JP2008117998A - Resin sealing mold and semiconductor package manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sealing mold which suppresses the formation of voids by reducing the remainder of air in a cavity and can obtain a resin sealing product of high quality. <P>SOLUTION: The resin sealing mold 1 includes a plurality of cavities 5, 7 which are continuously formed through a first gate 8 and dummy cavities 10, 11 which are continuously formed through cavities 5d, 7d and a second gate 13 in the final stage, and the sectional area of the second gate is formed smaller than the sectional area of the first gate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin sealing mold and a method for manufacturing a semiconductor package. Specifically, the present invention relates to a resin sealing mold used in a sealing process in manufacturing a semiconductor package component and a method for manufacturing a semiconductor package.

  In general, a semiconductor package component is manufactured by sealing a semiconductor chip mounted on a lead frame with a thermosetting resin whose main component is an epoxy resin (see, for example, Patent Document 1). .

  Here, a resin sealing device called a molding device is used for manufacturing semiconductor package components, and after positioning and arranging the lead frame between a pair of upper and lower molding dies (resin sealing dies). The semiconductor chip on the lead frame is sealed by closing the pair of molds and injecting molten resin into the cavity formed inside.

Hereinafter, a conventional resin-sealed mold will be described with reference to the drawings.
FIG. 4 is a schematic diagram for explaining a conventional resin-sealed mold. The resin-sealed mold 101 shown here is composed of an upper mold 102 and a lower mold 103, and the upper mold shown by reference numeral a in the figure. A plurality of culls 104 are formed in a row on the mating surface side (two culls are shown for convenience of illustration in FIG. 4), and four upper cavities 105 (105a, 105b, 105c, 105d) and an upper dummy cavity 110 are formed (in FIG. 4, for convenience of illustration, an upper cavity and an upper dummy cavity are shown only on one side of the cull). Further, on the mating surface side of the lower mold indicated by the symbol b in the figure, a pot 106 is formed at a position corresponding to each cull, and a lower mold cavity 107 (107a, 107b, 107c, 107d) and a lower die dummy cavity 111 is formed at a position corresponding to the upper die dummy cavity.

  Here, the pot, the lower mold cavity and the lower mold dummy cavity are continuously formed through the gates 108 (108a, 108b, 108c, 108d, 108e). Specifically, the pot communicates with the first-stage lower mold cavity 107a through the gate (1) 108a, and the first-stage lower mold cavity communicates with the second-stage lower mold cavity 107b through the gate (2) 108b. The second-stage lower mold cavity communicates with the third-stage lower mold cavity 107c through the gate (3) 108c, and the third-stage lower mold cavity communicates with the fourth-stage lower mold cavity 107d through the gate (4) 108d. The lower die cavity in the fourth stage communicates with the lower die dummy cavity via the gate (5) 108e.

  In addition, when the upper mold and the lower mold are combined, the lower mold dummy cavity has air that is present inside the cull, pot, gate, upper mold cavity, lower mold cavity, upper mold dummy cavity, and lower mold dummy cavity. An air vent 112 is provided to allow the air to escape to the outside.

  In the conventional resin-sealed mold configured as described above, the tablet-shaped resin is put into the pot, the upper mold is closed and the mold is clamped, and then the preheated mold (upper mold and lower mold) is used. The resin melts upon receiving heat. The molten resin is pressed by a plunger (not shown) located below the pot, and the first-stage cavity, the second-stage cavity, the third-stage cavity, the fourth-stage cavity, The dummy cavities are injected in this order.

JP 2002-164365 A

  However, in the conventional resin-sealed mold described above, since all the gates are configured to have substantially the same cross-sectional area, a large amount of resin material flows into the dummy cavity together with air, and the cavity (1 Air tends to remain in the second-stage cavity, second-stage cavity, third-stage cavity, and fourth-stage cavity).

  That is, dummy cavities are provided for the purpose of reducing voids in semiconductor package components (products), but the gate that communicates the fourth (final) cavity with the dummy cavity is the other gate (first tier). The gate that communicates the second cavity and the second cavity, the gate that communicates the second cavity and the third cavity, and the gate that communicates the third cavity and the fourth cavity). In other words, since the resin material flows easily in the gate connecting the fourth-stage cavity and the dummy cavity as in the case of other gates because the area is configured to be an area, the dummy is removed from the fourth-stage cavity. The fluidity of the resin material toward the cavity is good, and a large amount of resin material flows into the dummy cavity simultaneously with the air, so that it is empty in the cavity. There is the more likely to remain.

  The present invention was devised in view of the above points, and it is possible to suppress the generation of voids by reducing the residual air in the cavity, and to obtain a high-quality resin-sealed product. The purpose is to provide a mold. It is another object of the present invention to provide a method for manufacturing a semiconductor package capable of suppressing the generation of voids by reducing the residual air in the cavity and obtaining a high-quality resin-encapsulated product.

  In order to achieve the above object, a resin-sealed mold according to the present invention includes a plurality of cavities formed continuously via a first gate, and the cavity and the second gate at the final stage. In the resin-sealed mold provided with a continuously formed dummy cavity and an air vent leading to the outside from the dummy cavity, the cross-sectional area of the second gate is larger than the cross-sectional area of the first gate. It is formed small.

  Here, the cross-sectional area of the second gate is made smaller than the cross-sectional area of the first gate (for example, the height of the second gate is made lower than the height of the first gate). The second gate has a smaller cross-sectional area than that of the first gate), that is, the second gate that connects the final cavity and the dummy cavity communicates with each other. The pressure in the cavity can be increased due to the poor fluidity of the resin material compared to the gate of 1.

  In order to achieve the above object, a method of manufacturing a semiconductor package according to the present invention includes a plurality of cavities formed continuously through a first gate, the cavity in the final stage, and a second gate. A step of disposing a lead frame in a resin-sealing mold provided with a dummy cavity continuously formed through the air, and an air vent leading to the outside from the dummy cavity, and the resin-sealing die including the lead frame And a step of injecting a sealing resin into a mold, wherein the sealing resin is sealed with the sealing resin in a state in which a cross-sectional area of the second gate is smaller than a cross-sectional area of the first gate. Injection into the mold.

  Here, the sealing resin is applied in a state where the cross-sectional area of the second gate is smaller than the cross-sectional area of the first gate (for example, the height of the second gate is lower than the height of the first gate). By injecting into the resin-sealed mold, that is, the fluidity of the resin material is poor in the second gate connecting the final cavity and the dummy cavity compared to the first gate connecting the cavities. The pressure in the cavity can be increased.

  In the resin-sealed mold and semiconductor package manufacturing method of the present invention described above, the pressure in the cavity can be increased, air can be efficiently discharged to the dummy cavity side, and the air in the cavity can be efficiently discharged. Can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.
FIG. 1 is a schematic diagram for explaining an example of a resin-sealed mold to which the present invention is applied. The resin-sealed mold 1 shown here is the same as the above-described conventional resin-sealed mold. A plurality of culls 4 are formed in one row on the mating surface side of the upper mold, which is composed of a mold 2 and a lower mold 3 and indicated by a symbol c in the figure (in FIG. 1, two culls are shown for convenience of illustration). ), A plurality of upper mold cavities 5 (5a, 5b, 5c, 5d) and an upper mold dummy cavity 10 are formed on both sides of the cull (in FIG. 1, for convenience of illustration, only the upper cavity and the upper cavity are provided on one side of the cull. Dummy cavity is shown). Further, a pot 6 is formed at a position corresponding to each cull on the mating surface side of the lower mold indicated by a symbol d in the figure, and lower mold cavities 7 (7a, 7b, 7c, 7d), and the lower die dummy cavity 11 is formed at a position corresponding to the upper die dummy cavity.

  Here, the pot and the lower mold cavity are formed continuously via the first gate 8 (8a, 8b, 8c, 8d), and the lower mold cavity and the lower mold dummy cavity in the fourth stage are the second gate 13. Is formed continuously. Specifically, the pot communicates with the first-stage lower mold cavity 7a via the first gate (1) 8a, and the first-stage lower mold cavity passes through the first gate (2) 8b. The second stage lower mold cavity communicates with the third stage lower mold cavity 7c via the first gate (3) 8c, and the third stage lower mold cavity communicates with the first gate (4 ) It communicates with the lower die cavity 7d of the fourth stage via 8d, and the lower die cavity of the fourth stage communicates with the dummy cavity via the second gate.

  In addition, when the upper mold and the lower mold are combined, the lower mold dummy cavity includes a cull, a pot, a first gate, a second gate, an upper mold cavity, a lower mold cavity, an upper mold cavity, and a lower mold. An air vent 12 for escaping air existing inside the dummy cavity to the outside is provided.

  Specifically, in the resin-sealed mold of the present embodiment, the cavity has a width (cavity width) indicated by symbol A in the figure of 3 mm, a depth indicated by symbol B in the figure (cavity depth) is 4 mm, and symbol C in the figure. The height indicated by (cavity height) is 1.125 mm, and the first gate has a width indicated by the symbol D in the figure (the width of the first gate) is 1.3 mm. The height indicated by the symbol E (the height of the first gate) is 0.4 mm, and the second gate has a width indicated by the symbol F in the drawing (the width of the second gate) of 2.5 mm. The height indicated by the symbol G in the drawing (the height of the second gate) is 0.015 mm. Further, the air vent is configured such that the width indicated by the symbol H in the figure (the width of the air vent) is 2.5 mm, and the height indicated by the symbol I in the figure (the height of the air vent) is 0.015 mm.

  FIG. 2 is a schematic view for explaining another example of a resin-sealed mold to which the present invention is applied. The resin-sealed mold 1 shown here is a resin-sealed mold to which the present invention is applied. As shown in FIG. 2, the upper die 2 and the lower die 3 are formed, and a plurality of culls 4 are formed in a row on the mating surface side of the upper die indicated by the symbol c in the drawing (in FIG. A plurality of upper mold cavities 5 (5a, 5b, 5c, 5d) and an upper mold dummy cavity 10 are formed on both sides of the cull (FIG. 2 shows one side of the cull for convenience of illustration). Only the upper cavity and upper dummy cavity are shown). Further, a pot 6 is formed at a position corresponding to each cull on the mating surface side of the lower mold indicated by a symbol d in the figure, and lower mold cavities 7 (7a, 7b, 7c, 7d), and the lower die dummy cavity 11 is formed at a position corresponding to the upper die dummy cavity.

  Here, the cull and upper mold cavities are continuously formed through the first gate 8 (8a, 8b, 8c, 8d), and the fourth stage upper mold cavity and the upper mold cavity are the second mold cavity. It is formed continuously through the gate 13. Specifically, Cull communicates with the first-stage upper mold cavity 5a via the first gate (1) 8a, and the first-stage upper mold cavity passes through the first gate (2) 8b. The second stage upper mold cavity 5b communicates with the third stage upper mold cavity 5c via the first gate (3) 8c, and the third stage upper mold cavity 5b communicates with the second stage upper mold cavity 5b. The upper mold cavity of the eye communicates with the upper mold cavity 5d of the fourth stage through the first gate (4) 8d, and the upper mold cavity of the fourth stage communicates with the dummy cavity through the second gate. is doing.

  In addition, when the upper mold and the lower mold are combined, the upper mold dummy cavity includes a cull, a pot, a first gate, a second gate, an upper mold cavity, a lower mold cavity, an upper mold cavity, and a lower mold. An air vent 12 for escaping air existing inside the dummy cavity to the outside is provided.

  Specifically, in the resin-sealed mold of the present embodiment, the cavity has a width indicated by the symbol J (cavity width) in the drawing of 3 mm, a depth indicated by the symbol K in the drawing (cavity depth) is 4 mm, and the symbol L in the drawing. The height (cavity height) indicated by is configured to be 1.125 mm, and the first gate has a width indicated by the symbol M in the figure (the width of the first gate) is 1.3 mm. The height indicated by the symbol N (the height of the first gate) is configured to be 0.4 mm, and the second gate has a width indicated by the symbol O in the drawing (the width of the second gate) is 2.5 mm. And the height indicated by the symbol P in the drawing (the height of the second gate) is 0.015 mm. Further, the air vent is configured such that the width indicated by the symbol Q in the figure (the width of the air vent) is 2.5 mm, and the height indicated by the symbol R in the figure is the height of 0.015 mm.

  In one example and another example of the resin-sealed mold to which the present invention described above is applied, the cross-sectional area of the second gate (2.5 mm × 0.015 mm) is equal to the cross-sectional area of the first gate (1.3 mm × 0.4 mm), and the second gate increases the pressure in the cavity formed by the upper mold cavity and the lower mold cavity due to the poor fluidity of the resin material compared to the first gate. be able to. When the pressure in the cavity is increased, air flows more easily than the resin material with viscosity. Therefore, air is efficiently discharged to the dummy cavity formed by the upper and lower dummy cavities. As a result, the remaining air in the cavity can be reduced, and a high-quality semiconductor package component can be manufactured.

  Further, since the air vent and the second gate are configured to have the same height, it is easy to form the air vent and the second gate by the same process (for example, the same polishing process). That is, when the heights of the air vent and the second gate are different, (1) the step of forming the first gate, (2) the step of forming the second gate, and (3) the step of forming the air vent. It is considered that three steps are required. By configuring the air vent and the second gate to have the same height, the air vent and the second gate can be formed in the same step. (1) The two steps of forming the first gate and (2) forming the air vent and the second gate are sufficient.

Hereinafter, a method for manufacturing a semiconductor package using an example of a resin-sealed mold to which the present invention is applied will be described. That is, an example of a semiconductor package manufacturing method to which the present invention is applied will be described.
FIG. 3A is a schematic view for explaining a lead frame used in a method for manufacturing a semiconductor package to which the present invention is applied. A lead frame 21 shown here is a lead frame base material (made of Cu (copper)). A Pd (palladium) layer (thickness of about 0.15 μm) 24 is formed on the entire surface of a Ni (nickel) layer (thickness of about 2 μm) 23 covering the entire surface of a thickness of about 200 μm) 22. To an Au (gold) vapor-deposited layer (thickness: about 0.01 μm) 25.

  In the method of manufacturing a semiconductor package to which the present invention is applied, the lead frame is positioned and arranged on the lower mold 3 in a state where the semiconductor chip 26 is mounted on the die pad portion 21a of the lead frame configured as described above. After the upper die 2 is clamped (see FIG. 3B), an epoxy resin sealing molten resin 27 is injected into the cavity to seal the semiconductor chip 26. That is, in the example of the resin-sealed mold to which the present invention is applied, the width of the first gate is 1.3 mm, the height of the first gate is 0.4 mm, and the width of the second gate is 2. 5 mm, the height of the second gate is 0.015 mm, and the epoxy resin-based sealing molten resin is used in a state where the cross-sectional area of the second gate is smaller than the cross-sectional area of the first gate. The semiconductor chip 26 is sealed by being injected into the cavity.

  In an example of the semiconductor package manufacturing method to which the present invention is applied, the second gate has a cross-sectional area smaller than that of the first gate, that is, the second gate is compared with the first gate. The molten resin for sealing is injected into the cavity in a state where the fluidity of the resin material is poor, and the pressure in the cavity formed by the upper mold cavity and the lower mold cavity can be increased. Air can be efficiently discharged to the dummy cavity side formed by the lower mold cavity, the remaining air in the cavity can be reduced, and a high-quality semiconductor package component can be manufactured.

The mold clamping pressure is 294 KN (30 ton), the injection pressure of resin (transparent resin for semiconductor production, thermosetting transparent resin, thermosetting resin, etc.) is 12.74 MPa (130 kgf / cm ² ), (1) A conventional resin-sealed mold (see FIG. 3) and (2) an example of a resin-sealed mold to which the present invention is applied (see FIG. 1) under conditions of an injection time of 25 seconds and a temperature of 155 ° C. It shows the void generation rate when a 3 mm × 4 mm × 1.125 mm (width × depth × height) semiconductor package component is resin-sealed.

  From Table 1 described above, it can be seen that the resin-sealed mold to which the present invention is applied can reduce the void generation rate as compared with the conventional resin-sealed mold.

It is a schematic diagram for demonstrating an example of the resin sealing metal mold | die to which this invention is applied. It is a schematic diagram for demonstrating another example of the resin sealing metal mold | die to which this invention is applied. It is a schematic diagram for demonstrating an example of the manufacturing method of the semiconductor package to which this invention is applied. It is a schematic diagram for demonstrating the conventional resin sealing metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin sealing metal mold 2 Upper mold 3 Lower mold 4 Cull 5 Upper mold cavity 6 Pot 7 Lower mold cavity 8 First gate 10 Upper mold cavity 11 Lower mold dummy cavity 12 Air vent 13 Second gate 21 Lead frame 21a Die pad part 22 Lead frame base material 23 Ni layer 24 Pd layer 25 Deposition layer 26 Semiconductor chip 27 Molten resin for sealing

Claims (5)

A plurality of cavities formed continuously through the first gate;
A dummy cavity formed continuously through the cavity of the final stage and the second gate;
In the resin-sealed mold provided with an air vent leading to the outside from the dummy cavity,
The resin-sealed mold, wherein a cross-sectional area of the second gate is formed smaller than a cross-sectional area of the first gate. The resin-sealed mold according to claim 1, wherein a height of the second gate is formed lower than a height of the first gate. The resin-sealed mold according to claim 1, wherein the height of the second gate is formed substantially the same as the height of the air vent. A plurality of cavities continuously formed through the first gate, a dummy cavity formed continuously through the final stage cavity and the second gate, and an air vent leading to the outside from the dummy cavity. Placing the lead frame in the provided resin-sealed mold; and
In a method for manufacturing a semiconductor package comprising a step of injecting a sealing resin into the resin-sealed mold in which a lead frame is disposed,
A method for manufacturing a semiconductor package, comprising injecting the sealing resin into the resin sealing mold in a state in which a cross-sectional area of the second gate is smaller than a cross-sectional area of the first gate. The manufacturing method of a semiconductor package according to claim 4, wherein the sealing resin is injected into the resin sealing mold in a state where the height of the second gate is lower than the height of the first gate. Method.

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