JP2012192532A - Resin molding method and resin molding apparatus - Google Patents

Abstract

[PROBLEMS] To improve the molding quality of a molded product.
A mold having a molding cavity, an overflow cavity provided around the molding cavity, and a boundary portion provided between the molding cavity and the overflow cavity and having an air vent formed therein. 2 is used. First, the workpiece W is clamped by the mold 2 and the resin is pumped to the molding cavity 11, and the resin 25 is filled into the molding cavity 11 while the outflow to the overflow cavity 12 is suppressed by the boundary portion 13. Next, the resin pressure is raised higher than a predetermined resin pressure, and the resin 25 flows out from the molding cavity 11 to the overflow cavity 12 through the air vent 18. Next, the resin 25 filled in the molding cavity 11 is cured by heating.
[Selection] Figure 4

Description

  The present invention relates to a technique effective when applied to a resin molding method and a resin molding apparatus.

  In a resin molding apparatus that resin molds a semiconductor chip or the like, an air vent for discharging air in the cavity is provided. Normally, an air vent forms an air vent groove on the clamp surface of the cavity side (opposite side) opposite to the cavity side where the gate is formed, and discharges the air in the cavity to the outside through the air vent groove when resin is injected. I am doing so. The air vent discharges air, while the resin having high fluidity has a problem that the resin easily leaks from the air vent groove. Therefore, an air vent pin is provided in the air vent groove, and an air vent mechanism for discharging air but preventing resin from leaking out may be provided.

  For example, in Japanese Patent Application Laid-Open No. 2009-292076 (Patent Document 1), in transfer molding, a movable pin is provided in a flow path of an air vent and a mold is closed, and then a resin flow head reaches a position immediately before the air vent by a plunger. The air is discharged until it reaches, and when it reaches, the movable pin is advanced into the air vent so that the air vent is closed (closed), and the resin is heated and cured with 100% filling of the molten resin in the cavity. A technique for molding is disclosed (see paragraphs [0030] and [0031] of the specification).

  Such a movable pin (air vent pin) is applied not only to transfer molding but also to compression molding. For example, in Japanese Patent Application Laid-Open No. 2010-36515 (Patent Document 2), an air vent pin provided in a clamper is used to open an air vent groove until just before mold closing, and the air vent groove is completely closed together with mold clamping. Thus, a technique is disclosed in which the cavity is completely sealed and compression molding is completed by thermosetting the resin in a compressed state (see paragraph [0021] of the specification).

  These techniques of Patent Documents 1 and 2 are for preventing a problem that the resin leaks from the air vent. Note that a pressure adjusting pin having a function different from that of the movable pin of Patent Document 1 and the air vent pin of Patent Document 2 is disclosed in Japanese Patent Application Laid-Open No. 2010-173083 (Patent Document 3).

  In this Patent Document 3, an excess resin accommodating portion communicating with the molding cavity is disposed in the resin filling step, and therefore, a part of the molten resin material flowing into the molding cavity is also in the excess resin accommodating portion. A technique for inflow is disclosed (see paragraph [0018] of the specification). Further, in the molding process of the thin resin package, an excess amount of the molten resin material exceeding the cavity capacity for molding the thickness of the thin resin package is caused to flow into the excess resin accommodating portion by the resin pressure based on the descending action of the cavity block. The technology is disclosed (see paragraph [0019] of the specification). This resin molded product is released by the elastic pressing force of the pressure adjusting pin provided in the excess resin container (see paragraph [0020] of the specification).

JP 2009-202076 A JP 2010-36515 A JP 2010-173083 A

  For example, in the case of transfer molding, when a workpiece is clamped by a mold composed of an upper mold and a lower mold, and resin molding is performed by filling a resin in the cavity, the thickness of the molded product becomes as thin as about 0.3 mm, for example. Since the melting of the molten sealing resin is easily promoted, the range in which the resin can flow is limited. For example, when the gap between the bottom of the cavity and the upper surface of the semiconductor element, for example, on the workpiece is narrow, it is difficult to fill the sealing resin or the filler in the resin is unevenly distributed.

  Therefore, the bottom of the cavity is deepened (retracted) by a predetermined thickness from the thickness of the molded product to ensure good resin flow, and after filling the cavity with the resin, the cavity depth is set to the thickness of the molded product. Until then, a technique for extruding excess resin in the cavity has been developed (Japanese Patent Laid-Open No. 2009-190400). However, in the molded product manufactured by this technique, a flow mark (pattern) is observed on the surface. The molded product in which the flow mark is generated is inferior in quality and decreases the manufacturing yield.

  An object of the present invention is to provide a technique capable of improving the molding quality of a molded product. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows. A resin molding method according to an embodiment of the present invention includes a molding cavity, an overflow cavity provided around the molding cavity, a boundary portion provided between the molding cavity and the overflow cavity, and an air vent formed therein. A resin molding method using a mold having the following: (a) clamping a workpiece with the mold and pumping resin to the molding cavity, while suppressing outflow to the overflow cavity at the boundary portion, A step of filling the molding cavity with resin; and (b) after the step (a), the resin pressure is raised higher than a predetermined resin pressure, and the resin flows out from the molding cavity to the overflow cavity via the air vent. And (c) after the step (b), the mold cavity is filled. Comprising a step of heating and curing the resin.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows. The molding quality of the molded product can be improved.

It is principal part sectional drawing which shows the resin mold apparatus in operation | movement in Embodiment 1 of this invention. It is principal part sectional drawing which shows the resin mold apparatus in operation | movement following FIG. It is principal part sectional drawing which shows the resin mold apparatus in operation | movement following FIG. It is principal part sectional drawing which shows the resin mold apparatus in operation | movement following FIG. It is a top view which shows an example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 1 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 1 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 1 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 1 of this invention. It is principal part sectional drawing which shows an example of the resin mold apparatus in Embodiment 2 of this invention. It is a top view which shows an example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 2 of this invention. It is a figure for demonstrating an example of the movable pin in Embodiment 2 of this invention, (a) is the figure seen in the x direction of FIG. 9, (b) is the figure seen in the z direction of FIG. 9, (c) ) Is a view seen in the y direction of FIG. It is a figure for demonstrating the other example of the movable pin in Embodiment 2 of this invention, (a) is the figure seen in the x direction of FIG. 9, (b) is the figure seen in the z direction of FIG. (C) is the figure seen in the y direction of FIG. It is principal part sectional drawing which shows the other example of the resin mold apparatus in Embodiment 2 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 2 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 2 of this invention. It is a top view which shows the other example of the workpiece | work taken out from the metal mold | die after shaping | molding in Embodiment 2 of this invention. It is principal part sectional drawing which shows an example of the resin mold apparatus in operation | movement in Embodiment 3 of this invention. It is principal part sectional drawing which shows the resin mold apparatus in operation | movement following FIG. It is principal part sectional drawing which shows the resin mold apparatus in operation | movement following FIG. It is a principal part enlarged view of FIG. It is principal part sectional drawing which shows the other example of the resin mold apparatus in operation | movement in Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof may be omitted.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to FIGS. In the resin molding apparatus 1A, the molding cavity 11 is arranged symmetrically with the cull 14 provided in the central portion of the mold 2. For clarity of explanation, however, the molding cavity 11 on one side is omitted in FIG. is doing. 5-8, the code | symbol of the component location of the metal mold | die 2 is attached | subjected to the location of the workpiece | work W formed corresponding to the component location of the metal mold | die 2, and description is clarified.

  A schematic configuration of the resin molding apparatus 1A will be described with reference to FIGS. The cross-sectional view of FIG. 1 corresponds to the arrow AA line of FIG.

  In this resin molding apparatus 1A, a molded product (work W) is carried (supplied) from a molded product supply unit (not shown) by a loader to a press unit provided with a mold 2 and molded by a unloader. (Work W) is taken out from the press section and stored in the molded product storage section. The mold 2 includes an upper mold 3 and a lower mold 4 that are arranged to face each other. In the resin molding apparatus 1A, the workpiece W placed on the lower mold 4 is clamped with the upper mold 3 and the lower mold 4 (that is, clamped with the mold 2) to perform resin molding. Note that the workpiece W shown in FIG. 1 has a plurality of semiconductor chips mounted on a wiring board.

  The mold 2 has a molding cavity 11 whose volume is variable depending on the height position of the clamp (clamper), and an overflow cavity 12 provided around the molding cavity 11. The molding cavity 11 has a concave shape that opens at the clamping surface of the upper mold 3. A work is placed on the lower mold 4, and the work is clamped and clamped together with the lower mold 4 to create an internal space. The semiconductor chip of the workpiece W is molded (sealed) with resin in the internal space of the molding cavity 11. The overflow cavity 12 has a concave shape that opens at the clamping surface of the upper mold 3, and stores excess resin that has flowed out of the molding cavity 11.

  Further, the molding cavity 11 and the overflow cavity 12 are slightly in communication with each other through the boundary portion 13 of the mold 2. As shown in FIG. 5, in this embodiment, the overflow cavity 12 is provided inside the workpiece W clamped by the mold 2.

  In the upper mold 3 of the mold 2, the upper mold base block 5 is fixedly assembled to a fixed platen (not shown). In addition, one concave upper chase block 10 is fixedly assembled to the upper base block 5 on the bottom side. An upper die stopper block 8 is attached to the outer lower portion of the upper die chase block 10. The upper die block 5 is mounted in the upper chase block 10 and fixed to the upper die cavity block 6 in a hole that penetrates the upper die chase block 10.

  The upper mold cavity block 6 forms the bottom of the molding cavity 11, and is formed by stacking multi-stage blocks having different external shapes as shown in FIG. An upper mold movable clamper block 7 (hereinafter referred to as the upper mold movable clamper 7) is assembled in a recess (the outer peripheral side of the upper mold cavity block 6) formed in a multistage manner. The upper mold cavity block 6 and the upper mold movable clamper 7 are assembled inside the concave upper mold chase block 10.

  The upper mold movable clamper 7 is slidably fitted in the upper mold base block 5 so as to be slidable and fitted through a spring 9 (also referred to as a spring) provided in a through hole of the upper mold chase block 10 and is fitted. Yes. The upper mold movable clamper 7 is provided with a plurality of through holes into which the upper mold cavity block 6 is inserted in accordance with the molding cavity 11. For this reason, the upper mold movable clamper 7 is arranged around the upper mold cavity block 6, and the bottom of the molding cavity 11 is formed by the upper mold cavity block 6 and the side is formed by the upper mold movable clamper 7.

  A cull 14, a runner 15, and a gate 16 communicating with the molding cavity 11 are provided in the center of the upper mold movable clamper 7 in this order. The gate 16 is provided on the side of the molding cavity 11. For this reason, the resin flows from the side of the molding cavity 11 through the gate 16 (see FIG. 5).

  An overflow cavity 12 is provided on the outer peripheral side of the clamp surface of the upper movable clamper 7. The overflow cavity 12 is provided on the side of the molding cavity 11 opposite to the gate 16 via a boundary portion 13. As shown in FIG. 5, the overflow cavity 12 is provided so as to extend in the direction along the side portion of the molding cavity 11.

  The overflow cavity 12 receives and accommodates the resin 25 (surplus resin) that has flowed out of the molding cavity 11. In some cases, the filler that causes the flow mark is pushed out of the resin 25 and unevenly distributed on the flow front side of the resin 25 that has flowed into the molding cavity 11. Therefore, an overflow cavity 12 is provided, and excess resin is allowed to flow from the molding cavity 11 to the overflow cavity 12 in consideration of the case where the filler is unevenly distributed.

  In addition, an air vent 18 is formed in the boundary portion 13 of the upper mold movable clamper 7 by a plurality of grooves 18a communicating the molding cavity 11 and the overflow cavity 12 (see FIG. 5). Since the resin flowing out from the molding cavity 11 flows into the overflow cavity 12 through the air vent 18, the amount of inflow is adjusted according to the groove depth, groove width, groove length, groove surface property and number of the groove 18a. be able to.

  The upper mold movable clamper 7 is assembled to the upper mold base block 5 via a spring 9 which is an elastic member, and comes into contact with the workpiece W placed on the lower mold 4. In the state shown in FIG. 1, the upper mold movable clamper 7 is suspended and supported (floating support) via a spring 9. The upper mold movable clamper 7 that forms the molding cavity 11 moves up and down, so that the depth of the molding cavity 11 can be relatively varied, that is, the volume of the molding cavity 11 can be varied.

  The upper die stopper block 8 is disposed around the upper die movable clamper 7 and is fixedly assembled to the upper die base block 5 via the upper die chase block 10. As shown in FIG. 1, the upper mold stopper block 8 is located outside the upper mold 3. Further, the upper die stopper block 8 is in contact with the lower die 4. The upper mold stopper block 8 is not an elastic member like the upper mold movable clamper 7 and is fixedly assembled to the upper mold base block 5. The lower mold 4 is close. Further, by providing an adjustment piece between the upper die stopper block 8 and the upper die chase block 10, the distance between the upper die 3 and the lower die 4 can be easily adjusted.

  In the present embodiment, a release film 17 covering the clamp surface is stretched on the clamp surface of the upper mold 3 including the molding cavity 11. The release film 17 is sucked and held on the upper mold surface by a suction mechanism using a gap between the blocks. For example, a long film material is used for the release film 17, and the release film 17 is provided so as to be drawn out from a feeding roll wound up in a roll shape, passed through an upper clamp surface, and wound up onto a winding roll.

  The lower mold 4 includes a lower mold chase block 21, a lower mold insert block 22, and a pot 23. The lower mold 4 is assembled to a movable platen (not shown). Specifically, the lower mold insert block 22 is assembled to the movable platen via the lower mold chase block 21 and a lower mold base block (not shown).

  As shown in FIG. 1, the lower chase block 21 is formed with a recess that is recessed by one step from the edge. The lower mold insert block 22 is fitted into the recess. Further, the edge of the lower die chase block 21 is located outside the lower die 4 and comes into contact with the upper die stopper block 8 of the upper die 3. That is, the upper mold 3 and the lower mold 4 are close to each other until the upper mold stopper block 8 and the edge of the lower mold chase block 21 come into contact with each other.

  The lower mold insert block 22 is assembled so as to be fitted into the recess of the lower mold chase block 21. On the upper surface of the lower mold insert block 22, a work placement portion on which the work W is placed is provided.

  In the central part of the lower mold chase block 21 and the lower mold insert block 22, through holes are provided at a plurality of locations for inserting the pots 23. A plunger 24 that moves up and down by a known transfer drive mechanism is provided in the pot 23. As the plunger 24, a multi-plunger in which a plurality of plungers 23 are provided on the support block corresponding to the plurality of pots 23 is used. A plurality of plungers 24 are provided to face each of the plurality of culls 14 shown in FIG.

  Hereinafter, a resin molding method using the resin molding apparatus 1 </ b> A for the workpiece W will be described with reference to FIGS. 1 to 4. As an example, the thickness of the molded product of the workpiece W will be described as 0.3 mm from the substrate surface.

  First, as shown in FIG. 1, the workpiece W loaded with the mold 2 opened is placed on the lower mold insert block 22 of the lower mold 4. Further, the release film 17 is adsorbed on the clamp surface of the upper mold 3, and the resin 25 (resin tablet) is supplied to the pot 23 of the lower mold 4. Subsequently, the upper mold 3 and the lower mold 4 are brought close to each other and clamping is started. As shown in FIG. 2, the upper mold movable clamper 7 abuts against the workpiece W via the release film 17, The workpiece W is clamped with the lower mold 4. Thereby, a predetermined clamping force (for example, 5 to 10 tons) balanced by the resistance force (biasing force) of the spring 9 is applied to the workpiece W.

  At this time, the workpiece W has an upper mold movable clamper while maintaining a retracted position in which the upper mold block 6 of the upper mold 3 is retracted by a predetermined thickness (eg, 0.2 mm) from the thickness dimension (eg, 0.3 mm) of the molded product. 7 is clamped. The upper die stopper block 8 is stopped at a predetermined interval (0.2 mm) from the lower die chase block 21.

  Subsequently, as shown in FIG. 3, the workpiece W is clamped by the mold 2, and the molten resin 25 is pumped to the molding cavity 11 while a predetermined clamping force (for example, 5 to 10 ton) is applied. The inside of the molding cavity 11 is filled with a predetermined resin pressure while suppressing the outflow to 12 at the boundary portion 13. This filling is performed in a state where the bottom of the molding cavity 11 is deepened by a predetermined thickness (for example, 0.2 mm) from the thickness dimension of the molded product. In this embodiment, the transfer drive mechanism (not shown) is operated to raise the plunger 24 and fill the molten resin 25 into the molding cavity 11 through the cull 14, the runner 15 and the gate 16, and the resin pressure is set to a predetermined first level. The holding pressure (for example, 1 to 3 MPa) is maintained for a predetermined time.

  At this time, since the upper cavity block 6 of the upper mold 3 is in a retracted position that is retracted by a predetermined thickness from the thickness dimension of the molded product, a gap between the upper surface of the workpiece W and the bottom surface of the upper mold cavity block 6 is widened. The molten resin 25 can be easily filled into the upper surface of the workpiece W.

  By feeding the molten resin 25 under pressure, the air in the molding cavity 11 is discharged through the air vent 18 formed at the boundary portion 13. Further, at the boundary portion 13, when filling the molding cavity 11 with the resin 25, the plurality of grooves 18 a have a predetermined groove depth and groove so that air is discharged and the resin 25 is prevented from flowing out. It is formed in width, groove length, groove surface properties, and number. At this time, the first holding pressure is performed by holding at a constant resin pressure for a predetermined time.

  Subsequently, the resin pressure is raised higher than a predetermined resin pressure (first holding pressure), and the resin flows out from the molding cavity 11 to the overflow cavity 12 through the air vent 18. Specifically, as shown in FIG. 4, the lower mold 4 is further raised, and the upper mold movable clamper 7 presses and shrinks the spring 9 to form the cavity bottom on the upper mold base block 5 side. When the upper die stopper block 8 and the lower die chase block 21 come into contact with each other, the ascent is stopped. At this time, the resin pressure rises (8 to 12 MPa) from the first holding pressure, and the resin 25 whose outflow is suppressed by the air vent groove 18a formed in the boundary portion 13 of the molding cavity 11 exceeds the limit and overflow cavity. 12 flows into.

  In the present embodiment, the groove depth, groove width, groove length, groove surface property, and number of the grooves 18a are adjusted in consideration of resin granularity, resin pressure, and the like. Moreover, as shown in FIG. 5, the groove 18a is provided in a shape (tapered shape) that opens to the overflow cavity 12 side. Thus, by resin molding and curing, the resin formed in the molding cavity 11 and the disposal resin formed in the overflow cavity 12 can be easily separated.

  In this embodiment, the bottom of the molding cavity 11 is expanded, and after filling the resin, the bottom of the molding cavity is pushed down (shallowed) until the thickness of the molded product is reached, so that the resin 25 in which the filler may be unevenly distributed is formed. Can flow into the overflow cavity 12. Therefore, it is possible to prevent the flow mark from being generated in the molded product and improve the molding quality.

  In addition, when filling the molding cavity 11 with the resin 25, since there is a high possibility that fillers are unevenly distributed particularly on the side of the molding cavity 11 opposite to the gate 16 side, in this embodiment, the overflow cavity 12 is By providing the side of the molding cavity 11 on the side opposite to the gate 16 side via the boundary portion 13, the resin 25 with a high possibility that the filler is unevenly distributed flows out to the overflow cavity 12 efficiently.

  Note that the resin of the molding cavity 11 that cannot enter the overflow cavity 12 by the upper mold cavity block 6 being pushed up to the molding position corresponding to the thickness dimension (for example, 0.3 mm) of the molded product by raising the lower mold. 25 is also pushed back to the pot 23 side through the gate 16. At this time, the plunger 24 is retracted by the resin pressure, and the excess resin can be returned to the pot.

  As described above, after the upper mold movable clamper 7 clamps the workpiece W, the upper mold cavity block 6 is relatively pushed out to the molding cavity 11 by further mold closing operation, so that the thickness dimension of the molded product as intended (( For example, 0.3 mm).

  Subsequently, the work 25 is resin-molded by heat-curing the resin 25 filled in the molding cavity 11. Specifically, the molten resin 25 is pumped to the molding cavity 11, and a resin pressure larger than the resin pressure of the first holding pressure (for example, 1 to 3 MPa) is set to a predetermined second holding pressure (for example, 8 to 12 MPa). Maintain and heat cure for a predetermined time. As a result, a molded product having a very thin package thickness can be mass-produced at a low cost without using a new facility.

  Thereafter, the upper mold movable clamper 7 moves the lower mold 4 slightly (for example, 0.2 mm) while clamping the workpiece W, and moves only the upper mold cavity block 6 to the retracted position to release the molded product. Let When the lower mold 4 is further moved downward to open the mold, the upper mold movable clamper 7 is opened away from the work W, and then the work W is taken out from the lower mold 4 and the lower mold surface is cleaned as necessary. Thus, one molding operation is completed.

  In the present embodiment, as shown in FIG. 5, the case where the overflow cavity 12 is provided on the side portion of the molding cavity 11 opposite to the gate 16 side via the boundary portion 13 has been described. As described above, the overflow cavity 12 may be provided on the other side portion of the molding cavity 11 excluding the side portion on which the gate 16 is provided via the boundary portion 13. Specifically, as shown in FIG. 6, the molding cavity 11 has a rectangular shape in plan view, so that the three side portions excluding one side portion where the gate 16 is provided are respectively connected via the boundary portion 13. An overflow cavity 12 is provided.

  At the time of filling the molding cavity 11 with the resin 25, the filler may be unevenly distributed in addition to the side portion opposite to the gate 16 side. Therefore, the overflow cavity 12 is provided via the boundary portion 13 on the other side portion of the molding cavity 11 excluding the side portion where the gate 16 is provided. Thereby, the resin 25 in which the filler is unevenly distributed at the side of the molding cavity 11 can flow out to the overflow cavity 12. Therefore, it is possible to prevent the flow mark from being generated in the molded product and further improve the molding quality.

  5 and 6, the case where the air vent 18 is formed by the plurality of grooves 18a communicating the molding cavity 11 and the overflow cavity 12 has been described. However, as shown in FIGS. The air vent 18 may be formed by a narrow long groove 18 b having a long side along the molding cavity 11 and a short side communicating the molding cavity 11 and the overflow cavity 12.

  Thus, even by providing the long groove 18 b along the molding cavity 11, it is possible to prevent the resin 25 (unnecessary resin) in which the filler is unevenly distributed on the side portion of the molding cavity 11 from remaining in the molding cavity 11. it can. Therefore, it is possible to prevent the flow mark from being generated in the molded product and further improve the molding quality. Further, by providing the long groove 18b, the resin 25 in which the filler is unevenly distributed can be efficiently discharged from the molding cavity 11 to the overflow cavity 12 at a time.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. In the resin molding apparatus 1B, the molding cavity 11 is arranged symmetrically with the cull 14 provided in the central portion of the mold 2. However, in order to clarify the explanation, the molding cavity 11 on one side is omitted in FIG. is doing. Further, in FIGS. 10 and 14 to 16, the reference numerals of the constituent parts of the mold 2 are attached to the parts of the workpiece W formed corresponding to the constituent parts of the mold 2 to clarify the explanation.

  9, as described with reference to FIG. 4, the stopper block 8 is brought into contact with the lower chase block 21, the bottom of the molding cavity 11 is pushed down to reduce the volume, and the resin is transferred to the overflow cavity 12. 25 is a state in which it has flowed out. Further, the cross-sectional view of FIG. 9 corresponds to the arrow AA line of FIG.

  In the resin molding apparatus 1B, an air vent 18 is formed in the boundary portion 13 of the upper mold movable clamper 7 by a plurality of grooves 18a communicating the molding cavity 11 and the overflow cavity 12 (see FIG. 10). A plurality of movable pins 26 that can move up and down so as to dam each of the plurality of grooves 18 a forming the air vent 18 are provided in the boundary portion 13. Specifically, the movable pin 26 is inserted into a through-hole penetrating the groove 18a to be dammed. The movable pin 26 is connected to the spring 27.

  In the first embodiment, the air vent groove 18a needs to have a predetermined groove depth, groove width, groove length, groove surface property and number, and it may be difficult to obtain an optimal solution depending on the resin. It is necessary to produce the same effect more easily. Therefore, in the second embodiment, the groove 18a is a mechanism that is hardly affected by the resin, and the movable pin 26 and the spring 27 that can move it vertically are provided. When the molten resin 25 is pumped into the molding cavity 11 and filled into the molding cavity 11 while the flow out of the overflow cavity 12 is suppressed by the boundary section 13, the movable pin 26 protrudes from the boundary section 13 by the spring 27. Be energized by.

  The tip of the movable pin 26 has a shape in which the molding cavity 11 side is lowered with respect to the overflow cavity 12 side. For example, a stepped shape as shown in FIG. 11A or a tapered shape as shown in FIG. It is said. Further, as shown in FIGS. 11B, 11C, 12B, and 12C, a groove 26a is formed on the distal end surface of the movable pin 26. FIG. The groove 26a forms the air vent 18.

  The movable pin 26 is shaped so that the molding cavity 11 side is lowered with respect to the overflow cavity 12 side, so that when the resin 25 flows out to the overflow cavity 12 through the air vent 18, the resin 25 is moved to the movable pin 26. It is pushed up against the urging force of the spring 27 by diving into the tip of the spring. Further, when the tip of the movable pin 26 is chamfered with a taper shape, the release film 17 can be prevented from being torn when the resin 25 pushes up the movable pin 26.

  In this way, the provision of the movable pin 26 and the spring 27 that enables the movable pin 26 to move up and down also suppresses the outflow to the overflow cavity 12 when the resin 25 is filled into the molding cavity 11. The resin 25 can flow out into the overflow cavity 12 when the bottom of the resin is pushed down. That is, by pressing down the bottom of the molding cavity 11, the resin 25 in which the filler is unevenly distributed can flow out to the overflow cavity 12. Therefore, it is possible to prevent the flow mark from being generated in the molded product and improve the molding quality.

  Although the case where the spring 27 is provided has been described with reference to FIG. 9, as shown in FIG. 13, the movable pin 26 may be moved up and down by connecting the actuator 28 to the movable pin 26. By providing the actuator 28, it is possible to control the movement amount and the protrusion timing of the movable pin 26, and it is possible to easily control the suppression of the resin 25 at the boundary portion 13 and the outflow of the resin 25 through the air vent 18. .

  Further, the case where the movable pin 26 is provided has been described with reference to FIG. 10, but as shown in FIG. 14, the movable plate 29 (shutter) that can move up and down so as to dam the long groove 18 b is provided at the boundary 13. May be provided. The tip of the movable plate 29 has such a shape that the molding cavity 11 side is lowered with respect to the overflow cavity 12 side as shown in FIGS. As described above, by using the plate-shaped movable plate 29 for the long groove 18 b, it is possible to allow excess resin in which filler is unevenly distributed to flow into the overflow cavity 12 at one time.

  Further, one overflow cavity 12 (see FIG. 10) extending in the direction along the side of the molding cavity 11 may be divided and provided as shown in FIG. Thereby, when the resin 25 in the overflow cavity 12 shrinks after heat curing, it is possible to prevent the workpiece W from being warped. Further, as shown in FIGS. 15 and 16, by providing the overflow cavity 12 outside the workpiece W clamped by the mold 2, it is possible to prevent the workpiece W from being further warped.

(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIGS. In the resin molding apparatus 1C, the molding cavity 11 is arranged symmetrically with the cull 14 provided in the central portion of the mold 2. For clarity of explanation, the molding cavity 11 on one side is omitted in FIG. is doing.

  The mold 2 of the resin mold apparatus 1C is mainly composed of an upper mold 3 in which a molding cavity 11 is formed and a lower mold 4 on which a work W is placed. In the upper mold 3, the surface of the upper mold 3 is disposed between the upper mold cavity block 6 and the upper mold movable clamper 7 and between the upper mold cavity block 6 and the central portion 7 a of the upper mold movable clamper 7. A film suction part 31 for sucking the release film 17 is provided. An airtight seal member 33 is provided between the upper mold movable clamper 7 and the upper mold chase block 32.

  The upper mold cavity block 6 is directly fixed to the upper mold chase block 32. Between the upper die chase block 32 and the upper die base block 5 to which the upper die chase block 32 is fixed, support members 34B and 35B on which coil springs 34A and 35A as elastic materials are mounted are provided. The upper mold movable clamper 7 and the upper mold center block 7a are attached to the support members 34B and 35B so as to be separated from the upper mold chase block 32. The release film 17 is adsorbed and held on the surface so as to cover the molding cavity 11 of the upper mold 3 by the film suction means 36 communicating with the film suction portion 31.

  The boundary portion 13 is formed with an air vent 18 for discharging air such as the pot 23, the molding cavity 11, and the overflow cavity 12 to the outside of the resin molding apparatus 1C (outside the mold) at the time of clamping. The air vent 18 is closed by advancing (advancing) the movable pin 26 provided in a penetrating manner in the upper mold movable clamper 7 so as to protrude from the clamp surface, and by retracting (retracting) from the clamp surface side. Opened.

  The movable pin 26 is biased downward by a coiled spring 27 that is elastically mounted between the upper die chase block 32 and the upper die base block 5 to which the upper die chase block 32 is fixed. Further, as shown in FIG. 10, the movable pin 26 is formed to have a diameter larger than the width of the groove 18 a in order to close the air vent 18, and the upper mold movable clamper 7 is placed on the air vent 18 on the clamp surface. It is provided so as to be able to advance and retract in the support direction (vertical direction in FIG. 17). Further, the tip of the movable pin 26 has a stepped shape as shown in FIG.

  Thereby, the movable pin 26 is urged by the spring 27 so as to protrude from the boundary portion 13 as shown in FIG. With this movable pin 26, the molten resin 25 can be pumped into the molding cavity 11, and the molding cavity 11 can be filled while suppressing the outflow to the overflow cavity 12 at the boundary portion 13.

  In the resin molding apparatus 1C, a seal for hermetically sealing the mold clamping surface when the upper mold 3 and the lower mold 4 are closed (clamped) at a position further outward than the plane position of the air vent 18. A member 38 is provided. Between the air vent 18 and the seal member 38, an air flow passage 41 is provided on the clamp surface of the lower mold 4 for circulating air discharged from the air vent 18. The air flow passage 41 communicates with an air supply / discharge device 42 (decompression mechanism) that depressurizes the inside of the molding cavity 11 that is blocked from the outside via the overflow cavity 12.

  Hereinafter, the resin molding method using the resin molding apparatus 1C for the workpiece W will be described as an example in which the thickness of the molded product of the workpiece W is 0.3 mm from the substrate surface.

  First, the work W carried in with the mold 2 opened is placed on the lower mold insert block 22 of the lower mold 4. Further, the release film 17 is adsorbed on the clamp surface of the upper mold 3. Further, a resin 25 (resin tablet) is supplied to the pot 23. Subsequently, as shown in FIG. 17, the upper die 3 and the lower die 4 are brought close to each other and clamped, and the workpiece W is clamped by the upper die 3 and the lower die 4. At this time, the workpiece W has the upper mold movable clamper while maintaining the retracted position in which the upper mold block 6 of the upper mold 3 is retracted by a predetermined thickness (for example, 0.2 mm) from the thickness dimension (for example, 0.3 mm) of the molded product. 7 is clamped.

  Subsequently, the air between the pot 23, the molding cavity 11, the overflow cavity 12, and the like is discharged by a pressure reducing action by the air supply / discharge device 42, and volatile components such as a solvent and air, moisture, and the like contained in the resin 25 are removed. It is discharged out of the resin molding apparatus 1C in advance. As a result, the amount of bubbles contained in the resin 25 subsequently poured into the molding cavity 11 can be reduced, and the molding quality can be improved.

  Subsequently, as shown in FIGS. 18 and 20, the workpiece W is clamped by the mold 2, and the molten resin 25 is pumped to the molding cavity 11 while a predetermined clamping force (for example, 5 to 10 ton) is applied. The molding cavity 11 is filled while maintaining a predetermined resin pressure (first holding pressure) while suppressing the outflow to the overflow cavity 12 at the boundary portion 13. Specifically, the plunger 24 is raised while the air suction operation by the air supply / discharge device 42 continues, and the molten resin 25 is filled into the molding cavity 11 through the cull 14, the runner 15, and the gate 16. After filling, the resin pressure is maintained at a predetermined first holding pressure (for example, 1 to 3 MPa) for a predetermined time. At this time, as shown in FIG. 20, the resin 25 is suppressed by the movable pin 26 of the boundary portion 13.

  In the process shown in FIGS. 17, 18, and 20, the height (gap) from the workpiece W to the tip of the movable pin 26 is clamped from the boundary portion 13 by the spring 27 when clamping by the upper movable clamper 7. It protrudes and discharges air, but the resin 25 has such a height that it cannot flow out. In this embodiment, even if the gap between the tip of the movable pin 26 and the work W is narrowed so that the resin 25 does not flow out by sucking air with the air supply / discharge device 42 (decompression mechanism), the air is discharged. can do.

  Subsequently, the resin pressure is raised higher than a predetermined resin pressure (first holding pressure), and the resin flows out from the molding cavity 11 to the overflow cavity 12 through the air vent 18. Specifically, as shown in FIG. 19, the lower mold 4 is further raised, and the upper mold movable clamper 7 presses and contracts the coil springs 34 </ b> A and 35 </ b> A to form the cavity bottom on the upper mold base block 5 side. The rise stops when it is substantially flush with the cavity block 6.

  At this time, the resin pressure rises (8 to 12 MPa) from the first holding pressure, and the resin 25 whose outflow is suppressed by the air vent groove 18a formed in the boundary portion 13 of the molding cavity 11 exceeds the limit and overflow cavity. 12 flows into. That is, the upper mold cavity block 6 is further extruded to a molding position corresponding to the thickness dimension (eg, 0.3 mm) of the molded product.

  Subsequently, the resin 25 filled in the molding cavity 11 is heat-cured and resin-molded with respect to the workpiece W. As a result, a molded product having a very thin package thickness can be mass-produced at a low cost without using a new facility. Further, by providing a pressure reducing mechanism, air can be efficiently discharged when the resin 25 is filled into the molding cavity 11. Further, the resin 25 in which the filler is unevenly distributed can be caused to flow out into the overflow cavity 12 by pushing down the bottom of the molding cavity 11. Therefore, it is possible to prevent the flow mark from being generated in the molded product and improve the molding quality.

  In the present embodiment, the case where the spring 27 is provided has been described with reference to FIG. 17, but as shown in FIG. 21, an actuator (not shown) is connected via the relay pin 44 passed through the ring-shaped packing 43. The movable pin 26 may be moved up and down by the air pressing force from the spring and the resistance force of the spring 45. By providing the actuator, the amount of movement of the movable pin 26 can be controlled, and the inhibition of the resin 25 at the boundary portion 13 and the outflow of the resin 25 through the air vent 18 can be easily controlled. Therefore, it is possible to prevent the flow mark from being generated in the molded product and improve the molding quality.

  Although the present invention has been specifically described above based on the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

  In the above embodiment, the fixed upper mold cavity block 6 and the movable clamper 7 movable relative to the fixed upper mold cavity block 6 are assembled, and applied to a mold having a molding cavity whose volume is variable depending on the height of the clamp (the clamper surface of the movable clamper 7). I explained the case. For example, the present invention may be applied to a mold having a molding cavity whose volume is variable by fixing a clamper block, assembling a cavity block movable relative to the clamper block, and moving the cavity block by an actuator or the like.

  In the embodiment, the case where the upper cavity 3 is provided with the molding cavity 11 and the overflow cavity 12 has been described. For example, a molding cavity and an overflow cavity may be provided in the lower mold by reversing the configurations of the upper mold 3 and the lower mold 4.

1A, 1B Resin mold device 2 Mold 3 Upper mold 4 Lower mold 11 Molding cavity 12 Overflow cavity 13 Boundary part 18 Air vent 25 Resin W Workpiece

Claims (8)

A resin molding method using a mold having a molding cavity, an overflow cavity provided around the molding cavity, and a boundary portion provided between the molding cavity and the overflow cavity and formed with an air vent. ,
(A) clamping the workpiece with the mold and pumping the resin into the molding cavity, and filling the molding cavity with the resin while suppressing the outflow to the overflow cavity at the boundary;
(B) after the step (a), increasing the resin pressure higher than a predetermined resin pressure, and flowing the resin from the molding cavity to the overflow cavity via the air vent;
(C) After the step (b), a step of heat curing the resin filled in the molding cavity;
A resin molding method comprising: The resin molding method according to claim 1,
In the step (a), resin is filled into the molding cavity in a state where the bottom of the molding cavity is deeper than the thickness dimension of the molded product,
In the step (b), the bottom of the molding cavity is shallowed until the thickness of the molded product is reached, and the resin flows out into the overflow cavity. A mold having a molding cavity, an overflow cavity provided around the molding cavity, and a boundary portion provided between the molding cavity and the overflow cavity and formed with an air vent;
The workpiece is clamped with the mold, the resin is pumped to the molding cavity, the resin is filled into the molding cavity while suppressing the outflow to the overflow cavity at the boundary, and then the resin is higher than a predetermined resin pressure. A resin molding apparatus, wherein pressure is increased, resin is flown out from the molding cavity to the overflow cavity through the air vent, and the resin filled in the molding cavity is heated and cured. In the resin mold device according to claim 3,
The side of the molding cavity is provided with a gate into which resin flows,
On the side of the molding cavity opposite to the gate side, the overflow cavity is provided via the boundary,
The resin mold apparatus, wherein the air vent is formed in the boundary portion by a plurality of grooves communicating the molding cavity and the overflow cavity. In the resin mold device according to claim 3,
The side of the molding cavity is provided with a gate into which resin flows,
On the other side part of the molding cavity excluding the side part on which the gate is provided, the overflow cavity is provided via the boundary part,
The resin mold apparatus, wherein the air vent is formed in the boundary portion by a plurality of grooves communicating the molding cavity and the overflow cavity. In the resin mold apparatus of Claim 4 or 5,
A resin mold apparatus, wherein a plurality of movable pins that can move up and down so as to dam each of the plurality of grooves are provided at the boundary portion. In the resin mold device according to claim 6,
The movable pin is connected to a spring and is urged by the spring so as to protrude from the boundary portion. When the resin flows out to the overflow cavity via the air vent, the movable pin is moved from the molding cavity. A resin molding apparatus characterized by being moved up by resin pressure. In the resin mold device according to claim 6,
The movable pin is connected to an actuator and is moved downward by the actuator so as to protrude from the boundary portion. When the resin flows out into the overflow cavity via the air vent, the movable pin is moved upward by the actuator. Resin mold apparatus characterized by being made.

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