JPH08183178A - Recording head, its manufacture and liquid jet recording device mounting recording head - Google Patents

Abstract

PURPOSE: To mount a driving IC on a base without using flux. CONSTITUTION: A base 10 is provided with a plurality of power-heat conversion bodies 10a and lead electrodes 10b, and a driving IC 30 is mounted on a base 10 by heating and fusion bonding under vacuum atmosphere after purifying a metal pump 10c on the surface of the base 10 and a soldering pump 31 of the driving IC 30 by sputter etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head for ejecting a recording liquid as flying droplets, a method of manufacturing the recording head, and a liquid jet recording apparatus equipped with the recording head.

[0002]

2. Description of the Related Art A liquid jet recording apparatus, a so-called ink jet printer, is extremely small in noise generation during recording (printing), is easy to speed up, and can record on plain paper. Due to its advantages, it has been of particular interest in recent years.

Among them, for example, JP-A-54-518.
75 publication and German publication (DOLS) 28430
The method described in Japanese Patent No. 64 has a feature different from other liquid jet recording methods in that thermal energy is applied to a recording liquid (ink) to obtain a driving force for droplet ejection.

That is, in the recording method disclosed in the above-mentioned publication, the recording liquid under the action of thermal energy causes a state change accompanied by a rapid increase in volume, and the action force based on this state change causes the recording head tip to move. A droplet is ejected from the orifice to form a flying droplet, which adheres to the recording medium (recording paper) and recording is performed.

In particular, German publication (DOLS) No. 2843
The liquid jet recording method disclosed in Japanese Patent Application No. 064 is not only very effectively applied to the on-demand recording method, but also can easily realize a full-line high-density multi-orifice recording head, and It has the outstanding advantage of being able to obtain high resolution and high quality images at high speed.

A recording head of a liquid jet recording apparatus of this type has an orifice provided for ejecting a recording liquid,
A liquid flow path having a part in which the thermal energy for discharging the droplets communicates with the orifice and acts on the recording liquid,
And an electrothermal converter that generates thermal energy. FIG. 6 shows an example of a conventional structure of such a recording head.

This is provided with a substrate (heater board) 1001 having a number of electrothermal converters 1001a equal to the number of recording dots and a lead electrode 1001b for connecting these to a driving circuit (not shown). 1
001a and a part of the lead electrode 1001b are the protective layer 100.
Covered by 4. The protective layer 1004 is for protecting the electrothermal converter 1001a and the lead electrode 1001b from the recording liquid, and an orifice and a liquid flow path (not shown) for ejecting droplets are provided on the protective layer 1004. . Each lead electrode 1001b is connected to one end of the flexible cable 1005 by a method such as wire bonding, soldering, thermocompression bonding, or tape carrier, and the other end of the flexible cable 1005 is connected to the drive circuit.

However, in such a recording head structure, it is necessary to extend the lead electrode 1001b to the end of the substrate 1001 in order to connect with the flexible cable 1005, and there are many lead portions of each lead electrode 1001b. Therefore, there were the following drawbacks.

(1) Since the lead electrodes are laid out, the area of the substrate becomes large.

(2) The area of the substrate is increased due to the connecting portion with the flexible cable.

(3) Since the connection density cannot be made smaller than about 100 μm, it cannot cope with the high density of 16 dots / mm or the like. It is also difficult to deal with the multi-orifice.

(4) If a multi-orifice is used, the connecting process will take time, resulting in poor production efficiency and high cost.

In order to solve these problems, a recording head in which a driving IC for driving each electrothermal converter is mounted directly on a substrate is being developed. In such a structure of the recording head, a wire bonding method, a tape carrier method, a flip chip method or the like is adopted to connect the electrode of the driving IC and the lead electrode of the electrothermal converter on the substrate. Among them, the flip chip method is most suitable for increasing the density of the lead electrodes and downsizing the recording head.
At present, a device capable of supporting a high recording density of 16 dots / mm has also been developed.

FIG. 5 shows a full-line type driving IC integrated recording head using the flip chip method, which is a long length having an electrothermal converter (not shown) and its lead electrode on a base plate 1015. Board 101
1 and a nozzle block 1012 that covers a part of its surface
And a plurality of driving ICs 1013 mounted on the exposed portion of the surface of the substrate 1011. The nozzle block 1012 has a large number of orifices (not shown) on its end face 1012a, and the recording liquid supplied from the recording liquid supply pipe 1014. Is brought into contact with the electrothermal converter to heat it, and is discharged as droplets from each orifice.

Next, a driving IC by the flip chip method
The mounting process will be described with reference to FIG.

First, a plurality of solder bumps are formed on each driving IC, and each lead electrode of the substrate is also opposed to the solder bump of the driving IC by a plating method, a thick film method, a thin film method or the like. , Metal bumps and common electrodes are formed.

In step S101, flux is applied to the drive IC mounting position on the substrate by a transfer method, a printing method, a dipping method, or the like. Driving IC in step S102
Are aligned (die bonding) so that the solder bumps of the driving IC and the metal bumps on the substrate face each other. At this time, generally, alignment is performed with high accuracy within an error range of several μm to several tens of μm.

Next, in step S103, heating is performed in the reflow furnace to melt the solder bumps of the driving IC,
Bond with metal bumps on the substrate. The flux is melted in the reflow furnace to remove the oxide film on the surface of the solder bumps and the metal bumps and prevent reoxidation of the surfaces to improve the wettability of the solder, etc., and during the reflow process. This is useful for preventing displacement of the driving IC due to mechanical vibration of the. In step S104, cleaning is performed to remove the flux. When using the rosin-based flux that is generally used, the cleaning solution is 1-
Solvent systems such as 1-1 trichloroethane are suitable. After the cleaning, in step S105, the drive IC is electrically inspected to see if the solder bumps are properly joined. Then, if normal, the drive IC is sealed with, for example, an epoxy-based sealing resin.

[0019]

However, according to the above-mentioned conventional technique, since the flux is used when the driving IC is mounted on the substrate, there are the following unsolved problems.

(1) When heated in a reflow furnace, rosin, a reactant and their reaction products in the flux are vaporized and adhere to the nozzle and orifice surface of the recording head and the electrothermal converter. As a result, the change in the state of the recording liquid due to the heat energy of the electrothermal converter is not uniform, resulting in deterioration of image quality.

(2) During flux cleaning, dissolved components of the flux in the cleaning liquid remain on the nozzles of the nozzle block, the orifice surface and the electrothermal converter, leading to deterioration in image quality. Further, during cleaning, it is unavoidable that minute dusts enter the nozzle together with the cleaning liquid, so that the nozzles are clogged with dusts, and the nozzles in which the dusts are clogged are not ejected, so that the image quality is deteriorated.

(3) The material of the nozzle block is mainly an organic resin, and if it is immersed in an organic solvent which is a cleaning solution for the flux, it causes the mechanical strength of the nozzle block to deteriorate due to swelling, etc. May be peeled off from.

(4) If the amount of flux is too large, the side surface of the flux is subjected to a downward pulling force due to the surface tension of the flux during the reflow, and the displacement of the drive IC occurs. Further, when the solvent in the flux is gasified, the gas under the driving IC does not escape sufficiently, and this expands and pushes up the driving IC, resulting in poor electrical connection.

The present invention has been made in view of the above problems of the prior art, and it is not necessary to use a flux when mounting a driving IC on a substrate, and the droplet discharge performance due to the flux is improved. An object of the present invention is to provide a high-performance recording head that is free from the risk of deterioration and poor connection of electrical connection parts, a method of manufacturing the recording head, and a liquid jet recording apparatus equipped with the recording head.

[0025]

In order to achieve the above object, the recording head of the present invention comprises a substrate having a wiring conductor connected to the electrothermal converting means, and drive circuit means for driving the electrothermal converting means. The drive circuit means is provided on the substrate by a step of cleaning the electric connection portions of the substrate and the drive circuit means, heating them by bringing them into contact with each other under a reduced pressure atmosphere, and fusing. It is characterized by being implemented.

The method of manufacturing the recording head of the present invention is
After cleaning the electric connection part of the substrate having the wiring conductor connected to the electrothermal conversion means and the electric connection part of the drive circuit means for driving the electrothermal conversion means, respectively, these are subjected to a reduced pressure atmosphere. It is characterized by having a mounting step of bringing them into contact with each other, heating and fusing.

The surface of each electrical connection may be cleaned by sputter etching.

[0028]

[Function] The surface of the electrical connection portion such as the metal bumps or solder bumps provided on the substrate and the driving circuit means is cleaned by sputter etching or the like so as to be free of an oxide film and the like, and then the substrate is subjected to a reduced pressure atmosphere. The drive circuit means is positioned on top and heated in a reflow oven or the like to fuse them together.

Since the substrate and the driving circuit means are heated under a reduced pressure atmosphere, there is no possibility that an oxide film will be formed again on the surface of each cleaned electrical connection portion. Therefore, it is not necessary to apply the flux to the substrate.

As a result, as in the case of using the flux, the electrothermal converting means of the substrate is contaminated by the vaporized component of the flux and the cleaning liquid used for cleaning the flux, and the droplet discharging function of the recording head is reduced. It is possible to avoid troubles such as deterioration and poor contact in the electrical connection portion.

[0031]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view showing a main part of a full line type recording head according to an embodiment. this is,
A substrate 10 having electrothermal converters 10a which are the same as the number of recording dots, which are electrothermal converters, and lead electrodes 10b which are wiring conductors connected to each electrothermal converter 10a;
The nozzle block 20 is composed of a resin layer 21 laminated on this and a glass top plate 22 that covers the top of the resin layer 21.
A plurality of drive ICs 30 as drive circuit means are mounted on a portion of the surface of 0 exposed from the nozzle block 20 by a flip chip method described later.

The nozzle block 20 forms a plurality of orifices 20a opening at its end surface, a liquid flow path (nozzle) 20b communicating with each orifice 20a, and a common liquid chamber 20c on the substrate 10.

Each electrothermal converter 10a is composed of a portion of the heating resistor 12 on the Si substrate 11 exposed from the interrupted portion of each lead electrode 10b.
As the material of (1), most materials can be adopted as long as desired heat is generated by energization.

Specific examples of the main material thereof include tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, hafnium, lanthanum, zirconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, vanadium, and the like. Are preferred.

Further, among these materials, metal borides are particularly excellent, and among them, hafnium boride has the most excellent characteristics, and then lanthanum boride, tantalum boride, vanadium boride, The order is niobium boride.

The heating resistor 12 is made of the above-mentioned material, and the Si substrate 11 is formed by electron beam evaporation or sputtering.
Formed on top.

As the material of the lead electrode 10b,
Those capable of forming a dense and pinhole-free inorganic insulating layer, such as Al, Ta, Ti, Mg, Hf, Zr, V, W,
Mo, Nb, Si, Cu, Ni, Pu, Pt, Pd, etc., or alloys thereof are suitable, and they are formed on the Si substrate 11 by a known method such as vapor deposition.

Each lead electrode 10b is an electrothermal converter 10
An end portion on the side opposite to a extends in the width direction of the substrate 10, and a metal bump 10c which is an electric connection portion for connecting to the driving IC 30 is provided in this portion. The metal bump 10c forms an intermetallic compound with solder (tin or lead), and if it is stable, most metals can be adopted.

The metal bump 10c is made of, for example, gold, silver, palladium, platinum, copper, nickel, tin, lead, etc. alone or as an alloy layer, and is formed by a plating method, a thick film method, a thin film method or the like.

The lead electrode 10b is connected to a common electrode 10d for electrically commoning the lead electrodes 10b and a terminal 10e, which are formed in the same manner as the metal bump 10c. A protective layer 13 is provided on the electrothermal converter 10a, the metal bumps 10c, the common electrodes 10d, and the lead electrodes 10b except for the through holes of the terminals 10e to protect them.

SiO is used as a material for forming the protective layer 13.
Inorganic oxides such as ₂ ; inorganic nitrides such as Si ₃ N; titanium oxide, vanadium oxide, niobium oxide, molybdenum oxide, tantalum oxide, tungsten oxide, chromium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, yttrium oxide, oxidation Transition metal compounds such as manganese, aluminum oxide, calcium oxide, strontium oxide,
Metal oxides such as barium oxide and silicon oxide and their composites, high resistance nitrides such as silicon nitride, aluminum nitride, boron nitride and tantalum nitride, and composites of these oxides and nitrides, and further amorphous silicon and amorphous selenium. Examples include various thin film materials such as semiconductors having a low resistance in the bulk, but having a high resistance in the manufacturing process such as a sputtering method, a CVD method, a vapor deposition method, a gas phase reaction method, and a liquid coating method.

A second protective layer (not shown) is formed on the protective layer 13. As the material, Al, Ta, Zr,
Metals such as Hf, V, Nb, Mg, Si, Mo, W, Y and La and oxides, carbides, nitrides and borides of their alloys are used.

On the other hand, each driving IC 30 includes switching circuits such as transistors or diodes, thyristors, etc. formed on a single crystal silicon substrate by using a semiconductor process, control circuits for controlling these switching circuits, and It is composed of an input / output unit for inputting / outputting an electric signal. In particular, in the present embodiment, the solder bumps 3 which are the electrical connection portions in which the electrodes connecting the above-mentioned input / output portions are made of an alloy (solder) containing tin and lead as main components.
The solder bump 31 is formed by a thin film method, a plating method, a dipping method, or a combination thereof.

Next, a process of mounting each driving IC 30 on the substrate 10 by the flip chip method will be described. In this method, each process is performed in a reduced pressure atmosphere. As shown in FIG. 2, first, the recording head and the driving IC 30 before mounting the driving IC 30 are carried into the load lock chamber 41 on the carrying-in side. The load lock chamber 41 is depressurized to a predetermined depressurized atmosphere (approximately 0.1 Torr or less). Next, these are carried to the sputter etching chamber 42 and sputter etched in an argon plasma atmosphere. The conditions at this time are that the argon gas pressure is about 10 mmTorr, the output is about 1 kW, and the etching time is about 5 minutes.

By this sputter etching treatment, the surface of the metal bump 10c of the substrate 10 is etched by several hundred angstroms, and the oxide layer (CuO, Cu ₂ O if the material of the metal bump 10c is copper) formed on the surface.
Are removed and the copper surface is exposed.

In the driving IC 30, the tin and lead oxide layers on the surface of the solder bump 31 are also removed. However, these sputter etching conditions are changed depending on the oxidation state of the surface of the metal bump 10c or the solder bump 31. If necessary, a load lock chamber for processing the driving IC 30 and a sputter etching chamber may be provided separately from those for processing the substrate 10.

The substrate 10 and the driving IC 30 that have been subjected to the sputter etching process are carried to the die bonding chamber 44 through the second load lock chamber 43, and the metal bumps 10c of the substrate 10 and the solder bumps 31 of the driving IC 30 are carried there. Are aligned so that they face each other, and both are united. The alignment accuracy at this time is about 40 μm so that the solder bump 31 does not come off from the facing metal bump 10c if the diameter of the solder bump 31 is, for example, 80 μm.
The following is acceptable.

Next, the die bonding chamber 44 is loaded into the reflow furnace 46 through the third load lock chamber 45. At this time, the driving IC 30 is given a shock to the substrate 10.
It is necessary to avoid misalignment.

In the reflow furnace 46, the die-bonded substrate 10 and the driving IC 30 are heated in a reduced pressure atmosphere by infrared radiation from an infrared heater or heat transfer from a flat heater. The conditions at this time are set by the composition ratio of tin and lead of the solder bump 31 and the heat capacity of the entire recording head. For example, in the case of eutectic solder of tin: lead = 40: 60, it may be heated at 220 ° C. for several seconds to several tens of seconds. After heating in this way, it is placed on a cooling plate and cooled immediately. Then, the recording head is carried into the fourth load lock chamber 47, the atmosphere is released, and the recording head is taken out. The bonding state of the bumps and the performance of the driving IC 30 are checked by an electrical inspection, and if there is no problem, the driving IC 30 is sealed with a sealing material such as epoxy resin.

According to the present embodiment, the solder bumps 31 and the metal bumps 10c are cleaned by sputter etching and then heated and fused under a reduced pressure atmosphere. The bumps 31 and the metal bumps 10c can be joined well. Therefore, it is possible to avoid troubles such as when using the flux. That is, there are the following advantages.

(1) Since the flux is not used, the vaporized component in the flux does not adhere to the nozzle of the recording head or the orifice surface when heated in the reflow furnace, and the ejection state of the recording liquid is not changed. Therefore, there is no variation in ejection among the nozzles, and a recording head with extremely high uniformity can be obtained.

(2) Since the flux is not cleaned, there is no risk that the flux residue in the cleaning solution will remain on the nozzles, the orifice surface and the heat generating resistor to deteriorate the recording quality. Further, similarly, there is no possibility that dust existing in the cleaning liquid will enter the nozzle and cause clogging of the dust in the nozzle.

(3) Since the flux is not cleaned, there is no risk of degrading the material of the nozzle block by swelling or the like and deteriorating the mechanical properties such as the adhesive strength of the nozzle. As a result, reliability with respect to nozzle peeling and the like is significantly improved.

(4) Since no flux is used, no ionic residue is generated, so that the electrical characteristics between the solder bumps are not deteriorated and a very reliable connection can be obtained.

(5) Since no flux is used, there is no obstacle such as displacement due to the flux.

(6) Since the processing is continuously performed in-line, highly uniform connection can be obtained and the productivity is also high.

Next, a liquid jet recording apparatus to which the recording head of this embodiment is applied will be described with reference to FIG.

In FIG. 3, each of the heads 101a to 101d is a full-line type recording head (hereinafter referred to as "head") according to the present embodiment, and these are arranged at predetermined intervals in the arrow X direction by the holder 102. It is fixedly supported parallel to each other. Each head 101a-101d
16 rows of discharge ports / m on the lower surface of the
3456 ejection openings are provided downward at an interval of m, which enables recording with a width of 216 mm.

These heads 101a to 101d are of a type that discharges the recording liquid by using thermal energy.
The head driver 120 controls the ejection.

A head unit is constructed by including the heads 101a to 101d and the holder 102, and the head unit is vertically moved by the head moving means 124.

Further, a cap 103a corresponding to the heads 101a to 101d and disposed adjacent to the lower portion thereof.
Each of 103d has an ink absorbing member such as a sponge inside.

The caps 103a to 103d are fixedly supported by a holder (not shown), and a cap unit is constituted by including the holder and the caps 103a to 103d, and the cap unit is the cap moving means 12.
5 is moved in the arrow X direction.

Each of the heads 101a to 101d is supplied with cyan, magenta, ink from the ink tanks 104a to 104d through the ink supply tubes 105a to 105d.
Ink of each color of yellow and black is supplied to enable color recording.

In addition, this ink supply utilizes the capillarity of the head discharge port, and each ink tank 104a-1.
The liquid level of 04d is set lower than the position of the discharge port by a certain distance.

Next, a carrying device for carrying the recording medium so as to face the recording head will be described.

The belt 106 is the recording paper 1 which is the recording medium.
It is for carrying 27 and comprises a chargeable seamless belt.

The belt 106 includes a driving roller 107, idle rollers 109 and 109a, and a tension roller 11.
It is driven by a belt drive motor 108 which is connected to the drive roller 107 and is driven by a motor driver 121.

Further, the belt 106 includes the heads 101a to 1a.
Immediately below the discharge port of 01d, the vehicle travels in the direction of the arrow X, and here, the fixed support member 126 suppresses the shake on the lower side.

Below the belt 106 in FIG.
A cleaning unit 117 that removes paper dust and the like adhering to the surface of 6 is provided.

Charger 11 for charging the belt 106
2 is turned on and off by the charger driver 122, and the electrostatic attraction force by this charging causes the recording paper 127
Are attracted to the belt 106.

Before and after the charger 112, the pinch rollers 111 and 11 for pressing the conveying recording paper 127 against the belt 106 in cooperation with the idle rollers 109 and 109a.
1a is arranged.

The recording paper 127 in the paper feed cassette 113 is fed one by one by the rotation of the paper feed roller 116, and is conveyed by the motor driver 123.
4 and the pinch roller 115 conveys it to the chevron guide 113 in the arrow X direction. The chevron guide 113 has a chevron-shaped space that allows the bending of the recording paper 127.

The recording paper 127 for which recording has been completed is discharged to the paper discharge tray 118.

The head driver 120, the head moving means 124, the cap moving means 125, the motor drivers 121 and 223 and the charger driver 122 are all controlled by the control circuit 119.

The present invention brings excellent effects particularly in a recording head and a recording apparatus of an ink jet recording system for forming recording by forming flying droplets by utilizing thermal energy in the liquid jet recording system. Is.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
No. 796, the present invention is preferably carried out using these basic principles. This recording method is applicable to both the so-called on-demand type and the continuous type.

To briefly explain this recording method, an electrothermal converter, which is a discharge energy generating means arranged corresponding to a sheet or a liquid path holding a recording liquid (ink), and a drive circuit means. At least one drive signal for giving a rapid temperature rise to the recording liquid (ink) in order to overcome the nucleate boiling phenomenon and to cause the film boiling phenomenon in response to the recording information which is the electric signal of the means for supplying the electric signal. By applying it through the drive circuit means, heat energy is generated and film boiling is caused on the heat acting surface of the recording head. In this way, bubbles can be formed one-to-one corresponding to the drive signal applied from the recording liquid (ink) to the electrothermal converter, which is particularly effective for the on-demand recording method. The growth and contraction of the bubbles cause the recording liquid (ink) to be ejected through the ejection port to form at least one droplet. If this drive signal is made into a pulse shape, the growth and contraction of the bubbles will be performed immediately and appropriately, so that the recording liquid (ink) with excellent responsiveness is obtained.
It is more preferable that the discharge can be achieved. As the pulse-shaped drive signal, U.S. Pat. No. 4,463,359,
Those described in US Pat. No. 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124, which is an invention relating to the rate of temperature rise on the heat acting surface, are adopted, more excellent recording can be performed.

The structure of the recording head is a combination of a discharge port, a liquid flow path, and an electrothermal converter as disclosed in the above-mentioned specifications (straight liquid flow path or right-angled liquid flow path).
In addition to the above, the present invention is also effective for those having a configuration in which the heat acting portion is arranged in the bending region as disclosed in US Pat. No. 4,558,333 and US Pat. No. 4,459,600. .

In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a structure in which a common slit is used as a discharge port of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective in a structure having a structure based on Japanese Patent Application Laid-Open No. 138461/1984, which discloses a structure in which the corresponding opening corresponds to the discharge portion. The recording head to which the present invention is effectively used is a full-line type recording head having a length corresponding to the maximum width of the recording medium that can be recorded by the recording apparatus. It may be a small recording head that runs in the width direction.

In addition, by being mounted on the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. The present invention is also effective when a cartridge-type recording head that is specially provided is used.

Further, it is preferable to add recovery means for the recording head and preliminary auxiliary means to the liquid jet recording apparatus of the present invention because the recording apparatus can be made more stable. Specifically, the recording head is preheated by a capping means, a cleaning means, a pressure or suction means, an electrothermal converter or a heating element other than this, or a combination thereof. It is also effective to perform stable recording by adding a means for performing a preliminary ejection mode for performing ejection different from the means and recording.

Further, the recording mode of the recording apparatus is not limited to the mode in which only the mainstream color such as black is recorded, and either the recording head may be integrally formed or a combination of plural recording heads may be used. However, the present invention is also extremely effective for an apparatus provided with at least one of a multicolor of different colors or a full color by color mixing.

In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0086]

Since the present invention is configured as described above, it has the following effects.

Since it is not necessary to use the flux when mounting the driving IC on the substrate, troubles such as deterioration of the droplet discharge performance and connection failure of the electrical connection portion due to the flux can be avoided.

As a result, a recording head having extremely high performance and stable droplet discharge performance can be obtained. By using such a recording head, the image quality of the liquid jet recording apparatus can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a main part of a recording head according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a device that mounts a driving IC.

FIG. 3 is a perspective view showing a liquid jet recording apparatus equipped with the recording head of FIG.

FIG. 4 is a flowchart illustrating a process of executing a driving IC according to a conventional example.

FIG. 5 is a perspective view showing a full-line type recording head.

FIG. 6 is a plan view showing a conventional example in which a substrate is connected to a flexible cable.

[Explanation of symbols]

 10 Substrate 10a Electrothermal Converter 10b Lead Electrode 10c Metal Bump 20 Nozzle Block 20b Liquid Channel 20c Common Liquid Chamber 30 Driving IC 31 Solder Bumps 41, 43, 45, 47 Load Lock Chamber 42 Sputter Etching Chamber 44 Die Bonding Chamber 46 Reflow furnace

Claims (5)

[Claims] 1. A substrate having a wiring conductor connected to the electrothermal converting means, and drive circuit means for driving the electrothermal converting means, the drive circuit means comprising the substrate and the drive circuit means. A recording head mounted on the substrate by a step of cleaning each electric connection part, contacting each other under a reduced pressure atmosphere, heating and fusing. 2. The electric connection part of the substrate having the wiring conductor connected to the electrothermal conversion means and the electric connection part of the drive circuit means for driving the electrothermal conversion means are cleaned and then depressurized. A method for manufacturing a recording head, comprising a mounting step of heating the sheets in contact with each other in an atmosphere to heat and fuse them. 3. The method of manufacturing a recording head according to claim 2, wherein the surface of each electrical connection portion is cleaned by sputter etching. 4. The recording head according to claim 2, wherein the electrical connection portion of the substrate is at least one metal bump, and the electrical connection portion of the drive circuit means is at least one solder bump. Manufacturing method. 5. A recording head according to claim 1, means for supplying an electric signal to a drive circuit means of the recording head, and a conveying device for conveying a recording medium so as to face the recording head. Liquid jet recording device.