JP5870385B2 - Mold and resin sealing device - Google Patents

Description

  The present invention relates to a molding die and a resin sealing device, and more particularly to a molding die and a resin sealing device capable of preventing a release film from being broken as much as possible.

  In order to form a semiconductor device by sealing a semiconductor element in a semiconductor device, a circuit board (including a lead frame) having one or more semiconductor elements mounted in a matrix is inserted into the resin sealing device, The elements are collectively sealed with resin, and after sealing, dicing is performed to separate the elements. In this case, in order to facilitate the peeling of the molded product from the cavity recess surface, there is a method in which a release film is adsorbed and held on the cavity recess surface and resin is filled into the cavity recess.

By the way, in the case of a memory element, for example, in order to increase the memory capacity, there is a stack structure in which memory elements are stacked. If a memory element having such a stack structure is sealed with a resin, the entire structure inevitably becomes thick.
However, on the other hand, there is a demand for thinning.
If a memory element having a stack structure is sealed with resin and is made thin, the resin covering the memory element itself must be thinned. However, reducing the thickness of the resin means that the resin passage in the cavity of the mold is narrowed so that the resin does not easily reach the upper surface of the semiconductor chip, and the resin is not easily filled. The problem of insufficient pressurization and the generation of weld lines occurred.

In order to solve the above problems, a transfer compression mold (Transfer Compression Mold: hereinafter referred to as TCM) method described in Patent Document 1 has been devised.
FIGS. 11-14 is the resin sealing apparatus 10 used for this TCM method.
12 is an upper mold | type and 14 is a lower mold | type.
The upper mold 12 includes a clamper 18 having a storage hole 16 formed in the mold opening / closing direction and a diameter-enlarging hole 17 following the storage hole 16, and a cavity block 20 stored in the storage hole 16 of the clamper 18. .

The lower mold 14 is formed by inserting and fixing a lower mold insert block 22 into a lower mold chase block 21.
The cavity block 20 includes a bottom surface 20a, a stepped wall surface 16a that forms part of the inner wall surface of the housing hole 16 between the bottom surface 20a of the cavity block 20 and the enlarged diameter hole 17, and an inner wall surface 17a of the enlarged diameter hole 17 that is defined as a cavity surface. The cavity recess 24 is formed in the space
The clamper 18 is supported on the mold base 26 side via a spring 28 so that a required gap 27 is formed between the clamper 18 and the mold base 26. Reference numeral 30 denotes a mold base, and the spring 28 is disposed in a through-hole 31 provided in the mold base 26 and abuts the lower surface of the mold base 30 and the upper surface of the clamper 18 to urge the clamper 18 downward. ing.

  32 is a pot provided through the lower mold 14, and 33 is a plunger that moves up and down in the pot 32 by a driving device (not shown). A resin tablet 34 is loaded in the pot 32. 35 is a gate, and 36 is a runner. A release film 38 is adsorbed and held on the wall surface of the runner 36, the gate 35, and the cavity recess 24. As shown in FIG. 15, the release film 38 has air in the cavity recess 24 formed by suction holes 40 formed in communication with the cavity recess 24 between the inner wall surface of the storage hole 16 and the outer wall surface of the cavity block 20. Is sucked and held along the cavity recess.

Note that a plurality of pots 32 are arranged at predetermined intervals in a direction perpendicular to the paper surface in FIG. 11, and one cavity recess 24 is formed on each side of each pot 32.
Although not shown, a driving device is provided that opens and closes the mold by relatively moving the lower mold 14 and the upper mold 12 in contact with each other. Reference numeral 42 denotes a stopper.

Next, resin sealing by a TCM (transfer compression mold) method will be described.
A circuit board 44 on which a plurality of semiconductor elements 43 are mounted in a matrix is disposed on the surface of the lower mold 14 corresponding to the cavity recess 24 (FIG. 11).
The release film 38 is supplied into the space between the lower mold 14 and the upper mold 12 that are opened by a supply device (not shown). Next, air in the space is sucked from the suction hole 40 and the release film 38 is sucked so as to be in close contact with the surface of the cavity recess 24.
The resin tablet 34 is supplied into the pot 32, and the lower mold 14 or the upper mold 12 is driven by a drive unit (not shown) to perform the first mold clamping.

In the first mold clamping stage, the parting surfaces of the lower mold 14 and the upper mold 12 are in contact with each other via the release film 38, and the spring 28 is slightly compressed so that the resin does not leak out from the cavity recess 24. The mold is clamped with a clamping force (FIG. 12).
The resin tablet 34 supplied into the pot 32 is heated and melted by a heater incorporated in the mold. At this stage, the plunger 33 is driven by the drive unit, the molten resin is pressed, and injected into the cavity recess 24 via the runner 36 and the gate 35.

In the first mold clamping stage, there is a sufficient gap between the upper surface of the semiconductor element and the bottom surface of the cavity recess 24 (the surface of the release film 38), and the molten resin is satisfactorily filled into every corner of the cavity recess 24. (FIG. 13).
Next, the upper mold 12 and the lower mold 14 further approach each other, and the second mold clamping is performed.
In the second mold clamping stage, the mold clamping is performed so that the two molds come closer to each other until the stopper 42 comes into contact with the upper surface of the lower mold insert block 21 against the urging force of the spring 28 (FIG. 14). ). As a result, as shown in FIG. 14, the cavity block 20 approaches the lower mold 14 and the space in the cavity recess 24 is narrowed, so that the molten resin in the cavity recess 24 is pushed back into the pot 32.
By holding the pressure in this state, the thermosetting resin is cured and the resin sealing is completed.
By opening the mold, taking out the molded product, and dicing, a single semiconductor device in which the semiconductor element is sealed with resin can be obtained.
By the above TCM method, it is possible to obtain a thin semiconductor device which is not filled with resin.

JP 2009-190400 A

However, the TCM method also has the following problems.
That is, in the TCM method, the mold clamping is performed in two stages of the first mold clamping and the second mold clamping. By the second mold clamping, the inner bottom surface of the cavity recess 24 is set to have a required height. Therefore, in the first mold clamping stage, it is inevitable that a step m (step wall surface 16a) is generated between the cavity block 20 and the enlarged diameter portion 17, as shown in FIG. Further, when the release film 38 is initially supplied into the cavity recess 24, the release film 38 does not come into contact with the corner portion of each step, and a gap is generated between the release film 38 and the corner portion as shown in FIG. .

  Then, by sucking air in the gap from the suction hole 40, as shown in FIG. 16, the release film 38 is brought into close contact with the inner wall of the corner portion. At that time, the release film 38 is forcibly stretched. As a result, the release film 38 may be torn. When the release film 38 is torn, the molten resin leaks, and as shown in the leaked resin 51 in FIGS. 17 to 19, the leaked resin adheres to the inner wall of the mold or the suction hole 40 is clogged with the leaked resin. The problem of end up occurred.

The above problem also occurs in a molding die disclosed in Japanese Patent Application Laid-Open No. 2003-291147.
This molding die has a cavity block movably accommodated in a cavity insert accommodation hole so that molded articles of various thicknesses can be molded with a common mold, and the cavity block bottom surface and cavity insert And a mold base in which an adjustment liner that defines the depth dimension of the cavity recess is replaceably mounted between the mold base and the mold base. Even in the case of this molding die, the cavity block is in a state of being moved in the cavity recess, so that there is a possibility that a step is generated as in the case of the TCM die, and the release film is torn.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a molding die and a resin sealing device that can prevent the release film from being broken as much as possible. .

A molding die according to the present invention comprises a top die and a bottom die, and is a molding die used for a resin sealing device that collectively seals inserted articles to be molded. One of the molds has a storage hole formed in the mold opening and closing direction and a clamper having an enlarged diameter hole following the storage hole, and a cavity block stored in the storage hole of the clamper, Cavity recesses provided in the mold corresponding to the resin-sealed region collectively are a bottom surface of the cavity block, an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. It is formed in a space having a cavity surface with a stepped wall surface forming a part and an inner wall surface of the enlarged diameter hole,
Molding metal in which a suction hole is formed between the inner wall surface of the storage hole and the outer wall surface of the cavity block so as to adsorb the release film supplied along the cavity recess to the cavity recess surface. in the mold, the peripheral edge portion of the bottom surface of the cavity block, said projecting into the cavity recess direction, the circular projection to reduce the depth of the cavities is provided et been by covering a portion of the step wall, the The protruding peripheral portion is provided such that an angle formed by an inner wall surface of the protruding peripheral portion and a bottom surface of the cavity block is an obtuse angle .

The inner wall surface of the enlarged diameter hole can be formed in a tapered surface extending from the end of the stepped wall surface.

The molding die according to the present invention includes a top die and a bottom die, and is a molding die used for a resin sealing device that collectively seals inserted articles to be molded. One of the molds has a clamper having a storage hole formed in the mold opening and closing direction and a diameter-enlarging hole following the storage hole, and a cavity block stored in the storage hole of the clamper The cavity concave portion provided in the mold corresponding to the region where the resin sealing is collectively performed is a bottom surface of the cavity block, and an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. Are formed in a space having a cavity surface that is a stepped wall surface and an inner wall surface of the enlarged-diameter hole, and communicated with the cavity recess between the inner wall surface of the storage hole and the outer wall surface of the cavity block, Along the cavity recess In a molding die in which a suction hole for adsorbing the supplied release film to the cavity recess surface is formed, the cavity block protrudes in the cavity recess inward at the periphery of the bottom surface of the cavity block to cover a part of the step wall surface. And a cavity that reduces the depth of the cavity recess is provided, and the clamper is supported on the mold base side via a spring with a required gap between the cavity block and the cavity block. Is fixed to the mold base side, and the mold base and the cavity block are provided so as to be movable toward and away from the clamper against the biasing force of the spring. Along with the block, the clamper moves relative to the other mold direction via the spring, and the clamper contacts the other mold surface. A first mold clamping, and a second mold clamping in which the spring is compressed from the first mold clamping and the cavity block further approaches the other mold direction to narrow the space of the cavity recess. The two-stage clamping is possible.

The molding die according to the present invention includes a top die and a bottom die, and is a molding die used for a resin sealing device that collectively seals inserted articles to be molded. One of the molds has a clamper having a storage hole formed in the mold opening and closing direction and a diameter-enlarging hole following the storage hole, and a cavity block stored in the storage hole of the clamper The cavity concave portion provided in the mold corresponding to the region where the resin sealing is collectively performed is a bottom surface of the cavity block, and an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. Are formed in a space having a cavity surface that is a stepped wall surface and an inner wall surface of the enlarged-diameter hole, and communicated with the cavity recess between the inner wall surface of the storage hole and the outer wall surface of the cavity block, Along the cavity recess In a molding die in which a suction hole for adsorbing the supplied release film to the cavity recess surface is formed, the cavity block protrudes in the cavity recess inward at the periphery of the bottom surface of the cavity block to cover a part of the step wall surface. Accordingly, a projecting portion for reducing the depth of the cavity concave portion is provided, and the molded product has a plurality of semiconductor elements mounted in a matrix on the circuit board, and the plurality of semiconductor elements are collectively connected to the circuit board. The semiconductor element is encapsulated with resin and diced after encapsulating, and the semiconductor element is separated into individual pieces, and the projecting peripheral portion is a resin encapsulated region, and is outside the outermost dicing position. And an angle formed by the inner wall surface of the projecting portion and the bottom surface of the cavity block is an obtuse angle .
The resin sealing device according to the present invention is characterized in that any one of the above molding dies is mounted.

  ADVANTAGE OF THE INVENTION According to this invention, the molding die and resin sealing apparatus which can prevent the tear of a release film as much as possible can be provided.

The fragmentary sectional view of the upper model in a TCM mold is shown. The fragmentary sectional view of other embodiment of the upper model in a TCM mold is shown. It is explanatory drawing which shows the dicing location of a to-be-molded body. It is explanatory drawing which shows the state at the time of the 2nd mold clamping of the upper mold | type in a TCM shaping | molding die. It is explanatory drawing which shows the other state at the time of the 2nd mold clamping of the upper mold | type in a TCM shaping | molding die. It is explanatory drawing which shows the other state at the time of the 2nd mold clamping of the upper mold | type in a TCM shaping | molding die. The fragmentary sectional view of other embodiment of the upper mold | type in a TCM shaping | molding die is shown. FIG. 9 shows a partial cross-sectional view of still another embodiment of an upper mold in a TCM mold. It is a graph which shows the relationship between the height of a protrusion part, resin pressure, and measured resin leak area. It is a graph which shows the other relationship between the height of a protrusion part, resin pressure, and measured resin leak area. It is sectional drawing at the time of mold opening of a TCM metal mold | die. It is sectional drawing which shows the state at the time of the 1st mold clamping of a TCM metal mold | die. It is sectional drawing of the resin injection | pouring state at the time of the 1st mold clamping of a TCM metal mold | die. It is sectional drawing which shows the state at the time of the 2nd mold clamping of a TCM metal mold | die. It is explanatory drawing which shows the state which the clearance gap produced between the release films in the corner part of a level | step difference. It is explanatory drawing which shows the state which attracted | sucked the release film and was made to contact | adhere to the cavity recessed part surface. It is explanatory drawing which shows the state which the resin leak produced in the corner part of a level | step difference. It is another explanatory drawing which shows the state which the resin leak produced in the corner part of a level | step difference. It is a fragmentary sectional view of FIG.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a partial cross-sectional view of an upper mold 12 in a TCM mold.
The TCM molding die or the TCM resin sealing device is the same as that shown in FIGS.
In the present embodiment, as described above, the upper mold 12 includes the storage hole 16 formed in the mold opening / closing direction and the clamper 18 having the enlarged diameter hole 17 following the storage hole 16, and the storage hole 16 of the clamper 18. And a cavity block 20 housed therein.

A cavity recess 24 provided in the mold corresponding to a region to be resin-sealed collectively includes a bottom surface 20a of the cavity block 20, and a storage hole between the bottom surface 20a of the cavity block 20 and the enlarged diameter hole 17. 16 is formed in a space in which the stepped wall surface 16a forming a part of the inner wall surface 16 and the inner wall surface 17a of the diameter expansion hole 17 are cavity surfaces.
A suction hole 40 is formed between the inner wall surface of the storage hole 16 and the outer wall surface of the cavity block 20. The suction hole 40 communicates with the cavity recess 24 and sucks the air in the cavity recess 24 by a suction device (not shown) to adsorb the release film 38 supplied along the cavity recess 24 to the surface of the cavity recess 24. To do.

In the present embodiment, a characteristic point is that a part of the step wall surface 16a that protrudes inwardly into the cavity recess 24 at the periphery of the bottom surface 20a of the cavity block 20 and constitutes a part of the wall surface of the cavity recess 24 is provided. This is in that a projecting peripheral portion 50 is provided so as to reduce the depth of the cavity concave portion 24 at the site.
The lower surface of the projecting peripheral portion 50 is preferably formed as a flat surface.
Further, the inner wall surface of the projecting portion 50 is formed so that the angle formed by the inner wall surface of the projecting portion 50 and the bottom surface 20a of the cavity block 20 is an obtuse angle (the size of the obtuse angle is not particularly limited, but is preferably about 135 °). Is preferably formed on a tapered surface. By forming such an obtuse angle, it is possible to prevent the release film 38 from being broken at this portion.

  Further, as shown in FIG. 2, it is preferable that the inner wall surface 17a of the enlarged diameter portion 17 is formed on a tapered surface extending from the lower end portion of the stepped wall surface 16a. The angle between this tapered surface and the mold parting surface is preferably about 60 to 70 °.

In addition, as shown in FIG. 3, the position which provides the protrusion part 50 shall be provided in the position which becomes outside the outermost dicing position P and Q of a to-be-molded product. In the case of a semiconductor device, the molded product includes a plurality of semiconductor elements 43 mounted in a matrix on the circuit board 44, and the plurality of semiconductor elements 43 are collectively resin-sealed on the circuit board 44. By dicing, the semiconductor element is separated into individual pieces.
Further, the resin sealing device in the present embodiment is a resin sealing device on which the molding die is mounted.

The molding die or the resin sealing device according to the present embodiment is configured as described above.
Resin sealing by the TCM method is performed by a method similar to that shown in FIGS.
1 and 2 show a state in which the release film 38 supplied into the lower mold 14 and the upper mold 12 is adsorbed to the cavity recess 24 surface by sucking air from the suction holes 40.
In the present embodiment, as described above, a part of the stepped wall surface 16 a that protrudes inward from the cavity recess 24 and covers a part of the wall surface of the cavity recess 24 is covered at the peripheral edge of the bottom surface 20 a of the cavity block 20. A protruding portion 50 is provided.
Thereby, as shown in FIG. 1 or FIG. 2, the depth of the cavity recessed part 24 of the said part became shallow, and the tear of the release film 38 adsorbed | sucked to the said part was able to be reduced as much as possible.

As shown in FIG. 4, the height of the projecting portion 50 is the height at which the lower surface of the projecting portion 50 coincides with the upper end of the inner wall surface 17a of the enlarged diameter portion 17, as shown in FIG. As shown in FIG. 6, a height that is slightly higher than the upper end of the inner wall surface 17a of the enlarged diameter portion 17, or a position that is slightly lower than the upper end of the inner wall surface 17a of the enlarged diameter portion 17 as shown in FIG. If the height is about a certain height, an excessive force is not applied to the release film 38 during the second mold clamping.
Although the height of the step m is exaggerated in the drawings, the height of the step m is actually about 0.5 mm depending on the mold.
The height of the protrusion 50 is preferably about 0.05 to 0.25 mm.

The shape of the protrusion 50 is not limited to that of FIG. 1 or FIG. 2, and the protrusion 50 having a stepped cross section shown in FIG. 7, the protrusion 50 having a curved surface 50a shown in FIG. It may be.
FIGS. 9 and 10 are graphs showing the results of actual measurement of the relationship between the height of the protrusion and the resin pressure and the tear area of the release film 38. As can be seen from FIGS. 9 and 10, the release film 38 is significantly less broken when the protrusion 50 is provided.

  In the above embodiment, the TCM mold and the molding die using the TCM mold and the resin sealing device have been described. However, the present invention provides a cavity recess as shown in Japanese Patent Application Laid-Open No. 2003-291147. Of course, the present invention can also be applied to a molding die and a resin sealing device in which the height of the inner bottom surface varies.

10 Resin sealing device 12 Upper mold 14 Lower mold 16 Storage hole 18 Clamper 20 Cavity block 21 Lower mold chase block 22 Lower mold insert block 24 Cavity recess 26 Mold base 27 Gap 28 Spring 30 Mold base 31 Through hole 32 Pot 33 Plan Jar 34 Resin tablet 35 Gate 36 Runner 38 Release film 40 Suction hole 43 Semiconductor element 44 Circuit board 50 Projection part m Step P, Q Outermost dicing position

Claims (8)

A molding die composed of an upper die and a lower die, and used for a resin sealing device that collectively seals the inserted molding object,
One of the upper and lower molds is
A clamper having a storage hole formed in the mold opening and closing direction and a diameter-enlarging hole following the storage hole;
A cavity block stored in the storage hole of the clamper,
Cavity recesses provided in the mold corresponding to the resin-sealed region collectively are a bottom surface of the cavity block, an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. It is formed in a space having a cavity surface with a stepped wall surface forming a part and an inner wall surface of the enlarged diameter hole,
Molding metal in which a suction hole is formed between the inner wall surface of the storage hole and the outer wall surface of the cavity block so as to adsorb the release film supplied along the cavity recess to the cavity recess surface. In the mold,
Protruding portions that project inwardly into the cavity recess and cover a part of the stepped wall surface to reduce the depth of the cavity recess are provided on the peripheral edge of the bottom surface of the cavity block,
The molding die, wherein the projecting peripheral portion is provided such that an angle formed by an inner wall surface of the projecting peripheral portion and a bottom surface of the cavity block is an obtuse angle. The molding die according to claim 1, wherein an inner wall surface of the diameter-expanded hole is formed as a tapered surface extending from an end portion of the stepped wall surface. A molding die composed of an upper die and a lower die, and used for a resin sealing device that collectively seals the inserted molding object,
One of the upper and lower molds is
A clamper having a storage hole formed in the mold opening and closing direction and a diameter-enlarging hole following the storage hole;
A cavity block stored in the storage hole of the clamper,
Cavity recesses provided in the mold corresponding to the resin-sealed region collectively are a bottom surface of the cavity block, an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. It is formed in a space having a cavity surface with a stepped wall surface forming a part and an inner wall surface of the enlarged diameter hole,
Molding metal in which a suction hole is formed between the inner wall surface of the storage hole and the outer wall surface of the cavity block so as to adsorb the release film supplied along the cavity recess to the cavity recess surface. In the mold,
Protruding portions that project inwardly into the cavity recess and cover a part of the stepped wall surface to reduce the depth of the cavity recess are provided on the peripheral edge of the bottom surface of the cavity block,
The clamper is supported on the mold base side through a spring with a required gap between the mold base and the clamper,
The cavity block is fixed to the mold base side, and the mold base and the cavity block are provided to be movable toward and away from the clamper against the biasing force of the spring.
Together with the mold base and the cavity block, the clamper moves relatively in the direction of the other mold through the spring, and the first mold clamping is brought into contact with the other mold surface;
From the first mold clamping, the spring is compressed, and the two-stage mold clamping can be performed with the second mold clamping in which the cavity block further approaches the other mold direction to narrow the space of the cavity recess. A molding die characterized by the above.   The molding die according to claim 3, wherein the projecting peripheral portion is provided such that an angle formed by an inner wall surface of the projecting peripheral portion and a bottom surface of the cavity block is an obtuse angle. The molding die according to claim 3 or 4, wherein an inner wall surface of the enlarged diameter hole is formed in a tapered surface extending from an end portion of the stepped wall surface. A molding die composed of an upper die and a lower die, and used for a resin sealing device that collectively seals the inserted molding object,
One of the upper and lower molds is
A clamper having a storage hole formed in the mold opening and closing direction and a diameter-enlarging hole following the storage hole;
A cavity block stored in the storage hole of the clamper,
Cavity recesses provided in the mold corresponding to the resin-sealed region collectively are a bottom surface of the cavity block, an inner wall surface of the storage hole between the bottom surface of the cavity block and the enlarged diameter hole. It is formed in a space having a cavity surface with a stepped wall surface forming a part and an inner wall surface of the enlarged diameter hole,
Molding metal in which a suction hole is formed between the inner wall surface of the storage hole and the outer wall surface of the cavity block so as to adsorb the release film supplied along the cavity recess to the cavity recess surface. In the mold,
Protruding portions that project inwardly into the cavity recess and cover a part of the stepped wall surface to reduce the depth of the cavity recess are provided on the peripheral edge of the bottom surface of the cavity block,
A plurality of semiconductor elements are mounted in a matrix on the circuit board, and the plurality of semiconductor elements are collectively sealed with resin on the circuit board and diced after sealing. Which is separated into pieces,
The protruding portion is a resin sealing portion region and is provided at a position outside the outermost dicing position, and an angle formed by the inner wall surface of the protruding portion and the bottom surface of the cavity block is A molding die characterized by being provided with an obtuse angle . The molding die according to claim 6 , wherein an inner wall surface of the enlarged diameter hole is formed as a tapered surface extending from an end portion of the stepped wall surface. Resin sealing apparatus characterized by molding die according to any one of claims 1 to 7 is mounted.

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