JPH06216177A - Semiconductor resin-sealing apparatus - Google Patents

Abstract

PURPOSE:To prevent the occurrence of voids caused by the mixing of bubbles into a resin when a semiconductor chip undergoes resin sealing. CONSTITUTION:In the chase of a lower die 24, the lower half part of a cavity corresponding to the package of a semiconductor component is formed. At the same time, a dam block 29, which is coupled and located in a gap part between lead parts 3 of a lead frame, is provided in the protruding shape. In the cavity, a gelled resin is injected with a resin injecting mechanism through a resin injecting path and a gate. Of the dam blocks 29, the side wall parts located in the vicinities of the four corner parts of the cavity are made to be notched shapes. Thus, resin wells (A) and (B) 34, into which a part of the resin injected into the cavity escapes, are formed. The cross-sectional area B of the resin well 34 far from the gate is formed larger than the cross-sectional area A of the resin well 34 closer to the gate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor resin sealing device used for resin sealing of semiconductor parts such as ICs.

[0002]

2. Description of the Related Art As a semiconductor component such as an IC, for example, there is one in which a large number of lead legs are led out from a side surface of a package formed by sealing a semiconductor chip with a resin. When manufacturing this type of semiconductor component, generally, as shown in FIG.
The lead frame 1 as shown in FIG.

The lead frame 1 includes a stage 2 for mounting a semiconductor chip (not shown), a plurality of lead portions 3 serving as lead legs of a semiconductor component, and a connecting portion 4 for connecting them to each other. It is formed by punching out from a metal plate. In this case, the semiconductor chip is the stage 2
After being mounted on the
A predetermined connection is made with the base end portion of, and thereafter, a square region P indicated by a two-dot chain line in the figure is resin-sealed by a resin sealing device. It should be noted that a large number of semiconductor components can be obtained from one lead frame 1.

As shown in FIGS. 8 and 9, the conventional resin encapsulation device is composed of an upper die 5 and a lower die 6, and the package P
A mold 8 having a cavity 7 corresponding to the above, a resin injection mechanism 9 for injecting a resin into the cavity 7 of the mold 8 in a mold clamped state, and the like are configured. At this time,
As shown in FIG.
The chase 10 on which is set is provided in a concave shape corresponding to the thickness of the lead frame 1.
Reference numeral 0 includes the lower half of the cavity 7, and is provided with a dam block 11 and the like which are fitted in a space between the lead portions 3 of the lead frame 1. In FIG. 8, for the sake of convenience, in order to clarify the concavo-convex relationship, a convex portion, that is, a portion which comes into close contact with the upper mold 5 during mold clamping is shown by hatching.

Further, the lower mold 5 is supplied with a resin tablet made of, for example, an epoxy resin and is heated by the pot 1.
2, and a groove-shaped resin injection path 13 for guiding the resin from the pot 12 into each of the cavities 7 is provided. The gate 14 is an inlet portion of the resin injection passage 13 to each of the cavities 7. The upper mold 5 is also provided with the upper half of the cavity 7 and the like. Then, as shown in FIG. 9, the resin injecting mechanism 9 supplies the resin R which is supplied into the pot 12 and gelated by heating.
Is extruded upward by the plunger 15 and the resin R is filled in the cavity 7 through the resin injection passage 13.

Thus, with the die 8 opened, the lead frame 1 with the semiconductor chip mounted thereon is set on the lower die 6, and after the die is clamped, the resin is injected into the cavity 7 by the resin injection mechanism 9. Is injected. Then, after the resin is cured, the mold is opened and the lead frame 1 on which the package P is formed is taken out. Thereafter, unnecessary resin such as culls and burrs is removed from the lead frame 1, and the connecting portion 4 is cut off to separate the individual semiconductor components.

[0007]

By the way, in the resin sealing device as described above, when the resin tablet placed in the pot 12 is gelled and injected into the cavity 7, the pot 12 and the resin are The air existing in the injection path 13 or the like is configured to escape from the inside of the cavity 7 to the outside.

However, in the past, when the gelled resin R was extruded, a part of the air in the pot 12 or the resin injection path 13 was caught in the flowing resin R to form a bubble state. There is a possibility that they may be mixed, and eventually voids may occur in the package P.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the occurrence of voids due to air being mixed into the resin when the semiconductor chip is sealed with the resin. It is to provide a semiconductor resin encapsulating device that can be used.

[0010]

SUMMARY OF THE INVENTION A semiconductor resin encapsulation device of the present invention is a mold in which a lead frame formed by connecting a plurality of lead portions is set, and a resin is provided in a cavity provided in the mold. And a resin injection mechanism for resin-sealing the semiconductor chip mounted on the lead frame, which is provided in the mold and fits into a space between the lead portions when the lead frame is set. It is characterized in that a resin pool, which is continuous with the corner portion of the cavity and through which a part of the resin injected into the cavity escapes, is formed in the dam block to be aligned.

In this case, it is more effective if the resin reservoir is formed so that the distance from the gate for injecting the resin into the cavity increases as the distance increases.

[0012]

When the resin is injected into the cavity of the mold by the resin injection mechanism, the remaining air may be entrained in the resin as air bubbles so as to be entrained in the resin. Here, it has been confirmed that the inclusion of air bubbles occurs in the tip side portion of the inflowing resin, and the occurrence of voids tends to occur mainly in the corners of the semiconductor component package.

According to the semiconductor resin sealing device of the present invention, the dam block is formed with the resin reservoir which is continuous with the corner of the cavity and allows a part of the resin injected into the cavity to escape. The resin containing the inflowing air bubbles is expelled to the resin pool. Therefore,
The resin with which the cavity is filled can be free of bubbles.

By the way, the resin is filled into the cavity through the gate. In this case, in the corners of the cavity, the resin is sequentially filled from the portion closer to the gate, and the portion far from the gate is finally filled with the resin. Will be filled. At this time, since the resin flows while mixing air bubbles also in the cavity, the amount of air bubbles mixed in the cavity at the last portion filled with the resin increases.

Therefore, if the resin reservoir is formed such that the distance from the gate for injecting the resin into the cavity becomes larger, the resin can be sufficiently expelled even if the amount of air bubbles mixed in the resin increases. It is possible to further enhance the effect of preventing the occurrence of voids.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The present embodiment corresponds to claim 2. Further, the appearance of the lead frame 1 shown in FIG. 6 is the same as that of the conventional one, so that a new illustration is omitted and the reference numerals are also made common.

First, the structure of the lead frame 1 used for manufacturing semiconductor components will be briefly described. As shown in FIG. 6, the lead frame 1 includes a semiconductor chip 21 (see FIG.
(Refer to FIG. 3), and a plurality of stages 2 which extend to both outer sides of the stage 2 and serve as lead legs of semiconductor components.
The lead portion 3 of the book and the connecting portion 4 which connects them to each other and is finally cut are formed by punching and forming from one metal plate.

In this case, the semiconductor chip 21 is mounted on the stage 2 and then bonded to the bonding wire 22 (see FIG. 2).
Predetermined connection with the base end portion of each lead portion 3, and thereafter, a square region P indicated by a two-dot chain line in FIG. 6 is resin-sealed by a resin sealing device to be described later to form a semiconductor component package. It is supposed to be. It should be noted that a large number of semiconductor components can be obtained from one lead frame 1.

Next, a resin sealing device according to this embodiment will be described with reference to FIGS. 1 to 5. First, although not shown in detail, the overall structure of the resin sealing device will be briefly described. The resin sealing device is provided so as to be fixed to and detachable from the upper mold 23. A die 25 composed of the lower die 24, a die drive mechanism (not shown) for clamping and opening the die 25, a temperature controller (not shown) for heating the die 25, and the lead frame 1 A transport mechanism (not shown) for loading and unloading the mold 25, a resin injection mechanism 26 for injecting resin into the mold 25 in the mold clamped state, a microcomputer for controlling each mechanism, and the like are configured.

Among them, the lead frame 1 is set in the mold 25, and a cavity 27 corresponding to a package of the semiconductor component is formed. That is, as shown in FIG. 5, the lower mold 24 has a chase 28 on which the lead frame 1 is set.
Are provided in a concave shape corresponding to the thickness of the lead frame 1.

The lower half of the cavity 27 is formed in the chase 28, and as shown in FIG. 1, the chase 28 is fitted into the space between the lead portions 3 of the lead frame 1. The dam block 29 is provided in a convex shape. In addition, in FIG. 5, in order to clarify the uneven relationship,
For convenience, the convex portion, that is, the portion that comes into close contact with the upper mold 23 during mold clamping is shown by hatching. Although not shown in detail, the upper mold 23 is provided with an upper half portion of the cavity 27 and the like.

Further, as shown in FIG. 3, the lower mold 24
For example, a circular pot 30 to which a resin tablet of epoxy resin is supplied and heated, and a groove-shaped resin injection passage 31 for guiding the resin from the pot 30 into the cavities 27 are provided. As shown in FIGS. 2 and 5, the gate 32 is an inlet portion of the resin injection path 31 to each of the cavities 27. In this case,
Further, as shown in FIG. 5, each gate 32 is provided at a position closer to the left end of each cavity 27 in the drawing. still,
As shown in FIG. 4, the upper mold 23 is also provided with a concave portion forming the upper end portion of the pot 30 and a groove portion forming the upper half portion of the resin injection passage 31.

Then, as shown in FIG. 4, the resin injection mechanism 26 supplies a resin tablet made of, for example, an epoxy resin into the pot 30, and the resin R gelated by heating is extruded upward by a plunger 33. The resin is injected from the gate 32 into the cavity 27 through the resin injection passage 31.

In the present embodiment, as shown in FIG. 1, of the dam block 29 formed on the chase 28 of the lower mold 24, the side walls near the four corners of the cavity 27 have a notched shape. By doing so, a resin reservoir 34 is formed at a side portion of the dam block 29, in which a part of the resin R injected into the cavity 27 escapes. In this case, as shown also in FIGS. 2 and 5, the resin pool 34 is continuously formed in the cavity 27 by forming one side wall portion of the dam block 29, which originally stands vertically upward, into a slanted notch. , Dam block 2 from its four corners
9 is formed in a triangular shape in cross section.

Further, in the present embodiment, as shown in FIG. 1, the cavity 27 is located at two corners on the left end side in the drawing,
That is, the cross-sectional area B of the resin puddle 34 located at the two corners on the right end side in the figure of the cavity 27, that is, the cross-sectional area B of the resin puddle 34 farther from the gate 32 than the cross-sectional area A of the resin puddle 34 closer to the gate 32. The resin pools 34 are formed so that Specifically, the ratio of the cross-sectional areas A and B (A: B) is
The ratio is set to be equivalent to the ratio (C: D) of the distance between the gate 32 and the end of the cavity 27 shown in FIG.

Next, the operation of the above configuration will be described.
The semiconductor component is manufactured by the following procedure. That is, first, with the mold 25 opened, the lower mold 24 is moved by the transfer mechanism.
The lead frame 1 having the semiconductor chip 21 mounted thereon is set on the chase 28, and together with this, the resin tablet is supplied into the pot 30. When the mold is clamped by the mold driving mechanism and the resin R in the pot 30 is gelled, the plunger 33 is lifted to move the resin R into the pot 30.
From the gate 32 through the resin injection path 31 to fill the cavity 27.

When the resin R is cured by further heating,
The mold is opened, and the lead frame 1 having the package P formed at a required position is taken out. Thereafter, unnecessary resin such as cull cured in the pot 30 and the resin injection passage 31 and flash cured in the resin reservoir 34 is removed from the lead frame 1, and the connecting portion 4 is cut off. It is separated into individual semiconductor components.

Thus, in the above process, when the resin R is injected into the cavity 27, a part of the air existing in the pot 30, the resin injection path 31, etc. is caught in the flowing resin R. In this way, air bubbles may be mixed in. If the resin R is hardened in the cavity 27 in a state where air bubbles remain mixed, voids will be generated in the package P. Here, it is confirmed that the above-described mixing of air bubbles into the resin R occurs in the front end side portion of the inflowing resin R, and thus the voids are likely to be concentrated mainly in the corners of the package P. Was done.

On the other hand, in this embodiment, the cavity 2
The side walls of the dam block 29 located near the four corners of No. 7 are notched to form the resin pool 34 in which part of the resin R injected into the cavity 27 escapes. The resin R containing the air bubbles that have flowed into the chamber is expelled to the resin pool 34. As a result, the resin R filled in the cavity 27 is
It is possible to prevent the inclusion of air bubbles, and it is possible to prevent the occurrence of voids as much as possible.

By the way, the resin R is filled into the cavity 27 through the gate 32. In this case, in the four corners of the cavity 27, the resin R is filled in order from the portion close to the gate 32. The resin R is finally filled in the distant portion. At this time, since the resin R also flows while mixing air bubbles in the cavity 27, the amount of the resin R in which air bubbles are mixed is increased by that much in the last portion of the cavity 27 where the resin R is filled. It will be.

However, in this embodiment, the resin pool 34
Are formed so that the distance from the gate 32 becomes larger, the resin R mixed with the bubbles can be sufficiently expelled to the resin reservoir 34 even if the amount of bubbles mixed in the resin R increases. In addition, the effect of preventing the generation of voids is further enhanced.

As described above, according to this embodiment, the resin pool 3 located at the four corners of the cavity 27 of the lower mold 24 for expelling a part of the resin R injected into the cavity 27.
4 is formed, unlike the conventional one, the occurrence of voids in the package P can be prevented as much as possible even if there is a situation in which bubbles are mixed in the resin R. Moreover, in particular, in this embodiment, the size of each resin reservoir 34 is changed according to the distance from the gate 32, so that the void prevention effect is further enhanced.

FIG. 7 shows another embodiment of the present invention. The present embodiment is different from the above one in the shape of the dam block 42 on the lower die 41, that is, the method of forming the resin reservoir 43.

That is, in the above embodiment, the dam block 29
The side walls near the four corners of the cavity 27 are notched to form the resin pool 34 having a triangular cross section at the side of the dam block 29. , The height dimension of the upper wall portion of the dam block 42 in the vicinity of the four corners of the cavity 27 is made smaller than the height dimension of the other dam block 42, so that the resin pool is positioned above the dam block 42. 43 is formed. Also in this embodiment,
By changing the height dimensions E and F, the size of the resin reservoir 43 is changed according to the distance from the gate 32.

Also in such a configuration, when the resin R is filled in the cavity 27, the resin R containing air bubbles can be expelled to the resin reservoir 43, as a result of the voids in the package P, as in the above embodiment. It is possible to obtain a similar effect such that the occurrence of the above can be prevented as much as possible.

In each of the above embodiments, each resin reservoir 34,
Although the size of 43 is changed according to the distance from the gate 32, by providing at least a resin pool, the resin R containing bubbles can be expelled and the occurrence of voids can be prevented as much as possible. It is possible (the invention of claim 1).

In addition, the present invention is not limited to the above embodiments, and various modifications such as a U-groove shape can be considered as the shape of the resin reservoir, and lead frames and semiconductor parts of various shapes can be formed. The present invention can be applied, for example, and can be appropriately modified and implemented without departing from the spirit of the invention.

[0038]

As is apparent from the above description, according to the semiconductor resin sealing device of the present invention, the dam provided on the mold and fitted in the space between the lead portions when the lead frame is set. The block has a resin pool that is continuous with the corner of the cavity and allows some of the resin injected into the cavity to escape, which is caused by air being mixed into the resin when the semiconductor chip is sealed with resin. It has an excellent practical effect that the generation of voids can be prevented as much as possible.

Further, in this case, if the resin reservoir is formed so that the distance from the gate for injecting the resin into the cavity is larger, the effect of preventing the occurrence of voids can be further enhanced. Is.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, which is shown in FIG.
Enlarged vertical sectional front view of the main part of the mold along the line

FIG. 2 is an enlarged plan view of a main part of a lower mold with a lead frame set.

FIG. 3 is a plan view of the lower mold with the lead frame set.

FIG. 4 is a vertical cross-sectional side view of the main part of the mold during molding along the line YY of FIG.

FIG. 5 is an enlarged plan view of the main part of the lower mold.

FIG. 6 is a plan view of the lead frame.

FIG. 7 is a view corresponding to FIG. 1 showing another embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 5 showing a conventional example.

FIG. 9 is a view corresponding to FIG.

[Explanation of symbols]

In the drawings, 1 is a lead frame, 3 is a lead portion, 21 is a semiconductor chip, 23 is an upper mold, 24 and 41 are lower molds, 25 is a mold, 26 is a resin injection mechanism, 27 is a cavity, 28 is a chase, 29. , 42 are dam blocks, 30 are pots, 3
1 is a resin injection path, 32 is a gate, 33 is a plunger, 3
Reference numerals 4 and 43 denote resin pools.

Claims (2)

[Claims] 1. A mold in which a lead frame formed by connecting a plurality of lead parts is set, and a semiconductor chip mounted on the lead frame by injecting resin into a cavity provided in the mold. And a resin injection mechanism for sealing the resin, wherein a dam block provided in the mold and fitted in a gap between the lead portions when the lead frame is set is connected to a corner portion of the cavity. A semiconductor resin encapsulation device, characterized in that a resin pool is formed in which a part of the resin injected into the cavity escapes. 2. The semiconductor resin encapsulation device according to claim 1, wherein the resin reservoir is formed such that the resin reservoir is larger as the distance from the gate for injecting the resin into the cavity is longer.