1. Field of the Invention
The present invention relates to a method for manufacturing a liquid discharge head.
2. Description of the Related Art
A liquid discharge head is used in a liquid discharge apparatus such as an ink-jet recording apparatus, and has a channel forming member and a substrate. The channel forming member is formed of resin or the like on the substrate, that is, on the front surface side of the substrate. Inside the channel forming member, a liquid channel is formed, and sometimes discharge ports communicating with the liquid channel are further formed. A liquid supply port penetrating the substrate is formed in the substrate.
As a method for manufacturing such a liquid discharge head, there has been a method in which a mold for a liquid channel and a channel forming member are formed on a substrate, and then a liquid supply port is formed in the substrate by etching or the like. In this method, in the step of forming a mold for a liquid channel and a channel forming member on the substrate, a liquid supply port is not yet formed in the substrate. That is, the front surface of the substrate can be made flat. Therefore, for example, such a problem can be prevented from occurring that a mold for a liquid channel to be formed just above a liquid supply port sags into a hole serving as a liquid supply port and, as a result, a liquid channel is deformed.
However, in this method, in the step of forming a liquid supply port in the substrate, a mold for a liquid channel and a channel forming member are already formed on the substrate. Therefore, the mold for a liquid channel and the channel forming member need to be protected from etchant or the like forming a liquid supply port, with a protective film or the like, and the manufacturing process is thereby complicated.
So, as a method for manufacturing a liquid discharge head, a method is possible in which a hole serving as a liquid supply port is formed in a substrate, and then a mold for a liquid channel and a channel forming member are formed on the substrate. In this method, since the protection of the mold for a liquid channel and the channel forming member when forming a liquid supply port is unnecessary, the manufacturing process is simplified. However, such a problem may occur that the mold for a liquid channel formed just above the liquid supply port sags into the hole serving as a liquid supply port and, as a result, a liquid channel is deformed.
To solve such a problem, Japanese Patent Laid-Open No. 2006-224598 describes forming a beam on the front surface side of a substrate so that a mold can be prevented from sagging into a liquid supply port by the beam.
An aspect of the present invention is a method for manufacturing a liquid discharge head including a substrate in which a liquid supply port is formed, a channel forming member that forms a liquid channel communicating with the liquid supply port on the substrate. The method includes preparing a substrate on which a hole serving as the liquid supply port is open, attaching a dry film on the substrate to cover an opening of the hole with the dry film, curing a cover part of the dry film that covers the hole, patterning the dry film to form a mold for the liquid channel, of a region of the dry film that includes the cover part, forming the channel forming member such that it covers the mold, and removing the mold to form the liquid channel.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
In the method described in Japanese Patent Laid-Open No. 2006-224598, a beam needs to be formed on the front surface side of a substrate. Therefore, the manufacturing process is thereby complicated.
Therefore, the present invention provides a method for manufacturing a liquid discharge head in which, even in a case where a hole serving as a liquid supply port is formed in a substrate and then a mold for a liquid channel is formed on the substrate, the mold for a liquid channel can be easily prevented from sagging into the hole serving as a liquid supply port and being deformed.
An example of a liquid discharge head manufactured by the present invention is shown in
Examples of the energy generating elements 1 include heating resistors and piezoelectric elements. The energy generating elements may be formed so as to be in contact with the front surface of the substrate, or may be formed in a hollow shape so as to be partly out of contact with the front surface of the substrate.
Examples of the substrate 2 include a silicon substrate formed of silicon. The above-described energy generating elements 1 are formed on a first surface (front surface) side of the substrate. The first surface and a second surface (back surface) that is a surface on the side opposite to the first surface can have a silicon crystal plane orientation of (100). That is, the substrate 2 can be a (100) substrate formed of silicon.
A liquid supply port 3 is formed in the substrate 2. The liquid supply port 3 is formed so as to penetrate the substrate from the first surface to the second surface. The energy generating elements 1 are formed on the first surface side of the substrate so as to be arranged in two lines on both sides of the opening of the liquid supply port 3. In addition to these, an insulating film, a cavitation resistant film, and the like (not shown) are formed on the substrate 2.
The channel forming member 15 is formed of resin or the like. The channel forming member 15 forms the liquid channel 5 and the discharge ports 4, and the discharge ports 4 are disposed at positions corresponding to the energy generating elements 1. The liquid supply port 3 and the liquid channel 5 communicate with each other. Liquid is supplied from the liquid supply port 3 to the liquid channel 5, is given energy by the energy generating elements 1, and is discharged from the discharge ports 4. There are terminals (bumps) 17 at both ends of the substrate 2. By electrically connecting the terminals 17 and a liquid discharge apparatus, the energy generating elements are electrically connected through the terminals to the outside, and can generate energy.
Next, a method for manufacturing a liquid discharge head of the present invention will be described with reference to
First, as shown in
Next, as shown in
After preparing the substrate 2 on which the hole serving as a liquid supply port is open in this way, a dry film 8 is attached to the first surface side of the substrate 2 as shown in
Next, curing and patterning of the dry film 8 are performed. Curing and patterning of the dry film 8 may be performed in any order, or may be performed in the same step. The dry film 8 is cured at least in a cover part thereof that covers the hole. Curing of the dry film 8 may be photo-curing or thermal curing. Curing the dry film 8 means increasing the hardness of the dry film 8 by irradiating the dry film 8 with light or heating the dry film 8.
A description will be given, for example, of a case where negative photosensitive resin is used as the dry film 8. In this case, by performing pattern exposure as shown in
In consideration of photo-curing the dry film 8, the dry film 8 can be formed of a photo-curable acrylic resin. A photo-curable acrylic resin is also superior in removability. When the dry film 8 is formed of a photosensitive resin, a negative photosensitive resin can be used. If the dry film 8 is formed of a negative photosensitive resin, the rigidity of the dry film 8 is easily increased by photo-curing, and the dry film 8 is easy to cure.
In consideration of thermally curing the dry film 8, the dry film 8 can be formed of a thermally curable acrylic resin containing an epoxy group-containing resin. Thermal curing is performed by heating the dry film. The heating temperature in this case is preferably higher than or equal to 120° C. and lower than or equal to 150° C.
As described above, curing and patterning of the dry film 8 may be performed in any order. For example, the dry film 8 is patterned by dry etching or the like, and then a cover part of the dry film 8 that covers the hole serving as a liquid supply port 3 is cured. Alternatively, after curing the whole of the dry film 8, the dry film is patterned, and the cover part is left.
In the present invention, the dry film 8 is patterned, and a region of the dry film that includes the cover part forms a mold for a liquid channel. By curing the cover part, the mold can be prevented from sagging into the liquid supply port, being deformed, and thereby deforming a liquid supply port. The mold can also be prevented from being deformed by vacuum pressure when vacuum suction is performed.
The thickness of the dry film 8 is preferably more than or equal to 3 μm and less than or equal to 30 μm. By making the thickness of the dry film 8 more than or equal to 3 μm, the dry film 8 can be prevented more effectively from sagging into the liquid supply port, and being deformed. By making the thickness of the dry film 8 less than or equal to 30 μm, the curing time and the removal time can be shortened.
Next, as shown in
Next, as shown in
Next, as shown in
After that, the substrate 2 is separated with a dicing saw or the like as needed, the energy generating elements 1 are electrically joined, and thus a liquid discharge head is manufactured.
Although an example has been described where a mold for a liquid channel is formed of a layer (sheet) of dry film, a mold for a liquid channel may be formed of, in addition to a layer of dry film, another dry film. Alternatively, a mold for a liquid channel may be formed of, in addition to a layer of negative dry film, a member formed of another material. This example will be described with reference to
First, as shown in
After preparing a substrate on which a hole serving as a liquid supply port is open in this way, a dry film 8 is attached to the first surface side of the substrate 2 as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
After that, the substrate 2 is separated with a dicing saw or the like as needed, the energy generating elements 1 are electrically joined, and thus a liquid discharge head is manufactured.
The first mold 11 and the second mold 13 can be simultaneously removed using a solvent or the like. In this respect, the first mold 11 and the second mold 13, in other words, the dry film 8 and the photosensitive resin layer 12 can be formed of the same type of photosensitive resins. “The same type” means that the basic structures of resins are the same, and does not mean that the molecular weights or the like of resins are exactly equal. When the first mold 11 and the second mold 13 are not simultaneously removed, for example, a method can be used in which the second mold 13 is removed by dry etching, and then the first mold 11 is removed by wet etching.
As described above, in
Next, the present invention will be described more specifically with reference to examples.
First, as shown in
Next, an etching mask was formed of polyether amide on the second surface side of the substrate 2, and 22 mass % of TMAH solution was introduced through the opening of the etching mask. After that, the etching mask was removed. Thereby, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
After that, the substrate 2 was separated with a dicing saw or the like, the energy generating elements 1 were electrically joined, and thus a liquid discharge head was manufactured.
No deformation of the liquid channel was observed in the manufactured liquid discharge head, and the manufactured liquid discharge head was satisfactory.
First, as shown in
Next, as shown in
Next, as shown in
Next, the dry film 8 was baked at 95° C. for three minutes, and as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
After that, the substrate 2 was separated with a dicing saw or the like, the energy generating elements 1 were electrically joined, and thus a liquid discharge head was manufactured.
In the manufactured liquid discharge head, the wall 16 shown in
A dry film 8 was cured by exposure in Example 1, whereas this step was not performed in Comparative Example 1. A dry film 8 was patterned by RIE. Except for this, a liquid discharge head was manufactured in the same manner as in Example 1.
In the manufactured liquid discharge head, the upper wall of the liquid channel was sagged, and the liquid channel was slightly deformed.
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. 2013-234943 filed Nov. 13, 2013, which is hereby incorporated by reference herein in its entirety.
Number | Name | Date | Kind |
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6960424 | Miyagawa et al. | Nov 2005 | B2 |
20090136875 | Kubota et al. | May 2009 | A1 |
20110151598 | Abo et al. | Jun 2011 | A1 |
20130017496 | Matsumoto et al. | Jan 2013 | A1 |
Number | Date | Country |
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2006-224598 | Aug 2006 | JP |
Number | Date | Country | |
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20150129542 A1 | May 2015 | US |