JP2016155307A - Molding method and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding method and a molded article which can effectively suppress generation of bubbles using a simple system without prolonging a molding cycle.SOLUTION: Since a projection MD1d first comes into contact with a photocurable resin PL supplied onto a substrate ST at the time of relative approach to a mold member MD1, a position where the flow of the photocurable resin PL is started can be controlled. Accordingly, as contact occurs always at a defined position, the flow of the photocurable resin PL is started from the contact point, whereby the amount of resin moving around can be adjusted, and a bubble can be prevented from being enclosed in the resin even after closing the mold member MD1.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a molding method and a molded product suitable for molding a molded product such as an optical element or a microchip.

  In recent years, there has been an attempt to use an energy curable resin such as a photocurable resin or a thermosetting resin in order to mold a molded product such as an optical element or a microchip. Since the energy curable resin has a property of being cured in a short time by applying energy, it is expected that a highly accurate molded product can be mass-produced at a low cost by using the energy curable resin. In particular, one type of optical element and microchip includes a product obtained by attaching a molded energy curable resin on, for example, a plate-like substrate. Such a product can be obtained by laminating a separately molded resin and a base material, for example, by dropping an energy curable resin on the base material and then covering the mold, and supplying energy from the outside, A product in which the resin molded by the mold is adhered to the base material can be obtained with fewer steps.

  By the way, in the process of applying the energy curable resin on the base material and covering the mold from above to perform the clamping operation, air bubbles may be involved when the mold comes into contact with the base material, which may lead to molding defects. is there. As measures against such entrainment of bubbles, for example, there are measures such as performing a mold clamping operation in a vacuum state, and applying energy curable resin on both surfaces of the substrate and the mold. However, the former measure requires a vacuum environment in which the mold is hermetically shielded. On the other hand, in the latter measure, before the application of the energy curable resin, both the base material and the mold application surface are directed upward in the direction of gravitational acceleration, and in the subsequent molding, the base material and the mold application surface face each other. Therefore, the configuration for driving the mold is complicated. Therefore, all of the conventional measures cause an increase in cost and an extension of the molding cycle.

  On the other hand, in Patent Document 1, when the template is approached in an inclined state with respect to the substrate, and approaches a predetermined distance, a resist solution is supplied from the side where both approach, and then the template is closed with respect to the substrate. Thus, a technique for developing a resist solution while suppressing entrainment of bubbles by utilizing a capillary phenomenon has been disclosed.

JP 2011-54755 A

  However, applying the technique of Patent Document 1 to supply an energy curable resin between the base material and the mold, the mold is inclined with respect to the base material, and the energy curable resin is However, there is a risk that contamination due to adhesion of the resin to the outer periphery of the mold may occur, or the resin may not be appropriately supplied to the transfer surface depending on the surface energy difference between the mold and the substrate. In addition, if the capillary phenomenon is used for supplying the energy curable resin, it takes a considerable time and the molding cycle is extended.

  The present invention has been made in view of the above-described problems, and provides a molding method and a molded product that can effectively suppress the generation of bubbles without using a simple facility and extending a molding cycle. Objective.

The molding method of the present invention is a molding method for molding a molded article by supplying an energy curable resin between a mold and a substrate that are relatively movable so as to approach or separate from each other.
A plurality of irregularities and protrusions are formed on the transfer surface of the mold, and the height of the protrusions in the relative movement direction is greater than the maximum depth of the irregularities,
When the energy curable resin is supplied between the mold and the base material, and the mold and the base material are brought closer to each other along the relative movement direction, the protrusions are formed on the energy curable resin. After the contact, the plurality of irregularities come into contact with the curable resin, thereby controlling the flow of the energy curable resin generated between the mold and the substrate.

The molding method according to the present invention is a molding method in which an energy curable resin is supplied between a mold and a substrate to mold a molded product,
By supplying the energy curable resin to one of the mold and the base material, bringing the other bent portion into contact with the energy curable resin, and then extending the other bending, The flow of the energy curable resin generated between the base material and the base material is controlled.

  According to the present invention, it is possible to provide a molding method and a molded product that can effectively suppress the generation of bubbles without using a simple facility and extending the molding cycle.

It is a perspective view which shows the manufacturing apparatus of the optical element in this embodiment. It is a figure which expand | deploys and shows the manufacturing apparatus of an optical element in the circumferential direction. It is a perspective view of transfer surface MD1a. It is the figure which looked at type | mold member MD1 'concerning the comparative example and base-material holding member MD2 from the direction orthogonal to a relative movement direction. It is the figure which looked at type | mold member MD1 concerning this Embodiment and base-material holding member MD2 from the direction orthogonal to a relative movement direction. It is a figure which shows the flow state of photocurable resin PL adhering on the base material ST in the 1st process part A over time about a comparative example. It is a figure which shows the flow state of the photocurable resin PL adhering on the base material ST in the 1st process part A about this Embodiment with time. It is a figure which shows the manufacturing apparatus of the optical element concerning another embodiment.

  Examples of the molded product molded in the present invention include an optical element and a microchip. The substrate is preferably a part of the molded product after molding. Examples of the “optical element” include a diffraction grating and a moth-eye element having a concavo-convex structure having a wavelength of visible light or less. Examples of the “energy curable resin” that can be used in the present invention include a photocurable resin and a thermosetting resin. In the case of a photocurable resin, the resin is cured by supplying light of a predetermined wavelength as energy, and in the case of a thermosetting resin, the resin is cured by supplying heat as energy.

  When using a photocurable resin as the energy curable resin, it is preferable that at least one of the mold and the substrate is formed of a light transmissive material. Further, when it is necessary to bend the mold, it is desirable to use flexible silicone (PDMS) or a film-like resin.

  When a thermosetting resin is used as the energy curable resin, an electric heater, a halogen heater, or the like can be used as an energy supply source. In this case, the mold and the substrate are desirably made of metal or glass. Further, when a glass mold and a halogen heater are used in combination, it is desirable that an infrared absorbing material is formed on the mold transfer surface (optical surface transfer surface) because heat generation is effectively generated.

  The mold is provided with a plurality of projections and depressions. The height of the protrusion in the relative movement direction is larger than the maximum depth of the unevenness. Concavities and convexities are those in which the structure formed by transferring this can exhibit the original function (for example, diffraction function) in the molded product. On the other hand, even if “projection” is transferred and molded, the same function cannot be obtained. is there. The protrusions may be formed independently of the unevenness, or may be formed as a part of the unevenness as long as the function of the structure transferred by the unevenness is not impaired. The unevenness is preferably a periodic repeating structure such as a line and space structure. The protrusions may be independent shapes such as a conical shape, a quadrangular pyramid shape, and a rod shape, or may be continuous at a certain height like a blade. However, it is preferable that the portion of the protrusion that first contacts the energy curable resin is sharp. The protrusions preferably have a height in the relative movement direction of the mold and the substrate of 1 μm or more and a maximum width orthogonal to the relative movement direction of 1 μm or more. It is preferable to make the surface energy smaller than the surface energy of the substrate to which the energy curable resin adheres, such as by using a water repellent treatment on the transfer surface of the mold or using a mold material having a small surface energy.

  Embodiments according to the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for carrying out the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a perspective view showing an optical element manufacturing apparatus capable of performing the molding method of the present invention. FIG. 2 is a diagram showing an essential part of the optical element manufacturing apparatus shown in FIG. 1 developed in the circumferential direction. In the manufacturing apparatus, the first disk DC1 and the second disk DC2 are arranged coaxially with a gap therebetween. The center of the first disk DC1 and the second disk DC2 is connected to the rotation shaft SFT through a spline or the like so as not to rotate relative to the rotation shaft SFT. The first disk DC1 and the second disk DC2 are driven to rotate synchronously.

  A plurality (eight in this case) of circular openings DC1a are formed in the first disk DC1, and a cylindrical mold member (type) MD1 is fixed in the circular openings DC1a. The lower end of the mold member MD1 has a rectangular plate shape and has a transfer surface MD1a on its lower surface.

  FIG. 3 is a perspective view of the transfer surface MD1a, but is partially exaggerated. In FIG. 3, the transfer surface MD1a forms a line-and-space structure MD1c, which is a plurality of irregularities, in the center of the rectangular plane MD1b. Further, a triangular pyramid-shaped protrusion MD1d is formed in the vicinity of the line and space structure MD1c. The height H of the protrusion MD1d in the relative movement direction is greater than the maximum depth (here, uniform) D of the line and space structure MD1c. As an example, the depth D is 100 nm or less, and the height H is 10 μm to 100 μm. The mold member MD1 is formed of transparent silicone (PDMS). Specifically, the mold member MD1 can be formed by transferring a mother transfer surface (not shown) of the mother mold to silicone.

  The second disk DC2 is formed with a plurality of (eight in this case) circular openings DC2a so as to have the same arrangement as the circular openings DC1a, and in the circular openings DC2a, a cylindrical substrate holding member is formed. MD2 is arranged so as to be movable in the axial direction of the rotation axis SFT. The substrate holding member MD2 has a function of holding a rectangular plate-like substrate ST corresponding to the transfer surface MD1a on the upper surface thereof. The base material ST and the base material holding member MD2 are preferably capable of transmitting light.

  A shielding part SH is formed so as to cover a part of the first disk DC1 and the second disk DC2 in the circumferential direction. On the top surface of the shielding part SH, a plurality of light sources OPS (two actually shown in FIG. 2 but three actually) are provided as energy supply sources for curing the energy curable resin that is the material of the optical element. It arrange | positions along the circumferential direction of 1 disk DC1 and 2nd disk DC2, and has faced the light emission surface below. The light source OPS is preferably provided immediately above the center trajectory of the mold member MD1 that rotates.

  On the other hand, as shown in FIG. 2, a plurality of light sources OPS (two actually shown in FIG. 2 but three actually) are arranged below the second disk DC2 so as to face the shielding part SH. Yes. The light source OPS can emit ultraviolet rays (hereinafter referred to as curing light).

  The light source OPS is controlled by the control circuit CONT, and is irradiated with curing light according to the angular positions of the first disk DC1 and the second disk DC2 (positional relationship between the mold member MD1 and the substrate holding member MD2 to be irradiated). It is preferable to adjust at least one of time and intensity of curing light.

  Below the second disk DC2, a pair of ring-shaped cam plates CP constituting a mold drive unit are fixedly arranged. As shown in FIG. 2, the cam surface CPa of the cam plate CP has a low portion CPb, an ascending slope CPc, a high portion CPd, and a descending slope CPe according to the position in the circumferential direction.

  As shown in FIG. 2, the first processing unit A, the second processing unit B, the third processing unit C, and the fourth processing unit D according to the rotational positions of the first disk DC1 and the second disk DC2. It has become. In the 1st process part A, dispenser DSP which can discharge a suitable quantity of photocurable resin is arrange | positioned. In the second processing unit B, light sources OPS are arranged in the circumferential direction. In the fourth processing unit D, an arm type robot RB for taking out the molded optical element OE is arranged.

  Here, the operation of the manufacturing apparatus and the optical element manufacturing process in the present embodiment will be described while paying attention to the pair of mold members MD1 and the base material holding member MD2. First, when the actuator AC is driven by power supply from a power source (not shown) and the rotation shaft SFT is rotated, the first disk DC1 and the second disk DC2 rotate in synchronization. Here, in the former stage in the first processing section A, the follower FW of the base material holding member MD2 is in the low portion CPb on the cam surface CPa of the cam plate CP, so that the mold member MD1 and the base material holding member MD2 are opened. Therefore, after placing the base material ST on the base material holding member MD2 by a robot arm (not shown), the photocurable resin is placed on the base material ST of the base material holding member MD2 via the dispenser DSP. PL can be dropped.

  Next, the mold member MD1 and the substrate holding member MD2 supplied with the photocurable resin PL therebetween move by the synchronous rotation of the first disk DC1 and the second disk DC2. Here, since the follower FW of the base material holding member MD2 rolls on the climbing slope CPc on the cam surface CPa of the cam plate CP, the base material holding member MD2 extends along the axial direction with respect to the mold member MD1. Gradually approach. When the follower FW reaches the high portion CPd on the cam surface CPa of the cam plate CP, both are brought into close contact with each other and the mold is clamped. Further, the mold clamping state of the mold member MD1 and the base material holding member MD2 is maintained while the follower FW rolls on the high portion CPd.

  Thereafter, the mold member MD1 and the base material holding member MD2 move to the second processing unit B by the synchronous rotation of the first disk DC1 and the second disk DC2 while maintaining the clamped state. In the second processing unit B, the light emitted from the light source OPS reaches the photocurable resin PL via the upper mold member MD1, and cures the photocurable resin PL. Since each pair of mold member MD1 and base material holding member MD2 similarly passes below the plurality of light sources OPS fixed at the same speed, this compares with the case of using individually provided light sources. Thus, uniform curing of the photocurable resin is ensured. In addition, by using a plurality of light sources OPS, a sufficient amount of light to be applied to the photocurable resin PL can be secured, and mass production by high-speed movement is possible.

  The mold member MD1 and the base material holding member MD2 that have passed through the second processing unit B move to the third processing unit C by the synchronous rotation of the first disk DC1 and the second disk DC2. Here, since the follower FW of the base material holding member MD2 rolls on the downward slope Cpe in the cam surface CPa of the cam plate CP, the base material holding member MD2 is gradually separated from the mold member MD1. The mold is opened.

  After the follower FW has finished rolling on the descending slope Cpe, the lower part CPb rolls again, so that the base material holding member MD2 is kept open with respect to the mold member MD1. At this time, since the surface energy on the transfer surface of the mold member MD1 is smaller than the surface energy of the substrate ST to which the photocurable resin adheres, the mold member MD1 can be easily released from the substrate ST. In the subsequent fourth processing section D, the arm of the robot RB is expanded and contracted to take out the optical element OE having the line and space structure formed with the transfer surface MD1a on the substrate ST and transport it to another process. Can do. Note that a new base material ST may be placed on the base material holding member MD2 at this time by the same robot RB. As described above, the operation of the manufacturing apparatus and the optical element manufacturing process have been described focusing on the pair of mold members MD1 and the base material holding member MD2, but the other mold members MD1 and the base material holding member MD2 are also sequentially shifted at different timings. Since a similar manufacturing process is followed, high-precision optical elements OE can be produced in large quantities.

  Next, the effect of this exemplary embodiment will be described with reference to a comparative example. FIG. 4 is a view of the mold member MD1 ′ and the substrate holding member MD2 according to the comparative example viewed from a direction orthogonal to the relative movement direction, and FIG. 5 is a diagram illustrating the mold member MD1 and the substrate holding member according to the present embodiment. It is the figure which looked at MD2 from the direction orthogonal to a relative moving direction. The comparative example is different from the present embodiment in that the protrusion MD1d is not provided, and other configurations are common.

  FIG. 6 is a diagram showing the flow state of the photocurable resin PL attached on the base material ST in the first processing section A over time in the comparative example, and FIG. 7 shows the first embodiment of the present embodiment. It is a figure which shows the flow state of the photocurable resin PL adhering on the base material ST in the process part A with time. Here, since the protrusion MD1d is not formed on the mold member MD1 ′ of the comparative example, the line-and-space structure MD1c with respect to the photocurable resin PL supplied on the base material ST at the time of relative approach to the mold member MD1. However, the position may not be determined due to the inclination of the mold member MD1, manufacturing error, or the like. If contact is made at the position of the mark x shown in FIG. 6 (a), the flow of the photocurable resin PL starts from this contact point, but the resin wraps around from both sides as shown in FIG. 6 (b). Therefore, as shown in FIG. 6C, there is a possibility that the bubbles BL are trapped inside. Even in the comparative example, the bubble may not be involved depending on the position of the first contact, but since the position is not fixed, there is a high uncertainty as to whether or not the bubble is involved.

  On the other hand, according to the present embodiment, the protrusion MD1d first comes into contact with the photocurable resin PL supplied on the substrate ST at the time of relative approach to the mold member MD1. Thereby, the position where the flow of the photocurable resin PL starts can be controlled. Specifically, since contact always occurs at a defined position (the position of the x mark shown in FIG. 7A), the flow of the photocurable resin PL starts from this contact point, and further comes closer. Even after the line and space structure MD1c is in contact with the photocurable resin PL, the amount of wraparound of the resin can be appropriately adjusted as shown in FIG. 7B, and as a result, the mold member MD1 as shown in FIG. 7C. It is possible to suppress the trapping of bubbles in the resin at the stage where the mold is clamped.

  FIG. 8 is a diagram illustrating an optical element manufacturing apparatus according to another embodiment. In the present embodiment, a flexible MD3 made of silicone (PDMS) is provided on the lower surface of the mold member MD1. The flexible MD3 curved in a free state is generally plate-shaped, and the left end in FIG. 8 is pin-coupled to the mold member MD1, and is attached to the mold member MD1 in a long hole MD3a formed at the right end. The fixed shaft FS is inserted. A line and space structure MD3b is formed on the lower surface of the flexible MD3 as in the above-described embodiment. However, no protrusion is formed. In the present embodiment, the substrate holding member MD2 is brought closer to the mold member MD1. Other configurations are the same as those of the above-described embodiment.

  First, in the mold open state shown in FIG. 8A, the flexible MD 3 is maintained in a state where the center is bent by its own elastic force or by gravity. From this state, after the photocurable resin PL is dropped on the base material ST, when the mold member MD1 and the base material holding member MD2 are brought relatively close to each other, first, the center of the flexible MD3 is the photocurable resin PL. First contact. If the approach is further continued, as shown in FIG. 8 (b), the flexure MD3 is extended by the pressure from the base material ST while the long hole MD3a and the fixed shaft FS move relative to each other. After the photocurable resin PL is cured in such a state, as shown in FIG. 8C, when the mold member MD1 and the base material holding member MD2 are separated from each other, the photocurable resin PL on the base material ST is formed. The line and space structure is transferred, and the flexible MD 3 returns to the original state. New molding becomes possible by exchanging the substrate ST.

  According to the present embodiment, the flexible MD3 gradually contacts the photocurable resin PL from the center of the photocurable resin PL on the substrate ST toward both sides while the flexure of the flexible MD3 is extended. Therefore, there is little risk of entrainment of bubbles. In addition, instead of the mold, the base material may be formed from a flexible material, and in the bent state, the base material may be extended after being brought into contact with the energy curable resin supplied to the mold.

  The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are apparent to those skilled in the art from the embodiments and ideas described in the present specification. It is.

A 1st processing part B 2nd processing part C 3rd processing part D 4th processing part AC Actuator CP Cam plate CPa Cam surface CPb Low part CPc Climbing slope CPd High part CPe Down slope CR Conveying part DC1 1st Disc DC1a Circular aperture DC2 Second disc DC2a Circular aperture SP Support portion DSP Dispenser FW Follower MD1 Mold member MD1a Transfer surface MD1b Rectangular plane MD1c, MD3b Line and space structure MD1d Projection MD2 Base material holding member MD3 Flexible OE Optical element OPS light source PL photo-curing resin RB robot SFT rotation shaft SH shielding part ST base material

Claims (8)

A molding method for molding a molded article by supplying an energy curable resin between a mold and a substrate that are relatively movable so as to approach or separate from each other,
A plurality of irregularities and protrusions are formed on the transfer surface of the mold, and the height of the protrusions in the relative movement direction is greater than the maximum depth of the irregularities,
When the energy curable resin is supplied between the mold and the base material, and the mold and the base material are brought closer to each other along the relative movement direction, the protrusions are formed on the energy curable resin. A molding method in which after the contact, the plurality of irregularities come into contact with the curable resin, thereby controlling the flow of the energy curable resin generated between the mold and the substrate.   The molding method according to claim 1, wherein a portion of the protrusion that first contacts the energy curable resin is pointed.   The molding method according to claim 1, wherein the protrusion has a height in the relative movement direction of 1 μm or more and a maximum width orthogonal to the relative movement direction of 1 μm or more.   The molding method according to claim 1, wherein a surface energy on a transfer surface of the mold is smaller than a surface energy of the base material to which the energy curable resin adheres.   The molding method according to claim 1, wherein the unevenness has a periodic repeating structure. A molding method in which an energy curable resin is supplied between a mold and a substrate to mold a molded product,
By supplying the energy curable resin to one of the mold and the base material, bringing the other bent portion into contact with the energy curable resin, and then extending the other bending, A molding method adapted to control the flow of the energy curable resin generated between the substrate and the substrate.   The molding method according to claim 6, wherein the other is a flexible silicone mold or a film-shaped resin mold.   A molded product molded by the molding method according to claim 1.

Images