JP2005119224A - Inkjet recording head and method for manufacturing the same, silicon-on-insulator base sheet and method for manufacturing the same, and substrate for inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording head capable of accomplishing both improvement of an ink refilling speed and improvement of a processing speed of a driving circuit for a discharging pressure generating element in order to realize high speed in an inkjet recording method. <P>SOLUTION: In the inkjet recording head performing recording by discharging a liquid for recording, its substrate is manufactured by using a silicon-on-insulator base sheet, and a plurality of discharging pressure generating elements and their driving circuits are formed on the surface of the substrate. A pressure chamber and an outputting hole for discharging a recording liquid are provided on the discharging pressure generating element, and a plurality of feeding holes communicating a common liquid chamber for feeding the liquid for recording from the back of the substrate to the surface with the pressure chamber, are provided to one pressure chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus that performs recording by ejecting a recording liquid to form droplets and attaching the droplets to a recording material such as paper.

  The ink jet recording method is a recording method in which recording is performed by discharging a recording liquid (ink) from an orifice provided in a recording head and attaching the recording liquid (ink) to a recording material such as paper. Various types of recording heads have been devised, such that high-speed recording is possible, and plain paper can be used and recording paper having a special configuration is not required.

  Among these ink jet recording heads, there is a “side shooter type” ink jet recording head that ejects ink droplets in a vertical direction with respect to a substrate on which a discharge pressure generating element is formed. In such an ink jet recording head, a common liquid chamber is often formed so as to penetrate the substrate in order to supply ink from the back surface of the substrate where the ink tank exists to the substrate surface where the discharge pressure generating element is provided. In the formation of the common liquid chamber, crystal anisotropic etching is often used because of high processing accuracy.

  On the other hand, the formation of a single-crystal Si semiconductor layer on an insulator is widely known as a silicon-on-insulator (SOI) technology, and has many advantages that cannot be reached by a bulk Si substrate for producing a normal Si integrated circuit. A lot of research has been done. That is, a semiconductor device using SOI technology has the following advantages.

1. 1. Easy dielectric separation and high integration. 2. Excellent radiation resistance 3. Floating capacitance is reduced and high speed is possible. 4. Well process can be omitted. 5. Prevent latch-up Fully depleted field effect transistors can be realized by thinning the film. In the inkjet recording head substrate on which the drive circuit of the discharge pressure generating element is formed, the use of an SOI substrate can reduce the cost by chip shrink and the signal from the recording apparatus main body. Higher processing speed can be expected. In addition, since the substrate has an insulating layer, the common liquid chamber and the supply port can be formed by selectively etching the substrate and the support substrate (see, for example, Patent Document 1).

JP 2002-234156 A

  In recent years, there is an increasing demand for higher speeds in the ink jet recording method. On the other hand, a method for increasing the number of recording liquid droplets discharged per unit time by increasing the ink refill speed after ink is discharged from each discharge port or increasing the number of discharge ports. Can be considered.

  The side shooter type ink jet recording head usually has a structure in which a pressure chamber is formed on each discharge pressure generating element and communicates with a common liquid chamber through a supply port to supply ink (FIG. 7). reference).

  In such a structure, in order to improve the ink refill speed, a method of reducing the flow resistance from the supply port to the discharge port by shortening the distance between the discharge port and the supply port or increasing the height and width of the pressure chamber. Can be considered.

  However, among these methods, the former method has a limit in approaching it due to the presence of a discharge pressure generating element and wiring connected thereto. Further, in the latter method, there is a limit to expanding the pressure chamber in the width direction because there is an adjacent pressure chamber, and expanding in the height direction has a long distance between the discharge pressure generating element and the discharge port. As a result, the discharge phenomenon is affected, so that there is a limit.

  Further, increasing the total number of recording droplets ejected within a unit time means that the amount of signals that the drive circuit of the ejection pressure generating element has to process within the unit time increases. In other words, in order to achieve high recording speed, it is necessary to improve the processing speed of the semiconductor elements constituting the drive circuit.

  Accordingly, the object of the present invention is to perform ink jet recording that achieves both improvement of the ink refill speed and improvement of the processing speed of the drive circuit for the discharge pressure generating element in order to realize high speed in the ink jet recording method. It is an object of the present invention to provide a head, a base used in the head, a silicon-on-insulator substrate used in the head, and a manufacturing method thereof.

  In order to solve the above problems, the present invention proposes the following.

  That is, in an ink jet recording head that performs recording by discharging a recording liquid, the base is made of a silicon-on-insulator substrate, and a plurality of discharge pressure generating elements and driving circuits thereof are formed on the surface of the base. On the discharge pressure generating element, a pressure port and a discharge port for discharging the recording liquid are provided, and a supply port through which the common liquid chamber and the pressure chamber for supplying the recording liquid from the back of the substrate to the surface communicate with each other Is an ink jet recording head characterized in that a plurality of are provided for one pressure chamber (FIGS. 1 and 2).

  In the ink jet recording head having such a structure, the refilling of the ink into the pressure chamber is performed through a plurality of supply ports from the common liquid chamber filled with sufficient ink, so that the speed is increased.

  Further, since the substrate is made of a silicon-on-insulator substrate, the processing speed of the discharge pressure generating element drive circuit formed on the surface is superior to that of a conventional bulk Si substrate.

  Due to the above two effects, the ink jet recording head of the present invention can perform higher speed recording.

  In this ink jet recording head, the insulating layer and the supporting substrate can be selectively etched, and the insulating layer does not exist at the supply port forming position. It can be manufactured by using a substrate for an ink jet recording head obtained by forming a discharge pressure generating element and its drive circuit in the process.

That is, in forming the common liquid chamber and the supply port. 1. A process of depositing a mask material on the back surface of the ink jet recording head substrate (the surface on which no discharge pressure generating element is present) 2. removing the mask material at the common liquid chamber forming position of the substrate; The process of forming a common liquid chamber and a supply port by advancing etching from the mask opening on the back surface of the substrate This is realized by the manufacturing method including the processes 1 to 3 described above.

Furthermore, the silicon-on-insulator substrate is
1. 1. Preparing a first substrate having a separation layer made of a porous silicon layer 2. forming a non-porous single crystal silicon layer on the separation layer; 3. forming an insulating layer on the non-porous silicon layer of the first substrate or on the second substrate; 4. Step of removing a portion of the insulating layer where the supply port is formed 5. A step of bonding the first substrate and the second substrate so that the insulating layer is sandwiched therebetween. The step of removing the porous silicon layer from the multilayer structure is realized by a manufacturing method including the steps 1 to 6 described above.

  Further, this ink jet recording head has a structure in which the insulating layer and the support substrate can be selectively etched, and the insulating layer does not exist at the supply port forming position, and is supported from the common liquid chamber to the supply port forming position. A substrate for an ink jet recording head obtained by forming a discharge pressure generating element and its drive circuit in a general-purpose semiconductor process on a silicon-on-insulator substrate characterized in that a sacrificial layer that can be etched faster than the substrate is formed. It can also be produced by using it.

The formation of the common liquid chamber and the supply port using this substrate is the same as the above-described process.
1. 1. A process of depositing a mask material on the back surface of the ink jet recording head substrate (the surface on which no discharge pressure generating element is present) 2. removing the mask material at the common liquid chamber forming position of the substrate; The process of forming a common liquid chamber and a supply port by advancing etching from the mask opening on the back surface of the substrate This is realized by the manufacturing method including the processes 1 to 3 described above.

  In particular, the distance between the common liquid chamber and the supply port is increased because each element is separated due to the wiring around the discharge pressure generating element, or because it is necessary to secure the substrate strength and the common liquid chamber must be made smaller. In such a case, it is conceivable to use such a substrate.

Furthermore, the silicon-on-insulator substrate used for this is
1. 1. preparing a first substrate having a separation layer made of porous silicon; 2. forming a non-porous single crystal silicon layer on the separation layer; 3. forming a sacrificial layer on the second substrate; 4. Step of forming an insulating layer on the non-porous silicon layer of the first substrate or on the second substrate 5. Step of removing a portion of the insulating layer where the supply port is formed 6. bonding the first substrate and the second substrate so that the insulating layer and the sacrificial layer are sandwiched between them; Step of removing the separation layer from the multilayer structure This is realized by a manufacturing method including the steps 1 to 7 described above.

  Further, the sacrificial layer is locally anodized on a second substrate made of single crystal silicon, and only silicon at an arbitrary position is formed as porous silicon, or on the second substrate. A digging is provided at an arbitrary position, and a metal such as aluminum is thicker than the digging depth on this surface, and then the second substrate is again formed by CMP or other methods after being formed by sputtering, electroplating or other methods. It can obtain by the method of grinding and forming until the surface of this is exposed.

  The ink jet recording head of the present invention is provided with a plurality of supply ports in each pressure chamber, the ink refill speed is high, and the base is made of a silicon-on-insulator substrate. The processing speed of the circuit is fast and high-speed printing is possible.

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

<Embodiment 1>
As shown below, a silicon-on-insulator substrate for an ink jet recording head is produced.

  First, a single crystal Si substrate was prepared in order to form a first substrate, and the surface was subjected to anodization treatment in an HF solution to form a porous Si layer (separation layer).

Next, CVD (Chemical
A single crystal Si layer was epitaxially grown by the Vapor Deposition method. Note that, in the previous stage of epitaxial growth, the surface of the porous Si layer, which is the separation layer, is exposed to H ₂ , so that the holes on the surface are filled and the surface becomes flat.

Next, an SiO ₂ layer was formed by thermal oxidation on the surface of the epitaxially grown single crystal Si layer.

This was coated with a positive resist, patterned by photolithography, and then immersed in buffered hydrofluoric acid to etch the SiO ₂ layer at the position where the supply port was to be formed (FIG. 3A).

Next, a Si substrate (second substrate) having the same size as the first substrate from which the resist is peeled and a drawing direction <100> is prepared, and the surface of the SiO ₂ layer of the first substrate and the second substrate are in close contact with each other. Then, heat treatment was performed at 1180 ° C. for 5 minutes, and bonding was performed.

  A fluid (here, water) from a nozzle having a diameter of 0.1 mm was sprayed onto the separation layer of the bonded substrate, and the separation substrate portion was completely separated while rotating the bonded substrate.

  Next, the porous layer remaining on the surface of the second substrate after separation was selectively etched using a mixed solution of hydrofluoric acid, hydrogen peroxide solution, and water as an etchant. As a result, a silicon-on-insulator substrate according to the present invention was obtained (FIG. 3B).

  Next, a heating resistor, which is a discharge pressure generating element, and an electrode (not shown) for receiving signals from the drive circuit and the recording apparatus main body are formed on the surface of the silicon-on-insulator substrate by a general-purpose semiconductor manufacturing process. A passivation layer (not shown) made of p-SiN was formed on the outermost surface. A thermal oxide film was formed on the opposite surface. As a result, an ink jet recording head substrate was obtained (FIG. 3C: plan view and D: sectional view).

  The surface of the substrate (the surface on which the discharge pressure generating element is formed) was solvent coated with elutionable UV positive resist polymethylisopropenyl ketone, which is a pressure chamber mold material, and patterned by photolithography.

  Further, the surface of the substrate was solvent-coated with a mixture of a cationic polymerization type epoxy and a photopolymerization initiator, and exposed and developed through a photomask so as to form discharge ports and electrode exposed portions (FIG. 5B). .

  Next, a cyclized rubber serving as a protective film was applied to the surface and side surface outer periphery of the substrate. A positive resist was applied to the back surface of the substrate, patterned using a photolithographic technique, and then immersed in buffered hydrofluoric acid to provide an opening in the oxide film on the back surface.

  After the positive resist on the back surface was peeled off, it was immersed in an aqueous tetramethylammonium solution and crystal anisotropic etching was advanced from the oxide film opening on the back surface to the passivation layer on the front surface to form a common liquid chamber and a supply port.

  Next, the passivation layer on the front side of the substrate was removed through the opening on the back surface by chemical dry etching, and the pressure chamber and the common liquid chamber were communicated through the supply port (FIG. 5C).

  Next, the cyclized rubber as a protective film was removed with xylene.

  The surface of the substrate was irradiated with UV light to expose polymethylisopropenyl ketone, which is a pressure chamber mold material, through epoxy, and further immersed in methyl lactate to remove it (FIG. 5C).

  Thus, the ink jet recording head of the present invention was obtained.

<Embodiment 2>
As shown below, a silicon-on-insulator substrate for an ink jet recording head is produced.

  First, a single crystal Si substrate was prepared in order to form a first substrate, and the surface was subjected to anodization treatment in an HF solution to form a porous Si layer (separation layer).

  Next, a single crystal Si layer was epitaxially grown on the separation layer by a CVD method.

Next, a SiO ₂ layer was formed by thermal oxidation on the surface of the epitaxially grown single crystal Si layer (FIG. 4A).

A positive resist was applied thereto, this was patterned by a photolithographic technique, and then immersed in buffered hydrofluoric acid to etch the SiO ₂ layer at the position where the supply port was to be formed.

  Next, a p-type Si substrate (second substrate) having the same size as the first substrate from which the resist has been peeled and having a drawing orientation <100> is prepared, and phosphorus is used for a general-purpose semiconductor process where a sacrificial layer is not formed. To provide an n-type region.

  This second substrate was anodized, and only the p-type region was made porous silicon to an arbitrary depth to form a sacrificial layer. However, the depth of this sacrificial layer must be less than the depth of the n-type region formed in the previous step.

Next, the SiO ₂ layer surface of the first substrate and the surface of the second substrate on which the sacrificial layer was formed were brought into close contact, and heat treatment was performed at 1180 ° C. for 5 minutes for bonding.

  A fluid (here, water) from a nozzle having a diameter of 0.1 mm was sprayed onto the separation layer of the bonded substrate, and the bonded substrate was rotated and completely separated at the separation layer (FIG. 1E). .

  Next, the porous layer remaining on the surface of the second substrate after separation was selectively etched using a mixed solution of hydrofluoric acid, hydrogen peroxide solution, and water as an etchant. As a result, a silicon-on-insulator substrate according to the present embodiment was obtained (FIG. 4B).

  By passing this silicon-on-insulator substrate through the same steps as in the first embodiment, an ink jet recording head could be manufactured (FIG. 6).

  However, in the present embodiment, the sacrificial layer was quickly etched in the crystal anisotropic etching step for forming the common liquid chamber, and a liquid path from the common liquid chamber to the supply port was formed (FIG. 6D).

  The present invention is applicable to an ink jet recording apparatus that performs recording by ejecting a recording liquid to form droplets and attaching the droplets to a recording material such as paper.

1 is a diagram showing a first embodiment of an ink jet recording head of the present invention. FIG. It is a figure which shows Embodiment 2 of the inkjet recording head of this invention. It is a figure which shows Embodiment 1 of the manufacturing method of the base | substrate for inkjet recording heads of this invention. It is a figure which shows Embodiment 2 of the manufacturing method of the base | substrate for inkjet recording heads of this invention. It is a figure which shows Embodiment 1 of the manufacturing method of the inkjet recording head of this invention. It is a figure which shows Embodiment 2 of the manufacturing method of the inkjet recording head of this invention. It is a figure which shows an example of the conventional inkjet recording head.

Explanation of symbols

101, 201, 310, 411, 501, 601, 701 Inkjet recording head substrate 102, 202, 506, 606, 702 Common liquid chamber 103, 203, 507, 607, 703 Supply port 104, 204, 508, 608, 704 Pressure chamber 105, 205, 306, 406, 706 Discharge pressure generating element 106, 206, 504, 604, 705 Discharge port 301, 401 First substrate 302, 402 Second substrate (support substrate)
303,403 Separation layer (porous silicon)
304, 404 Non-porous single crystal silicon layer 305, 405 SiO ₂ layer 307, 407 Wiring connecting the discharge pressure generating element and its drive circuit 308, 408 Portion where the supply port is formed 309, 409 Oxide film 410 on the back surface of the substrate 410 Sacrificial layer 502 Pressure chamber mold (polymethylisopropenyl ketone resin)
503 Epoxy resin 505,605 Protective film (cyclized rubber)

Claims (10)

  In an ink jet recording head that performs recording by discharging a recording liquid, the base is made of a silicon-on-insulator substrate, and a plurality of discharge pressure generating elements and driving circuits are formed on the surface of the base. A pressure chamber and a discharge port for discharging the recording liquid are provided on the generating element, and a supply port for connecting the common liquid chamber and the pressure chamber for supplying the recording liquid from the back of the substrate to the surface is one. An ink jet recording head comprising a plurality of pressure chambers. In silicon on insulator substrate,
A silicon-on-insulator substrate, wherein the insulating layer and the supporting substrate inside the substrate can be selectively etched, and the insulating layer does not exist at the supply port forming position. In silicon on insulator substrate,
The insulating layer inside the substrate and the supporting substrate can be selectively etched, and the insulating layer does not exist at the supply port formation position, and the support substrate extends from the common liquid chamber formation position to the supply port formation position. A silicon-on-insulator substrate, wherein a sacrificial layer that can be etched more quickly is formed.   4. The silicon-on-insulator substrate according to claim 3, wherein the sacrificial layer is porous silicon, polycrystalline silicon, aluminum, or other metal. In a method for manufacturing a silicon-on-insulator substrate.
1. 1. Preparing a first substrate having a separation layer made of a porous silicon layer 2. forming a non-porous single crystal silicon layer on the separation layer; 3. Forming an insulating layer on the non-porous single crystal silicon layer of the first substrate or on the second substrate (supporting substrate). 4. Step of removing a portion of the insulating layer where the supply port is formed 5. A step of bonding the first substrate and the second substrate so that the insulating layer is sandwiched therebetween. The process of removing the said isolation layer from the said multilayered structure The process of the above 1-6 is included, The manufacturing method of the silicon | silicone on insulator board | substrate characterized by the above-mentioned. In the method for producing a silicon-on-insulator substrate,
1. 1. Preparing a first substrate having a separation layer made of a porous silicon layer 2. forming a non-porous single crystal silicon layer on the separation layer; 3. forming a sacrificial layer on the second substrate (support substrate); 4. Step of forming an insulating layer on the non-porous silicon layer of the first substrate or on the second substrate 5. Step of removing a portion of the insulating layer where the supply port is formed 6. bonding the first substrate and the second substrate so that the insulating layer and the sacrificial layer are sandwiched between them; The process of removing the said separated layer from the said multilayered structure The process of the said 1-7 is included, The manufacturing method of the silicon | silicone on insulator board | substrate characterized by the above-mentioned.   7. The silicon according to claim 6, wherein the sacrificial layer is formed by anodizing locally on a second substrate made of single crystal silicon and forming only silicon at an arbitrary position as porous silicon. A method for producing an on-insulator substrate.   The sacrificial layer is formed by digging at an arbitrary position on the second substrate made of single crystal silicon, and a metal such as aluminum is thicker than the digging depth on this surface. 7. The method for manufacturing a silicon-on-insulator substrate according to claim 6, wherein the silicon-on-insulator substrate is formed by polishing until the surface of the second substrate is exposed again by CMP or another method after the film formation by the method.   5. A substrate for an ink jet recording head, comprising an ejection pressure generating element and a drive circuit thereof formed on the silicon-on-insulator substrate according to claim 2. In the manufacturing method of the inkjet recording head using the base | substrate of Claim 9,
1. 1. A process of forming a mask material on the back surface of the substrate for an inkjet recording head (the surface on which no discharge pressure generating element is present) 2. removing the mask material at the common liquid chamber forming position of the substrate; Process for forming a common liquid chamber and a supply port by advancing etching from a mask opening on the backside of the substrate. A method for producing an ink jet recording head, comprising the steps 1 to 3 described above.

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