on a micro machine or the like at a pitch which permits connection to a flexible substrate or the like since the flexible substrate is used for connecting the micro machine or the like to an external substrate. The pitch which permits connection to the flexible substrate is usually on the order of 100 &mgr;M. The inventor has made various examinations and confirmed that a limit of a wiring pitch lies in the vicinity of 60 &mgr;m for conventional connectors made of polyimide.
Accordingly, a terminal portion must be configured large only for enabling connection to the flexible substrate though actuators can be configured compact by the micro machining technology. As a result, there is posed a problem that the large terminal portion reduces a number of micro machines which can be cut out from a single silicon wafer.
Since manufacturing of the micro machines requires not only precise working typically represented by anisotropic etching of a silicon wafer but also expensive materials and expensive machines in particular, there has been desired to configure connecting terminals so as to occupy an area as small as possible, thereby manufacturing a large number of micro machines from a single silicon wafer with a high efficiency.
Furthermore, there is another problem that a trouble such as enhancement of a resistance value between terminals, improper joining or short circuit between adjacent terminals may be caused due to a difference between an coefficient of thermal expansion of a material (mainly silicon) of the connection object
1
and that of a material (mainly polyimide) of the connector
4
.
This point will be described below in detail.
When the bonding tool
8
is brought near for connecting the connection object
1
to the connector
4
, the connection object
1
and the connector
4
start swelling under an influence due to the heater
9
built in the bonding tool
8
.
Since polyimide has a coefficient of thermal expansion which is larger than that of silicon at this time, the connector
4
swells larger than the connection object
1
, thereby deviating the terminal electrodes
5
from the terminal electrodes
3
as shown in FIG.
31
. Since the connection object
1
such as the printer engine or the LCD cell of liquid crystal panel is configured finer year by year and a pitch
10
between the electrode terminals
3
is narrowed to cope with the finer connection object (refer to FIG.
30
), the trouble such as the enhancement of a resistance value between the terminals, improper joining or short circuit between adjacent terminals may be caused even when positions of the terminal electrodes are slightly deviated.
When the terminal electrodes are arranged at a narrower pitch and are thinner, a space reserved between adjacent terminal electrodes are smaller, thereby producing a fear that short circuit may be caused between the adjacent terminal electrodes.
DISCLOSURE OF THE INVENTION
The present invention relates to a narrow pitch connector which is capable of coping with fine pitches between electrodes, an electrostatic actuator, a piezoelectric actuator, a micro machine and a liquid crystal panel which include the narrow pitch connector, an ink jet head which uses the electrostatic actuator or the piezoelectric actuator, and an ink jet printer and an electronic appliance on which the ink jet heads are mounted.
(1) A narrow pitch connector in a mode of the present invention is a connector which comprises a plurality of first terminal electrodes and second terminal electrodes which are formed on a substrate, and wires which electrically connect the first terminal electrodes with the second terminal electrodes: the above described wires having a function of making conversion from a pitch of the first terminal electrodes to a pitch of the second terminal electrodes, wherein grooves are formed between the first terminal electrodes respectively.
By forming the grooves between the first terminal electrodes, the present invention makes it possible to prevent the terminal electrodes from being deformed by heat and pressure or sho
Fujii Masahiro
Koeda Hiroshi
Sato Eiichi
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