JP2015144200A - Molding die, resin molding device, and resin molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die which is improved in yield by shortening a resin passage connected to a cavity, by making it difficult to generate voids and reducing unnecessary resin as much as possible when transfer-molded.SOLUTION: In the another molding die 3, a cavity block 4 which forms an outer periphery of a cavity recess 3a and presses a work-piece W, a gate plate 8 which forms a bottom part of the cavity recess 3a and in which a resin passage 8a is formed, and a pot block 9 which forms a pot 9a communicated with the resin passage 8a, are laminated so as to be separable from each other. The cavity is filled with a molding resin 5 by operating a transfer mechanism 7 to fill the molding resin 5 from the bottom part of the cavity recess 3a through the resin passage 8a from the pot 9a the another molding die 3.

Description

  The present invention relates to a mold for resin-molding a substrate on which a general-purpose inverter circuit is mounted, for example, by transfer molding, a resin mold apparatus and a resin mold method for resin-molding using the mold.

  When resin-molding a board equipped with a general-purpose inverter circuit or memory, in order to mold at lower cost, the transfer mechanism is operated from the pot to which the mold resin is supplied, and the mold resin is placed in the cavity via the die cull and runner gate. It has been studied to press-feed and resin mold by transfer molding. The following has been proposed as a prior art for resin molding a molded product having a plurality of semiconductor elements and electronic components mounted on a substrate.

  When multiple semiconductor elements and electronic components are mounted on a single substrate and sealed together with resin, the cavity area is large and the distance from the resin inlet to the air vent at the cavity end is long, making it easy to entrain air. Therefore, a resin molding apparatus in which a resin injection port and an air escape port are formed corresponding to a semiconductor element has been proposed. When a substrate on which a semiconductor element is mounted is placed on a lower mold and resin molding is performed on the substrate, a gate, an intermediate mold provided with an air discharge passage, a pot for injecting resin from above, and a runner communicating with the gate The upper mold formed with is overlapped and clamped. Then, the sealing resin put into the pot is pressed with a plunger, and the resin is molded while discharging the air in the cavity through the air discharge passage from the air escape port provided on the cavity while injecting the resin into the cavity through the runner gate. (See Patent Document 1).

  Alternatively, the second mold and the third mold are overlapped with the first mold and the second mold and the third mold are overlapped so that the mold does not easily warp or bend and the mold can be easily released. The upper surface of the individual cavity through the vertical runner of the second mold that sandwiches the substrate and communicates with the runner formed between the first mold and the second mold from the pot provided in the third mold Further, a resin molding apparatus that fills the mold resin is disclosed (see Patent Document 2).

JP 2008-47573 A JP 2007-130976 A

  In Patent Documents 1 and 2 described above, since the resin path from the pot to the cavity is long and a large amount of unnecessary resin is generated, the yield may be lowered and the production efficiency is also lowered. Further, in Patent Document 1, since an air discharge passage different from the gate is formed in the intermediate mold, the mold structure becomes complicated, and unnecessary resin must be removed from the upper mold runner and the intermediate plate provided with a plurality of gates. There is. In Patent Document 2, since the resin path is long and the form of the unnecessary resin is complicated, a large eject structure for releasing the unnecessary resin is required.

  The object of the present invention is to solve the above-mentioned problems of the prior art, a mold that shortens the resin path connected to the cavity during transfer molding, hardly generates voids, and reduces unnecessary resin as much as possible to improve the yield, and this An object of the present invention is to provide a resin molding apparatus and a resin molding method capable of simplifying mold maintenance and improving production efficiency by reducing unnecessary resin generated by transfer molding as much as possible.

In order to achieve the above object, the present invention comprises the following arrangement.
A mold that clamps the workpiece with one mold for placing the workpiece and the other mold with the cavity recess formed therein, and molds the resin, wherein the other mold is an outer periphery of the cavity recess. And a cavity block that presses the workpiece, a gate plate that forms the bottom of the cavity recess and is formed with a resin passage, and a pot block that forms a pot communicating with the resin passage is separable. A transfer mechanism including a plunger that is stacked and can fill mold cavity supplied to the pot of the pot block from the bottom into the cavity recess through the resin path of the gate plate is connected to the other mold. It can be moved up and down.

  Thereby, the mold resin can be efficiently filled into the cavity by operating the transfer mechanism and filling the mold cavity from the bottom to the cavity concave portion arranged directly below through the resin path from the pot of the other mold. it can. Further, since the mold resin supplied to the pot is filled from the bottom of the cavity recess, the resin path connected to the cavity is extremely short, and it is possible to reduce the unnecessary resin generated in the transfer mold as much as possible and improve the yield.

The other mold includes a cavity block that forms an outer periphery of the cavity recess and presses the workpiece, a gate plate that forms a bottom of the cavity recess and is formed with a resin path, and a resin path. Pot blocks forming a communicating pot are detachably stacked.
As a result, after the resin molding, the mold can be released with the mold placed on one mold simply by opening the mold, separating the cavity block from the gate plate, and the gate plate in the pot block. Unnecessary resin remaining on the gate can be removed simply by removing it, and mold maintenance can be performed efficiently.

  The pot block may be provided with an ejector pin that penetrates the gate plate so as to protrude into the cavity recess when the mold is opened. Thereby, since the ejector pin protrudes toward the resin sealing portion when the mold is opened, the molded product having a large capacity can be easily released from the cavity recess.

In the resin molding apparatus, the above-described mold die is provided, and after the resin molding, the gate plate separated from the other die is taken out of the die, and the degate pins are inserted into the resin path to eliminate unnecessary resin. Is separated and removed.
Thereby, unnecessary resin generated in the resin mold is reduced as much as possible to simplify the mold maintenance and improve the production efficiency. The gate plate can be cleaned and reused repeatedly.

Further, in the resin molding method, a step of setting a workpiece in one mold opened using any of the mold molds described above, and a cavity of the other mold disposed opposite to the one mold The step of supplying mold resin to a pot block formed with a pot formed so as to communicate with the concave portion and the cavity block formed with a through hole forming the outer periphery of the cavity concave portion are overlapped with the workpiece. Forming a cavity recess with a gate plate formed with a resin path overlapping with a hole and clamping the workpiece with the one mold and the other mold; and operating a transfer mechanism to the pot Fill the mold resin from the bottom of the cavity recess through the resin path from the pot through the resin path and heat cure Characterized in that it comprises a step of, a.
According to this, the yield can be improved by omitting the unnecessary resin generated in the mold, and the mold maintenance can be simplified to improve the production efficiency.

After the heat curing, the mold is opened to separate the molded product from the other mold while the work is placed on the one mold, and the cavity block is removed from the other mold. And removing the gate plate from the pot block, and separating and removing unnecessary resin cured in the resin path of the gate plate.
Accordingly, the molded product can be released simply by separating the other mold from the one mold, and the molded product can be easily taken out from the one mold.
Further, the mold maintenance can be easily performed by simply removing the gate plate from the pot block of the other mold and separating and removing the minimum necessary resin cured in the resin path.

  If the above-described mold is used, the resin path connected to the cavity during transfer molding can be shortened, voids are hardly generated, and unnecessary resin can be reduced as much as possible to improve the yield. Further, in the resin molding method, it is possible to simplify the mold maintenance and improve the production efficiency by reducing unnecessary resin generated in the transfer molding as much as possible by using the mold.

It is a section explanatory view of a mold. It is sectional explanatory drawing of the mold metal mold | die which concerns on another example. It is sectional explanatory drawing which shows the process of the resin mold method. FIG. 4 is a cross-sectional explanatory view showing a step of the resin molding method following FIG. 3. FIG. 5 is an explanatory cross-sectional view showing steps of a resin molding method following FIG. 4. FIG. 6 is a cross-sectional explanatory view showing the steps of the resin molding method following FIG. 5. FIG. 7 is an explanatory cross-sectional view showing a resin molding method subsequent to FIG. 6. FIG. 8 is an explanatory cross-sectional view illustrating a resin molding method subsequent to FIG. 7. FIG. 9 is an explanatory cross-sectional view showing a resin molding method subsequent to FIG. 8.

  Hereinafter, the configuration of a mold according to the present invention and a preferred embodiment of a resin molding method using the same will be described in detail with reference to the accompanying drawings. In the following, the configuration of the mold mold will be described centering on one cavity recess, but the mold mold as a whole includes a configuration in which the same configuration is formed at a plurality of locations.

  In FIG. 1, the mold 1 clamps the work W with a lower mold 2 (one mold) on which the work W is placed and an upper mold 3 (the other mold) in which a cavity recess 3a is formed. Resin mold. The workpiece W is assumed to be a relatively large circuit board in which an inverter circuit is formed as a power supply circuit on the board.

A workpiece W is placed on the lower mold 2. The substrate portion of the workpiece W is clamped by the cavity block 4. The cavity block 4 is provided with a through hole 4a that forms the outer periphery of the cavity recess 3a.
The workpiece W may be placed on the lower mold clamping surface. However, as shown in FIG. 2, a substrate recess 2a is provided, and the workpiece W is set in the substrate recess 2a and clamped with the cavity block 4. Good.
The workpiece W may be held by suction using a suction hole (not shown) formed on the mounting surface of the lower mold 2.

  In FIG. 1, the upper mold 3 is formed with a plurality of pots 9a that communicate with the same cavity recess 3a and supply mold resin in close proximity (directly above). A transfer mechanism 7 including a multi-plunger 6 capable of pressing the mold resin 5 (resin tablet or the like) supplied to each of the plurality of pots 9a is provided to be movable up and down with respect to the upper mold 3.

  Specifically, the upper die 3 forms a cavity block 4 that forms the outer periphery of the cavity recess 3a and presses the work W, and a gate plate 8 that forms the bottom of the cavity recess 3a and has a resin passage (gate 8a). A plurality of pots 9a to which the mold resin 5 is supplied and a pot block 9 provided with a heat source such as a heater (not shown) for heating the mold resin are detachably stacked.

  A back plate 10 is stacked on the pot block 9. The back plate 10 also has a through hole corresponding to the pot 9a. An elastic member 11 is inserted between the back plate 10 and the pot block 9. The ejector pin 12 inserted into the pot block 9 is always urged by the elastic member 11 so as to pass through the gate plate 8 from the pot block 9 and protrude into the cavity recess 3a when the mold is opened.

The transfer mechanism 7 is provided with a multi-plunger 6 so as to face the pot 9a, and the multi-plunger 6 is provided so as to be lifted and lowered collectively by a drive source 7a (servo motor).
The cavity block 4 may be provided integrally with the upper die 3 (gate plate 8). However, in consideration of mold release operation with the workpiece W and die maintenance, the cavity block 4 is aligned on the workpiece W separately from the upper die 3. You may make it mount.
Further, the workpiece W supplied to the lower mold 2 may be sucked and attracted to the lower mold clamping surface.
Further, the upper mold 3 and the lower mold 2 are opened and closed by a mold opening / closing mechanism (not shown) that raises and lowers the movable platen along the tie bar through a drive transmission mechanism such as a toggle link from a drive source.

Next, a resin molding method including the above-described mold 1 will be described with reference to FIGS. Hereinafter, as an example, the upper mold 3 will be described as a movable mold, and the lower mold 4 will be described as a fixed mold.
In FIG. 3, the workpiece W is set on the lower mold 2 with the mold 1 opened. Further, a mold resin 5 (for example, a resin tablet) is supplied to the pot 9a of the upper mold 3. A mold opening / closing mechanism (not shown) is operated to close the upper mold 3 and the lower mold 2. The upper die 3 is lowered and the cavity block 4 is aligned and superposed on the workpiece W. As a result, the workpiece W is clamped to the lower mold 2 and the cavity block 4 at the periphery of the substrate. The cavity block 4 may be assembled integrally with the upper die 3 or may be supplied to the workpiece W separately from the upper die 3. Note that the ejector pin 12 biased by the elastic member 11 protrudes from the cavity recess 3 a of the upper mold 3.

  As shown in FIG. 4, the transfer mechanism 7 is driven so that the multi-plunger 6 enters (lowers) the pots 9a and the mold resin 5 melted in the pots 9a is communicated directly through the gates 8a. One cavity recess 3a is filled. At this time, it is preferable that the mold resin is filled while letting the air in the cavity recess 3a escape from an air vent (not shown) formed on the laminated surface of the cavity block 4 and the gate plate 8 or the like.

Further, when the multi-plunger 6 pushes the mold resin 5 and abuts against the pot bottom, the ejector pin 12 moves relative to the pot block 9 as shown in FIG. The front end is retracted into the gate plate 8.
When the mold resin is filled into the cavity recess 3 from the plurality of pots 9a, it is cured as it is (cure).

  In FIG. 6, when the transfer mechanism 7 is driven and the multi-plunger 6 is retracted from the pot 9a after heat curing, the ejector pins 12 push down the molded product to release the molded product. As shown in FIG. 7, when the mold 1 is opened and the upper mold 3 is separated from the lower mold 2, the workpiece W can be taken out while being placed on the lower mold 2.

Next, as shown in FIG. 8, the cavity block 4 is removed from the upper mold 3 that has been opened, and the gate plate 8 is further removed. On the gate plate 8, unnecessary resin 13 remains in the gate 8a.
As with the gate 8a of the gate plate 8, a degate jig 14 provided with a degate pin 14a is prepared. As shown in FIG. The unnecessary resin 13 can be separated and removed by being inserted into the gate 8a. Depending on the tapered shape of the gate 8a, the degate jig 14 may be disposed on the lower side of the degate plate 8, and the detent pin 14a may be pushed upward to separate and remove the unnecessary resin 13. .

  As described above, when the mold 1 described above is used, the resin path connected to the cavity is shortened when transfer molding is performed, and voids are hardly generated, and the unnecessary resin 13 is reduced as much as possible to improve the yield. . Further, in the resin molding method, it is possible to simplify the mold maintenance and improve the production efficiency by reducing unnecessary resin generated by transfer molding using the mold 1 as much as possible.

Note that the unnecessary resin 13 may be separated and removed by inserting the degate pins 14a individually into the gate 8a without using the degate jig 14.
In the mold 1, the upper mold 3 is a movable mold and the lower mold 2 is a fixed mold, but the upper mold 3 may be a fixed mold and the lower mold 2 may be a movable mold, or both may be movable molds.
The mold resin is not limited to a solid resin such as a resin tablet, and various resins such as a granular resin, a powdery resin, and a liquid resin can be used.
In the present embodiment, the description has been given using the mold having two pots and the plunger. However, these are not necessarily two, and may be one, or three or more. There is no limitation to the number.
Moreover, you may use a release film for a metal mold | die clamp surface as needed.

  W Work 1 Mold die 2 Lower die 2a Substrate recess 3 Upper die 3a Cavity recess 4 Cavity block 4a Through hole 5 Mold resin 6 Multi-plunger 7 Transfer mechanism 7a Drive source 8 Gate plate 8a Gate 9 Pot block 9a Pot 10 Back plate 11 Elastic member 12 Ejector pin 13 Unnecessary resin 14 Digate jig 14a Degate pin

Claims (5)

A mold that clamps the workpiece with one mold on which the workpiece is placed and the other mold on which the cavity recess is formed, and resin molds,
The other mold communicates with the resin path, the cavity block that forms the outer periphery of the cavity recess and presses the workpiece, the gate plate that forms the bottom of the cavity recess and is formed with the resin path. The pot block forming the pot is laminated so as to be separable,
A transfer mechanism having a plunger capable of filling mold cavity supplied to the pot of the pot block from the bottom into the cavity recess through the resin path of the gate plate is provided to be movable up and down relative to the other mold. Mold metal mold characterized by being made.   2. The mold according to claim 1, wherein an ejector pin that is urged so as to protrude into the cavity recess when the mold is opened is provided through the gate plate.   The mold plate according to claim 1 or 2 is provided, and after resin molding, the gate plate separated from the other mold is taken out of the mold, and a degate pin is inserted into the resin path. A resin molding apparatus characterized by separating and removing unnecessary resin. A step of setting a workpiece in one mold opened using the mold according to any one of claims 1 to 3;
Supplying mold resin to a pot block in which a pot formed so as to communicate with a cavity recess of the other mold disposed opposite to the one mold is formed;
The cavity recess is formed with the gate plate on which the resin block that overlaps the through-hole is formed by superimposing a cavity block in which a through-hole forming the outer periphery of the cavity recess is formed on the workpiece, and the workpiece is placed on the one side Clamping with the other mold and the other mold,
Operating the transfer mechanism to cause the plunger to enter the pot, filling the mold resin from the bottom of the cavity recess through the resin path, and heat-curing the resin mold method. Opening the mold after the heat curing and separating the molded product from the other mold while placing the workpiece on the one mold; and
Removing the cavity block from the other mold and removing the gate plate from the pot block;
5. A resin molding method according to claim 4, further comprising: separating and removing unnecessary resin cured in the resin path of the gate plate.

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