JPH06151492A - Method and apparatus for molding semiconductor device - Google Patents

Abstract

PURPOSE:To provide a device and method for manufacturing a resin sealed semiconductor device by which the generation of voids is eliminated by uniformly filling the cavity of a metallic mold with a resin so as to improve the yield of the device. CONSTITUTION:In the title method by which such a semiconductor device that a semiconductor chip 15 is buried in a molded body by holding a lead frame 5 mounted with the chip 15 between a pair of counterposed forces 1 and 2 and filling the cavity 13 formed around the chip 15 with a resin 16, the lead frame 5 is vertically positioned and the resin 16 is injected into the cavity 13 from the bottom side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for molding a semiconductor device, and more particularly to a method and an apparatus for molding a resin-sealed semiconductor device in which a semiconductor chip is molded with a resin molding material and packaged. .

[0002]

2. Description of the Related Art A resin-sealed semiconductor device is formed as a molded body by resin-sealing a semiconductor chip mounted on a lead frame using a mold. A mold used in molding a conventional resin-encapsulated semiconductor device is shown in FIGS. 8 and 9. FIG. 8 is a perspective view showing a state in which the upper and lower molds are separated from each other, and FIG. 9 is a sectional view showing a state in which the two molds are pressure-bonded and resin is injected. When molding a conventional resin-encapsulated semiconductor device, as shown in the figure, the upper mold 2
2 and the lower mold 21, the lead frame 25 to be resin-sealed is horizontally mounted on the lower mold 21 via the positioning fixing pins 24, and the parting surfaces 23 of the upper mold 22 and the lower mold 21 are projected. In addition, the lead frame 25 was sandwiched between the upper and lower molds to inject the resin.

In the state where the parting surfaces 23 are butted against each other (FIG. 9), the cavity 3 is provided between the upper die 22 and the lower die 21 in correspondence with each chip mounting portion 26 of the lead frame 25.
3 is formed. A semiconductor chip 35 is mounted on each chip mounting portion 26, and a lead frame 25 is provided via a wire 34.
Are connected to the corresponding lead terminals of. The resin 36 is injected into the cavity 33 from the injection port 31 by the plunger 30 via the pot 29 and the runner 28. A groove 27 for air escape is provided at the end of the cavity 33 on the side opposite to the inlet 31. 32 is an ejector pin.

When the resin is injected from the injection port 31 into the cavity 33 of the mold having the above-mentioned structure, the resin 36 becomes the cavity 3
The inside of 3 is horizontally advanced along the lead frame 25 to fill the inside of the cavity and seal the semiconductor chip 35 with resin.

FIG. 13 and FIG. 14 show the overall structure of a semiconductor resin encapsulation apparatus using the above-mentioned conventional horizontally arranged mold. FIG. 13 is a partially transparent perspective view, and FIG. 14 is a vertical sectional view. An upper die 53 and a lower die 54 are fixed to an upper platen 51 and a lower platen 52 provided in the housing 50, respectively. The upper and lower platens 51, 52 are the guide posts 5
5, the lower platen 52 slides vertically along the guide posts to press or separate the two dies 53, 54 from each other. In the resin sealing step, both dies are pressure-contacted with each other and resin is filled in a cavity formed between both parting surfaces (pressure-contacting separation surfaces) 71, 72 to seal the semiconductor chip in the cavity with resin.

As shown by an arrow A, a cleaner 56 that can reciprocate in the horizontal direction is provided in the housing 50. The cleaner 56 has an air blow portion 60 in the opening 61 at the tip.
And a brush 59, which are inserted between the molds 51 and 52 separated at the time of cleaning after the resin sealing step is completed, and the brush 59
Rubbing the parting surfaces 71, 72 to scrape off dust such as residual resin adhering to the parting surfaces,
Compressed air is ejected from the air blow portion 60 as indicated by arrow B to blow off dust adhering to the mold. The dust removed from the parting surface of the mold passes through the opening 61 and is indicated by the arrow C.
And is discharged to the outside through the hose 57. The dust scattered in the housing 50 is sucked into the duct 58 provided in the upper part of the housing as indicated by an arrow D and discharged to the outside.

[0007]

However, in the conventional resin encapsulation method for a semiconductor device described above, problems such as the generation of voids (air bubbles) in the resin mold and improper encapsulation occur. This will be described in detail with reference to FIGS. 10 to 12. Figure 10
FIGS. 12A to 12C sequentially show a state in which the resin 36 is filled into the cavity 33 of the conventional horizontally arranged mold. In each figure, (A) is a plan view and (B) is a sectional view. First, as shown in FIG. 10, the resin 36 injected from the injection port 31 provided at the right end of the cavity 33.
Fills the inside of the cavity 33 horizontally from right to left along the lead frame 25. At this time, due to the influence of gravity and the resistance due to the wires and the like on the upper side of the lead frame 25, there is a difference in the filling progress speed between the upper side and the lower side of the lead frame 25, and the lower side of the lead frame advances somewhat faster.

When the resin 36 further advances into the cavity, as shown in FIG. 11, with the lower portion of the lead frame 25 almost filled, the upper portion of the lead frame 25 has a high traveling speed because of resistance due to the wires and semiconductor chips. As the time elapses, the planar progressing state becomes non-uniform as shown in FIG.

As described above, since the filling speed of the resin 36 is not uniform, as shown in FIG. 12, when the cavity 33 is completely filled with the resin, the air escape at the left end of the cavity 33 is released. Void (air bubble) on the upper side near the groove 27
40 occurs, or a resin unfilled portion is formed.

When such voids and unfilled portions are formed, not only the appearance becomes defective, but also functional reliability is deteriorated due to defective sealing, which causes a decrease in yield. It was In addition, such problems as the occurrence of voids have become more and more serious as it becomes more difficult to uniformly fill the resin with the increase in size of semiconductor chips and the reduction in thickness of semiconductor devices.

In the conventional semiconductor resin sealing device shown in FIG. 13, the dust removed from the parting surfaces of the upper and lower molds is surely sucked through the opening 61 and passed through the hose 57. There is a problem in that it cannot be completely discharged to the outside and redeposited onto the lower mold 54. Further, the dust floating in the housing 50 cannot be completely removed through the duct 58, and the floating dust adheres to the semiconductor chip before sealing to deteriorate the quality of the semiconductor device and to improve the reliability of the function. There was a problem of damaging.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and the resin is uniformly filled in the cavity of the mold to eliminate the generation of voids and to improve the yield and to improve the yield around the resin sealing portion. An object of the present invention is to provide a method and an apparatus for manufacturing a resin-encapsulated semiconductor device capable of reliably removing dust.

[0013]

In order to achieve the above object, in the present invention, a lead frame having a semiconductor chip mounted thereon is sandwiched between a pair of opposing mold members (molds), and the semiconductor chip is surrounded by the lead frame. In a method of molding a semiconductor device, in which a molding material (resin) is filled in the formed cavity and the semiconductor chip is embedded and sealed in a molding body,
The lead frame is arranged vertically, and a molding material is injected into the cavity from the lower side of the cavity.

In a preferred embodiment, the parting surfaces of the pair of molds are arranged vertically, the lead frame is arranged vertically along the parting surfaces, and the lead frame holding portion at the lower end of the cavity is arranged. The resin injection port is arranged, and the air escape port is arranged in the lead frame sandwiching portion at the upper end of the cavity to fill the resin from below along the lead frame in the cavity.

An apparatus used in the method for molding a semiconductor device is composed of a pair of dies having a parting surface and arranged to face each other, and a lead frame having a semiconductor chip to be resin-sealed is sandwiched between the dies, A molding device for a semiconductor device, wherein a parting surface of both molds is butted to form a cavity filled with resin between the molds, and a semiconductor chip on the lead frame is arranged in the cavity.
The parting surface is vertically arranged, the lead frame is vertically mounted along the parting surface, the resin injection port is arranged at the lower end of the cavity, and the air escape port is arranged at the upper end of the cavity. Is configured.

The resin sealing device for a semiconductor device according to the present invention includes a pair of molds whose parting surfaces are arranged vertically, and clean air supply means for supplying clean air to the molds from above. It has and.

In a preferred embodiment, a pair of molds having vertical parting surfaces, a housing for hermetically housing the molds, and a mold drive for pressing and separating the molds from each other. And a clean air supply means for supplying clean air into the housing from above, and a lead frame in which a semiconductor chip to be resin-sealed is mounted between both molds as in the molding apparatus described above. A molding apparatus for a semiconductor device in which a cavity for holding a resin is filled between the molds by sandwiching the molds with each other and the parting surfaces of the molds are butted to each other, and the semiconductor chip on the lead frame is disposed in the cavity. The lead frame is vertically mounted along the vertically arranged parting surface, a resin injection port is arranged at the lower end of the cavity, and air is introduced at the upper end of the cavity. And mouth are configured to be positioned.

In a further preferred embodiment, there is provided a parting surface cleaning means which can be inserted between the molds while the parting surface is separated. In a further preferred embodiment, an exhaust duct for sucking and exhausting the air in the housing is provided below the mold.

[0019]

The longitudinal direction of the cavity cross section is vertically arranged, and the lead frame is vertically mounted in the cavity.
The resin that is the molding material is injected from the lower side of the cavity and is filled upward against the gravity. The mold is hermetically housed in a housing, and clean air is supplied from above through a filter, for example, and sucked and discharged from below.

[0020]

1 and 2 show a mold for molding a resin-encapsulated semiconductor device according to an embodiment of the present invention. FIG. 1 is a perspective view showing a state where a pair of left and right molds are separated, and FIG. 2 is a sectional view showing an initial state of resin injection. A molding apparatus for carrying out the method of the present invention comprises a receiving side mold 1 on the left side of the drawing and a pressing side mold 2 on the right side of the drawing.
The lead frame 5 is mounted on the parting surface 3 of the substrate through the pilot pin 4 for positioning and fixing. The parting surfaces 3 of the left and right dies 1 and 2 are butted against each other to sandwich the lead frame 5 between the dies. This parting surface 3 is arranged vertically. Therefore, the lead frame 5 mounted on the parting surface 3 is also vertically arranged. The lead frame 5 has a plurality of chip mounting portions 6 arranged in parallel, a semiconductor chip 15 is mounted on each chip mounting portion 6, and is connected to the corresponding lead terminals of the lead frame 5 via the wires 14.

In the state where the parting surfaces 3 of the left and right dies 1 and 2 are butted against each other (FIG. 2), a cavity 13 is formed around each chip mounting portion 6, and a mold is formed in the cavity 13. The thermosetting resin 16 which is a material is filled. Reference numeral 12 is an ejector pin that serves as a guide when the molds 1 and 2 are combined and separated. The cavity 13 is
As shown in FIG. 2, the longitudinal direction of the cross section is formed vertically,
The resin injection port 1 is provided in the center of the lower end of the lead frame holding part
1 is provided, and a groove 7 for air escape is opened in the lead frame sandwiching portion at the center of the upper end portion. The resin 16 is injected from the pot 9 by pressing the plunger 10 as indicated by the arrow, and is injected into the cavity from the injection port 11 at the lower end of the cavity 13 via the runner 8.

FIGS. 3, 4, and 5 are explanatory views sequentially showing a state in which the resin in the cavity 13 is filled. In each figure, (A) is a cross-sectional view of the cavity portion, and (B) is a front view of the lead frame portion. Figure 3
Indicates the initial stage of filling. The resin 16 is the cavity 13
Since it travels upward from the lower end injection port 11 against gravity, the resistance is made uniform and the upper end surface rises in a substantially balanced state as compared with the above-described conventional horizontal arrangement configuration (FIG. 10). To do.

FIG. 4 shows a state in which the cavity is further filled with resin to cover the semiconductor chip 15. Even when the resin 16 is more than half filled in the cavity 13 in this way, variations in the resistance of the semiconductor chips, wires, etc. with respect to the progress of the resin 16 are canceled by the action of gravity, and the above-described conventional horizontal arrangement configuration (FIG. Unlike the case of 11), the upper end surface rises in the cavity 13 while maintaining a substantially uniform state.

As described above, since the resin 16 is filled in the cavity 13 with the tip end surface in the resin advancing direction being substantially uniform, the air is reliably discharged from the air escape groove at the upper end of the cavity. Therefore, as shown in FIG. 5, the voids 40 and the resin non-filled portion formed in the conventional horizontal arrangement configuration (FIG. 12) are not formed in the state where the resin 16 has progressed in the entire cavity 13, and the cavity 16 is not formed. The entire inside of 13 is completely filled with resin 16.

FIGS. 6 and 7 are a perspective view and a sectional view of a semiconductor device molding apparatus having a vertically arranged left and right mold structure according to the present invention having the above-described structure, respectively.

A receiving side platen 64 and a pressing side platen 65 are provided in the sealed casing 50 so as to be able to approach and separate from each other via a guide post 68. In this example, the left holding platen 65 slides on the guide post 68 by a driving means (not shown) and moves toward the right receiving platen 64. A receiving side mold 66 and a pressing side mold 67 are mounted on each platen 64, 65. The die 66 corresponds to the receiving die 1 shown in FIG. 1 described above, and a lead frame similar to that of FIG. 1 is mounted on the vertically arranged parting surface 73. The die 67 corresponds to the pressing die 2 in FIG. 1, and the parting surface 74 thereof is arranged vertically.
The structures of the molds 66 and 67 are substantially the same as the structures of the molds 1 and 2 described with reference to FIGS.

An air supply duct 62 is provided on the upper side of the housing 50. A filter 63 is provided in the air supply duct 62 at a position corresponding to above the molds 66, 67. Mold 66,
On the lower side of 67, a cleaner 56 is provided so as to be able to enter between the parting surfaces 73 and 74 of the molds 66 and 67 separated as indicated by arrow E. An opening 6 is provided at the upper end of the cleaner 56.
1 is formed, and the air nozzle 60 and the brush 59 are provided in the opening 61. 57 is a hose for discharging dust. An exhaust duct 69 is provided below the molds 66 and 67 in the housing 50.

The mold 6 is manufactured by the resin sealing device having the above structure.
When the semiconductor package is molded between 6 and 67, the resin sealing step is performed as described with reference to FIGS.

When the resin sealing is completed, the mold 67 is replaced by the mold 6.
The molded semiconductor package is taken out of the mold 6 and then the parting surfaces 73 and 74 of both molds are cleaned. Cleaning is separated mold 6
The cleaner 56 is inserted between 6 and 67, and dust such as residual resin on the parting surfaces 73 and 74 is scraped off by the brush 59, and high-pressure air is ejected from the air nozzle 60 as indicated by an arrow H. Blow off. The dust blown off is sucked through the opening 61 of the cleaner 56 as indicated by an arrow J and is discharged to the outside through the hose 57.

At the time of this cleaning, clean air is supplied from the air supply duct 62 through the filter 63 from above the mold as indicated by arrow F, and through the exhaust duct 69 provided on the lower side of the mold as shown by arrow G to the outside. Is discharged to.
As a result, the dust floating in the housing 50 is sucked into the exhaust duct 69 without being redeposited on the vertical parting surfaces 73 and 74 and discharged to the outside. By constantly circulating such clean air, it is possible to prevent dust from adhering to the semiconductor chip before resin sealing and obtain a high quality resin sealed product.

[0031]

As described above, in the present invention, the lead frame having the semiconductor chip to be resin-sealed is arranged vertically and the cavity is filled with the resin from the bottom to the top in the vertical direction. , It is possible to minimize the variation in resistance to the resin filling in the cavity by the action of gravity, and it is possible to fill the resin in a uniform state, preventing the occurrence of voids and the formation of unfilled parts, etc. In addition, deterioration of the reliability of the function due to defective sealing is prevented, and the yield is improved.

Further, by supplying clean air from above the mold and discharging it from below, the dust floating around the parting surface of the mold is carried along the flow of clean air from the top to the bottom. The sealing surface and the semiconductor chip before resin sealing are kept clean and a high quality semiconductor device can be obtained.

The present invention is not limited to the wire bonding structure using the lead frame described in the above embodiment,
It can be applied to a TAB structure using a tape carrier and other semiconductor device structures by resin encapsulation, and the same effects as those of the above-described embodiment can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a pair of molds for molding a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a state in which the molds of FIG. 1 are combined.

3 is an explanatory diagram of a state of an initial stage of resin filling when resin sealing is performed using the mold of FIG.

FIG. 4 is an explanatory diagram of a state of an intermediate stage of resin filling when resin sealing is performed using the mold of FIG.

5 is an explanatory diagram of a state at a completion stage of resin filling when resin sealing is performed using the mold of FIG.

FIG. 6 is a perspective view of a semiconductor resin sealing device according to an embodiment of the present invention.

7 is a sectional view of the resin sealing device of FIG.

FIG. 8 is a perspective view of a conventional mold for molding a resin-sealed semiconductor device.

9 is a cross-sectional view showing a state in which the molds of FIG. 8 are combined.

10 is an explanatory diagram of a state at an initial stage of resin filling when resin sealing is performed using the mold of FIG.

11 is an explanatory diagram of a state of an intermediate stage of resin filling when resin sealing is performed using the mold of FIG.

12 is an explanatory diagram of a state at a completion stage of resin filling when resin sealing is performed using the mold of FIG.

FIG. 13 is a perspective view of a conventional semiconductor resin sealing device.

14 is a cross-sectional view of the resin sealing device of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Receiving side mold, 2; Holding side mold, 3; Parting surface, 5; Lead frame, 6; Chip mounting part, 7; Air escape groove, 8; Runner, 9; Pot, 10 Plunger, 11; Resin injection port, 13; Cavity, 14;
Wire, 15; semiconductor chip, 16; resin.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 13, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 7]

[Figure 5]

[Figure 6]

[Figure 8]

[Figure 9]

[Fig. 13]

FIG. 14

[Figure 10]

FIG. 11

[Fig. 12]

Claims (7)

[Claims] 1. A lead frame on which a semiconductor chip is mounted is sandwiched between a pair of facing mold materials, and a mold material is filled in a cavity formed surrounding the semiconductor chip to put the semiconductor chip in a molded body. In the method for molding a semiconductor device to be embedded, the lead frame is arranged vertically, and a molding material is injected into the cavity from below the cavity. 2. The parting surfaces of the pair of mold materials are vertically arranged, the lead frame is vertically arranged along the parting surfaces, and a molding material injection port is provided in a lead frame sandwiching portion at the lower end of the cavity. 2. The semiconductor device according to claim 1, wherein the semiconductor device is arranged and an air vent is arranged in a lead frame sandwiching portion at an upper end of the cavity, and the molding material is filled from below along the lead frame in the cavity. Molding method. 3. A lead frame comprising a pair of facing mold members having a parting surface and having a semiconductor chip to be mold-sealed sandwiched between the mold members, and the parting surfaces of the mold members are abutted to each other. In a molding device of a semiconductor device, in which a cavity for filling a molding material is formed between both mold materials, and a semiconductor chip on the lead frame is arranged in the cavity, the parting surface is arranged vertically, and the parting surface is arranged vertically. The lead frame is mounted vertically along the cavity, a molding material injection port is arranged at the lower end of the cavity, and an air escape port is arranged at the upper end of the cavity. Molding equipment. 4. A molding apparatus for a semiconductor device, comprising: a pair of mold members having a parting surface arranged vertically and clean air supply means for supplying clean air to the mold members from above. 5. A pair of mold members whose parting surfaces are arranged vertically, a casing for hermetically containing the mold members, a mold member driving means for pressing and separating the mold members, and a clean member in the casing. 4. The apparatus for molding a semiconductor device according to claim 3, further comprising clean air supply means for supplying air from above. 6. The apparatus for molding a semiconductor device according to claim 5, further comprising a parting surface cleaning means that can be inserted between the two mold members in a state where the parting surface is separated. 7. The apparatus for molding a semiconductor device according to claim 6, wherein an exhaust duct for sucking and exhausting the air in the housing is provided below the mold member.