JP3711728B2 - Method for casting a microstructure and casting mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for casting a microstructure and a casting mold, and in particular, casting a microstructure suitable for molding a resin part in which a large number of cylindrical microholes and micropartitions are arranged. The present invention relates to a molding method and a casting mold.
[0002]
[Prior art]
As a conventional microstructure in which a large number of cylindrical minute holes and minute partition walls are arranged, for example, there is an ink discharge head of an ink jet printer.
[0003]
6A and 6B show an ink discharge head of an ink jet printer. FIG. 6A shows a resin-integrated nozzle plate 101 as an ink discharge head. In the nozzle plate 101, a large number of cylindrical micro holes 102 having a diameter of several tens of μm and a depth of several tens to several hundreds of μm are arranged. The cylindrical minute holes 102 are ejection openings for ejecting ink dots toward the printing paper. In order to obtain high-quality print quality, the intervals between the cylindrical minute holes 102, the cylindrical minute holes 102, and the like. It is required that the parallelism of the cylindrical inner surface 103 and the smoothness and cylindricity of the cylindrical inner surface 103 be several μm or less.
[0004]
In FIG. 6B, the ink discharge head 104 is formed of a resin-integrated type and has a plurality of ink flow paths 105. Between the ink flow paths 105, the width and the height are several tens. A large number of μm ink flow path walls 106 are arranged.
[0005]
FIG. 7 shows a conventional casting method for a microstructure. When the resin structure microstructure shown in FIG. 6 is cast-molded, the conventional cast molding method uses first a main material such as a monomer or prepolymer in the casting machine vacuum chamber. And vacuum defoaming the curing agent (701). These materials that have been degassed under vacuum are stirred and mixed (702), and the materials that were stirred and mixed are poured into a casting mold prepared in advance (703), and left for a predetermined time to be cured (704). After sufficiently curing to form a molded body, the casting mold is opened and the molded body is taken out (705).
[0006]
Here, in the ink discharge heads 101 and 104 of the ink jet printer as shown in FIG. 6, the dimensions and inner dimensions of the cylindrical minute holes 102 of the nozzle plate 101 and the ink flow path 105 of the ink discharge head 104 are determined depending on the purpose of use. High precision is required for side smoothness. Therefore, when these are integrally molded with resin, not only the dimensional accuracy is ensured during molding, but also the dimensions and inner surface smoothness are accurately maintained even during mold release, and the shape of the thin partition walls is maintained without defects. Thus, a reliable and unreasonable mold release is required.
[0007]
In the above-described conventional method for casting a microstructure, the molded body is solidified and contracted (704) in the casting mold, so that it is difficult to perform the mold release process (705) after molding the part.
[0008]
With respect to this mold release processing, for example, as disclosed in Japanese Patent Laid-Open No. 5-269800, the mold is mechanically released using an ejector pin, or disclosed in Japanese Patent Laid-Open No. 8-90617. As described above, there are some which perform release using gas pressure.
[0009]
[Problems to be solved by the invention]
However, according to the conventional cast molding method of a microstructure that performs mechanical release with an ejector pin as disclosed in Japanese Patent Laid-Open No. 5-269800, a microstructure molded body having a large number of microstructures is obtained. However, since its structural strength is relatively weak compared to the interfacial stress with the forming mold, there has been a problem that the shape is lost and the dimensional accuracy is deteriorated. In addition, when the mold core encased in the resin molded body, which is a micro structure, is very small, the mechanical strength of the mold core is relatively low compared to the interfacial stress with the resin when mechanical release is performed with an ejector pin. Due to its weakness, there was a problem that the mold core was deformed or broken.
[0010]
Further, according to the conventional microstructure forming method for mold release using gas pressure as disclosed in JP-A-8-90617, molding of a microstructure having a large number of microstructures is performed. Since the shape of the body is fine and complicated, there is a problem that it is difficult to construct a gas flow path that is necessary when performing release by gas pressure.
[0011]
Accordingly, an object of the present invention is to provide a casting method and a casting mold for a microstructure capable of accurately producing a microstructure having a large number of minute and complicated microstructures.
[0012]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a microstructure forming method in which a molding material is injected into a molding space formed in a molding die to form a microstructure. An elastic member having a shape complementary to the microstructure is arranged to form the molding space, the molding material is injected into the molding space to form the microstructure, and the elastic member is vibrated. And providing a method for casting the microstructure, wherein the microstructure is separated from the elastic member .
[0013]
In order to achieve the above object, the present invention provides a microstructure forming method in which a molding material is injected into a molding die to form a microstructure, and a core member having a predetermined shape is formed in the molding die. A first step of forming and forming a molding space corresponding to the shape of the microstructure by injecting an elastic member into the molding die in which the core member is arranged, and molding in the molding space formed in the molding die A second step of injecting a material to form a microstructure, and a third step of vibrating the core member to separate the microstructure from the core member and the elastic member. A method for casting a structure is provided.
[0014]
Further, in order to achieve the above object, the present invention provides a casting mold in which a molding material is injected to form a microstructure, and is arranged in the internal space, the top plate, the side plate, and the bottom plate that form the internal space. A core member having a predetermined shape, an elastic member that is injected into the space in which the core member is disposed, forms a molding space in the internal space and molds the microstructure together with the core member, and faces the molding space of the core member. Casting of a micro structure characterized by comprising: a vibration source that is installed in a portion that is not provided and imparts vibration to the core member when the micro structure is separated; and a clamp mechanism that fixes and holds the upper plate and the side plate Providing a mold.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The microstructure molding method and casting mold of the present invention will be described in detail below.
[0016]
FIG. 1 shows a microstructure forming apparatus of the present invention. This microstructure casting apparatus includes a chamber 11, a substrate 12 provided on the bottom surface of the chamber 11, a buffer member 13 provided on the substrate 12, and a cast molding provided on the buffer member 13. The casting mold 10 is fixed to the substrate 12 with screws through a buffer member 13.
[0017]
The casting mold 10 is positioned by the outer frame including the bottom plate 14, the side plate 15, and the upper plate 16, the bush 25 provided in contact with the bottom plate 14 and the side plates 15 on both sides, and the bush 25. A core 20 provided in the mold 10 and a vibration source 22 such as an ultrasonic vibrator provided on the bottom surface of the core 20 are provided. The bottom plate 14, the side plate 15, and the upper plate 16 are fixed by screwing, and the side plate 15 and the upper plate 16 are fixed by a clamp mechanism 17. The upper plate 16 is provided with a material injection port 18 for injecting material into the casting mold 10. The side plate 15 and the bush 25 on one side (right side in FIG. 1) are provided with power line inlets 15 a and 25 a, and the vibration source 22 is supplied with power from the vibration power supply control device 24 via the power line 23. The core 20 is composed of a base portion 20a and a microprojection portion 20b, and a portion where the microprojection portion 20b rises from the base portion 20a is a corner portion 29 having a curved cross section.
[0018]
FIG. 2 is an enlarged view of the lower left side surface of the casting mold 10. In FIG. 2, the core 20 is screwed to the side plate 15 by screws 26, and the vibration source 22 is screwed to the core 20 by screws 27.
[0019]
The microstructure is cast and formed by the casting apparatus for the microstructure having the above-described configuration. Hereinafter, a method for casting a microstructure will be described.
[0020]
FIG. 3 shows a method for casting a microstructure according to the present invention. FIG. 3A shows a first step of forming a molding space corresponding to the shape of the microstructure to be manufactured by injecting an elastic member into the cavity and molding and solidifying it. FIG. 3B shows a case where a molding material is injected into a molding space corresponding to the shape of the microstructure formed in the cavity to form the microstructure, and the elastic member is vibrated to remove the microstructure from the core. The 2nd process to isolate | separate is shown. Hereinafter, the cast molding method of the microstructure of the present invention will be described with reference to FIGS. 1 and 3.
[0021]
First, in the first step, a casting main agent having good releasability such as silicon rubber and a curing agent are vacuum degassed (301) and mixed to generate a material for the elastic member 21 (302). A predetermined amount of the material of the elastic member 21 is poured from the material inlet 18 of the casting mold 10 (303) and left for a predetermined time to cure the elastic member 21 (304). A space surrounded by the cured elastic member 21, the side plate 15, the upper plate 16, and the core 20 becomes a cavity for molding the microstructure 19. Here, since the upper plate 16 serves as an upper lid that constitutes a cavity when the microstructure 19 is molded, the upper plate 16 is fixed to the side plate 15 by the clamp mechanism 17 to prevent floating. The amount of the elastic member 21 poured in is measured in advance so that a space (cavity) corresponding to the shape and size of the microstructure 19 to be obtained is formed, or directly by using a laser distance meter or the like. You may make it determine by measuring the height of a liquid level.
[0022]
Next, in the second step, the main material such as monomer and prepolymer and the curing agent are vacuum degassed (305). Next, the main material and the curing agent are stirred and mixed (306), and then the mixed material is poured into a cavity formed in the casting mold 10 (307) and left for a predetermined time to cure the mixed material. (308).
[0023]
After the mixed material is sufficiently cured to form a microstructure 19, the clamp mechanism 17 and the upper plate 16 are removed. In this state, the vibration power source control device 24 is operated to drive the vibration source 22. Due to the vibration of the vibration source 22, the core 20 vibrates, and the adhesion at the contact interface between the core 20 pressed into the microstructure 19 and the microstructure 19 decreases, and the microstructure 19 is separated. The mold becomes easy. Therefore, the microstructure 19 can be easily taken out from the casting mold 10 (309).
[0024]
The core 20 has a good vibration propagation efficiency and prevents the corner portion 29 of the core 20 from being broken due to stress concentration caused by vibration. It is desirable that it be represented by a quadratic curve.
[0025]
The length of the micro-projections 20b of the core 20 is determined from the vibration propagation efficiency, the core material strength, and the press-fitting length into the micro structure 19, but in general, when the core material 20 is nickel or super steel material, the micro structure It is desirable that it is twice or more the press-fitting length into the body 19.
[0026]
As described above, the elastic member 21 is an element constituting a cavity for forming the microstructure 19, but when the core 20 vibrates, the elastic member 21 serves as a vibration absorbing material or a buffer material that prevents excessive bending of the core 20 due to vibration. The function is also demonstrated. The elastic member 21 is also required to have releasability because it is in direct contact with the microstructure 19, and silicon rubber is most desirable as the main agent. Since silicon rubber is excellent in durability, it can be used repeatedly several tens of times.
[0027]
The vibration source 22 preferably has a small amplitude so as not to cause the micro structure 19 and the core 20 to be damaged or broken, and preferably has a high frequency in order to obtain a sufficient release effect. Child is desirable.
[0028]
Further, the bottom plate 14 of the casting mold 10 is fixed to the substrate 12 via the buffer member 13 in order to prevent diffusion of vibration energy.
[0029]
As described above, according to the casting molding method for microstructures according to the present invention, a microstructure having a large number of minute structures without causing defects or defects in the shape of the molded product or damage to the casting mold. The body can be cast.
[0030]
FIG. 4 shows another embodiment of the microstructure casting apparatus of the present invention. This microstructure casting apparatus has an upper plate core 28 attached to the cavity side of the upper plate 16 of the casting mold 10 of the microstructure casting apparatus shown in FIG. An arbitrary shape can be selected for the upper plate core 28, whereby an arbitrary shape can be formed on the upper side of the microstructure 19.
[0031]
FIG. 5 shows another embodiment of the casting mold of the microstructure casting apparatus of the present invention. The casting mold 10 shown in FIG. 5 has a vibration source 22 attached to the side plates 15 on both sides. Thus, the attachment position of the vibration source 22 is not limited to the back side of the core 20 as shown in FIG. 1, and any position can be selected as long as a release effect can be obtained. The design flexibility of the casting mold 10 is great.
[0032]
Next, the microstructure 19 formed by the above-described method for casting a microstructure according to the present invention will be described with reference to FIGS. 1, 3 and 6 while showing a specific form. The nozzle plate 101 shown in FIG. 6A was formed by the method for casting a microstructure according to the present invention. The nozzle plate 101 has an outer dimension of 0.5 mm × 2 mm × 10 mm, and cylindrical minute holes 102 having a diameter of 0.06 mm are arranged at a pitch of 0.09 mm. In this case, a tungsten alloy is used for the core 20, and the height of the minute protrusion 20 b of the core 20 is 4 mm. Silicon rubber KE-12 (manufactured by Shin-Etsu Silicone) is cast into the casting mold 10 provided with the core 20 (step 303) and cured (step 304) to form a cavity. Thereafter, quinnate 999S (manufactured by Nippon Zeon), which is a urethane resin, was injected (step 307) and cured (step 308), and the nozzle plate 101 was molded. At the time of mold release (step 308), an ultrasonic vibration having a frequency of 16 KHz and an amplitude of 5 μm is applied to the core 20 from the vibration source 22, and the nozzle plate 101 is separated from the casting mold 10 to obtain a good molded body. It was. The diameter accuracy of the cylindrical minute holes 102 arranged in the molded nozzle plate 101 is ± 0.01 mm, and the pitch accuracy is ± 0.015 mm, and a highly accurate microstructure can be obtained.
[0033]
Also, the ink discharge head 104 for the ink jet printer shown in FIG. 6B was formed. The ink discharge head 104 has outer dimensions of 10 mm in width, 10 mm in length, and 1 mm in height, and an ink channel 105 having a width of 0.03 mm, a height of 0.03 mm, and a pitch of 0.06 mm is formed. Further, the ink flow path wall 106 formed between the ink flow paths 105 has a width of 0.03 mm and a height of 0.03 mm. Here, the core 20 was made of a nickel alloy, the height of the minute protrusion 20 b was set to 2 mm, and the core 20 was placed in the casting mold 10. Silicon rubber KE-12 (manufactured by Shin-Etsu Silicone) is cast into the casting mold 10 (step 303) and cured (step 304) to form a cavity, and then a urethane resin quinnate 999S (manufactured by ZEON Corporation) Was injected (step 307) and cured (step 308), and the ink discharge head 104 was molded. At the time of mold release (step 308), an ultrasonic vibration having a frequency of 16 KHz and an amplitude of 5 μm is applied to the core 20 from the vibration source 22 to separate the ink discharge head 104 from the casting mold 10 to obtain a good molded body. did it. The formed ink flow path 105 and the ink flow path wall 106 have a width dimensional accuracy of ± 0.007 mm and a pitch accuracy of ± 0.01 mm, and a highly accurate microstructure having no shape defect was obtained.
[0034]
【The invention's effect】
As described above, according to the casting molding method and the casting mold of the microstructure of the present invention, a part of the cavity that becomes the mold of the microstructure is formed in the casting mold by the elastic material. Since the core and elastic material are vibrated when releasing the molded product that is a structure, the molded product does not cause defects in the shape of the molded product, breakage, or damage to the casting mold. Parts with many structures can be manufactured with high accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a microstructure casting apparatus according to the present invention.
FIG. 2 is an enlarged schematic view of the lower left side of the microstructure casting apparatus according to the present invention.
FIG. 3 is a view showing a method for casting a microstructure according to the present invention.
FIG. 4 is a schematic view showing a microstructure casting apparatus according to the present invention.
FIG. 5 is a schematic view showing a casting mold of a microstructure casting apparatus according to the present invention.
FIG. 6 is a schematic view showing a microstructure.
FIG. 7 is a view showing a conventional method for casting a microstructure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Casting mold 11 Chamber 12 Board | substrate 13 Buffer member 14 Bottom plate 15 Side plate 15a, 25a Power line drawing port 16 Upper plate 17 Clamp mechanism 18 Material injection port 19 Micro structure 20 Core 20a Base 20b Micro projection 21 Elastic member 22 Vibration source 23 Power line 24 Vibration power source control device 25 Bush 26, 27 Screw 28 Upper plate core 101 Nozzle plate 102 Cylindrical minute hole 103 Cylinder inner side surface 104 Ink ejection head 105 Ink channel 106 Ink channel wall

Claims (7)

In a casting method of a microstructure that forms a microstructure by injecting a molding material into a molding space formed in a mold,
An elastic member having a shape complementary to the microstructure is arranged in the mold to form the molding space,
Injecting the molding material into the molding space to form the microstructure,
A method for casting a microstructure, wherein the elastic member is vibrated to separate the microstructure from the elastic member . In the casting molding method of a microstructure that forms a microstructure by injecting a molding material into a mold,
A core member having a predetermined shape is arranged in the mold, and an elastic member is injected into the mold in which the core member is arranged to form a molding space corresponding to the shape of the microstructure. And the process of
A second step of injecting a molding material into the molding space formed in the molding die to form the microstructure.
A third step of vibrating the core member to separate the microstructure from the core member and the elastic member;
A method for casting a microstructure, comprising:   In the third step of separating the microstructure from the core member and the elastic member, the core member is vibrated after the microstructure is cured, and a contact interface between the microstructure and the core member is obtained. The method for casting a microstructure according to claim 2, wherein the method is a step of separating by reducing adhesion. In a casting mold of a microstructure that injects a molding material to form a microstructure,
An upper plate, a side plate and a bottom plate forming an internal space;
A core member having a predetermined shape disposed in the internal space;
An elastic member that is injected into the space where the core member is disposed and forms a molding space in the internal space together with the core member to mold the microstructure.
A vibration source that is installed in a portion of the core member that does not face the molding space and applies vibration to the core member during separation of the microstructure;
A clamp mechanism for fixing and holding the upper plate and the side plate;
A mold for forming a microstructure characterized by comprising:   5. The mold casting mold for a microstructure according to claim 4, wherein the core member has a protrusion corresponding to the groove of the microstructure, and the protrusion has a curved base.   5. The microstructure casting mold according to claim 4, wherein the vibration source is an ultrasonic vibrator.   5. The microstructure casting mold according to claim 4, wherein the elastic member is silicon rubber.

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