Patent Grant
8728718
1. Field of the Invention
The present invention relates to a method for manufacturing a liquid ejection head.
2. Description of the Related Art
Liquid ejection apparatuses are known as apparatuses in which a liquid is ejected from an ejection port onto a recording medium to record images. In liquid ejection apparatuses, an ejection port is formed in a liquid ejection head. Such an ejection port is formed by, for example, conducting exposure and development of a photosensitive resin layer disposed on or above a substrate.
In recent years, there has been a demand for recording of high-resolution images, which has lead to a need to decrease the size of liquid droplets to be ejected. The size of liquid droplets to be ejected may be decreased by reducing the diameter of an ejection port; however, simply reducing the diameter of an ejection port increases the fluid resistance of liquid droplets during ejection thereof. A problem such as a decreased ejection rate of liquid droplets therefore occurs in some cases.
An ejection port having a so-called tapered shape is known as an ejection port used for overcoming such a problem, in which the cross-sectional area of the ejection port decreases as it extends from the substrate side toward a surface in which the ejection port opens. In a method disclosed in Japanese Patent No. 4498363, a recess is formed in a surface of a photosensitive resin layer (side that serves as a surface in which the ejection port opens), and a tapered ejection port is formed at the bottom of the recess by photolithography. In this method, the recess functions as a concave lens in an exposure process, and light can be refracted by the concave lens to form an ejection port into a tapered shape.
The present invention provides a method for manufacturing a liquid ejection head having a substrate and a channel-forming member having an ejection port from which a liquid is ejected, the method including the steps of: (a) forming a negative photosensitive resin layer on or above the substrate; (b) forming a lens layer on the negative photosensitive resin layer, the lens layer having a lens; (c) exposing the negative photosensitive resin layer through the lens to form an ejection port in the negative photosensitive resin layer; and (d) removing the lens layer.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
In the case where a liquid ejection apparatus including a member having a surface in which an ejection port opens continuously ejects liquid, the liquid may adhere onto this surface. In particular, a liquid adhering to part of such a surface near the opening of an ejection port may disturb ejection of liquid in an intended direction; thus, liquid does not always land on a target position in some cases. Accordingly, a liquid adhering onto a surface in which an ejection port opens has been wiped off with a blade formed of, for instance, rubber.
In the method disclosed in Japanese Patent No. 4498363, however, an ejection port is formed at the bottom of a recess. Hence, the blade does not sufficiently enter the recess and may not sufficiently wipe off a liquid adhering to part of a surface in which the ejection port opens, the part being near the opening of the ejection port.
The present invention therefore enables manufacturing of a liquid ejection head which has an ejection port having a tapered shape and in which a liquid adhering to part of a surface in which the ejection port opens can be sufficiently wiped off with a blade, the part being near the opening of the ejection port.
A liquid ejection head to be manufactured in the present invention will now be described with reference to the drawings.
In the liquid ejection head illustrated in
In the liquid ejection head illustrated in
As illustrated in
In the liquid ejection head, all of the ejection ports 11 do not necessarily have the same tapered shape. For example, a taper angle may be changed on the basis of the ejection characteristics of a liquid to be ejected from an ejection port, or an ejection port having a straight shape (namely, θ=90°) instead of a tapered shape may be provided.
A method for manufacturing a liquid ejection head of the present invention will now be described with reference to the drawings.
As illustrated in
Then, as illustrated in
In addition, the SU-8 series and KMPR-1000 (trade names, manufactured by Kayaku MicroChem Corporation) and TMMR S2000 and TMMF S2000 (trade names, manufactured by TOKYO OHKA KOGYO CO., LTD.) may be used for the negative photosensitive resin layer 4.
In order to form the negative photosensitive resin layer 4, a coating liquid containing the above-mentioned composition is applied onto the substrate 1 by spin coating, roll coating, or slit coating so as to cover the pattern 3. Alternatively, a dry film of the above-mentioned composition may be disposed on or above the substrate 1 so as to cover the pattern 3. The negative photosensitive resin layer 4 can have any thickness. The thickness may be in the range of 5.0 to 100.0 μm from the surface of the substrate 1.
The surface of the negative photosensitive resin layer 4 eventually serves as the ejection port-opening surface. Hence, in order to impart water repellency or hydrophilic properties to the ejection port-opening surface, the surface of the negative photosensitive resin layer 4 may be subjected to a water-repellent treatment or hydrophilic treatment in the process illustrated in
A lens layer 5 is subsequently formed on the negative photosensitive resin layer 4. In order to form the lens layer 5, a lens layer-forming material 16 is applied onto the negative photosensitive resin layer 4 as illustrated in
Then, as illustrated in
The mold 14 can be formed of a material exhibiting excellent strength and processability, such as metallic materials, glass, ceramic materials, silicon, quartz, plastic materials, and photosensitive resins. Each protrusion pattern 15 of the mold 14 may be also formed of the same material as used for the mold 14 and may be formed so as to be integrated with the mold 14. The shape of the protrusion patterns 15 corresponds to the shape of the lenses 6 to be formed. Each protrusion pattern 15 has at least an inclined surface which defines the taper angle of the ejection port 11 to be eventually formed. The inclined surface may be a curved surface. However, in view of pressing efficiency during transfer, the inclination of the inclined surface preferably remains constant. In other words, the protrusion pattern 15 may have the shape of a circular cone, an elliptic cone, or a pyramid.
The lens layer-forming material 16, namely, the lens layer 5 may contain a resin as described above. In particular, this resin may be a resin to which the protrusion patterns 15 of the mold 14 are smoothly transferred by an imprinting method and which sufficiently transmits light used for patterning the negative photosensitive resin layer 4 and is easily removable after curing of the negative photosensitive resin layer 4. The lens layer 5 may transmit not less than 50% of light used for patterning the negative photosensitive resin layer 4 (light transmittance of not less than 50%). Examples of such a resin include vinyl ketone-based polymeric compounds such as polymethyl isopropenyl ketone and polyvinyl ketone; positive resists soluble in organic solvents, such as copolymers of methacrylic acid and methyl methacrylate; positive resists such as polyvinyl alcohols and novolac resin-based resists; cyclized rubbers such as polyisoprene rubber; epoxy resins such as a bisphenol A epoxy resin, a phenol novolac epoxy resin, a cresol novolac epoxy resin, and a multifunctional epoxy resin having an oxycyclohexane skeleton; and alkylsiloxane-containing epoxy resins. In view of removability, positive photosensitive resins may be particularly used. In the case where the resin used for forming the lens layer 5 is a cationically polymerizable epoxy resin, the lens layer 5 contacting the negative photosensitive resin layer 4 is cured during the patterning of the negative photosensitive resin layer 4, which leads to formation of a thin film having a thickness of approximately not more than 2 μm in some cases. Such a thin film about 2 μm or less in thickness, however, does not significantly affect the performance of the liquid ejection head.
The lens layer-forming material 16 can be applied onto the negative photosensitive resin layer 4 by, for instance, spin coating, slit coating, or laminating. In forming the lens layer-forming material 16 on the negative photosensitive resin layer 4, the negative photosensitive resin layer 4 and the lens layer-forming material 16 may remain immiscible to each other. Accordingly, the lens layer-forming material 16 may be dissolved in a solvent, applied onto a film such as a polyethylene terephthalate (PET) film, and dried to form a dry film thereon, and the dry film may be laminated on the negative photosensitive resin layer 4 with a laminator.
In a direction perpendicular to the substrate 1, the thickness of the lens layer 5 may be at least 1.5 times and at most 5.0 times the depth of each lens 6 to be formed. The depth of each lens 6 in the direction perpendicular to the substrate 1 refers to the largest depth of the lens 6 in the direction perpendicular to the substrate 1; for example, if each lens 6 is in the form of a cone, it refers to the height of the cone, in other words, the length of the line segment between the center of the bottom of the cone and the apex thereof. Depending on the materials and formation processes of the negative photosensitive resin layer 4 and the lens layer 5, if the thickness of the lens layer 5 is less than 1.5 times the depth of each lens 6, the protrusion pattern is transferred even to the negative photosensitive resin layer 4 when the mold 14 is pressed, which may lead to formation of a recess in the ejection port-opening surface. If the thickness of the lens layer 5 is larger than 5.0 times the depth of each lens 6, the lens layer 5 may not be properly removed with the result that the remaining lens layer 5 may give unevenness to the ejection port-opening surface.
After formation of the lens layer 5 having the lenses 6, as illustrated in
In general, in the case where a negative photosensitive resin layer is patterned, the negative photosensitive resin layer shrinks on curing or heating due to thermal treatment after exposure to light, which results in a change in the shape of the pattern in some cases. In the present invention, since the lens layer 5 is formed on the negative photosensitive resin layer 4, such a change in the shape of the pattern can be reduced.
Then, as illustrated in
Then, as illustrated in
In the first embodiment, each ejection port 11 of the produced liquid ejection head has a tapered shape. Furthermore, since the lens layer 5 is removed, the ejection port-opening surface can be made flat, and a liquid adhering to part of the ejection port-opening surface near the opening of each ejection port 11 can be smoothly wiped off with a blade.
The second embodiment is different from the first embodiment in that the formation of the lenses 6 is changed after the process illustrated in
With reference to
Then, the lens layer 5 is disposed on the negative photosensitive resin layer 4. As illustrated in
The lens layer-forming material 16, namely, the lens layer 5 may be formed of a resin. Furthermore, the lens layer 5 may be formed of a material which is highly adhesive to the negative photosensitive resin layer 4 and removable from the mold 14. In particular, the same material as used for the lens layer-forming material 16 in the first embodiment may be employed. The mold 14 may be also formed of the same material as mentioned in the first embodiment. In the second embodiment, however, the mold 14 may be composed of quartz, which can readily transmit light used for alignment and thereby facilitates alignment, because alignment accuracy is needed during bonding of the negative photosensitive resin layer 4 and the lens layer 5.
In the second embodiment, the lens layer 5 has been formed on the mold 14 having the protrusion patterns 15 before the lens layer 5 is pressure-bonded to the negative photosensitive resin layer 4. After the pressure-bonding of the lens layer 5 onto the negative photosensitive resin layer 4 and the formation of the lens 6, a liquid ejection head is manufactured as in
In the second embodiment, each ejection port 11 of the produced liquid ejection head has a tapered shape. Furthermore, since the lens layer 5 is removed, the ejection port-opening surface can be made flat, and a liquid adhering to part of the ejection port-opening surface near the opening of each ejection port 11 can be smoothly wiped off with a blade.
The third embodiment is different from the first embodiment in that the formation of the lenses 6 is changed after the process illustrated in
As illustrated in
Then, the lens layer 5 is formed in each gap 18 to form the lens 6. In particular, a lens layer-forming material, such as a resin and a liquid, is placed to each gap 18, and this lens layer-forming material is processed into the lens layer 5. In the case where a resin is used to form each lens layer 5, a resin is placed to the gap 18. Examples of a technique for placing a resin to each gap 18 include a technique in which a resin dissolved in a solvent is placed to the gap 18 and a technique in which the resin material is formed into a dry film and then laminated inside the gap 18. In the case where a liquid is used to form each lens layer 5, a liquid is placed to the gap 18. A liquid which does not dissolve the negative photosensitive resin layer 4 and the frame 17 may be employed, and a liquid having a high boiling point and vapor pressure may be used. Specifically, for instance, various oils such as a silicone oil, water-soluble solvents, and organic solvents may be used. In particular, a silicone oil may be used to form a good lens 6. As illustrated in
The frame layer 17 needs to transmit light used for patterning the negative photosensitive resin layer 4. The frame layer 17 may transmit not less than 50% of light used for patterning the negative photosensitive resin layer 4 (light transmittance of not less than 50%). In addition, the frame layer 17 may be readily removed after curing of the negative photosensitive resin layer 4. The frame layer 17 may be formed of a resin, in particular, a photosensitive resin as described above; in view of removal thereof, the frame layer 17 may be formed of a positive photosensitive resin. Examples of the resin used for forming the frame layer 17 include novolac-naphthoquinone resists, vinyl ketone-based polymeric compounds such as polymethyl isopropenyl ketone and polyvinyl ketone, copolymers of methacrylic acid and methyl methacrylate, and polyvinyl alcohol-based resists. In order to form the gaps 18 in the frame layer 17, a resist may be applied onto the frame layer 17 to form a mask. In this case, the frame layer 17 may be formed of cyclized rubbers such as polyisoprene rubber; epoxy resins such as a bisphenol A epoxy resin, a phenol novolac epoxy resin, a cresol novolac epoxy resin, and multifunctional epoxy resin having an oxycyclohexane skeleton; and alkylsiloxane-containing epoxy resins.
After the lenses 6 are formed above the negative photosensitive resin layer 4, a liquid ejection head is manufactured as in
In the third embodiment, each ejection port 11 of the produced liquid ejection head has a tapered shape. Furthermore, since the lens layer 5 is removed, the ejection port-opening surface can be made flat, and a liquid adhering to part of the ejection port-opening surface near the opening of each ejection port 11 can be smoothly wiped off with a blade.
The fourth embodiment is different from the first embodiment in that the formation of the lenses 6 is changed after the process illustrated in
As illustrated in
A developer is used in a process for forming recesses in the positive photosensitive resin layer 19 and in a development process for removing the positive photosensitive resin layer 19, the recesses being to be formed into the lenses 6. The negative photosensitive resin layer 4 may be insoluble in the developer. The positive photosensitive resin layer 19 may exhibit high resolution which enables smooth photolithographic patterning. From these standpoints, the material used for forming the positive photosensitive resin layer 19 may be a material which contains a novolac resin and a naphthoquinonediazide derivative and which can be developed with an alkaline solution. Specific examples thereof include naphthoquinone-based positive photoresists, such as the OFPR series and the THMR-iP series (trade names, manufactured by TOKYO OHKA KOGYO CO., LTD.) and the NPR series (trade name, manufactured by Nagase ChemteX Corporation).
Examples of a technique for forming the positive photosensitive resin layer 19 include, but are not limited to, spin coating, slit coating, and laminating. In view of the immiscibility of the positive photosensitive resin layer 19 with the negative photosensitive resin layer 4, a technique for forming the positive photosensitive resin layer 19 may involve applying a positive photosensitive resin onto a film such as a PET film, and forming the film into a dry film, and then laminating the dry film on the negative photosensitive resin layer 4 with a laminator.
After the lenses 6 are formed above the negative photosensitive resin layer 4, a liquid ejection head is manufactured as in
In the fourth embodiment, each ejection port 11 of the produced liquid ejection head has a tapered shape. Furthermore, since the lens layer 5 is removed, the ejection port-opening surface can be made flat, and a liquid adhering to part of the ejection port-opening surface near the opening of each ejection port 11 can be smoothly wiped off with a blade.
The fifth embodiment is different from the first embodiment in that the formation of the lenses 6 is changed after the process illustrated in
As illustrated in
The shape of each water-repellent pattern 20 is similar to the shape of the ejection port 11 to be formed; when the water-repellent pattern 20 is viewed from the above, the center thereof may be aligned with the center of the ejection port 11. Each water-repellent pattern 20 is smaller than the ejection port 11 when viewed from the above, but the size of the water-repellent pattern 20 may be appropriately adjusted on the basis of the taper angle of each ejection port 11. The height of each water-repellent pattern 20 may be not less than 5 μm to properly form the lens layer 5. The height may be not more than 50 μm because it is difficult to remove the water-repellent patterns 20 having an excessively large height.
The water-repellent patterns 20 can be formed by appropriately selecting a technique such as offset printing, microcontact printing, or ink jet recording with a piezoelectric device or a heating device. Before formation of the water-repellent patterns 20, the surface of the negative photosensitive resin layer 4 may be subjected to silane treatment or dry etching to enhance the adhesion of the water-repellent patterns 20 onto the negative photosensitive resin layer 4 or to reduce bleeding of the water-repellent patterns 20 on the negative photosensitive resin layer 4.
Then, the lens layer 5 and the lenses 6 are formed. A liquid containing a lens layer-forming material used for forming the lens layer 5 is applied onto the negative photosensitive resin layer 4. The liquid containing a lens layer-forming material may have the following characteristics: being less likely to dissolve the negative photosensitive resin layer 4 and the water-repellent patterns 20, contacting the non-water-repellent region 21 at a low contact angle, and being capable of sufficiently transmitting light used for patterning the negative photosensitive resin layer 4. Liquids each having high boiling point and vapor pressure can be used for such a liquid, and specific examples thereof include nonreactive silicone oils in which a hydrophilic organic group, such as a polyether group, is substituted for one of methyl groups of dimethylpolysiloxane. The liquid containing a lens layer-forming material can be applied onto the negative photosensitive resin layer 4 by, for example, slit coating with a bar coater or another machine; ink jet recording with a piezoelectric device, heating device, or another device; spraying; or immersion. The lens layer 5 is formed on the negative photosensitive resin layer 4 in this manner. Since the water-repellent patterns 20 are formed on the negative photosensitive resin layer 4, the liquid containing a lens layer-forming material moves from the surfaces of the water-repellent patterns 20 to the surface of the non-water-repellent region 21. The lens layer 5 having slopes that serve as the lenses 6 is thus formed as illustrated in
After the lenses 6 are formed above the negative photosensitive resin layer 4, a liquid ejection head is manufactured as in
In the fifth embodiment, each ejection port 11 of the produced liquid ejection head has a tapered shape. Furthermore, since the lens layer 5 is removed, the ejection port-opening surface can be made flat, and a liquid adhering to part of the ejection port-opening surface near the opening of each ejection port 11 can be smoothly wiped off with a blade.
The present invention will now be described further in detail with reference to Examples of the present invention.
A liquid ejection head was manufactured through processes illustrated in
Then, a dry film of polyisoprene rubber (trade name: OBC, manufactured by TOKYO OHKA KOGYO CO., LTD.) that served as the lens layer-forming material 16 was formed on the negative photosensitive resin layer 4 by a lamination method so as to have a thickness of 11.0 μm (
Then, the mold 14 having the conical protrusion patterns 15 each having an apex angle of 120° (incident angle Φ1=30°), a height of 7.5 μm, and a diameter of 26.0 μm at the bottom was pressed against the lens layer-forming material 16 such that 5.0 μm of each protrusion pattern 15 penetrated into the lens layer-forming material 16 in the height direction of the protrusion pattern 15 (
Then, the negative photosensitive resin layer 4 was exposed to a pattern of light through the lenses 6 and the photomask 8 having the light-shielding pattern 7 covering regions to be formed into ejection ports. An i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) was used as an exposure apparatus, and the exposure dose was 4000 J/m2. The light-shielding pattern 7 had a round shape having a diameter of 16.0 μm. After the exposure, the negative photosensitive resin layer 4 was heated at 100° C. for 4 minutes (thermal treatment) to cure the exposed part of the negative photosensitive resin layer 4, thereby forming the channel-forming member 9 (
Then, a mixture liquid of xylene/methyl isobutyl ketone (mass ratio: 6/4) was used to remove the unexposed part of the negative photosensitive resin layer 4 and the lens layer 5, thereby forming the ejection ports 11 (
Then, a mask was disposed on the back surface (side opposite to the top surface) of the substrate 1, and the side of the top surface of the substrate 1 was protected by a rubber film. In this state, the substrate 1 was anisotropically etched from the back surface side with TMAH to form the supply port 13 in the substrate 1. The rubber film was removed after the anisotropic etching, the product was exposed from the top surface side with an exposure apparatus (trade name: UX3000, manufactured by USHIO INC.) to decompose the pattern 3, and the pattern 3 was removed by being dissolved with methyl lactate. The liquid channel 12 was formed in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Example 1 had a taper angle θ of 76°.
A liquid ejection head was manufactured through processes illustrated in
Then, a mold having conical protrusion patterns each having an apex angle of 100° (incident angle Φ1=40°), a height of 7.5 μm, and a diameter of 18.0 μm at the bottom was pressed against the lens layer-forming material 16 such that 5.0 μm of each protrusion pattern penetrated into the lens layer-forming material 16 in the height direction of the protrusion pattern. This process was carried out at a mold temperature of 60° C. and a transfer pressure of 0.2 MPa. Then, the protrusion patterns were separated to complete the formation of the lens layer 5 having the lenses 6 (
The negative photosensitive resin layer 4 was exposed to a pattern of light through the lenses 6 and the photomask 8 having the light-shielding pattern 7 covering regions to be formed into ejection ports. An i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) was used as an exposure apparatus, and the exposure dose was 3000 J/m2. The light-shielding pattern 7 had a round shape having a diameter of 16.0 μm. After the exposure, the negative photosensitive resin layer 4 was heated at 100° C. for 4 minutes to cure the exposed part of the negative photosensitive resin layer 4, thereby forming the channel-forming member 9 (
Then, a mixture liquid of xylene/methyl isobutyl ketone (mass ratio: 6/4) was used to remove the unexposed part of the negative photosensitive resin layer 4 and the lens layer 5 to form the ejection ports 11 (
Then, a mask was disposed on the back surface (side opposite to the top surface) of the substrate 1, and the side of the top surface of the substrate 1 was protected by a rubber film. In this state, the substrate 1 was anisotropically etched from the back surface side with TMAH to form the supply port 13 in the substrate 1. The rubber film was removed after the anisotropic etching, the product was again exposed from the top surface side with an exposure apparatus (trade name: UX3000, manufactured by USHIO INC.) to decompose the pattern 3, and the pattern 3 was removed by being dissolved with methyl lactate. The liquid channel 12 was formed in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Example 2 had a taper angle θ of 70°.
A liquid ejection head was manufactured through processes illustrated in
Then, the resin layer 23 was exposed to a pattern of light through the photomask 8 with an i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA). The exposure dose was 4000 J/m2. After the exposure, the product was heated at 90° C. for 3 minutes to form a base 24 of a channel-forming member (
Then, polymethyl isopropenyl ketone (trade name: ODUR-1010, manufactured by TOKYO OHKA KOGYO CO., LTD.) was applied to a thickness of 18.0 μm from the substrate 1 to form a support member 25. The base 24 and the support member 25 were flattened by chemical mechanical polishing (CMP) so as to have a thickness of 16.0 μm from the substrate 1 (
Then, the cationically polymerizable epoxy resin composition containing components shown in Table 1 was applied onto the base 24 and the support member 25 to a thickness of 10.0 μm to form another resin layer 23 and then heated at 90° C. for 5 minutes. A film of a polyisoprene rubber (trade name: OBC, manufactured by TOKYO OHKA KOGYO CO., LTD.) that served as the lens layer-forming material 16 was formed on the resin layer 23 so as to have a thickness of 11.0 μm (
Then, the mold 14 having conical protrusion patterns each having an apex angle of 120° (incident angle Φ1=30°), a height of 7.5 μm, and a diameter of 26.0 μm at the bottom was pressed against the lens layer-forming material 16 such that 5.0 μm of each protrusion pattern penetrated into the lens layer-forming material 16 in the height direction of the protrusion pattern. This process was carried out at a temperature of the mold 14 of 60° C. and a transfer pressure of 0.2 MPa. Then, the protrusion patterns were separated to complete the formation of the lens layer 5 having the lenses 6 (
Then, the resin layer 23 was exposed to a pattern of light through the lenses 6 and the photomask 8 having the light-shielding pattern 7 covering regions to be formed into ejection ports. An i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) was used as an exposure apparatus, and the exposure dose was 4000 J/m2. The light-shielding pattern 7 had a round shape having a diameter of 16.0 μm. After the exposure, the resin layer 23 was heated at 100° C. for 4 minutes to cure the exposed part of the resin layer 23, thereby forming an orifice plate 26 that was part of the channel-forming member (
Then, a mixture liquid of xylene/methyl isobutyl ketone (mass ratio: 6/4) was used to remove the unexposed part of the resin layer 23 and the lens layer 5 to form the ejection ports 11 (
The supply port 13 was finally formed as in Example 1, and the support member 25 was removed by being dissolved to form the liquid channel 12. A liquid ejection head was manufactured in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Example 3 had a taper angle θ of 76°.
A liquid ejection head was manufactured through processes illustrated in
Then, a dry film 27 containing a cationically polymerizable epoxy resin composition composed of components shown in Table 2 was applied onto the base 24 and the unexposed part of the resin layer 23 by a lamination method so as to have a thickness of 10.0 μm and then heated at 90° for 5 minutes. A dry film of a polyisoprene rubber (trade name: OBC, manufactured by TOKYO OHKA KOGYO CO., LTD.) was formed on the dry film 27 by a lamination method so as to have a thickness of 11.0 μm. A mold having conical protrusion patterns each having an apex angle of 120° (incident angle Φ1=30°), a height of 7.5 μm, and a diameter of 26.0 μm at the bottom was subsequently pressed against the dry film of a polyisoprene rubber such that 5.0 μm of each protrusion pattern penetrated into this dry film in the height direction of the protrusion pattern. This process was carried out at a mold temperature of 60° C. and a transfer pressure of 0.2 MPa. Then, the protrusion patterns were separated to form the dry film of a polyisoprene rubber into the lens layer 5 having the lenses 6 (
Then, the dry film 27 was exposed to a pattern of light through the lenses 6 and the photomask 8 having the light-shielding pattern 7 covering regions to be formed into ejection ports. An i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) was used as an exposure apparatus. The exposure dose was 800 J/m2. The light-shielding pattern 7 had a round shape having a diameter of 16.0 μm. After the exposure, the dry film 27 was heated at 100° C. for 4 minutes to cure the exposed part of the dry film 27, thereby forming an orifice plate 26 that was part of the channel-forming member (
Then, a mixture liquid of xylene/methyl isobutyl ketone (mass ratio: 6/4) was used to remove the unexposed part of the dry film 27 and the lens layer 5, thereby forming the ejection ports 11 (
The supply port 13 was finally formed as in Example 1, and the template was removed by being dissolved to form the liquid channel 12. A liquid ejection head was manufactured in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Example 4 had a taper angle θ of 76°.
A liquid ejection head was manufactured through processes illustrated in
After the formation of the negative photosensitive resin layer 4, a dry film of an epoxy resin composition composed of the components shown in Table 3 was formed as the lens layer-forming material 16 on the negative photosensitive resin layer 4 by a lamination method so as to have a thickness of 6.0 μm (
The component A in Table 3 was an alkylsiloxane-containing epoxy resin having a structural units represented by the following general formulae (a) and (b).
Then, a mold having conical protrusion patterns each having an apex angle of 150° (incident angle Φ1=150°), a height of 6.0 μm, and a diameter of 45.0 μm at the bottom was pressed against the lens layer-forming material 16 such that 4.0 μm of each protrusion pattern penetrated into the lens layer-forming material 16 in the height direction of the protrusion pattern. This process was carried out at a mold temperature of 60° C. and a transfer pressure of 0.2 MPa. Then, the protrusion patterns were separated to complete the formation of the lens layer 5 having the lenses 6 (
Then, the negative photosensitive resin layer 4 was exposed to a pattern of light as in Example 1 (
The supply port 13 was finally formed as in Example 1, and the pattern 3 was removed by being dissolved to form the liquid channel 12. A liquid ejection head was manufactured in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Example 5 had a taper angle θ of 82°.
The lens layer 5 was formed through the process illustrated in
Then, the negative photosensitive resin layer 4 is formed as in Example 1 through the processes up to and including
After the lens layer 5 and lenses 6 overlying the negative photosensitive resin layer 4 were formed in this manner, a liquid ejection head was manufactured as in
Each ejection port of the liquid ejection head manufactured in Example 6 had a taper angle θ of 76°.
Polymethyl isopropenyl ketone (trade name: ODUR-1010, manufactured by TOKYO OHKA KOGYO CO., LTD.) replaced polyisoprene rubber (trade name: OBC, manufactured by TOKYO OHKA KOGYO CO., LTD.) used for the lens layer-forming material 16 in Example 6. Except this change, a liquid ejection head was manufactured as in Example 6.
Each ejection port of the liquid ejection head manufactured in Example 7 had a taper angle θ of 76°.
The processes up to and including
Then, in order to form the lens layer 5 having the lenses 6, a silicone oil that was the material used for forming the lenses 6 was ejected to the gaps 18 with a liquid ejection apparatus including a piezoelectric device to place the silicone oil to the gaps 18 (
Then, a liquid ejection head was manufactured as in
Each ejection port 11 of the liquid ejection head manufactured in Example 8 had a taper angle θ of 76°.
An aqueous solution containing polyvinyl alcohol was placed to the gaps 18 in place of the silicone oil used in Example 8. After placing this aqueous solution to the gaps 18, the product was heated at 80° C. for 3 minutes to form the polyvinyl alcohol into a film having a thickness of 5.0 μm, thereby forming the lens layer 5.
Then, a liquid ejection head was manufactured as in Example 8. The ejection ports 11 were formed through exposure with an i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) at an exposure dose of 5000 J/m2. The light-shielding pattern 7 had a round shape having a diameter of 16.0 μm. The unexposed part of the negative photosensitive resin layer 4 was removed with methyl isobutyl ketone, and the frame layer 17 and the lens layer 5 were removed with a stripping solution (trade name: remover 1112A, manufactured by Rohm and Haas Electronic Materials Company).
Each ejection port of the liquid ejection head manufactured in Example 9 had a taper angle θ of 76°.
The processes up to and including
Then, the positive photosensitive resin layer 19 was exposed to a pattern of light with an exposure apparatus (trade name: mask aligner MPA-600Super, manufactured by CANON KABUSHIKI KAISHA). In this case, a filter which was able to transmit the g-line (wavelength: 436 nm) was used. The pattern formed in a mask for forming each recess had a round light-transmitting portion having a diameter of 20.0 μm. An exposure dose was 3000 J/m2, and the focus was 50.0 μm from the surface of the positive photosensitive resin layer 19 in a depth direction. The exposed part was subsequently removed by being dissolved with an alkaline developer (trade name: NMD-3, manufactured by TOKYO OHKA KOGYO CO., LTD.) to form the lens layer 5 having the recesses that served as the lenses 6 (
Then, a liquid ejection head was manufactured as in
Each ejection port 11 of the liquid ejection head manufactured in Example 10 had a taper angle θ of 75°.
In the processes in Example 10, TMMR S2000 (trade name, manufactured by TOKYO OHKA KOGYO CO., LTD.) was used to form the negative photosensitive resin layer 4. Furthermore, OFPR-800 (trade name, manufactured by TOKYO OHKA KOGYO CO., LTD., naphthoquinone-based positive photoresist) replaced NPR-9630 (trade name, manufactured by Nagase ChemteX Corporation, naphthoquinone-based positive photoresist) used in Example 10, and the thickness thereof was 3.0 μm.
The positive photosensitive resin layer 19 was exposed to a pattern of light at an exposure dose of 6000 J/m2, and the pattern formed in a mask for forming each recess had a round shape having a diameter of 22.0 μm and a gradation structure in which light transmittance decreased as the round pattern extended toward the outer side. The ejection ports 11 were formed through exposure with an i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) at an exposure dose of 16000 J/m2. Except those changes, a liquid ejection head was manufactured as in Example 10.
Each ejection port of the liquid ejection head manufactured in Example 11 had a taper angle θ of 85°.
The positive photosensitive resin layer 19 was laminated so as to have a thickness of 7.0 μm in Example 12, whereas it was laminated so as to have a thickness of 4.0 μm in Example 10.
Then, the positive photosensitive resin layer 19 was exposed to a pattern of light. An i-line exposure stepper (manufactured by CANON KABUSHIKI KAISHA) was used as an exposure apparatus. The pattern formed in a mask for forming each recess had a round light-transmitting portion having a diameter of 20.0 μm. The exposure dose was 4000 J/m2, and focus was 50.0 μm from the surface of the positive photosensitive resin layer 19 in the depth direction. The exposed part was subsequently removed by being dissolved with an alkaline developer (trade name: NMD-3, manufactured by TOKYO OHKA KOGYO CO., LTD.) to form the lens layer 5 having the recesses that served as the lenses 6 (
Then, a liquid ejection head was manufactured as in
Each ejection port 11 of the liquid ejection head manufactured in Example 12 had a taper angle θ of 70°.
The processes up to and including
Then, as illustrated in
Then, a liquid ejection head was manufactured as in
Each ejection port 11 of the liquid ejection head manufactured in Example 13 had a taper angle θ of 77°.
The water-repellent patterns were formed by ink jet recording with a piezoelectric device in Example 14, whereas they were formed by offset printing in Example 13. The lens layer was formed by offset printing in Example 14, whereas it was formed by ink jet printing in Example 13. In addition, the water-repellent patterns to be formed were changed as described below. A liquid ejection head was manufactured as in Example 13 except those changes.
Each ejection port of a liquid ejection head manufactured in Example 14 had a taper angle θ of 77°.
The thickness of the lens layer-forming material 16 formed in Example 1 was changed from 11.0 μm to 30.0 μm. A liquid ejection head was manufactured as in Example 1 except this change; however, time taken for completely removing the lens layer was much longer than Example 1.
Each ejection port of the liquid ejection head manufactured in Example 15 had a taper angle θ of 76°.
The thickness of the lens layer-forming material 16 formed in Example 1 was changed from 11.0 μm to 7.0 μm. A liquid ejection head was manufactured as in Example 1 except this change.
Each ejection port of the liquid ejection head manufactured in Example 16 had a taper angle θ of 76°; however, the ejection port-opening surface was slightly recessed.
The processes up to and including
Then, as illustrated in
Then, as illustrated in
Then, a mixture liquid of xylene/methyl isobutyl ketone (mass ratio: 6/4) was used to remove the unexposed part of the negative photosensitive resin layer 4 to form the ejection ports 11 (
Then, a mask was disposed on the back surface (side opposite to the top surface) of the substrate 1, and the side of the top surface of the substrate 1 was protected by a rubber film. In this state, the substrate 1 was anisotropically etched from the back surface side with TMAH to form the supply port 13 in the substrate 1. The rubber film was removed after the anisotropic etching, the product was exposed from the top surface side with an exposure apparatus (trade name: UX3000, manufactured by USHIO INC.) to decompose the pattern 3, and the pattern 3 was removed by being dissolved with methyl lactate. The liquid channel 12 was formed in this manner (
Each ejection port 11 of the liquid ejection head manufactured in Comparative Example had a taper angle θ of 80°.
Evaluation
Each of the manufactured liquid ejection heads was filled with a black ink, and the ink was continuously ejected from the ejection ports of each liquid ejection head. Then, it was found that ink droplets were ejected in an unintended direction in each liquid ejection head in some cases. Each ejection port-opening surface was observed with an optical microscope, and it was found that ink was adhering to part of the ejection port-opening surface near the openings of some ejection ports. Then, each ejection port-opening surface to which ink had been adhering was wiped with a blade formed of chlorinated butyl rubber to remove the ink adhering to the ejection port-opening surface. After the removal of the ink, an ink was ejected again.
As a result, an ink was properly ejected from the liquid ejection heads manufactured in Examples. Ink droplets were, however, ejected in an unintended direction in the liquid ejection head manufactured in Comparative Example in some cases. Each ejection port-opening surface was therefore observed with an optical microscope again, and it was found that the ink which had been adhering to part of the ejection port-opening surface near the openings of the ejection ports was properly removed in the liquid ejection head manufactured in Example. In contrast, it was found that the ink was remaining on part of the ejection port-opening surface near the openings of the ejection ports, namely in recesses, in the liquid ejection head manufactured in Comparative Example.
The present invention enabled manufacturing of a liquid ejection head which had an ejection port having a tapered shape and in which a liquid adhering to part of an ejection port-opening surface near the opening of an ejection port was able to be sufficiently wiped off with a blade.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-124836 filed May 31, 2012, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-124836 | May 2012 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20060172227 | Shaarawi et al. | Aug 2006 | A1 |
| 20120047736 | Horiuchi | Mar 2012 | A1 |
| 20130266901 | Ikegame et al. | Oct 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 4498363 | Jul 2010 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20130323650 A1 | Dec 2013 | US |
