JP2849299B2 - Manufacturing method of composite precision molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a resin layer made of a reaction-curable resin on a glass or metal substrate, and forming optical parts such as small-diameter aspherical lenses, microlenses, lens arrays, and diffracted photons. The present invention relates to a method of manufacturing a composite precision molded product for manufacturing a part requiring precise dimensional accuracy.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 52-2565.
As disclosed in Japanese Patent Application Laid-Open Publication No. 1-6 and JP-A-54-6006, a resin layer made of a photo-curable resin or a thermosetting resin is formed on a glass substrate as a base material, and only a glass material is formed. A method of creating an aspherical lens that is difficult to process is known. This method is generally called a replica molding method. According to this replica molding method, since optical components such as aspherical lenses for cameras and diffractive photons having a fine shape need only be molded with a resin layer having a small thickness deviation with respect to a glass substrate, the replica molding method is relatively simple. It can be easily formed. However, for example, FIGS.
As shown in (d), the center thickness is 100 μm on the glass substrate.
As described above, when the thickness deviation of the resin layer is large, such as when a microlens having an outer diameter of about 0.2 mm to several millimeters is formed, transfer defects such as sink marks and distortion caused by curing shrinkage of the resin layer and In addition, there is a problem that molding defects such as mixing of air bubbles occur. Here, reference numeral 50 in the figure indicates a mold for molding, and FIGS.
The resin 54 of the ultraviolet curing type is supplied to the cavity 52 formed at 0, and the resin 54 is cured while being sandwiched between the surface of the mold 50 and the glass substrate 56, so that the resin 54 is placed on the glass substrate 56. 4 shows a procedure for forming the micro lens 58.

[0003] As a method of solving the above-mentioned molding defects, for example, JP-A-60-56544 and JP-A-Hei.
As disclosed in Japanese Patent Publication No. 171932, there is known a method of performing molding again using a defective molded article processed in the first molding as a base material. Specifically, FIG.
As shown in FIGS. 11E to 11G, a small amount of the resin 54 is supplied to the cavity 52 of the mold 50, and a thin layer of the resin is formed into the sink portion 60a of the defective molded product 60 as the second molding. This compensates for the defective shape of the sink portion 60a. Thus, if the molding process is performed twice, the thickness of the resin layer at the time of the second molding process becomes very thin,
The curing shrinkage of the resin can be suppressed to a minute amount, and the surface accuracy of the completed lens can be improved.

[0004]

However, in such a case where the molding is performed twice, the same mold is used twice, so that the life of the expensive mold is shortened, and as a result, the cost of the product is increased. There was a problem. Further, in the case of mass production, there is a problem that the cost of the product also increases because the scale of the molding apparatus is large and expensive.

Japanese Patent Application Laid-Open No. 55-132221 discloses a method in which, instead of performing molding twice, a resin is light-cured while applying pressure to a mold and a glass substrate, and the product is processed in one molding. Is disclosed. However, in this case, it is difficult to determine the molding conditions due to the short photocuring time of the resin and the difficulty in making the illuminance in the mold uniform, and there is a problem that mass production is difficult.

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method of forming a resin layer having a relatively large thickness deviation on a base material. It is an object of the present invention to provide a method for manufacturing a composite precision molded product in which layers can be accurately and inexpensively manufactured.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems and achieve the object, a method of manufacturing a composite-type precision molded product of the present invention comprises forming a resin layer on a surface of a base material made of a predetermined material. A method of manufacturing a composite-type precision molded product for manufacturing a molded product in which the base material and the resin layer are integrated by molding, wherein the mold is formed into a mold for molding the resin layer. Filling a cavity formed in an inverted shape with respect to the completed shape of the resin layer with a reaction curable liquid resin having substantially the same volume as the cavity and curing the resin to form a first resin layer; In the molding step 1, a small amount of the reaction-curable liquid resin is dropped on the open-side cured surface of the first resin layer, and the base material is placed on the reaction-curable liquid resin and cured. A second molding step of forming a second resin layer; It is characterized by comprising a releasing step of releasing the molded article from the first resin layer and the second resin layer are integrated.

[0008]

As described above, since the method for producing a composite precision molded article according to the present invention is constituted, in the first molding step, the surface of the resin layer on the open side of the cavity is cured and shrunk. Thus, even if the resin layer shrinks, the cavity and the resin layer do not separate, and the surface of the first resin layer on the side in contact with the cavity is accurately formed into a desired shape. Then, by forming the second resin layer for joining the first resin layer and the base material in the second molding step, the composite precision molded product can be easily and accurately processed. Also, 2
No matter how many times the molding process is performed, the surface of the cavity itself remains 1
Because it is used only once, it does not shorten the life of the mold,
A composite precision molded product can be manufactured at low cost.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a procedure of forming a microlens by applying the method of manufacturing a composite precision molded product according to one embodiment.

In FIG. 1, a mold 10 disposed in a manufacturing apparatus is made of glass, metal, plastic, or the like, and has a cavity formed on a top surface thereof with a high optical surface precision by polishing or cutting in advance. A part 12 is formed. The cavity portion 12 is formed in a shape inverted from the shape required for the completed microlens.

Next, a procedure for forming a microlens as an example of a composite precision molded product will be described with reference to FIG. First, as shown in FIG. 1B, a liquid ultraviolet curable resin 14 is supplied to the cavity 12 of the mold 10 so that the liquid level just fills the cavity 12.
At this time, it is desirable that the liquid level of the ultraviolet-curable resin 14 coincides with the mold surface 10a around the cavity 12 as shown in FIG. As a method for adjusting the height of the liquid level with high precision, a method of controlling the volume of the resin 14 with a high-precision dispenser, supplying the resin 14 in an excessive amount, and applying a liquid protruding from the cavity 12 to a doctor blade or the like A method of scraping with a jig or the like can be considered.

Next, as shown in FIG. 1 (c), the resin 14 in the cavity 12 is irradiated with ultraviolet light from above.
To cure. Here, as in the conventional example shown in FIG. 11, the resin 54 is supplied so as to protrude from the cavity 52, and when the substrate 56 is placed on the resin 54 and cured, when the resin 54 cures and contracts. Peeling occurs at the interface between the mold 50 and the resin 54, causing sink failure or the like in the resin 54. This is because a silane coupling process or the like is usually performed between the substrate 56 and the resin 54 in order to improve the adhesion, whereas the interface between the mold 50 and the resin 54 facilitates the release. This is because the adhesive strength is set to be weak. That is, peeling does not occur at the interface between the substrate 56 and the resin 54 bonded with a strong adhesive force, and peeling occurs at the interface between the mold 50 and the resin 54 bonded with a weak adhesive force, causing sink marks or the like. That is. In contrast, FIG.
In the state shown in (c), the liquid surface 14a of the resin 14 is open to the air, so that the liquid surface 14a can freely contract without being restricted by anything. for that reason,
When the resin 14 is cured in the state shown in FIG. 1C, even if the resin 14 shrinks, the interface 1 between the resin 14 and the air is reduced.
Only a defect such as sink occurs at 4a, and no sink defect occurs at the interface between the mold 10 (cavity 12) and the resin 14. Therefore, the surface shape of the microlens is formed into a shape in which the surface shape of the cavity 12 is accurately transferred.

Next, as shown in FIG. 1 (d), a small amount of a liquid ultraviolet curable resin 14 is dropped onto the interface 14a which has already been cured and has a sink mark failure or the like. The transparent glass substrate 16 is placed as shown in FIG. Then, in this state, the resin 14 is irradiated with ultraviolet rays from above the glass substrate 16 to be cured. At this time, since the resin 14 in the cavity 12 has already been cured, in the second molding step, a thin layered resin 1 along the glass substrate 16 is formed.
4 only cures, the amount of cure shrinkage is extremely small, and new peeling occurs at the interface between the cavity 12 and the resin 14 or the already cured cavity 12
It does not cause any distortion in the inner part.

In FIG. 1D, the resin is dropped on the interface 14a, but the method of supplying the resin is not limited to this. For example, as shown in FIG.
The resin may be dropped on the mold 6, and the mold 10 may be covered from above. Alternatively, as shown in FIG. 3, the mold 10 and the glass substrate 16 are opposed to each other. It may be supplied by using or by inserting a needle of a dispenser.

Then, finally, as shown in FIG. 1 (f), the mold is released, whereby a microlens having a molding surface with good precision is completed. In the above description, the resin 14
Has been described as a case where a transparent glass substrate 16 is used as the substrate. However, as the resin material, in addition to the UV-curable resin, a thermosetting or room temperature-curing epoxy, silicone, polyester, Urethane or a resin curable by active energy rays other than ultraviolet rays, for example, infrared rays, visible rays, electron rays, X-rays and the like may be used. Resin materials include acrylics such as urethane acrylate, epoxy acrylate, polyester acrylate, and polyether acrylate, as well as a single composition in which a photoinitiator is mixed with epoxy, silicone, polyester, urethane, or a mixture of several types of monomers. Compositions and the like can be used. The substrate may be a metal plate, a plastic plate, or the like.

The manufacturing method of the present invention can be applied not only to the above-mentioned microlens manufacturing but also to a diffraction grating having a repetitive shape of irregularities shown in FIG. 4, a mountain-shaped blazed grating shown in FIG. 7, a reflection prism as shown in FIG. 7, a groove part for an ink nozzle for a printer as shown in FIG. 8, a concave lens as shown in FIG. Applicable to the production of large parts.

Incidentally, a film such as an anti-reflection film, a reflection film, or a hard coat film may be applied to these molded parts later,
As shown in FIG. 10, resin layers may be formed on both surfaces of the substrate. Next, a specific example in which an optical component is actually formed based on the manufacturing method of the above-described embodiment will be described. (First example) The material of the mold is phosphor bronze, and the diameter is 1.8 mm.
A convex lens mold having a radius of curvature of 1.6 mm and a surface accuracy of one Newton ring or less as shown in FIG. 1A was prepared by a precision cutting method. Next, a urethane acrylate ultraviolet curing resin having a viscosity of 3500 cps is dropped and filled just as shown in FIG.
Ultraviolet rays having an illuminance of 30 mW / cm ² were irradiated for 30 seconds to cure the resin in the cavity. Next, as shown in FIG. 1 (d), a very small amount of the same urethane acrylate-based UV-curable resin as above is dropped on the cured surface, and the surface of the resin is preliminarily treated with a silane coupling agent to obtain a transparent and thick resin. A 1 mm glass substrate was placed so that bubbles were not involved. Then, as shown in FIG.
After irradiating the ^second UV for 2 minutes, subjected to release as shown in FIG. 1 (f), thereby completing the composite lens. When the surface accuracy of this convex lens was measured, it was one Newton ring, and good transferability was exhibited. (Second example) The mold material is aluminum and the cross-sectional shape is 2
A groove having a shape of 00 μm square and a length of 10 mm as shown in FIG. 6 was formed by precision cutting. Next, as shown in FIG. 1 (b), the same ultraviolet curable resin as in the first example was dropped and filled so as to just fill the cavity of the mold.
The resin in the cavity was cured by irradiating with ultraviolet rays of mW / cm ² for 30 seconds. Next, as shown in FIG. 1 (d), a very small amount of the same ultraviolet curable resin as above is dropped on the cured surface, and a transparent glass plate having a thickness of 1 mm, the surface of which is pre-treated with a silane coupling agent, is placed on the resin. The substrate was placed so that bubbles were not involved. Then, as shown in FIG. 1 (e), ultraviolet rays of 30 mW / cm ² were again irradiated for 2 minutes,
The mold was released as shown in (f) to complete the composite groove part. Observation of the surface of the composite groove component with a microscope revealed that good transferability was exhibited. (Comparative Example 1) Using exactly the same mold and UV-curable resin as in the first example described above, as shown in FIG. 11 (b), the resin was dropped and filled so as to slightly overflow the cavity of the mold. A transparent glass substrate having a thickness of 1 mm, the surface of which was pretreated with a silane coupling agent in advance, was placed on the glass so as not to involve bubbles. Then, as shown in FIG. 11C, the mold was released by irradiating with ultraviolet rays of 30 mW / cm ² for 2 minutes to complete the composite convex lens. Observation of this convex lens revealed that sink marks were generated on the lens surface, and the surface precision was poor at 20 or more Newton rings and the transferability was poor. (Comparative Example 2) Using the same mold and UV-curable resin as in the above second example, the resin was dropped and filled to an extent slightly overflowing the cavity of the mold, and the surface was previously silane-coupled onto this resin. Transparent and 1m thick pretreated with agent
m glass substrate was placed so as not to involve bubbles. Then, the mold was released by irradiating with ultraviolet rays of 30 mW / cm ² for 2 minutes to complete a composite groove component as shown in FIG. Observation of the surface of this composite groove component with a microscope revealed that several sink marks with a diameter of about 0.2 mm were present, indicating poor transferability.

As described above, according to the manufacturing method of one embodiment, it is possible to manufacture a highly accurate composite molded article without shortening the life of the mold. The present invention can be applied to a modification or modification of the above embodiment without departing from the gist of the invention.

[0019]

As described above, according to the method of manufacturing a composite precision molded article of the present invention, in the first molding step, the surface of the resin layer on the open side of the cavity is cured and contracted. Even when the resin layer shrinks, the cavity and the resin layer do not separate, and the surface of the first resin layer on the side in contact with the cavity is accurately formed into a desired shape. Then, by forming the second resin layer for joining the first resin layer and the base material in the second molding step, the composite precision molded product can be easily and accurately processed. Even if molding is performed twice, the surface of the cavity itself is used only once, so that the life of the mold is not shortened, and a composite precision molded product can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a procedure for forming a microlens based on a manufacturing method according to one embodiment.

FIG. 2 is a view showing another method for supplying a resin.

FIG. 3 is a view showing another method for supplying a resin.

FIG. 4 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 5 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 6 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 7 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 8 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 9 is a diagram showing an example of an optical component manufactured by the manufacturing method according to one embodiment.

FIG. 10 is a diagram showing an example of an optical component manufactured by the manufacturing method of one embodiment.

FIG. 11 is a view showing a conventional method for producing a composite molded article.

[Explanation of symbols]

 10,50 mold 12,52 cavity 14,54 UV curable resin 16,56 glass substrate 60 defective molding

Claims (1)

(57) [Claims] 1. A composite precision molded article for producing a molded article in which the base material and the resin layer are integrated by molding a resin layer on the surface of a base material made of a predetermined material. In a manufacturing method, a cavity formed in a mold for molding and processing the resin layer and formed into a shape inverted from a completed shape of the resin layer has a reaction hardening having substantially the same volume as the cavity. Filling and curing a mold liquid resin, a first molding step of forming a first resin layer, and a small amount of the reaction-curable liquid resin is dropped on a cured surface on an open side of the first resin layer, A second molding step of mounting and curing the base material on the reaction-curable liquid resin to form a second resin layer; and forming the base material and the first resin layer from the mold. A mold release step of releasing the molded product in which the second resin layer is integrated. Characteristic method for manufacturing complex-type precision molded products.