JPH06349870A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent short circuit and discontinuity of a metal fine wire caused by positional fluctuation of a semiconductor pellet due to a resin flow at the time of resin sealing. CONSTITUTION:A semiconductor pellet 7 is mounted on the surface of a resin body 6a stuck to the lower surface of a lead frame 1 while sealing the lower half of a package and the upper half of the package including the semiconductor pellet 7 is sealed by a resin body 11a so as to suppress positional fluctuation in resin sealing of the semiconductor pellet 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and its manufacturing method, and more particularly to a resin-sealed semiconductor device and its manufacturing method.

[0002]

2. Description of the Related Art As shown in FIG. 2A, a conventional method for manufacturing a resin-sealed semiconductor device has an island 12 in the center, and an internal lead and an external lead arranged around the island 12. The semiconductor pellet 7 is mounted on the island 12 supported by the lead frame 1 with the hanging pins (not shown) of the lead frame 1 and the metal fine wire 8 is bonded to the semiconductor pellet 7 and the internal leads of the lead frame 1. Connect between and.

Next, as shown in FIG. 2B, a lead frame 1 having a semiconductor pellet 7 mounted thereon is mounted on a lower mold 4 for sealing having a cavity 2 and a gate 3 and a cavity 9 is provided thereon. The mold 5 is placed on top and clamped, and the thermosetting resin 6 is injected from the gate 3 into the cavities 2 and 9.

Next, as shown in FIG. 2 (c), the resin filled in the cavities 2 and 9 is thermoset and sealed by the resin body 6a, and then separated from the upper and lower molds 4 and 5.

[0005]

In this conventional semiconductor device, the island on which the semiconductor pellets are mounted is usually
Since it is supported by the lead frame only with the hanging pins,
It is weak in strength, and the position of the semiconductor pellets fluctuates due to the stress of the injection resin during the mounting or bonding process or resin encapsulation. There are problems such as short circuit between them, disconnection of metal thin wires, and metal thin wires and islands exposed from the resin body (package).

Further, during resin encapsulation, the resin flows separately under the mold island (lower cavity) and over the semiconductor pellet (upper cavity), but if the position of the semiconductor pellet moves from its original position. However, there is a problem that the flow velocity of the resin in the upper and lower cavities changes and a resin filling difference occurs in the upper and lower cavities, which further accelerates the fluctuation of the position of the semiconductor pellet and entraps air bubbles in the package. It was

[0007]

The semiconductor device of the present invention comprises:
A first resin body that has an opening for mounting an element in the center and that adheres to the lower surface of a lead frame in which internal leads are arranged around the opening to seal the lower half of the package; The first resin body has a semiconductor pellet that is mounted on the surface of the resin body and is electrically connected to the internal leads, and a second resin body that seals the upper half of the package including the semiconductor pellet.

According to the method of manufacturing a semiconductor device of the present invention, a lead frame having an opening for mounting an element in the center and having internal leads arranged around the opening is mounted on a mold and resin is injected, Forming a first resin body that adheres to the lower surface of the lead frame and seals the lower half of the package; and after removing the lead frame from the mold, on the surface of the first resin body in the opening. Mounting the semiconductor pellet, connecting the semiconductor pellet and the internal lead with a fine metal wire, and forming a second resin body in which the upper half of the package including the semiconductor pellet is resin-sealed. It is configured to include and.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

1 (a) to 1 (e) are cross-sectional views showing a sequence of steps for explaining a manufacturing method according to an embodiment of the present invention.

First, as shown in FIG. 1A, a lead having an opening for mounting an element in the center thereof, and an internal lead arranged around the opening and an external lead outside the internal lead. After positioning and mounting the frame 1 on a lower mold 4 for sealing having a molding cavity 2 and a gate 3 and placing an upper mold 5 for sealing having a flat surface on the mold and clamping the mold, A thermosetting resin 6 such as epoxy is injected into the cavity 2 from the gate 3 and filled.

Next, as shown in FIG. 1B, the resin 6 filled in the cavity 2 is semi-cured to form a resin body 6a, and a semi-finished product bonded to the lead frame 1 is formed. Separated from the mold 5 and the lower mold 4.

Next, as shown in FIG. 1C, a semiconductor pellet 7 is mounted on the surface of the resin body 6a in the opening of the lead frame 1 using silver paste. Next, the electrode pad of the semiconductor pellet 7 and the inner lead of the lead frame are bonded and connected with a thin metal wire 8. here,
Since the resin body 6a already exists in the lead frame 1, it is expected that the heat conduction to the semiconductor pellet 7 and the internal leads is poor. In that case, the thickness of the resin body 6a should be made as thin as possible or In addition to increasing the amount of filler component such as alumina mixed therein to improve the thermal conductivity, it is possible to perform bonding not only by thermocompression bonding but also by increasing ultrasonic output.

Next, as shown in FIG. 1D, the lower die 4
The semi-finished product is mounted on the lower mold 4a having the same cavity as above, the upper mold 5a having the cavity 9 and the gate 10 is placed on the upper mold, and the thermosetting resin 11 is injected into the cavity 9 from the gate 10. .

At this time, the size of the cavity 9 must be smaller than the cavity 2 by several tens to 100 μm or more in consideration of the clearance between the pin hole and the positioning pin, the shift of the upper and lower molds, and the like.

Next, as shown in FIG. 1 (e), after filling the cavity 9 with the resin 11, the upper and lower molds 5a and 4a are heated to cure the resin, and the resin is sealed with the resin bodies 6a and 11a. A stopped resin-encapsulated semiconductor device is configured.

The resin body 6a and the resin body 11a may have different filler amounts, or thermosetting resins having different components may be used.

[0018]

As described above, according to the present invention, the semiconductor pellet is mounted on the surface of the resin body which is adhered to the lower surface of the lead frame to seal the lower half of the package, and the semiconductor pellet and the inner lead of the lead frame are mounted. After electrically connecting between the two, by sealing the upper half of the package with resin, it is possible to eliminate fluctuations in the position of the semiconductor pellets and prevent contact and disconnection of the bonding wires caused by fluctuations in the position of the semiconductor pellets. Has the effect of improving reliability.

Further, since it is not necessary to consider the balance of the resin flow injected into the upper and lower cavities, the thickness of the resin body pre-bonded to the lead frame can be made thin, so that the package can be made thin. Therefore, the heat dissipation effect can be increased.

[Brief description of drawings]

1A to 1C are cross-sectional views showing a manufacturing process of an embodiment of the present invention in the order of steps.

2A to 2C are cross-sectional views showing the order of steps for explaining a conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

 1 Lead Frame 2,9 Cavity 3,10 Gate 4,4a Lower Mold 5,5a Upper Mold 6,11 Resin 6a, 11a Resin Body 8 Metal Fine Wire 12 Island

Claims (2)

[Claims] 1. A first resin body which has an opening for mounting an element in the center and which is adhered to the lower surface of a lead frame in which internal leads are arranged around the opening to seal the lower half of the package, A semiconductor pellet that is mounted on the surface of the first resin body in the opening and is electrically connected to the internal leads, and a second resin that seals the upper half of the package including the semiconductor pellet. A semiconductor device having a body. 2. A lead frame having an opening for mounting an element in the center and having internal leads arranged around the opening is mounted in a mold, resin is injected, and the lower surface of the lead frame is bonded. Forming a first resin body that seals the lower half of the package; mounting a semiconductor pellet on the surface of the first resin body in the opening after separating the lead frame from the mold; It includes a step of connecting the semiconductor pellet and the internal lead with a thin metal wire, and a step of forming a second resin body in which an upper half of a package including the semiconductor pellet is resin-sealed. Manufacturing method of semiconductor device.