JP2006175638A - Sheet resin for compression molding and compression molding method - Google Patents

Abstract

The present invention provides a sheet-like resin in which air hardly remains in a mold and a compression molding method using the same.
A sheet-like resin 10 is a plate-like body accommodated in a mold 12 as a raw material for compression molding, and has a vent hole 14 penetrating in the thickness direction.
[Selection] Figure 1

Description

  The present invention relates to a compression molding sheet resin used for sealing electronic components, for example, and a compression molding method using the same.

  2. Description of the Related Art Conventionally, a compression molding method using a sheet-like resin is known as one method for sealing an electronic component such as a semiconductor with a resin. Briefly, the object to be sealed and the sheet-shaped resin as a raw material are accommodated in a heated mold to soften the sheet-shaped resin, and the softened resin is pressed with a mold to seal the object to be sealed. While forming into a predetermined shape. The resin is thermosetting, and after being softened, it is further heated and cured.

  The sheet-like resin is molded into a shape that can be accommodated in the mold with an appropriate gap, and can be easily carried into the mold.

  Exhaust holes are formed in the mold, and when the mold pressurizes the softened resin into a predetermined shape, the air in the gap between the mold and the sheet-shaped resin is exhausted to the outside through the exhaust holes.

  However, the resin may be deformed in such a manner as to partition the inside of the mold during the molding process, and the air in the part partitioned from the exhaust hole by the resin may be trapped in the mold. Due to such air, a part of the surface of the resin is not sufficiently heated, the softening becomes insufficient, and a defective part may be formed.

  Further, due to air trapped in the mold, a concave portion may be formed on the surface of the product, or a void may be formed inside the product. Even if the volume of the gap is small, the air expands due to heating, so that recesses and voids with unacceptable sizes may be formed in the product.

  On the other hand, a method has been proposed in which the air in the mold is easily exhausted by making the central portion of the sheet-like resin protrude from the peripheral portion (see, for example, Patent Document 1).

JP-A-9-129659

  However, since the sheet-like resin whose central portion protrudes from the peripheral portion has a greater degree of freedom of deformation in the molding process than the sheet-like resin having a uniform thickness, deformation in an aspect that partitions the inside of the mold occurs. Is also possible. In addition, the sheet-shaped resin with the central part protruding from the peripheral part forms a large gap between the mold and the sheet-shaped resin with a uniform thickness. There is concern about being done.

  The present invention has been made in view of the above problems, and an object thereof is to provide a sheet-like resin in which air hardly remains in a mold and a compression molding method using the same.

  The present invention solves the above-mentioned problems with a sheet-like resin for compression molding, which is a plate-like body accommodated in a mold as a raw material for compression molding and has a vent hole penetrating in the thickness direction.

  By forming a vent hole in this way, even if the sheet-shaped resin is deformed so as to partition the inside of the mold, the air in the partitioned gap passes through the vent hole from one side of the sheet-shaped resin to the other side. It moves and is exhausted to the outside.

  Moreover, it may replace with a ventilation hole and may form the notch connected to thickness direction both surfaces.

  Further, a ventilation groove communicating with the peripheral edge may be formed on at least one surface in the thickness direction. As described above, when the ventilation groove is formed in the sheet-shaped resin, even if the sheet-shaped resin is deformed so as to partition the inside of the mold, the air in the partitioned gap moves to the periphery of the sheet-shaped resin through the ventilation groove. And exhausted to the outside.

  Moreover, it is good also as a structure which forms several protrusion on the at least one surface of the thickness direction of sheet-like resin, and forms the space | gap which can ventilate between a type | mold in the state fitted to the type | mold.

  In this way, by forming a void that can be intentionally ventilated, reliable exhaust is possible. Further, by forming a plurality of protrusions, it is possible to suppress the degree of freedom in the molding process of the sheet-like resin to be small, and to suppress deformation of the sheet-like resin that partitions the mold.

  According to the present invention, high-quality compression molding can be realized by reliably exhausting the air in the mold.

  Hereinafter, preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a sheet-like resin 10 according to the first embodiment of the present invention is a plate-like body accommodated in a mold 12 as a raw material for compression molding, and a vent hole 14 penetrating in the thickness direction. It is characterized by the formation. Other configurations are not considered particularly important for understanding the present embodiment, and thus description thereof will be omitted as appropriate.

  As shown in FIG. 2, the sheet-like resin 10 is a substantially rectangular plate-like body having a uniform thickness, and the material is a thermosetting resin.

  The vent holes 14 have a substantially circular cross section, and are formed at appropriate intervals in a plurality of (9 places in the first embodiment) portions of the sheet-like resin 10. The diameter of the vent hole 14 is preferably 1 mm or more, and more preferably 3 mm or more.

  A plurality of objects to be sealed 16 are fixed to one side of the substrate 18.

  The mold 12 includes an upper mold 20, a lower mold 22, a frame-shaped mold 24, and a heater (not shown) for heating them.

  The upper mold 20 includes a suction mechanism or a chuck mechanism (not shown), and can hold / release the surface of the lower surface of the substrate 18 opposite to the surface to which the object to be sealed 16 is fixed.

  The lower mold 22 includes an upper end portion 22A, an intermediate portion 22B, and a base portion 22C. The upper end portion 22A is fitted inside the frame-shaped mold 24 so as to be slidable in the vertical direction. The intermediate portion 22B penetrates the lower end portion of the frame mold 24 and connects the upper end portion 22A and the base portion 22C. A compression spring 26 is mounted between the base portion 22 </ b> C and the frame-shaped mold 24.

  The inside of the frame-shaped mold 24 and the upper side of the upper end portion 22A of the lower mold 22 constitute a cavity 24A. The frame-shaped mold 24 is formed with exhaust holes 24B for exhausting the air inside the cavity 24A to the outside. A pressure reducing device 28 for sucking air in the cavity 24A is connected to the exhaust hole 24B via a pipe 27.

  The lower mold 22 and the frame-shaped mold 24 can be moved up and down in the vertical direction with respect to the upper mold 20, and the periphery of the substrate 18 is sandwiched from both sides in the vertical direction by the frame-shaped mold 24 and the upper mold 20. Since the upper mold 20 is approached, the sheet-like resin 10 can be pressurized.

  Next, the operation of the sheet-like resin 10 in the mold 12 will be described.

  First, in a state where the lower mold 22 and the frame mold 24 are separated from the upper mold 20, the substrate 18 is held on the lower surface of the upper mold 20 so that the object to be sealed 16 faces downward. Further, the sheet-like resin 10 is carried into the cavity 24A.

  Next, the lower mold 22 and the frame-shaped mold 24 are brought close to the upper mold 20, the periphery of the substrate 18 is sandwiched between the upper mold 20 and the frame-shaped mold 24, and the object to be sealed 16 is accommodated in the cavity 24A. . The upper mold 20, the lower mold 22, and the frame-shaped mold 24 are constantly heated by a heater, and the sheet-shaped resin 10 that is carried into and accommodated in the cavity 24A is softened.

  In this state, the lower die 22 is further brought closer to the upper die 20 against the reaction force of the compression spring 26 while sucking the air in the cavity 24A by the pressure reducing device 26 and exhausting it outside the frame-like die 24. And pressurizing the softened resin. Thus, the resin is molded into the shape of the cavity 24A while sealing the object 16 to be sealed.

  At this time, as shown in FIG. 3, the sheet-like resin 10 may be deformed in such a manner as to partition the cavity 24A. In FIG. 3, the gap between the sheet-like resin 10 and the mold 12 is drawn to be significantly larger than actual for understanding the present embodiment. However, since the vent hole 14 is formed in the sheet-like resin 10, the air in a portion that is partitioned from the exhaust hole 24 </ b> B side by the sheet-like resin 10 passes through the vent hole 14 on one side of the sheet-like resin 10. To the other side and exhausted to the outside through the exhaust hole 24B. Therefore, high quality compression molding can be realized. Note that a part or all of the vent holes 14 are displaced from the object to be sealed 16 in the direction perpendicular to the paper surface and are not closed by the part to be sealed 22A.

  After the compression molding, the resin and the substrate 18 are cut for each of the objects to be sealed 16 to complete a plurality of products.

  In the first embodiment, the pressure reducing device 28 sucks the air in the cavity 24A. However, the pressure reducing device may be omitted if the air in the cavity 24A can be exhausted sufficiently.

  In the first embodiment, the vent hole 14 has a circular cross section and nine holes are formed. The shape and number of the vent holes are appropriately determined according to the shape of the mold and the shape of the object to be sealed. do it. For example, like the sheet-like resin 30 according to the second embodiment of the present invention shown in FIG. 4, three elongated slit-like vent holes 32 may be formed.

  In the first embodiment, a plurality of objects to be sealed 16 are simultaneously sealed with resin by one compression molding. However, one object to be sealed is sealed with resin by one compression molding. The present invention can also be applied when stopping.

  Next, a third embodiment of the present invention will be described.

  As shown in FIG. 5, the sheet-like resin 40 according to the third embodiment has a notch that communicates with both sides in the thickness direction instead of the vent hole 14 with respect to the sheet-like resin 10 according to the first embodiment. The difference is that 42 is formed. Since other structures are the same as those of the sheet-like resin 10, description thereof is omitted.

  The notches 42 are formed into a plurality of (six in this embodiment) in the form of elongated slits substantially perpendicular to the periphery. Specifically, three cutouts 42 are formed at appropriate intervals at three positions on one peripheral edge, and three cutouts 42 are formed at three positions on the other peripheral edge symmetrically with these. .

  Even if the sheet-like resin 40 is deformed in such a manner as to partition the cavity 24A when being molded, the air in the portion partitioned from the exhaust hole 24B side by the sheet-like resin 40 is the same as the sheet-like resin 10. Moves from the one side of the sheet-like resin 40 to the other side through the notch 42 and is exhausted from the exhaust hole 24B side.

  In the third embodiment, the notches 42 are slit-like and are formed at six locations in the sheet-like resin 40. The shape and number of the notches are the shape of the mold or the shape of the object to be sealed. What is necessary is just to determine suitably according to.

  Next, a fourth embodiment of the present invention will be described.

  As shown in FIG. 6 and FIG. 7, the sheet-like resin 50 according to the fourth embodiment is a ventilation that communicates with the periphery of the sheet-like resin 10 according to the first embodiment instead of the vent hole 14. The difference is that the grooves 52 are formed on both surfaces in the thickness direction. Since other structures are the same as those of the sheet-like resin 10, description thereof is omitted.

  The ventilation grooves 52 are formed in a lattice pattern substantially parallel to the periphery of the sheet-like resin 50.

  Even when the sheet-like resin 50 is deformed in such a manner as to partition the cavity 24A when being molded, the air in the portion partitioned from the exhaust hole 24B side by the sheet-like resin 50 passes through the ventilation groove 52 and the sheet. It moves to the peripheral part of the resin 50 and is exhausted to the outside through the exhaust hole 24B.

  In the fourth embodiment, the ventilation groove 52 is formed in a lattice pattern, but the ventilation groove pattern may be appropriately determined according to the shape of the mold and the shape of the object to be sealed. Further, the pattern of the ventilation grooves may be different on both sides of the sheet-like resin. Moreover, you may form a ventilation groove only in the single side | surface of sheet-like resin.

  Next, a fifth embodiment of the present invention will be described.

  As shown in FIGS. 8 and 9, the sheet-like resin 60 according to the fifth embodiment has a plurality of (this first-like) on one surface in the thickness direction with respect to the sheet-like resin 10 according to the first embodiment. The fifth embodiment is different in that five projections 62 are formed and an air-permeable gap is formed between the projection 12 and the mold 12. Since other structures are the same as those of the sheet-like resin 10, description thereof is omitted.

  The protrusions 62 have a substantially circular cross section and are formed in the vicinity of the central portion and the four corners of the sheet-like resin 10, and these protrusion amounts are substantially equal.

  By thus forming a gap that can be intentionally ventilated, the air in the gap can be reliably exhausted. In addition, since a plurality of protrusions 62 are formed, the degree of freedom in the deformation process of the sheet-like resin 60 is suppressed to be small, and the deformation of the sheet-like resin in a manner that partitions the mold is suppressed.

  In the fifth embodiment, the protrusions 62 have a substantially circular cross section and are formed at five locations on the sheet-like resin 60. The shape and number of protrusions are the shape of the mold or the shape of the object to be sealed. What is necessary is just to determine suitably according to. For example, two elongated two protrusions parallel to one side of the sheet-like resin may be formed. Moreover, you may form a some protrusion on both surfaces of sheet-like resin.

  In the first to fifth embodiments, each of the sheet-like resin is formed with any one of a vent hole, a notch, a vent groove, and a protrusion. You may form in one sheet-like resin. For example, the air hole and the notch may be formed in one sheet-like resin.

  In the first to fifth embodiments, the sheet-like resin is substantially rectangular, but the shape of the sheet-like resin may be determined according to the shape of the mold or the like.

  The present invention can be used for compression molding for sealing electronic components, for example.

1 is a side sectional view schematically showing the structure of a sheet-like resin and a compression molding die according to a first embodiment of the present invention. Plan view of the sheet resin Side sectional view schematically showing a deformation mode in the mold of the sheet-like resin The top view of sheet-like resin concerning a 2nd embodiment of the present invention. The top view of sheet-like resin concerning a 3rd embodiment of the present invention. The top view of sheet-like resin concerning a 4th embodiment of the present invention. Side sectional view along line VII-VII in FIG. The top view of sheet-like resin concerning a 5th embodiment of the present invention. Side view of the sheet resin

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 30, 40, 50, 60 ... Sheet-like resin 12 ... Type | mold 14, 32 ... Air hole 16 ... Sealed object 18 ... Board | substrate 20 ... Upper mold | type 22 ... Lower mold | type 22A ... Upper end part 22B ... Middle part 22C ... Base part 24 ... Frame type 24A ... Cavity 24B ... Exhaust hole 26 ... Compression spring 27 ... Piping 28 ... Pressure reducing device 42 ... Notch 52 ... Ventilation groove 62 ... Protrusion

Claims (6)

A sheet-like resin for compression molding, which is a plate-like body accommodated in a mold as a raw material for compression molding, and has a vent hole penetrating in the thickness direction. A sheet-like resin for compression molding, which is a plate-like body accommodated in a mold as a raw material for compression molding, and has cutouts communicating with both sides in the thickness direction. A sheet-like resin for compression molding, characterized in that it is a plate-like body accommodated in a mold as a raw material for compression molding, and a ventilation groove communicating with the periphery is formed on at least one surface in the thickness direction. It is a plate-like body accommodated in a mold as a raw material for compression molding, and a plurality of protrusions are formed on at least one surface in the thickness direction, and a ventilation space is formed between the mold and the mold. A sheet-like resin for compression molding characterized by the above. The sheet-like resin for compression molding according to any one of claims 1 to 4 and an object to be sealed are accommodated in the mold, the sheet-like resin is heated and softened, and the softened resin is A compression molding method characterized in that it is molded into a predetermined shape while sealing the object to be sealed by pressing with a mold. In claim 5,
A compression molding method characterized by sucking air in the mold and exhausting it outside, pressurizing the softened resin with the mold and sealing the object to be sealed into a predetermined shape .

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