JP2000033702A - Thermal ink jet head and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small thermal ink jet head and a manufacturing method thereof capable of enhancing a migration resistance of a wiring pattern and improving the productivity. SOLUTION: A diffusion section 31 for a switching transistor array and a diffusion section 32 for a latch circuit and a shift resistor circuit are formed by a diffusion treatment of an LSI, an oxide film is formed and a wiring pattern 34-1 for a power source of the LSI is formed. At that time, a wiring pattern 2-1 for a common electrode and a wiring pattern 4-1 for an individual electrode in a heating head section are formed. Then, a passivation film 35 is formed, a contact hole is formed and an unnecessary part of the passivation film 35 is removed. After that, a heating resistor layer 36 of Ta-Si-O sharing a resistive protection film is formed in a head process and a conductive protection film having a composition of W-Al, W-Ti or W-Si is formed thereon and an electrode film 37 of Au is formed thereon. Then, each of the wiring patterns 2, 4, 34 is formed and a heating section of heating resistors 5 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal ink jet head having a large head driving force in a smaller number of steps and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, thermal ink jet printers have been widely used. In the thermal ink jet system, a heating element is heated to generate nuclear bubbles on the heating element in the process of forming ink droplets ejected for printing. These nuclei bubbles coalesce to produce film bubbles. The film bubbles adiabatically expand and grow to push the surrounding ink. The grown film bubbles shrink due to the heat taken by the surrounding ink. Eventually, a series of steps of instantaneously eliminating the film bubbles and waiting for the next heater heating is realized. The film boiling phenomenon is used in the above steps (1) to (4).

The film boiling phenomenon occurs when an object heated to a high temperature such as quenching of iron is immersed in a liquid and when the surface temperature of the object in contact with the liquid is rapidly increased. The film boiling phenomenon used in a thermal ink jet printer is based on the latter method of "rapidly increasing the surface temperature of an object in contact with a liquid". Further, in such a thermal inkjet head, there is also a configuration in which not only monochrome printing but also full-color printing is performed by discharging inks of three primary colors.

As a method for manufacturing this full-color thermal ink jet head, a plurality of heating elements, a drive circuit for individually driving these heating elements, an ink supply path, and an ink discharge nozzle (orifice) are utilized by utilizing a silicon LSI formation processing technique and a thin film technique. Are monolithically formed on a single silicon chip.

According to this method, for example, when a print head having a resolution of 360 dpi (dots / inch) is to be formed on a silicon chip having a width of 10 mm, 128 dots are required.
A plurality of heating elements, a driving circuit, and an orifice (generally a term used for an energy transmission hole or window formed on the end or wall surface of a waveguide or the like), 25 if the resolution is 720 dpi
Six heating elements, a drive circuit, and an orifice are formed.

[0006]

By the way, even though a plurality of heating elements and a driving circuit for individually driving the heating elements are formed monolithically on a single silicon chip, conventionally, an LSI section is conventionally used. In many cases, the forming step and the step of forming the heat-generating head portion have different production lines or processing plants, and the processing accuracy is also greatly different.

On the other hand, at present, as described above, in addition to the demand for multicolor printing for full-color printing and the demand for multi-nozzles for increasing the printing speed, there is an extremely strong demand for a reduction in the price of a print head. To reduce the price of the print head, reduce the size of the thermal inkjet head, that is, reduce the size of the substrate (silicon chip) as much as possible, and increase the number of substrates taken from one silicon wafer. The yield of the wafer must be improved.

On the other hand, in order to perform full-color printing with a thermal ink jet head, usually, four rows of nozzles (orifices) are required. In order to reduce the size of a high-definition multi-nozzle thermal inkjet head, it is essential to reduce the size of a circuit for driving a heating resistor.

However, when the driving current of the heating resistor is 1
Since it is as large as 50 to 100 mA per heating resistor,
The switching transistor for driving this becomes large, and in driving the heating resistor, it is necessary to simultaneously print with at least 10 ink ejection nozzles, that is, to drive 10 heating resistors simultaneously for efficiency. However, in that case, the drive current flowing at one time increases. Therefore, it is necessary to lower the wiring resistance,
Since it is difficult to form an electrode wiring film thick by a thin film forming technique such as sputtering, the line width of the electrode wiring must be made large (wide). Further, in order to prevent migration (electromigration), which is a phenomenon in which ions are eluted from the surface of a metal conductor due to impurity elements such as chlorine and moisture in semiconductors and electronic circuits, the line width of the electrode wiring must be made large. . Otherwise,
Elution of ions may cause disconnection of wiring.

With respect to the relationship between the drive current and the wiring width, for example, in order to flow a current of 1 A as a whole, A
An electrode wiring of 1 (aluminum) requires a thickness of 1 μm and a total width of 1 mm. The reason is that in order to prevent migration in a normal Al wiring, 10 ⁵ A /
This is because it is designed in cm ² . For this reason, in a thermal inkjet head having four nozzle rows, an LSI
Requires a width of as much as 4 mm. This cannot meet the demand for downsizing.

However, instead of increasing the width of the electrode wiring, there has been proposed a technique in which the electrode wiring is formed in two layers and is vertically thicker, thereby solving the above problem.
However, as described above, forming the electrode wiring in two layers in the LSI part forming step and the heating head part forming step in which the production line or the processing plant is separate means that the thin film formation by sputtering or the like is performed in two steps. It has to be performed twice, which causes a problem of productivity reduction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances,
An object of the present invention is to provide a small-sized thermal ink jet head which can prevent disconnection of electrode wirings, has good productivity and is small in size, and a method of manufacturing the same.

[0013]

First, a method of manufacturing a thermal ink jet head according to the present invention is a method of manufacturing a thermal ink jet head having a print head unit and a drive circuit unit for driving the print head unit on the same substrate. Forming a power supply wiring of the drive circuit section in the step of forming the electrode wiring of the print head section, and forming an electrode wiring of the print head section in the step of forming the power supply line of the drive circuit section. Thus, knitting is performed including a step of forming both the electrode wiring of the print head section and the power supply wiring of the drive circuit section into a multilayer structure of two or more layers.

[0014] Between the step of forming the common electrode wiring of the print head section and the step of forming the power supply wiring of the drive circuit section,
For example, the method includes a passivation film forming step and a contact hole forming step. Further, the electrode wiring of the print head section includes, for example, a lowermost electrode layer, a resistive protective film, a conductive protective film, and an uppermost electrode layer.

A thermal ink jet head according to a fourth aspect of the present invention is a thermal ink jet head having a print head unit and a drive circuit unit for driving the print head unit on the same substrate. An electrode wiring formed in a multilayer having a layer and an upper layer,
The drive circuit section has at least a lower layer and an electrode wiring formed in a multilayer having an upper layer, and the lower layer of the print head section and the lower layer of the drive circuit section are made of the same material in the same process. The upper layer of the print head unit and the upper layer of the drive circuit unit are formed by the same process and using the same material.

The electrode wiring of the head section comprises, for example, a lowermost electrode layer, a resistive protective film, a conductive protective film, and an uppermost electrode layer.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 (a), (b), (c) and FIG.
3A, 3B, and 3C are diagrams illustrating a method of manufacturing a thermal inkjet head according to an embodiment in the order of steps. FIGS. 1 (a), (b), and (c) show schematic plan views and cross-sectional views, respectively, and the upper parts of FIGS. 2 (a), (b), and (c) show FIGS.
It is a diagram showing a partially enlarged plan view of (b), (c) in detail,
The middle part is an AA 'cross-sectional view of the upper part (see FIG. 3A), and the lower part is an BB' cross-sectional view of the upper part (see FIG. 3A). The cross-sectional views shown below each of FIGS. 1 (a), (b) and (c) are the same as the cross-sectional views shown in the middle section of FIGS. 2 (a), (b) and (c). is there.

In these figures, for convenience of explanation, all of the thermal ink jet heads for full color are shown.
Although only a plurality of heating heads (the same as the configuration of the monochrome inkjet head) are shown, actually, as described later, a plurality of such heating heads (usually four) are formed, It is formed on one substrate (silicon chip).

First, a basic manufacturing method will be described. First, as a step 1, a drive circuit having power supply wiring and terminals thereof are formed on a silicon substrate of 4 inches or more by LSI forming processing, and an oxide film having a thickness of 1 to 2 μm is formed. Next, as a step 2, using a thin film technique,
A resistive protective film made of -Si-O or the like; a conductive protective film made of W-Al (or W-Ti, W-Si) or the like;
Further, each electrode film of a common electrode and an individual wiring electrode made of Au is formed, a pattern of a wiring portion is formed on the conductive protection film and the electrode film by photolithography, and a fine heating resistor (heat generation) is formed on the resistive protection film. Element) pattern is formed. In this step, the position of the heat generating portion of the heat generating resistor is determined.

FIGS. 1 (a) and 2 (a) show a state immediately after the above steps 1 and 2 are completed. That is, a common electrode 2, a common electrode power supply terminal 3 (see FIG. 1A), individual wiring electrodes 4, a large number of heating resistors (heating elements) 5, a driving circuit 6, and a driving circuit terminal 7 are provided on the silicon substrate 1.
(See FIG. 1A). The detailed configuration of the electrode portion will be described later.

Subsequently, in step 3, the individual heating elements 5
A partition member made of an organic material such as photosensitive polyimide is formed to a height of about 20 μm by coating to form an ink groove corresponding to
Curing (dry curing, baking) by applying heat of 00 ° C. to 400 ° C. for 30 minutes to 60 minutes is performed to form and fix a 10 μm-high partition wall made of the photosensitive polyimide on a silicon substrate. Further, in step 4, a groove-shaped ink supply path is formed on the surface of the silicon substrate by wet etching or sand blasting, and an ink supply hole communicating with the ink supply path and opening on the lower surface is formed.

FIGS. 1 (b) and 2 (b) show a state immediately after the above steps 3 and 4 are completed. That is, a groove-shaped ink supply path 8 and an ink supply hole 10 are formed, and a part where the common electrode 2 is located on the left side of the ink supply path 8 and a part where the right individual wiring electrode 4 is provided. A partition 9 (9, 9) is provided between each heating resistor 5 and each heating resistor 5.
-1, 9-2) are formed. If the portion 9-1 on the individual wiring electrode 4 is a comb body, the portion 9-2 extending between the heating resistors 5 is a comb that is laminated between the heating resistors 5 of the partition 9. It has a shape corresponding to the teeth of As a result, fine ink grooves in which the heating resistors 5 are located at the roots between the teeth are formed by the number of the heating resistors 5 using the teeth of the comb as partition walls. By changing the length of the teeth of the comb, the conductance of the flowing ink changes, and the interference between the ink flowing in the adjacent ink grooves is also affected.

Thereafter, in step 5, an orifice plate of a polyimide film having a thickness of 10 to 30 μm is coated on one side with a very thin thermoplastic polyimide as an adhesive, for example, to a thickness of 2 to 5 μm. The ink groove formed by the partition wall 9-2 is covered with the uppermost layer of the laminated structure, thereby forming an individual fine passage (ink groove). Then, pressure is applied while heating at 200 to 300 ° C. to fix the orifice plate. Then N
A metal film such as i, Cu, or Al having a thickness of about 0.5 to 1 μm is formed.

In step 6, the metal film on the orifice plate is patterned to form a mask for selectively etching polyimide.
A plurality of nozzle holes (orifices) are collectively formed by making holes of 40 μmφ to 20 μmφ in accordance with the above metal film mask by dry etching such as R or the like. The holes may be formed using an excimer laser or the like.

FIGS. 1 (c) and 2 (c) show the process 5 described above.
And the state immediately after the end of step 6. That is, the orifice plate 11 is connected to the drive circuit 6 and the power supply terminals 3 and 7.
And the above-mentioned ink groove is also covered to form a pit-like ink groove (ink supply path) 12 having a height corresponding to the thickness of the partition 9 of 10 μm. A nozzle hole (orifice) 13 is formed in the orifice plate 11 at a portion corresponding to the heating resistor 5 by dry etching.
3 is completed.

By attaching the orifice plate 11 and then processing the nozzle hole (orifice) in accordance with the pattern of the base, that is, the position of the heating resistor 5, the orifice plate having the orifice processed in advance is bonded. It is a much more productive and practical method. In the case of dry etching, the mask is N
By using a metal film such as i, Cu, or Al, a selectivity between the resin and the metal film of about 100 can be obtained. Therefore, it is sufficient to form a mask with a metal film of 1 μm or less for etching a polyimide film of 20 to 40 μm.

The process up to this point is performed in a wafer state.
Finally, as a step 7, cutting is performed by using a dicing saw or the like, the unit is divided into individual units, die-bonded to a mounting board, and terminals are connected to complete.

In the above example, the drive circuit 6 is shown in an exposed state, but a protective film is actually formed. Instead of forming the protective film later, the orifice plate 11 is extended rightward in FIG. 1 (c) (the same applies to FIG. 2 (c)) and laminated.
Alternatively, the protective film of the drive circuit 6 may also be used.

The mono-color head 14 having the above-described one row of nozzle holes 13 has a structure of a monochrome ink-jet head. However, in full-color printing, as described above, yellow (Y), which is a subtractive three primary colors, is used as described above. , Magenta (M), and cyan (C), plus black (Bk) dedicated to black portions of characters and images, and a total of four inks are required. Therefore, at least four nozzle rows are required. According to the above-described manufacturing method, 4
The heating heads in a row can be monolithically configured, and the positional relationship between the rows can be accurately arranged by today's semiconductor manufacturing technology.

FIG. 3A shows the above-described monocolor head 14.
FIG. 4B is a diagram showing a state in which four full color thermal ink jet heads 15 are arranged side by side, and FIG.
FIG. 3 is a view showing a state in which a number of substrates (chips) of the thermal inkjet head 15 are formed on a silicon wafer 17. FIG. 2A shows a type in which the orifice plate 11 also serves as the protective film of the drive circuit 6 (see FIGS. 1C and 2C).

As shown in FIG. 3A, the thermal ink jet head 15 has four monocolor heads 14 (14a, 14b, 14c, 14c) on a large substrate 16.
d) are formed side by side. The thermal inkjet head 15 is, for example, from right to left,
It is configured to eject magenta, cyan, yellow, and black inks.

This thermal ink jet head 15
Is a heating resistor 5 for printing (see FIGS. 2 (a) and 2 (b)).
Are selectively energized in accordance with the print information, and heat is generated instantaneously to cause a film boiling phenomenon, and ink droplets are ejected from the nozzle holes 13 corresponding to the heating resistor 5. In such a thermal ink jet head, ink droplets
Is ejected in a substantially spherical shape having a size corresponding to the diameter of the paper, and is printed on the paper with a size approximately twice as large as the diameter.

Then, in the above-described method for manufacturing the thermal ink jet head 15, as described in steps 1 and 2, the electrode wiring is formed in both the step of forming the LSI section and the step of forming the heating head section. Therefore, by mutually using the process of one electrode wiring and also performing the other electrode wiring, a thicker electrode layer is formed without increasing the number of processes. Hereinafter, this will be described.

FIG. 4 shows a main part of the thermal ink jet head 15 which has completed the above steps 1 and 2.
FIG. 3 is an equivalent circuit diagram showing a heating head section and an LSI section separately. As shown in FIG.
And a common electrode 2, an individual wiring electrode 4, and a heating resistor (heating element) 5 shown in FIG. And the LSI unit 1
9 includes a power supply line 21 not shown in the previous figure, a switching transistor array 22, a latch circuit 23, a shift register circuit 24, and the like.

FIGS. 5 (a) to 5 (e) are views showing the AA 'cross section of FIG. 4 in the order of steps, and FIGS. 6 (a) to 5 (e)
It is a figure which similarly shows B 'cross section in process order. FIG. 5 (a)
6 (a) to 6 (e) and 6 (a) to 6 (e), the same components as those shown in FIGS. 1 to 4 are denoted by the same reference numerals as in FIGS. FIG. 7 is a flowchart showing the manufacturing process of the present embodiment. Steps indicated by symbols a, b, c, d, and e in the flowchart of FIG. 6 are used to form (a), (b), (c), (d), and (e) in FIGS. Each corresponds.

First, as shown in the LSI process of FIG. 7, processing such as LSI diffusion is performed (step S1). Thereby, the diffusion portions 31 (see FIG. 6A) of the switching transistor array 22 and the diffusion portions 32 (see also FIG. 6A) such as the latch circuit 23 and the shift register circuit 24 shown in FIG. 4 are formed. You.

Subsequently, after forming the oxide film 33, the LSI power supply wiring 34-1 is formed using, for example, an Al-based electrode material. Then, at this time, the common electrode wiring 2-1 and the individual wiring electrode line 4-1 of the heating head portion 18 are simultaneously formed of the same material (step S2). 5 (a) and FIG.
The structure shown in (a) is formed.

Next, a passivation film 35 is formed (Step S3). This is a process of growing an oxide film such as silicon oxide, or a layer such as a nitride film, a PSG film, an organic insulating film, etc. on the surface of a semiconductor chip in order to stabilize the characteristics of the semiconductor element. As a result, moisture absorption of the semiconductor chip is prevented, the surface of the transistor is isolated from surrounding electrical and chemical states, and electrical stability is obtained. In this step, the configuration shown in FIGS. 5B and 6B is formed.

Next, a contact hole is formed, and an unnecessary portion of the passivation film 35 is removed (step S4).
In this processing, the individual wiring electrode line 4-1 is connected to the switching transistor array 22 of the diffusion unit 31, the LSI power supply line 34-1 is connected to the latch circuit 23 of the diffusion unit 32, and a hole is formed. For example, implantation of polysilicon or the like is performed. Thereby, FIG. 5 (c) and FIG. 6 (c)
Is formed.

Up to this point, the process of forming the original LSI portion 19, that is, the process of forming the drive circuit and its power supply wiring, has been described.
Electrode wiring (common electrode 2-1 and individual wiring electrode 4-1)
Is also performed. Thereby, the first of each wiring
A layer is formed.

Subsequently, as shown in FIG. 7, the process of the head process is started. First, a heating resistor layer 36 also serving as a resistive protection film such as Ta-Si-O is formed (step S5).
Furthermore, a barrier layer (W-A containing 10% or less of aluminum, titanium, or silicon in tungsten)
A conductive protective film having a composition of 1, W-Ti, or W-Si, not shown in FIGS. 5 and 6, is formed (step S6), and an electrode film 37 of Au is formed (step S7). ). Thus, the configuration shown in FIGS. 5D and 6D is formed.

The resistive protective film 36 and the conductive protective film serve to protect the structure of the lower layer when forming the electrode film 37 of Au. Further, the conductive protective film enhances the adhesion between the Au electrode layer 37 and the resistive protective film 36, and forms the common electrode wiring 2-1, the individual wiring electrode line 4-1 and the LSI power supply wiring 34-1 and the resistance. This is for realizing electrical integration with the Au electrode layer 37 via the conductive protective film 36.

Following the above steps, a wiring is formed.
Further, a heating resistor is formed (step S8). As a result, as shown in FIGS. 5 (e) and 6 (e), the common electrode wiring 2-1 made of Al, the individual wiring electrode 4-1 and the LSI
The Au electrode film 37 overlaps with the power supply wiring 34-1.
2-2, individual wiring electrode line 4-2, and LSI power supply wiring 34-2 are formed.
Is formed.

Au has a very high conductivity, and in the portion where the resistive protective film 36 and the Au electrode film 37 are formed in two layers, the current hardly flows through the resistive protective film 36 and the Au
It flows only to the electrode film 37 (the end of the common electrode wiring 2-2 and the individual wiring electrode line 4-2 in FIG. 6E). Then, a large load is generated in the heat-generating portion of the heat-generating resistor 5 composed of only the resistive protective film 36, and heat is generated.

Up to this point, the process of forming the original heating head portion 18, that is, the process of forming the heating resistor, its common electrode, and the individual wiring electrode has been described. In this process, as described above, the power supply line of the LSI portion 19 is formed. 34-2 is also formed. Thereby, an upper layer of each wiring is formed.

Thereafter, the partition wall 9 is formed as shown in FIGS. 1B and 2B (step S9), and a silicon hole for forming the ink supply passage 8 and the ink supply hole 10 is formed. Etc. are continued (step S10).

As described above, the power supply wiring of the LSI section and the electrode wiring of the heating head section can be formed into a multi-layer thick film structure without increasing the number of manufacturing steps conventionally performed. Since the lower layer is an Al electrode system but the upper layer is an Au electrode system, resistance to migration increases and more current can flow. In addition, the width of the electrode can be reduced by an amount corresponding to an increase in the thickness of the multilayer structure. That is, if the width is conventionally 1 mm, the width may be 0.5 mm.

In general, the size of the chip of the conventional full-color thermal ink-jet head is 15 × 12 mm, but the size of the chip of the thermal ink-jet head 15 in this embodiment shown in FIG. Can be reduced to 15 × 10 mm. FIG.
When the silicon wafer 17 shown in (b) is a 5-inch wafer and the number of chips to be collected is calculated, the chip size is 15
68 × 12 mm, chip size 15 × 10
In the case of mm, the number is 80 pieces. That is, the number of thermal ink jet heads 15 in the present embodiment is 12 more than the conventional one, that is, the number of picked-up inks is increased by 18%.

The present invention is not limited to the method of ejecting ink in the direction perpendicular to the surface of the heating element as in the above embodiment, but the thermal ink jet head of the method of ejecting ink in the direction parallel to the surface of the heating element. It can also be suitably applied.

[0050]

As described above in detail, according to the present invention, the power supply wiring of the LSI section and the electrode wiring of the heating head section are formed in a multilayer structure without increasing the number of conventional manufacturing steps. An ink jet head can be easily manufactured, and therefore, the yield of a wafer can be improved and the unit price of a thermal ink jet head can be reduced.

Further, since a conductive protective film as a barrier layer is interposed, the upper layer of the wiring can be formed of an Au electrode system, and therefore, a thermal ink jet head having an increased migration resistance and a long service life can be obtained. It can be formed.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are a schematic plan view and a cross-sectional view illustrating a method of manufacturing a thermal inkjet head according to an embodiment in the order of steps.

FIG. 2 (a), (b), (c) are the upper row of FIG. 1 (a), (b),
(c) is a partially enlarged plan view of the top view, the middle section is an AA 'cross-sectional view of the upper section, and the lower section is a BB' cross-sectional view of the upper section.

FIG. 3A shows a state in which four mono-color heads are arranged side by side to form a full-color thermal ink-jet head, and FIG. 3B shows a state in which a number of chips of the thermal ink-jet head are formed on a silicon wafer. FIG.

FIG. 4 is an equivalent circuit diagram showing a main part of the ink jet head after the steps 1 and 2 divided into a heating head section and an LSI section.

5 (a) to 5 (e) are views showing a section taken along line AA 'of FIG. 4 in the order of steps.

6 (a) to 6 (e) are views showing a cross section taken along line BB 'of FIG. 4 in the order of steps.

FIG. 7 is a flowchart showing steps.

[Explanation of symbols]

Reference Signs List 1 silicon substrate 2 common electrode 2-1 Al common electrode wiring (lower layer) 2-2 Au common electrode wiring (upper layer) 3 common electrode power supply terminal 4 individual wiring electrode 4-1 Al individual wiring electrode line (lower layer) 4 -2 Au individual wiring electrode wire (upper layer) 5 Heating resistor (heating element) 6 Drive circuit 7 Drive circuit terminal 8 Ink supply path 9 (9-1, 9-2) Partition wall 10 Ink supply hole 11 Orifice plate 13 Nozzle hole (orifice) 14 (14a, 14b, 14c, 14d) Monocolor head 15 Full-color thermal inkjet head 16 Substrate (chip) 17 Silicon wafer 18 Heating head unit 19 LSI unit 21 Power supply line 22 Switching transistor array 23 Latch circuit 24 shift register circuit 31, 32 diffusion part 33 oxide film 34 LSI power supply wiring 34-1 l of LSI power supply wiring (lower layer) 34-2 Au of the LSI power source wiring (upper layer) 35 passivation film 36 resistant protective film and heating resistor layer 37 Au electrode film

Claims (5)

[Claims] 1. A method of manufacturing a thermal ink jet head having a print head unit and a drive circuit unit for driving the print head unit on the same substrate, wherein a power supply of the drive circuit unit is provided in a step of forming electrode wiring of the print head unit. The wiring is formed, and in the step of forming the power supply wiring of the drive circuit section, the electrode wiring of the print head section is formed, whereby both the electrode wiring of the print head section and the power supply wiring of the drive circuit section are formed in two layers. A method for manufacturing a thermal ink jet head, having a multilayer structure as described above. 2. A method according to claim 1, wherein a step of forming a common electrode line of the print head unit and a step of forming a power supply line of the drive circuit unit are performed.
2. The method according to claim 1, further comprising a step of forming a passivation film and a step of forming a contact hole. 3. The thermal ink jet according to claim 1, wherein the electrode wiring of the print head unit comprises a lowermost electrode layer, a resistive protective film, a conductive protective film, and an uppermost electrode layer. Head manufacturing method. 4. A thermal inkjet head having a print head unit and a drive circuit unit for driving the print head unit on the same substrate, wherein the print head unit is formed as a multilayer having at least a lower layer and an upper layer. An electrode wiring; and a multi-layered electrode wiring having at least a lower layer and an upper layer in the drive circuit unit. The lower layer of the print head unit and the lower layer of the drive circuit unit are in the same process. Wherein the upper layer of the print head unit and the upper layer of the drive circuit unit are formed of the same material in the same step. 5. The thermal ink jet head according to claim 4, wherein the electrode wiring of the print head section comprises a lowermost electrode layer, a resistive protective film, a conductive protective film, and an uppermost electrode layer.