JPH09207346A - Manufacture of thermal ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for manufacturing a thermal ink jet recording head producing a high definition print. SOLUTION: In the method for manufacturing a thermal ink jet recording head wherein heating elements 4 for jetting ink droplet, electrode wiring 1, 5 for conducting the heating elements 4, layers 7, 8 for protecting the electrode wiring and heating elements 4 against ink, and a port for jetting ink subjected to the action of thermal energy are formed on a substrate 6 and control elements 12 for driving the heating elements 4 are built in the substrate 6, a multilayer structure of a part of electrode wiring for conducting the heating elements 4 and the electrode wiring to be connected with the control elements 12 is formed on the substrate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a method of manufacturing a liquid jet recording type thermal ink jet recording head,
In particular, it belongs to the technical field relating to power supply to a heat generating resistor that ejects liquid.

[0002]

2. Description of the Related Art A thermal ink jet recording head that uses heat to eject ink is a method of ejecting the ink by transmitting the energy of bubbles generated as a result of passing a current through a heating resistor to heat the ink in a thin nozzle. The ejection direction of the ink droplets is parallel to the heating resistor,
Some of them discharge perpendicularly to the heating resistor.

Conventionally, a method of manufacturing a thermal ink jet recording head of a liquid jet recording system includes a step of forming an element (IC) for driving and controlling a thermal ink jet printer on a substrate such as a silicon wafer, a film forming step, a photolithography step and , A nozzle forming process. Since the present invention relates to the driver manufacturing process and the film forming process, the description of the nozzle forming process will be omitted.

The thermal ink jet recording head is broadly divided into one in which the drive control element is mounted on the same substrate on which the heating resistor and the electrode wiring are formed, and only the heating resistor and the electrode wiring are formed on the substrate. , A separate driver for drive control, wire bonding or TAB
It is divided into those connected by joining.

FIG. 5 is an explanatory view showing the basic structure of a conventional thermal ink jet recording head, and FIG. 6 is a sectional view showing a section taken along the line AA 'in FIG. FIG. 5 particularly shows a basic film structure of a thermal ink jet recording head.

In both of these figures, a thermal oxidation film or the like which is the insulating heat storage layer 2 is provided on a substrate silicon wafer 6 or the like, and a first heating resistance film 4 and an electrode wiring film 5 are formed thereon in this order. There are a protective film 7 (ink resistant layer), a second protective film 8 (anticavitation layer), and the like.

Further, nozzles are formed in these, and electrical signal connection with the outside is performed by wire bonding, TAB bonding or the like to obtain a thermal ink jet recording head.

[0008]

In the conventional thermal ink jet recording head, the electrode wiring for energizing the heating resistor is arranged on the same layer on the + (plus) side and the- (minus) side. A folded electrode is required, and the electrode wiring width is doubled. Further, if the electrode wiring width is reduced, wiring resistance increases and power loss increases. Therefore, the density (dot density) of the heating resistor is about 360 dp.
The limit is i to 400 dpi.

The present invention solves the above-mentioned problems of the prior art and makes it possible to increase the density of the heating resistors by 600 dpi in one row of the heating resistor array, thereby enabling higher-definition printing, and a thermal ink jet recording head. It is intended to provide.

[0010]

The present invention achieves the above object by a manufacturing method having the following constitution.

(1) A drive electric circuit for driving a heating resistor is incorporated in the substrate, and the heating resistor for discharging droplets, electrode wiring for energizing the heating resistor, and the heating resistor. A substrate having a protective layer for protecting the electrode and the electrode wiring from a liquid for ejecting, a liquid passage for causing heat generation energy when the heating resistor is energized to act on the liquid, and an ejection port for ejecting the liquid on which the heat energy acts. A method of manufacturing a thermal ink jet recording head formed on the substrate, comprising: forming a multi-layered structure of a part of an electrode wiring for energizing the heating resistor and an electrode wiring connected to the driving electric circuit on the substrate. A method of manufacturing a thermal ink jet recording head having a feature.

(2) In the method of manufacturing the thermal ink jet recording head described in (1) above, a part or all of either the plus electrode or the minus electrode of the electrode wiring connected to the heating resistor is heated to generate heat. A method of manufacturing a thermal ink jet recording head, which comprises arranging and forming the lower layer of a resistor below a heat storage layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that, in a driver mounting head of a thermal ink jet recording head, an A1 wiring film used in a driver mounting step is used for a folded electrode wiring for supplying power to a heating resistor. To do.
That is, the electrode wiring in the folded portion has a multi-layer structure in which it is arranged under the oxide or nitride of silicon which is the heat storage layer. The details of the above embodiment will be described by way of examples.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing the structure of the essential part of an embodiment of the present invention.

FIG. 1A is a plan view of an essential part of an embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA 'of FIG. FIG. 2 is a sectional view showing the ejection direction of ink droplets of the thermal ink jet recording head manufactured in one example.

Reference numeral 1 is a lower layer folded electrode wiring, 2 is a heat storage layer for insulation and heat insulation, 3 is a contact hole, 4 is a heating resistance film, and 5 is an upper layer A1 electrode wiring.

An embodiment of a method of manufacturing a thermal ink jet recording head according to the present invention will be described below step by step.

A drive control element 12 (power transistor, NAND circuit, etc.) of the thermal ink jet recording head.
Are created in advance by using semiconductor technology. Then, a heating resistor, electrode wiring, a protective film, and a nozzle for ejecting ink droplets are arranged. When arranging the electrode wiring at the time of making the drive control element 12, the electrode wiring on the folded side of the heating resistor portion 4 is also patterned at the same time with a width of 8 μm, and the electrode opposite to the heating resistor 4 is VH. Connect to the line.

Next, a film 2 of silicon oxide or nitride, which is an insulating and heat storage layer, is formed on the drive control element 12 by using PCVD or the like to form a thermal ink jet recording element. To do. Wiring 1 of the drive control element 12
Of the above-mentioned CVD so as to be electrically connected to the heat generating resistor side of the return electrode wiring of the heat generating resistor portion 4 which was simultaneously formed when the A contact hole 3 is opened in the silicon oxide or nitride film 2. In this embodiment, in order to reduce the electric resistance, 4 × 21 μm
Open the rectangular contact hole.

Further, Ta, which is a heating resistor, is formed on the silicon oxide or nitride film 2 formed by the above CVD.
The N film 4 and the like are formed, further, the electrode wiring film A1 and the like are formed by a film forming device such as a sputtering device, and each is patterned by using a photolithography technique. At this time, as shown in FIG. 1A, the patterning position is the heating resistor 4
Then, patterning is performed so that the position of the folded electrode wiring 1 in the lower layer becomes 3 μm.

Next, as shown in the cross-sectional view of FIG. 2, a first protective film 7 such as a silicon oxide or a nitride which is an ink resistant layer and a second protective film such as a Ta film which is an cavitation resistant layer. The film 8 is formed by a sputtering apparatus or the like and patterned. Further, the nozzle 9 and the ink supply unit 10 are arranged and electrical wiring is connected to form a thermal ink jet recording head. The thermal ink jet recording head manufactured in this embodiment is of the type shown in FIG. 2 in which ink droplets are ejected in parallel with the heating resistor. In addition, 11 shown in FIG. 2 is a nozzle wall, and 12 is the above-mentioned drive circuit section (driver).

FIG. 1A shows the detailed dimensions of the heating resistor portion of the thermal ink jet recording head prepared in the above embodiment. In this example, the heating resistor 4 having a width of 28 μm was patterned and created. When the width of the folded electrode wiring 1 in the lower layer is 8 μm, the distance from the heating resistor 4 is 3 μm. Furthermore, when the distance between adjacent heating resistors is 3 μm, the total pitch is 42 μm,
It can be 0 dpi.

(Other Embodiments) FIG. 1 (a) is also a plan view of essential parts of another embodiment of the present invention, and FIG. 1 (b) is a sectional view taken along the line A--A in FIG. 1 (a). FIG. FIG. 3 is a sectional view showing the ink droplet ejection direction of a thermal ink jet recording head manufactured in another embodiment. FIG. 4 is an explanatory view showing the arrangement of the heating resistors of this embodiment.

Reference numeral 1 is a lower layer folded electrode wiring, 2 is a heat storage layer for insulation and heat insulation, 3 is a contact hole, 4 is a heating resistance film, and 5 is an upper layer A1 electrode wiring.

Another embodiment of the method for manufacturing a thermal ink jet recording head according to the present invention will be described below in order.

Drive control elements (power transistors, NAND circuits, etc.) 12 of the thermal ink jet recording head
Are fabricated in advance on the Si substrate 6 using semiconductor technology. And the heating resistor, the electrode wiring, the protective film, and
A nozzle for ejecting ink droplets is arranged. At this time, as shown in FIG. 4, the heater resistors 4 having the same shape are formed in left and right symmetrical positions across the width of the ink supply port 10 by a half pitch in the heater position calculation so as to be symmetrical. Leave. A1 when the drive control element 12 is built
When arranging the wiring, the electrode wiring on the folded back side of the heating resistor portion is also patterned and arranged with a width of 8 μm at the same time, and the electrode opposite to the heating resistor 4 is connected to the VH line.

Next, a film 2 of silicon oxide or nitride, which is an insulating and heat storage layer, is formed on the drive control element 12 by using CVD or the like to form a thermal ink jet recording element.
Etc. are formed into a film. The heating resistor portion of the electrode wiring on the folded side of the heating resistor portion 4 that was formed at the same time when the A1 wiring 1 of the drive control element 12 was patterned was electrically connected to the folded electrode wiring side of the thermal ink jet recording element. A contact hole 3 is opened in the above-described CVD silicon oxide or nitride film 2 so as to be conductive. In this embodiment, a rectangular contact hole of 4 × 21 μm is opened to reduce the electric resistance.

Further, on the silicon oxide or nitride film 2 formed by the P-CVD, a T is a heating resistor.
The aN film 4 and the like are formed, and the electrode wiring film A1 and the like are further formed by a film forming device such as a sputtering device, and each is patterned using a photolithography technique. At this time, as shown in FIG. 1A, the patterning position is patterned so that the position between the heating resistor 4 and the lower folded electrode wiring 1 is 3 μm. Next, as shown in the sectional view of FIG. 3, a first protective film 7 such as a silicon oxide or a nitride which is an ink resistant layer, and a second protective film 8 such as a Ta film which is an anticavitation layer. Is formed by a sputtering device or the like and patterned. Next, anisotropic etching or
The ink supply port 10 is opened by using sandblast or the like.

Further, the nozzle 9 and the ink supply unit 10 are arranged and electrical wiring is connected to form a thermal ink jet recording head.

FIG. 1A shows the detailed dimensions of the heating resistor portion of the thermal ink jet recording head prepared in the above embodiment. In this example, the heating resistor 4 having a width of 28 μm was patterned and created. When the width of the folded electrode wiring 1 in the lower layer is 8 μm, the distance from the heating resistor 4 is 3 μm. Furthermore, when the distance between adjacent heating resistors is 3 μm, the total pitch is 42 μm.
It can be dpi.

Further, as shown in FIG. 4, by disposing the heating resistors 4 at the left and right symmetrical positions across the ink supply port 10 with a shift of a half pitch, a total of 1200 dpi is obtained. Note that this thermal ink jet recording head is of a type that discharges perpendicularly to the surface of the heating resistor 4, as shown in FIG. 3, unlike the above-described embodiment.

[0032]

As described above, according to the present invention,
By forming the folded electrode wiring under the heat storage layer in advance in the driver mounting step, the thermal ink jet recording head completed by the above method can have a higher density heater arrangement than the conventional method. Also,
600 dpi for a head that ejects ink droplets in parallel to the heater surface. In the configuration in which ink droplets are ejected perpendicularly to the heater surface, the heaters can be shifted by half a pitch and arranged in two cases to achieve 1200 dpi, and it is possible to manufacture and provide a thermal ink jet recording head capable of higher-definition printing. Becomes

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the ejection direction of ink droplets of the thermal inkjet recording head manufactured in one example.

FIG. 3 is a cross-sectional view showing the ejection direction of ink droplets of another embodiment.

FIG. 4 is an explanatory diagram showing a 1200 dpi heater arrangement according to another embodiment.

FIG. 5 is a partially cutaway perspective view showing a structure of a main part of a conventional thermal inkjet recording head.

FIG. 6 is a cross-sectional view showing a film structure of a heating resistor of a conventional thermal ink jet recording head.

[Explanation of symbols]

1 Lower Layer Folded Electrode Wiring 2 Insulation Thermal Storage Layer (CVD Silicon Oxide or Nitride Film) 3 Contact Hole 4 Heating Resistor Film 5 Upper Electrode Wiring Film 6 Si Substrate 7 First Protective Film (Inkproof Layer) 8 Second protective film (anti-cavitation layer) 9 Nozzle section 10 Ink supply port 11 Nozzle wall 12 Drive control element (driver)

Claims (2)

[Claims] 1. A drive electric circuit for driving a heating resistor is incorporated in a substrate, the heating resistor for discharging droplets, electrode wiring for energizing the heating resistor, and the heating resistor. On the substrate, there are provided a protective layer for protecting the electrode wiring from a liquid ejected, a liquid passage for causing the heat generation energy when the heating resistor is energized to act on the liquid, and an ejection port for ejecting the liquid on which the heat energy acts. A method of manufacturing a thermal ink jet recording head, wherein a multi-layer structure of a part of the electrode wiring that conducts electricity to the heating resistor and an electrode wiring that connects to the driving electric circuit is formed on the substrate. And a method for manufacturing a thermal ink jet recording head. 2. The method for manufacturing a thermal ink jet recording head according to claim 1, wherein a part or all of one of a positive electrode and a negative electrode of electrode wiring connected to the heating resistor is the heating resistor. A method of manufacturing a thermal ink jet recording head, characterized in that the thermal ink jet recording head is formed by arranging the heat storage layer below the lower heat storage layer.