JP2006007712A - Manufacturing method of ink-jet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an ink-jet recording head with high precision using amorphous carbon. <P>SOLUTION: A metal mold 32 is formed using the method such as a Ni-electroforming on a matrix 30 formed in a lithography process such as a LIGA process or Si process. The shape of a nozzle plate 10 is formed on a thermoplastic resin 12 by the steps comprising a step of charging the thermoplastic resin 12 into a lower mold 34, a step of pressing the metal mold 32 as an upper mold on the former and a step of conveying and pressing the metal mold 32 in sequence by the way of step and repeat. A nozzle 14, an ink passage 16 and a chamber 18 are formed by the steps comprising a step of heating the metal mold 32 and the lower mold 34, a step of rising the temperature until reaching a B stage (gelated state) where the thermoplastic resin 12 gets softened and then a step of performing a stamping (in-print) with the metal mold 32. The applicable thermoplastic resin 12 is prepared by using the thermoplastic resin with a small coefficient of linear expansion such as an amide-imide and PPS as a binder and by adding the amorphous carbon particles to a filler agent using the binder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an ink jet recording head, and more particularly to a method for manufacturing an ink jet recording head in which a nozzle and a chamber plate are formed of a thermoplastic resin.

  In recent years, inkjet nozzles are required to have a fine size and high accuracy along with high image quality. At the same time, an increase in the size of the ink jet recording head itself is required for speeding up. Needless to say, low cost is also required, and various methods and materials have been proposed as methods for producing inkjet nozzles that achieve these.

  For example, amorphous carbon is already known to have excellent wear resistance and chemical resistance (ink resistance, etc.) and can be expected to have a chemically stable strength. An ink jet recording head using this as a material for a nozzle plate has been proposed (see, for example, Patent Document 1).

  However, after forming the plate with amorphous carbon, the nozzle holes are opened with a laser, so the processing of fine shapes is a factor that increases costs as the number of nozzles increases as the nozzle density increases. Become.

  There has also been proposed a method of forming a plate with resin and then converting the resin into amorphous carbon by heat treatment (see, for example, Patent Document 2).

  However, the heat treatment for converting the resin to amorphous carbon causes a shrinkage of about 20% in the resin dimensions, which greatly affects the dimensional accuracy of the plate obtained after processing, and precision processing of the fine structure It becomes difficult to form with.

  Recently, there is a demand for a large-sized head having a paper width size in order to increase the processing speed. However, if the head is increased in size, the required processing accuracy becomes more severe and the cost also increases.

An object of the present invention is to perform resin molding with high accuracy and low cost by preventing shrinkage of a resin due to heat treatment when amorphous carbon is used as a raw material in molding using a fine mold.
Japanese Patent Laid-Open No. 10-138396 (FIG. 1, pages 4 to 5) Japanese Patent Laid-Open No. 10-24595 (FIG. 1, pages 2 to 3)

  In consideration of the above-described facts, an object of the present invention is to provide a highly accurate ink jet recording head manufacturing method using amorphous carbon.

  The method for manufacturing an ink jet recording head according to claim 1 is a method for manufacturing an ink jet recording head in which a nozzle and a chamber plate are formed of a thermoplastic resin, and amorphous carbon is added to the thermoplastic resin as a filler agent, The nozzle and the chamber plate are integrally formed on the thermoplastic resin by stamping with a fine mold formed from a mother mold formed by a lithography process.

  In the invention with the above configuration, amorphous carbon is added as a filler agent to the thermoplastic resin, so that it has the characteristics of amorphous carbon that is excellent in wear resistance and chemical resistance (ink resistance, etc.) and chemically stable. However, a nozzle and a chamber plate can be formed by stamping with a thermoplastic resin that does not need to be fired, and an inkjet recording head that is highly accurate, long, and low in cost can be manufactured.

  The method for producing an ink jet recording head according to claim 2, wherein the filler added to the thermoplastic resin comprises adding amorphous carbon particles having an average particle size of 5 μm or less in a weight ratio of 30% to 95%. .

  In the invention having the above-described configuration, it is possible to obtain a thermoplastic resin that does not impair the characteristics of the amorphous carbon and can obtain a material having a desired linear expansion coefficient.

  According to a third aspect of the present invention, there is provided a method of manufacturing an ink jet recording head, wherein the thermoplastic resin layer is formed on a protective sheet, and the nozzle and the chamber plate are molded.

  In the invention with the above configuration, it is possible to prevent a failure in which the mold collides with the lower mold during stamping and is damaged, or the thermoplastic resin forms burrs around the nozzle when forming the nozzle hole.

  According to a fourth aspect of the present invention, there is provided an ink jet recording head manufacturing method comprising: providing a water repellent layer between the protective sheet and the thermoplastic resin.

  In the invention with the above configuration, since the ink discharge surface of the nozzle plate excluding the nozzle holes is covered with the water repellent layer, it is possible to prevent deterioration in discharge performance due to the adhesion of ink droplets to the ink discharge surface of the nozzle plate. .

  Since the present invention has the above-described configuration, it can be a highly accurate ink jet recording head manufacturing method using amorphous carbon.

  FIG. 1 shows a method of manufacturing an ink jet recording head according to the first embodiment of the present invention.

  First, as shown in FIG. 1A, a mother die 30 is formed by a lithography process such as a LIGA process or a Si process. The master mold 30 is made by processing a material such as PMMA by a LIGA process that can cope with fine and deep (high aspect ratio) irregularities, or made of photosensitive glass, or a Si substrate is processed by photolithography and dry etching. It is desirable to form by such a method. This mother die 30 is a male die having substantially the same shape as the completed nozzle plate 10.

  A mold 32 is formed on the mother die 30 using a technique such as Ni electroforming as shown in FIG. The ink jet nozzle plate 10 can be resin-molded using the mold 32 as a female mold.

  As shown in FIG. 1 (c), the thermoplastic resin 12 is poured into the lower mold 34, and a mold 32 formed by using a technique such as Ni electroforming is pressed thereon as an upper mold. The shape of the nozzle plate 10 is formed on the thermoplastic resin 12 by sequentially feeding and pressing the mold 32 by & repeat.

  Specifically, by heating the mold 32 and the lower mold 34, raising the temperature to the B stage (gelled state) where the thermoplastic resin 12 is softened, and stamping (imprinting) with the mold 32, the nozzle 14, An ink flow path 16 and a chamber 18 are formed. If the stamping is repeated many times while shifting the position of the mold 32, it is possible to cope with a long head.

  As the thermoplastic resin 12 used here, for example, a thermoplastic resin having a small linear expansion coefficient such as amidoimide or PPS (polyphenylene sulfide resin) as a binder and amorphous carbon particles added to a filler agent is used. Thereby, since the thermoplastic resin 12 contains the amorphous carbon particles appropriately, it has the excellent wear resistance and chemical resistance of the amorphous carbon, is chemically stable and has high strength.

  When the shape of the nozzle plate is formed on the thermoplastic resin 12 and the lower mold 34 is cooled and the thermoplastic resin 12 is cured and then released, as shown in FIG. 1D, the nozzle 14, the ink flow path 16, the chamber The thermoplastic resin 12 processed into the shape of the nozzle plate 10 provided with 18 is obtained.

  FIG. 2A is a plan view of the inkjet nozzle plate 10 at the time of completion, and shows the positional relationship between the nozzles 14 and the ink supply paths 16 when viewed from the ink ejection direction. A cross section taken along the broken line A-A ′ is shown in FIG. In the stamping described in FIG. 1C, the nozzle plate 10 as shown in FIG. 2A is formed by repeating the stamping while feeding the mold 32 by a certain amount. Although four rows of nozzles 14 are formed in FIG. 2A, it goes without saying that a large number of nozzles 14 can be formed by repeating stamping while sequentially feeding the mold 32.

  FIG. 3 shows the relationship between the filler addition rate and the linear expansion coefficient of the thermoplastic resin according to the first embodiment of the present invention.

  As the thermosetting resin 12 used in the first embodiment, for example, a resin obtained by adding amorphous carbon particles as a filler to a phenol resin is used. The particle size of a general filler agent is 0.5 to 10 μm, but in the case of the amorphous carbon particles of this example, 5 μm or less is preferable. If the particle size exceeds 5μm, the characteristics (friction resistance, impact resistance, etc.) of amorphous carbon may be impaired, and at the same time, there is a risk of dropping of particles during processing. In this embodiment, a nozzle having a particle diameter of 5 μm or less is used.

  The filler addition rate to the resin does not impair the characteristics of the amorphous carbon, and the addition rate of the filler agent (amorphous carbon) is the weight as the addition rate at which a material having a desired linear expansion coefficient (0.002% or less) can be obtained. The ratio is 30 to 95% (the hatched area in the figure), but when imprinting is performed as in this example, the addition rate of amorphous filler is preferably about 50 to 90% in consideration of workability and the like. It is. In the case of NIP (nanoimprint) using a nano mold made of Ni electroforming or the like, if the addition rate exceeds 95%, the periphery of the nozzle may be roughened, so it is desirable to keep the addition rate within the above range.

  FIG. 4 shows a method of manufacturing an ink jet recording head according to the second embodiment of the present invention.

  First, as shown in FIG. 4A, a mother die 30 is formed by a lithography process such as a LIGA process or a Si process. The master mold 30 is made by processing a material such as PMMA by a LIGA process that can cope with fine and deep (high aspect ratio) irregularities, or made of photosensitive glass, or a Si substrate is processed by photolithography and dry etching. It is desirable to form by such a method. This mother die 30 is a male die having substantially the same shape as the completed nozzle plate 10.

  A die 32 is formed on the mother die 30 using a technique such as Ni electroforming as shown in FIG. The ink jet nozzle plate 10 can be resin-molded using the mold 32 as a female mold. Up to this stage, there is no difference from the first embodiment.

  Next, as shown in FIG. 4C, a layer of the thermoplastic resin 12 is formed on the protective sheet (sacrificial layer) 36, and a method such as Ni electroforming is performed on the layer of the thermoplastic resin 12. The shape of the nozzle plate 10 is formed on the thermoplastic resin 12 by pressing the mold 32 formed by using the upper mold as the upper mold and sequentially feeding and pressing the mold 32 by step & repeat.

  Specifically, as shown in FIG. 4D, the mold 32 and the lower mold 34 are heated, and the temperature is raised to the B stage (gelled state) where the thermoplastic resin 12 is softened. The nozzle 14, the ink flow path 16, and the chamber 18 are formed by printing. If the stamping is repeated many times while shifting the position of the mold 32, it is possible to cope with a long head.

  At this time, the mold 32 collides with the lower mold 34 at the time of stamping, and the projections forming the holes of the nozzle 14 are damaged by the collision with the lower mold 34, or the thermoplastic resin 12 is formed when the nozzle 14 holes are formed. A failure such as the formation of burrs around the nozzle 14 can be considered.

  In this embodiment, the protective sheet 36 is provided under the thermoplastic resin 12 as shown in FIG. 4E, so that the mold 32 does not come into direct contact with the lower mold 34 and the hole of the nozzle 14 is formed. Protrusions or the like that remain on the protective sheet 36 do not reach the lower die 34.

  The protective sheet 36 is completely removed after the nozzle plate 10 is formed, so that there is no possibility of affecting the discharge surface side of the nozzle plate 10.

  FIG. 5 shows a method of manufacturing an ink jet recording head according to the third embodiment of the present invention.

  First, a matrix is created by a lithography process such as a LIGA process or a Si process. The matrix is made by processing a material such as PMMA using a LIGA process that can cope with fine and deep (high aspect ratio) irregularities, or using photosensitive glass, or processing a Si substrate by photolithography and dry etching. It is desirable to form by such a method. This mother mold is a male mold having substantially the same shape as the nozzle plate 10 to be completed.

  On this mother mold, a mold 32 is formed using a technique such as Ni electroforming. The ink jet nozzle plate 10 can be resin-molded using the mold 32 as a female mold. Up to this stage, there is no difference from the first and second embodiments.

  Next, as shown in FIG. 5A, a water repellent layer 38 is provided on a protective sheet (sacrificial layer) 36, and a layer of the thermoplastic resin 12 is formed thereon. The water repellent layer 38 is a layer made of, for example, a fluorine resin, and covers the ink discharge surface of the nozzle plate 10 with a water repellent surface, thereby preventing deterioration in discharge performance due to ink droplet adhesion.

  As shown in FIG. 5B, the mold 32 formed by using a method such as Ni electroforming is pressed on the thermoplastic resin 12 layer as an upper mold, and the mold 32 is sequentially stepped and repeated. The shape of the nozzle plate 10 is formed on the thermoplastic resin 12 by feeding and pressing.

  Specifically, by heating the mold 32 and the lower mold 34, raising the temperature to the B stage (gelled state) where the thermoplastic resin 12 is softened, and stamping (imprinting) with the mold 32, the nozzle 14, An ink flow path 16 and a chamber 18 are formed. If the stamping is repeated many times while shifting the position of the mold 32, it is possible to cope with a long head.

  At this time, the mold 32 collides with the lower mold 34 at the time of stamping, and the projections forming the holes of the nozzle 14 are damaged by the collision with the lower mold 34, or the thermoplastic resin 12 is formed when the nozzle 14 holes are formed. Since the protective sheet 36 is provided under the thermoplastic resin 12 as shown in FIG. 5C in order to prevent a failure such as the formation of burrs around the nozzle 14, the mold 32 directly contacts the lower mold 34. As in the second embodiment, the protrusions that form the holes of the nozzle 14 stay on the protective sheet 36 and prevent the nozzle 14 from reaching the lower die 34.

  In this embodiment, a water repellent layer 38 is provided between the protective sheet 36 and the thermoplastic resin 12, and the protective sheet 36 is peeled off and removed by the water repellent layer 38 after the nozzle plate 10 is formed, so that FIG. Thus, the ink discharge surface of the nozzle plate 10 excluding the nozzles 14 can be covered with the water repellent layer 38. As a result, deterioration of ejection performance due to adhesion of ink droplets to the ink ejection surface of the nozzle plate 10 is prevented. Compared with a processing method such as performing a water-repellent coating after processing, the water-repellent layer is formed simultaneously with the molding of the nozzle plate 10 and the nozzle 14 is not clogged.

It is sectional drawing which shows the manufacturing method of the inkjet recording head which concerns on the 1st form of this invention. It is a figure which shows the structure of the inkjet recording head which concerns on the 1st form of this invention. It is a figure which shows the relationship between the filler addition rate and the linear expansion coefficient in the raw material of the inkjet recording head which concerns on the 1st form of this invention. It is sectional drawing which shows the manufacturing method of the inkjet recording head which concerns on the 2nd form of this invention. It is sectional drawing which shows the manufacturing method of the inkjet recording head which concerns on the 3rd form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nozzle plate 12 Thermoplastic resin 14 Nozzle 16 Ink flow path 18 Chamber 30 Master mold 32 Mold 34 Lower mold 36 Protection sheet 38 Water repellent layer

Claims (4)

A method of manufacturing an ink jet recording head in which a nozzle and a chamber plate are formed of a thermoplastic resin,
Amorphous carbon is added as a filler to the thermoplastic resin,
The method for manufacturing an ink jet recording head, wherein the nozzle and the chamber plate are integrally formed on the thermoplastic resin by stamping with a fine mold formed from a mother mold formed by a lithography process.
The filler added to the thermoplastic resin is
2. The method of manufacturing an ink jet recording head according to claim 1, wherein amorphous carbon particles having an average particle diameter of 5 [mu] m or less are added in a weight ratio of 30% to 95%.
3. The method of manufacturing an ink jet recording head according to claim 1, wherein the thermoplastic resin layer is formed on a protective sheet, and the nozzle and the chamber plate are molded.
The method of manufacturing an ink jet recording head according to claim 3, wherein a water repellent layer is provided between the protective sheet and the thermoplastic resin.

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