JP2005144890A - Mold device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold device which can hold a stamper while it is aligned. <P>SOLUTION: The mold device has a fixed mold 11 having a base plate 13 with a central hole 13a formed in the central part, a cylindrical member 14 for alignment with its one end side fitted into the central hole 13a of the base plate 13, a stamper support plate 15 in which the other end side of the cylindrical member 14 is fitted into the central part, and the stamper 18 is fixed to its one surface, and a mold clamping ring 19 fixed to the base plate 13 to surround the stamper support plate 15 and a movable mold 21 which forms a cavity Ca with the fixed mold 11 while being closed. A pressing screw 32 for pressing the stamper support plate 15 toward the center of the mold clamping ring 19 is arranged in the ring 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mold apparatus for molding a base material for an information recording medium, for example.

  As this type of mold apparatus, a disk substrate molding mold apparatus 20 disclosed in Japanese Patent Laid-Open No. 9-29789 is known. As shown in FIG. 1 of the publication, the disk substrate molding die apparatus 20 includes a fixed mold 21 and a movable mold 22 and is configured to mold a disk substrate for an information recording medium. Yes. In this case, a fixed mold block 24 for fixing to the injection molding machine is attached to the fixed mold 21. A sprue bush 27 is disposed at the center of the fixed mold 21, and a stamper holder 29 is disposed on the outer periphery of the sprue bush 27. Further, a fixed-side stamper 28 is attached to one surface side of the fixed mold 21 in a state of being positioned (centered) by a stamper holder 29.

  The movable mold 22 includes a movable mold body 30 in which a stamper mounting portion 31 having a circular cross section is formed, a disk-shaped stamper mounting block 32 fitted into the stamper mounting portion 31, and a movable side stamper attached to the stamper mounting block 32. 33. In this case, the stamper mounting block 32 is formed to be slightly smaller in diameter than the stamper mounting portion 31, and between the outer peripheral wall of the stamper mounting block 32 and the inner peripheral wall of the stamper mounting portion 31 is about 0.01 mm to 0.1 mm. There is a gap. The movable mold body 30 is provided with a centering mechanism 40, and this centering mechanism 40 is used to center the movable stamper 33 attached to the stamper mounting block 32. Within this range, the stamper mounting block 32 can be moved. In this case, the alignment mechanism 40 includes a plurality of centering screws 43, coil springs 44, and balls 45, respectively. The centering screw 43 is disposed in a guide hole 41 formed in the movable mold main body 30, and the ball 45 is opposed to the guide hole 41 in the movable mold main body 30 while being urged by the coil spring 44. It is disposed in the bottomed hole 42 formed at the position.

When centering the movable side stamper 33 using the centering mechanism 40, for example, the centering screw 43 is screwed in a direction in which the center of the movable side stamper 33 coincides with the center of the fixed side stamper 28. At this time, the coil spring 44 that urges the ball 45 facing the centering screw 43 is compressed. As a result, the stamper mounting block 32 moves and the movable side stamper 33 is centered. In this case, the ball 45 urged by the coil spring 44 and the tip of the centering screw 43 are brought into contact with the outer peripheral surface of the stamper mounting block 32 so that the stamper mounting block 32 is held in the centered state.
Japanese Patent Laid-Open No. 9-29789 (page 3-5, FIG. 1)

  However, the conventional disk substrate molding die apparatus 20 has the following problems. That is, in this disk substrate molding die apparatus 20, the ball 45 urged by the coil spring 44 and the tip of the centering screw 43 are brought into contact with the outer peripheral surface, whereby the stamper is mounted in the centered state. The block 32 is held. That is, the stamper mounting block 32 is held by the urging force of the coil spring 44. However, since an extremely large pressure is applied to the cavity by injection of the resin during injection molding, it is difficult to hold the stamper mounting block 32 without misalignment with the urging force of the coil spring 44 alone. Therefore, the disk substrate molding die apparatus 20 has a problem that the centered movable side stamper 33 may be misaligned again due to continuous molding.

  The present invention has been made in view of such problems, and a main object of the present invention is to provide a mold apparatus that can hold a centered stamper in that state.

  In order to achieve the above object, a mold apparatus according to the present invention comprises a base plate having a central hole with a circular cross section formed at the center thereof, and a cylindrical shape whose one end is fitted into the center hole of the base plate. An alignment member, a stamper support plate in which the other end side of the alignment member is fitted at the center thereof and a stamper is fixed to one surface thereof, and is fixed to the base plate so as to surround the stamper support plate A first mold having a closed mold clamping ring, and a second mold that forms a cavity in combination with the first mold when the mold is closed, at the center of the mold clamping ring. At least one of a pressing screw member that presses the stamper support plate toward the inner surface and a tension screw member that pulls the stamper support plate toward the inner peripheral surface of the mold clamping ring. It is arranged in the ring.

  In this case, it is preferable to form the positioning member by forming the one end side and the other end side to have different thicknesses.

  Moreover, it is preferable that the one end side is formed thinner than the other end side to constitute the alignment member.

  According to the mold apparatus according to the present invention, one end side of the alignment member is fitted into the center hole of the base plate, and the other end side of the alignment member is fitted into the center portion of the stamper support plate. Pressing of the stamper support plate toward the center of the mold clamping ring by the pressing screw member disposed on the mold clamping ring fixed to the base plate, and toward the inner peripheral surface of the mold clamping ring by the pulling screw member By pulling at least one of the stamper support plates, spiral or concentric fine irregularities (eg, groove patterns) formed on the stamper can be centered (positioned) with high precision and pressed. Since the positioning member is slightly plastically deformed by the pressing by the screw member or the pulling by the pulling screw member, the stamper support plate Without moved relative to over scan plate can be held in that position by a member for alignment. Therefore, even when a large injection pressure is repeatedly applied during injection molding, the stamper can be maintained in the centered state, and as a result, a groove pattern that is centered with high accuracy is formed even if injection molding is continued. A good base material can be continuously formed.

  Further, according to the mold apparatus according to the present invention, the one end side and the other end side of the alignment member are formed to have different thicknesses, so that the position of both is equal to that of the configuration in which both thicknesses are equal to each other. Since the alignment member can be easily deformed, the stamper support plate can be moved and centered with a small force. Therefore, the stamper can be easily centered.

  Further, according to the mold apparatus according to the present invention, since the one end side of the alignment member is formed thinner than the other end side, the one end side can be easily deformed. Even if one end side of the alignment member fitted in the center hole is deformed and galling occurs with the inner peripheral surface of the center hole, the alignment member can be easily pulled out from the base plate while being deformed again. As a result, the maintenance work of the first mold and the replacement work of the positioning member can be easily performed.

  Hereinafter, the best mode of a mold apparatus according to the present invention will be described with reference to the accompanying drawings.

  First, a disk-shaped substrate D (hereinafter also simply referred to as “substrate D”) formed by the mold apparatus according to the present invention will be described. A base material D shown in FIG. 1 is a base material for an optical recording medium (information recording medium) such as a CD (Compact Disc) or a DVD (Digital Versatile Disc), and uses a mold apparatus 1 described later. It is molded by injection molding a resin (for example, polycarbonate). In this case, the base material D is formed in a disk shape (flat plate shape) having a diameter of about 120 mm and a thickness of about 1.2 mm, for example. In addition, a ring-shaped protrusion Dr that is used when a resin is dropped onto the substrate D in the step of forming a resin layer on the surface of the substrate D is formed at the center of the substrate D. Further, a groove pattern (not shown) having an arrangement pitch of, for example, 0.32 μm is formed on the surface of the substrate D (the upper surface in the figure).

  Next, the configuration of the mold apparatus 1 will be described with reference to the drawings. The mold apparatus 1 shown in FIG. 2 includes a fixed mold 11 and a movable mold 21 that can move toward and away from the fixed mold 11, and both molds 11 in a closed state. The base material D shown in FIG. 1 can be molded by injecting the molten resin into the cavity Ca formed by the nozzle 21 from an injection molding machine (not shown). The fixed-side mold 11 corresponds to the first mold in the present invention, and as shown in FIG. 2, the mounting plate 12, the base plate 13, the alignment member 14, the stamper support plate 15, the sprue bushing 16, the stamper A holder 17, a stamper 18, and a mold clamping ring 19 are provided. As shown in FIG. 3, the mounting plate 12 is configured in a disc shape, and a central hole 12 a having a circular cross section is formed at the center thereof. The mounting plate 12 is configured to be attachable to a stationary platen in an injection molding machine (not shown). The base plate 13 is formed in a disk shape having substantially the same diameter as the mounting plate 12, and a stepped center hole 13 a having a circular cross section (circular shape) is formed at the center thereof. Further, as shown in FIG. 2, the base plate 13 is attached to the mounting plate 12 with screws 31, 31,. As shown in FIG. 3, the alignment member 14 is formed in a stepped cylindrical shape, and as shown in FIG. 2, one end side (the upper end side in the figure) is formed in the center hole 13 a of the base plate 13. It is inserted. In this case, the alignment member 14 is formed such that one end side is thinner than the lower end side.

  As shown in FIG. 3, the stamper support plate 15 is formed in a disk shape having a smaller diameter than the base plate 13, and a stepped center hole 15 a having a circular cross section is formed at the center thereof. Further, the surface of the stamper support plate 15 (the lower surface in the figure, which corresponds to one surface in the present invention and is also referred to as “mirror surface” hereinafter) is formed in a mirror shape, and the stamper 18 is fixed to the mirror surface. In this case, an air suction hole (not shown) for adsorbing and fixing the stamper 18 is formed on the mirror surface. Further, as shown in FIG. 2, the stamper support plate 15 has the other end side (the lower end side in the figure) of the alignment member 14 fitted into the center hole 15a and the back side (the upper face in the figure) is the base plate. The screw is fixed to the base plate 13 by screws 31, 31,. As shown in FIG. 3, the sprue bushing 16 is formed with a recess for inserting an injection nozzle (not shown) of an injection molding machine at the time of molding at one end (upper part in the figure). A runner 16a (center hole) is formed at the center. Further, as shown in FIG. 2, the sprue bushing 16 is fitted into and fixed to the center hole 12 a of the mounting plate 12 and the center hole 13 a of the base plate 13.

  As shown in FIG. 3, the stamper holder 17 is formed in a cylindrical shape, and is configured to be able to hold the stamper 18 at a tip portion (a lower end portion in the figure). Further, as shown in FIG. 2, the stamper holder 17 is fitted into a gap between the sprue bushing 16, the alignment member 14 and the stamper support plate 15 while holding the stamper 18. As shown in FIG. 3, the stamper 18 is formed in a disc shape as a whole, and an insertion hole 18 a for fitting the tip end portion of the stamper holder 17 is punched and formed at the center thereof. Further, on the surface of the stamper 18 (the lower surface in the figure), a spiral (or concentric circle) fine uneven pattern capable of forming a groove pattern with an arrangement pitch of 0.32 μm, for example, on the surface of the substrate D during molding. (Not shown) is formed. Further, as shown in FIG. 2, the stamper 18 is fixed to the stamper support plate 15 in a state where the stamper 18 is held by fitting the distal end portion of the stamper holder 17 into the insertion hole 18a.

  As shown in FIG. 3, the mold clamping ring 19 is formed in a ring shape whose inner diameter is slightly larger than the outer diameter of the stamper support plate 15, and surrounds the stamper support plate 15 as shown in FIG. The base plate 13 is screwed with screws 31, 31,. As shown in FIG. 4, the mold clamping ring 19 has eight screw holes 19 a, 19 a... For screwing a pressing screw (pressing screw member in the present invention) 32, and the mold clamping ring 19. The four insertion holes 19b, 19b,... For inserting the gauge gauges 41, 41,... For measuring the width of the gap between the inner peripheral surface and the outer surface of the stamper support plate 15 are clamped rings. 19 is formed along the direction from the outer periphery to the center. In this case, the pressing screw 32 is formed on the base plate 13 in order to align (center) the center of the stamper support plate 15 screwed to the mold clamping ring 19 and the center of the base plate 13 (center of the cavity Ca). It is used when the stamper support plate 15 is pressed toward the center.

  The movable mold 21 corresponds to the second mold in the present invention. As shown in FIG. 2, the mounting plate 22, the base plate 23, the mirror plate 24, the outer ring 25, the protruding sleeve 26, and the gate cut sleeve 27. And an ejection pin 28. The mounting plate 22 is configured in a disc shape so that it can be mounted on the moving side platen of the injection molding machine. The base plate 23 is formed in a disc shape having substantially the same diameter as the mounting plate 22 and is attached to the base plate 23 by screws 31, 31,. The surface of the mirror plate 24 (upper surface in the figure) is formed in a mirror shape and is formed in a disk shape as a whole, and is attached to the mounting plate 22 by screws 31, 31,. The outer peripheral ring 25 is formed in a cylindrical shape and is fitted on the outer periphery of the mirror plate 24. The protruding sleeve 26 is formed in a cylindrical shape, and is slidably disposed in center holes formed in the central portions of the mounting plate 22, the base plate 23, and the mirror plate 24. The gate cut sleeve 27 is formed in a cylindrical shape as a whole, and has a convex portion for gate cut formed at the tip (the upper end in the figure), and is slidably disposed in the protruding sleeve 26. It is installed. The protruding pin 28 is formed in a cylindrical shape and is slidably disposed in the gate cut sleeve 27.

  Next, a method for assembling the fixed mold 11 and the movable mold 21 in the mold apparatus 1 will be described with reference to the drawings.

  When assembling the fixed mold 11, first, one end side (upper end side) of the alignment member 14 is fitted into the lower portion of the center hole 13 a of the base plate 13 in the direction shown in FIG. Next, the stamper support plate 15 is moved in the direction indicated by (2), and the other end side (lower end side) of the alignment member 14 is fitted into the center hole 15a of the stamper support plate 15. Next, the back surface of the stamper support plate 15 is brought into contact with one surface (lower surface) of the base plate 13, and in this state, the stamper support plate 15 is screwed to the base plate 13 with screws 31. At this time, the outer peripheral surface on one end side of the alignment member 14 and the inner peripheral surface forming the central hole 13a in the base plate 13 are in close contact (or substantially in close contact), and the other end side of the alignment member 14 The outer peripheral surface of the stamper and the inner peripheral surface forming the center hole 15a in the stamper support plate 15 are in close contact (or substantially in close contact), so that the center of the base plate 13 and the center of the stamper support plate 15 are made to coincide with each other with high accuracy. It is done. That is, it is centered with high accuracy. Next, after screwing the pressing screws 32, 32... Into the screw holes 19 a, 19 a... Of the mold clamping ring 19, the mold clamping ring 19 is moved in the direction shown in (3). The one end face (upper end face) is screwed with a screw 31 in a state where the one end face (upper end face) is in contact with one surface of the base plate 13. Subsequently, the mounting plate 12 is moved in the direction indicated by (4), and the mounting plate 12 and the base plate 13 are screwed with screws 31. Next, the sprue bushing 16 is moved in the direction indicated by (5), and the sprue bushing 16 is fitted and fixed in the center hole 12a of the mounting plate 12 and the center hole 13a of the base plate 13. Next, after the tip end portion of the stamper holder 17 is fitted and held in the insertion hole 18a of the stamper 18, the stamper holder 17 is moved in the direction indicated by (6), and the sprue bushing 16, the alignment member 14 and the stamper are moved. The stamper holder 17 is fitted into the gap with the support plate 15. Thereby, the assembly of the stationary mold 11 is completed.

  In this case, for example, the stamper support plate is formed when the insertion hole 18a is punched and formed with the center being displaced with respect to the center of the stamper 18 (virtual center of the uneven pattern formed on the stamper 18). Despite the fact that 15 is centered with high accuracy with respect to the base plate 13, the center of the stamper may be misaligned with respect to the base plate 13 due to factors other than the assembly accuracy of the mold. For this reason, in order to center the stamper 18 with respect to the base plate 13, the position of the stamper support plate 15 is finely adjusted. At this time, as shown in FIG. 4, the pressing screws 32, 32... Are screwed in until the front end portion comes into contact with the outer peripheral surface of the stamper support plate 15. Next, the gauge gauges 41, 41,... Are inserted into the insertion holes 19b, 19b,. Subsequently, the misalignment amount and direction between the virtual center and the center of the base plate 13 in the concavo-convex pattern of the stamper 18 fixed to the stamper support plate 15 are measured using, for example, an optical measuring device. In this case, as shown in FIG. 5, for example, when the virtual center P2 of the uneven pattern in the stamper 18 is misaligned in the upper right direction in the figure with respect to the center P1 of the base plate 13, Screw the screw 32a in the direction of the arrow. At this time, the stamper support plate 15 is pressed toward the center P1 (center of the mold clamping ring 19) by screwing the pressing screw 32a. In addition, the screws 31, 31... That fasten the base plate 13 and the stamper support plate 15 and the alignment member 14 are slightly plastically deformed by pressing, and as a result, the stamper support plate 15 (stamper 18). Moves toward the center P1 (in the lower left direction). Next, while confirming the indication value of the dial gauge 41, the pressing screw 32a is screwed in until the stamper support plate 15 moves by a distance corresponding to the misalignment amount. Thereby, the alignment member 14 (stamper 18) is centered with high accuracy with respect to the base plate 13. Further, since the alignment member 14 is fitted and screwed with screws 31, 31,..., The centered alignment member 14 is securely held in that state.

  In this case, since the one end side of the positioning member 14 is formed thinner than the other end side, the positioning member 14 is pressed by the pressing screw 32 as compared with a configuration in which both thicknesses are equal to each other. Deforms easily. For this reason, the stamper support plate 15 can be moved with a small force. Therefore, the stamper support plate 15 (stamper 18) can be easily centered. In addition, since one end side can be easily deformed, for example, one end side of the alignment member 14 fitted in the center hole 13a of the base plate 13 is deformed and squeezed between the inner peripheral surface of the center hole 13a. Even if this occurs, the positioning member 14 can be easily pulled out from the base plate 13 while being deformed again. As a result, the maintenance work of the fixed mold 11 and the replacement work of the positioning member 14 can be easily performed. Can do.

  On the other hand, when assembling the movable mold 21, the base plate 23 and the mirror plate 24 are first screwed with screws 31. Next, the outer ring 25 is fitted into the outer periphery of the mirror plate 24. Next, the mounting plate 22 and the base plate 23 are screwed with screws 31. Subsequently, a protruding sleeve 26 is mounted in the center hole of the mounting plate 22, the base plate 23 and the mirror plate 24. Next, the gate cut sleeve 27 is mounted in the protruding sleeve 26. Next, the protruding pin 28 is mounted in the gate cut sleeve 27. Thereby, the assembly of the movable mold 21 is completed.

  Next, a forming method for forming the substrate D using the mold apparatus 1 will be described with reference to the drawings.

  First, the fixed mold 11 is mounted on the injection molding machine by fixing the mounting plate 12 to the stationary platen of the injection molding machine. Next, the movable plate 21 is mounted on the injection molding machine by attaching the mounting plate 22 to the movable platen of the injection molding machine. Next, the driving mechanism of the injection molding machine is operated to close the fixed side mold 11 and the movable side mold 21. At this time, as shown in FIG. 2, a disk-shaped cavity Ca capable of forming the base material D is formed by both molds 11 and 21. Subsequently, molten resin (for example, polycarbonate) is injected from the nozzle of the injection molding machine. At this time, the melted resin is filled into the cavity Ca through the runner 16 a of the sprue bushing 16. Next, when the resin in the cavity Ca is in a soft state, the gate cut sleeve 27 and the protruding pin 28 are moved forward (moved upward) toward the sprue bushing 16 to thereby move the resin in the runner 16a and the cavity Ca. Cut the resin with the gate.

  Next, after the resin in the cavity Ca is sufficiently cooled and solidified, the driving unit of the injection molding machine is operated to move the movable side mold 21 away from the fixed side mold 11 and the mold apparatus 1 is moved. Move to mold open state. Subsequently, the resin remaining in the runner 16a and the substrate D are pushed out by moving the protrusion pin 28 and the protrusion sleeve 26 to the fixed mold 11 side. Thereby, shaping | molding of the base material D is completed. In this case, since the virtual center of the uneven pattern in the stamper 18 and the center of the base plate 13 (cavity Ca) are centered with high accuracy, the center of the base material D is the center of the base material D. A groove pattern centered with high accuracy is formed. On the other hand, in this mold apparatus 1, the alignment member 14 and the screw 31 that screws the base plate 13 and the stamper support plate 15 are slightly plastically deformed. Therefore, the stamper support plate 15 is held at that position by the alignment member 14 and the screw 31 without moving relative to the base plate 13. Therefore, even if a large injection pressure is repeatedly applied during injection molding, the stamper support plate 15 is maintained in the centered state. As a result, a good base material D is always formed even if injection molding is continued.

  Thus, according to this mold apparatus 1, one end side of the alignment member 14 is fitted into the center hole 13a of the base plate 13, and the other end side of the alignment member 14 is connected to the center hole of the stamper support plate 15. In this state, the stamper 18 is pressed toward the center of the mold clamping ring 19 by a pressing screw 32 disposed on the mold clamping ring 19 fixed to the base plate 13. Center (virtual center of the uneven pattern formed on the stamper 18) can be centered (aligned) with high accuracy, and the stamper support plate 15 is held at that position by the alignment member 14 and the screw 31. Therefore, even if injection molding is continuously performed, a good base material D on which a groove pattern centered with high accuracy is formed is connected. It can be molded.

  In addition, this invention is not limited to said structure. For example, the configuration example in which the stamper support plate 15 is pressed toward the center of the mold clamping ring 19 by screwing the pressing screw 32 has been described above. However, as in the fixed mold 51 shown in FIG. It is also possible to employ a configuration in which the stamper support plate 15 is pulled toward the inner peripheral surface of the mold clamping ring 52 by screwing the pulling screw member 33 in the present invention into the stamper support plate 15. In this case, as shown in the figure, a screw hole 15 b is formed in the outer peripheral surface of the stamper support plate 15 so that the screw portion of the tension screw 33 can be screwed. The mold clamping ring 52 is formed with an insertion hole 52a through which the threaded portion of the pulling screw 33 can be inserted instead of the screw hole 19a. Also in the fixed side mold 51, as in the mold apparatus 1, one end side of the alignment member 14 is fitted into the center hole 13a of the base plate 13, and the other end side of the alignment member 14 is supported by the stamper. The stamper support plate 15 is fitted to the center hole 15a of the plate 15 and the stamper support plate 15 is directed toward the inner peripheral surface of the mold clamping ring 52 by a pulling screw 33 disposed on the mold clamping ring 52 fixed to the base plate 13 in this state. By pulling, the stamper support plate 15 can be centered with high accuracy, and the stamper support plate 15 can be held at that position by the positioning member 14 and the screw 31. Therefore, the injection molding is continuously performed. Even if it carries out, the favorable base material D in which the groove pattern centered with high precision was formed can be shape | molded continuously.

2 is a cross-sectional view of a substrate D. FIG. 1 is a cross-sectional view of a mold apparatus 1. FIG. 3 is an exploded cross-sectional view of a fixed side mold 11. FIG. It is the sectional view on the AA line in FIG. FIG. 4 is a bottom view of the fixed mold 11. 3 is a cross-sectional view of a fixed side mold 51. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold apparatus 11,51 Fixed side metal mold | die 13 Base board 13a Center hole 14 Positioning member 15 Stamper support plate 18 Stamper 19 Clamping ring 21 Movable side metal mold 31 Screw 32 Pressing screw 33 Pulling screw Ca Cavity

Claims (3)

A base plate in which a central hole having a circular cross section is formed at the center thereof, a cylindrical alignment member whose one end is fitted into the center hole of the base plate, and the alignment member at the center thereof A first mold having a stamper support plate in which the other end side of the stamper is fitted and a stamper is fixed to one surface thereof, and a mold clamping ring fixed to the base plate so as to surround the stamper support plate, and a mold A second mold that forms a cavity in combination with the first mold in the closed state;
At least one of a pressing screw member that presses the stamper support plate toward the center of the mold clamping ring and a tension screw member that pulls the stamper support plate toward the inner peripheral surface of the mold clamping ring is the mold clamping. Mold device arranged on the ring.   The mold apparatus according to claim 1, wherein the alignment member is formed to have different thicknesses on the one end side and the other end side.   The mold apparatus according to claim 2, wherein the one end side of the alignment member is formed thinner than the other end side.

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