JP2019171817A - Mold for molding resin - Google Patents

Abstract

To provide a mold in which burrs are hardly generated even if a cavity space is changed repeatedly in a mold for manufacturing two kinds of resin molded articles having different sizes.SOLUTION: A mold 2 includes a lower mold 4, an upper mold 3, and a slide core 5. The upper mold 3 is opposed to the lower mold 4 and can be moved forward and backward relative to the lower mold 4. The slide core 5 is fitted to the lower mold 4. One surface of the slide core 5 defines a portion of the cavity. A core lift column 7 passing through the lower mold 4 is disposed below the slide core 5. The slide core 5 is configured to be able to slide from a first position to a second position in a direction to move forward and backward with respect to the cavity in a state where it is separated from the lower mold 4. The lower mold 4 and the upper mold 3 form a first cavity with the slide core 5 in the first position interposed therebetween, and a second cavity is formed to sandwich the slide core in the second position.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in the present specification relates to a mold used for resin injection molding or transfer molding.

  Patent Document 1 discloses a mold in which a part of a mold slides and is filled with resin in two stages. The metal mold | die of patent document 1 is as follows. In the state where the upper mold is clamped with respect to the lower mold, the first cavity space is formed by positioning the inner mold at the first position. After filling the first cavity space with the first mold resin, the second cavity space is formed by moving the inner mold to the second position. Then, the second mold resin is filled into the second cavity space. If the metal mold | die of patent document 1 is used, the process which covers the semiconductor chip mounted in the package base material with 1st mold resin with 1 manufacturing apparatus, and the process which further covers 1st mold resin with 2nd mold resin will be performed. Can do.

JP 2011-243801A

  The mold of Patent Document 1 can be used as a mold for producing two types of resin molded products having different sizes. That is, the metal mold of Patent Document 1 can produce a first resin molded product molded in the first cavity and a second resin molded product molded in the second cavity.

  The metal mold | die of patent document 1 is equipped with the inner side metal mold | die which changes the size of cavity space. The inner mold is fitted to the upper mold, and one surface thereof constitutes a part of the cavity. The inner mold is slidably fitted to the upper mold so as to advance and retreat with respect to the cavity. When the change of the cavity space is repeated, that is, when the inner mold repeatedly slides, a gap due to sliding friction may be generated between the upper mold and the inner mold. The gap between the upper mold and the inner mold causes burrs in the resin molded product. The present specification relates to a mold for manufacturing two types of resin molded products having different sizes, and provides a mold in which burrs hardly occur even when the cavity space is repeatedly changed.

  The mold disclosed in this specification includes a lower mold, an upper mold, a slide core, and a moving mechanism. The slide core corresponds to the inner mold of Patent Document 1. The upper mold faces the lower mold, and can be moved forward and backward relative to the lower mold. The slide core is fitted in the lower mold. One side of the slide core defines part of the cavity. The moving mechanism can separate the slide core from the lower mold. The slide core is configured to be slidable from the first position to the second position in a direction of moving back and forth with respect to the cavity while being separated from the lower mold. The lower mold and the upper mold form a first cavity with the slide core in the first position interposed therebetween, and form a second cavity with the slide core in the second position interposed therebetween. In this mold, with the upper mold and the lower mold opened, the slide core is once separated from the lower mold and slid in that state. Therefore, the slide core does not slide with the lower mold. Therefore, even if the change of the cavity space is repeated, there is no gap at the mold boundary, and a large burr does not occur in the molded product. In particular, when an epoxy resin with high fluidity is used as the resin to be injected, burrs are likely to occur. The mold disclosed in this specification is particularly useful for a mold using a resin having high fluidity such as an epoxy resin.

  Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a perspective view of the metal mold | die of an Example (state with the slide core arrange | positioned in the 1st position). It is a perspective view of the metal mold | die of an Example (state with the slide core arrange | positioned in the 2nd position). It is a perspective view of the metal mold | die of an Example (state which separated the slide core). It is sectional drawing of the metal mold | die of an Example (state which the upper metal mold | die and the lower metal mold closed with the slide core of the 1st position on both sides). 4A is a cross-sectional view cut along the XZ plane, and FIG. 4B is a cross-sectional view cut along the YZ plane. It is sectional drawing of the metal mold | die of an Example (state which opened the upper metal mold | die). 5A is a cross-sectional view cut along the XZ plane, and FIG. 5B is a cross-sectional view cut along the YZ plane. It is sectional drawing of the metal mold | die of an Example (state which the slide core raised). 6A is a cross-sectional view cut along the XZ plane, and FIG. 6B is a cross-sectional view cut along the YZ plane. It is sectional drawing of the metal mold | die of an Example (state which the slide core moved to the 2nd position from the 1st position). It is sectional drawing of the metal mold | die of an Example (The state which the upper metal mold | die and the lower metal mold | die closed with the slide core of the 2nd position on both sides).

  A mold 2 according to an embodiment will be described with reference to the drawings. FIG. 1 shows a perspective view of the mold 2. The mold 2 is used for manufacturing a resin package for molding a semiconductor element by transfer molding. In FIG. 1, illustrations of a heating pot, a plunger, and the like necessary for the transfer molding apparatus are omitted. Also, the mechanism for holding the semiconductor element in the cavity is not shown. The same applies to the subsequent drawings. Further, the + Z direction of the coordinate system in the drawing indicates “up”.

  In the present embodiment, in order to facilitate understanding of the drawings, the mold 2 is described as having a simple-shaped cavity for manufacturing a rectangular parallelepiped resin package. However, the cavity of the mold 2 may have a complicated shape.

  The mold 2 includes an upper mold 3, a lower mold 4, and a slide core 5. The lower mold 4 is supported by a surface plate (not shown). The upper mold 3 is supported by a lift actuator (not shown) and can move up and down with respect to the lower mold. In other words, the upper mold 3 can be advanced and retracted relative to the lower mold 4. FIG. 1 shows a state where the upper mold 3 is moved upward, that is, a state where the mold 2 is opened.

  The slide core 5 can move in the X-axis direction of the coordinate system in the drawing, and the slide core 5 in FIG. 1 is located at the first position X1. A region surrounded by the cavity surface 5a of the slide core 5, the upper mold 3, and the lower mold 4 corresponds to the cavity. The size of the cavity changes depending on the position of the slide core 5. The cavity when the upper mold 3 is lowered from the state of FIG. 1 and the lower mold 4 and the upper mold 3 are closed with the slide core 5 at the first position X1 interposed therebetween is referred to as a first cavity Cv1. The length of the first cavity Cv1 in the X direction is represented by the symbol L1.

  FIG. 2 shows a perspective view of the mold 2 when the slide core 5 is located at the second position X2. In FIG. 2, the upper mold 3 and the upper portion of the vertical rail 6 are not shown. The cavity when the upper mold 3 (not shown) is lowered from the state of FIG. 2 and the lower mold 4 and the upper mold 3 are closed with the slide core 5 at the second position X2 interposed therebetween is referred to as a second cavity Cv2. . The length of the second cavity Cv2 in the X direction is represented by the symbol L2. The mold 2 can make a resin package having a length L1, and can also make a resin package having a length L2 by moving the slide core 5. That is, the mold 2 can be used to manufacture two types of resin packages. In addition, since the size of the cavity can be changed simply by moving the slide core 5, so-called mold change can be performed quickly.

  Returning to FIG. 1, the description of the mold 2 will be continued. Two vertical rails 6 are arranged on the sides of the upper mold 3 and the lower mold 4. A horizontal beam 8 is connected to the lower portion of the vertical rail 6. The upper part of the vertical rail 6 is a hook 6 a that protrudes above the upper surface of the upper mold 3.

  As will be shown later, the core lift column penetrates the lower mold 4 below the slide core 5 in the vertical direction. When the upper mold 3 is further raised from the state of FIG. 1, the hook 6 a is hooked on the upper surface of the upper mold 3, and the vertical rail 6 and the cross beam 8 are raised together with the upper mold 3. The cross beam 8 pushes up the core lift column. The upper part of the core lift column is in contact with the slide core 5. When the core lift column rises, the core lift column pushes up the slide core 5.

  The vertical rail 6 may have the following structure. That is, the vertical rail is provided with a long and narrow elongated hole in the vertical direction. Bolts pass through the long holes, and the bolts are fixed to the side surfaces of the upper mold 3. When the upper mold 3 is raised, the vertical rail does not move until the bolt reaches the upper end of the long hole. When the upper mold 3 further rises after the bolt reaches the upper end of the long hole, the vertical rail rises together with the upper mold 3 by the bolt locked to the upper end of the long hole. When the vertical rail rises, the horizontal beam connected under the vertical rail also rises, and the core lift column mounted on the horizontal beam also rises.

  FIG. 3 shows a perspective view of the mold 2 with the slide core 5 removed. Also in FIG. 3, illustration of the upper mold | type 3 and the upper part of the vertical rail 6 are abbreviate | omitted. FIG. 3 shows a state in which the cross beam 8 is raised. As described above, the core lift column 7 passes through the lower mold 4 in the vertical direction below the slide core 5, and the cross beam 8 pushes up the core lift column 7. In FIG. 3, the slide core 5 is removed, but when the core lift column 7 is lifted, the slide core 5 moves in a direction away from the lower mold 4. The slide core 5 slides in the X-axis direction in the figure, that is, in a direction to advance and retreat with respect to the cavity, while being separated from the lower mold 4. That is, the slide core 5 does not need to be slid in a state of being fitted to the lower mold 4 (and the upper mold 3). Therefore, there is no gap due to sliding friction at the boundary between the lower mold 4 (or the upper mold 3) and the cavity surface 5a of the slide core 5 in the cavity (for example, the position indicated by the arrow S in FIG. 2).

  With reference to FIGS. 4 to 8, the structure of the mold 2 will be described again together with the procedure for changing the mold from the first cavity Cv1 to the second cavity Cv2. FIG. 4 shows a cross-sectional view of the mold 2. FIG. 4 is a cross-sectional view when the upper mold 3 and the lower mold 4 are closed across the slide core 5 at the first position X1. FIG. 4A shows a cross section of the mold 2 cut along an XZ plane passing through the slide core 5 and the core lift column 7. FIG. 4B shows a cross section of the mold 2 cut along a YZ plane passing through the slide core 5 and the core lift column 7. 5A, FIG. 6A, FIG. 7 and FIG. 8 to be referred to later also show the same cross section as FIG. FIG. 5B and FIG. 6B also show the same cross section as FIG. 4A, 5A, and 6A, the vertical rail 6 and the horizontal beam 8 are not shown.

  As described above, the core lift column 7 penetrates the lower mold 4 in the vertical direction, and the lower part projects downward from the lower mold 4. The lower surface of the core lift column 7 is in contact with the horizontal beam 8, and the upper surface is in contact with the lower surface of the slide core 5.

  FIG. 5 shows a state in which the upper mold 3 is moved upward and the mold 2 is opened. FIG. 5 shows a state in which the upper mold 3 is raised until it comes into contact with the hook 6 a of the vertical rail 6. A thick arrow line in FIG. 5 indicates the moving direction of the upper mold 3. When molding a resin package having a length L1, the molded resin package is taken out in the state of the mold 2 in FIG.

  FIG. 6 shows a state where the upper mold 3 has moved further upward. When the upper mold 3 moves further upward from the state of FIG. 5, the vertical rail 6 on which the hook 6 a is hooked on the upper mold 3 is also lifted upward. A horizontal beam 8 is connected to the lower part of the vertical rail 6, and the horizontal tension 8 also rises. A core lift column 7 is placed on the lateral cover 8, and the core lift column 7 is also raised. Since the slide core 5 is placed on the upper surface of the core lift column 7, the slide core 5 is also raised. That is, the slide core 5 is separated from the lower mold 4. A thick arrow line in FIG. 6 indicates a moving direction of the upper mold 3 and the slide core 5.

  The slide core 5 mounted on the core lift column 7 is movable in a direction that moves forward and backward with respect to the cavity. The operator moves the slide core 5 from the first position X1 to the second position X2 while being separated from the lower mold 4 (see FIG. 7). In FIG. 7, the phantom line indicated by reference numeral 5b indicates the slide core 5 when located at the first position X1. A thick arrow line indicates the moving direction of the slide core 5. After the slide core 5 is moved to the second position X2, the upper mold 3 is lowered and the mold is closed, whereby a second cavity Cv2 having a length L2 is obtained (see FIG. 8). The thick arrow lines in FIG. 8 also indicate the moving direction of the upper mold 3 and the core lift column 7.

  As well shown in FIG. 7, the slide core 5 can be slid without the cavity surface 5 a and its periphery touching the upper mold 3 and the lower mold 4. A gap between the edge of the cavity surface 5a and the lower mold 4 (or the upper mold 3) causes a large burr. In the mold 2 of the embodiment, there is no gap due to sliding friction between the edge of the cavity surface 5a and the lower mold 4 (or the upper mold 3). Therefore, a big burr | flash does not generate | occur | produce.

  Points to be noted regarding the technology described in the embodiments will be described. In the figure, the shape of the mold 2 is simplified. The transfer mold is accompanied by a sprue, a gate, and a runner, which are not shown. Further, in addition to the mold, the molding apparatus requires parts such as a heating pot and a plunger, which are not shown. Further, the mechanism for interlocking the upper mold 3 and the core lift column 7 is not limited to the illustrated one. A dedicated actuator for moving the core lift column 7 up and down may be provided.

  In the mold 2 of the embodiment, the operator moves in the direction of moving back and forth with respect to the cavity of the slide core 5. A dedicated actuator for moving the slide core 5 may be provided.

  The technique described in the embodiment can be applied to a mold used for injection molding, insert molding, transfer molding, and the like. The technique described in the embodiment is particularly suitable for a mold using a resin having high fluidity such as an epoxy resin.

  The core lift column 7 and the horizontal beam 7 and the vertical rail 6 that operate the core lift column 7 in the embodiment correspond to an example of a moving mechanism that separates the slide core 5 from the lower mold 4.

  As shown in FIGS. 4 to 8, in the mold 2 of the embodiment, the cavity is mainly formed in the lower mold 4, and the lower surface (surface facing the cavity) of the upper mold 3 is flat. It was. The upper mold 3 may be provided with a recess that constitutes a part of the cavity. In that case, a structure in which a part of the slide core is fitted in the recess of the upper mold 3 in the closed mold may be used.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Mold 3: Upper mold 4: Lower mold 5: Slide core 5a: Cavity surface 6: Vertical rail 6a: Hook 7: Core lift column 8: Cross beam Cv1: First cavity Cv2: Second cavity

Claims (1)

It is a mold for resin molding,
A lower mold,
An upper mold that faces the lower mold and is capable of moving forward and backward relative to the lower mold;
A slide core that fits into the lower mold and defines a portion of the cavity;
A moving mechanism for separating the slide core from the lower mold;
With
The slide core is configured to be slidable from a first position to a second position in a direction moving forward and backward with respect to the cavity in a state of being separated from the lower mold.
The lower mold and the upper mold form a first cavity across the slide core in the first position, and form a second cavity across the slide core in the second position. Mold.

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