JPH0837201A - Method of manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To suppress a displacement in a chip location when sealed with resin by a method wherein a chip is mounted onto a smaller tab than a chip area and sealing resin is injected into a cavity on the chip mounting surface side of a lead frame set in a resin sealing die. CONSTITUTION:First, a semiconductor chip 2 is joined to a tab 4. At this time, adhesives are applied to only the tab 4 to fix the semiconductor chip 2. Next, an electrode pad on the semiconductor chip 2 is electrically connected with a top end part of an inner lead 6 via a bonding wire 15. A lead frame 3 that wire bonding is completed is set in a resin sealing die 10. In the resin sealing die 10, a gate 12 for injecting sealing resin into a cavity 11 is formed on the mounting surface side of the semiconductor chip 2 when setting the lead frame 3. Thus, sealing resin 14 injected from the gate 12 is first plugged from the mounting surface of the semiconductor chip 2, and since any pressure is not applied from the rear surface side of the tab 4, a chip location is stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of semiconductor manufacturing, and is particularly effective when applied to packaging technology for semiconductor devices.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device has a structure in which a semiconductor chip is mounted on a tab having an area equal to or larger than that area. If you have such a tab,
There is a problem that a lead frame is required for each chip size and the cost of the lead frame increases. In order to solve this problem, for example, Japanese Patent Laid-Open No. 63-2047.
No. 53, page 2, upper right column, lines 4 to 8, and FIG. 1 on page 6, a semiconductor element (chip) is mounted on a die pad (tab) of a lead frame. In a semiconductor device resin-sealed with a thermosetting resin in a placed state, a die pad formed smaller than a bottom surface of a semiconductor element is used.

In a conventional semiconductor device having a structure in which a semiconductor chip is mounted on a tab having an area equal to or larger than the area of the semiconductor device, the gate portion of the resin-sealing mold for resin-sealing the semiconductor chip is mounted in the semiconductor chip mounting direction. It is installed on the chip mounting surface or the anti-chip mounting surface regardless of the above.

[0004]

However, when the tab shape is smaller than the chip area, the tab lead for supporting the tab has a long structure. In this structure, as shown in FIG. 7, when a resin injection gate 37 is provided on the opposite side of the mounting surface of the semiconductor chip 31 of the tab 33 with the lead frame 32 sandwiched during resin encapsulation, The pressure due to the injection of the stopping resin 39 is received from the opposite side of the semiconductor chip 31 mounting surface, and a gap is created between the chip portion not fixed to the tab 33 and the tab lead 34, and the position of the semiconductor chip 31 is located on the chip mounting surface side The problem of displacement to was newly found. This phenomenon becomes remarkable as the chip area increases.

When the position of the chip is displaced toward the chip mounting surface side, the bonding wire electrically connecting the electrode pad of the semiconductor chip and the inner lead is exposed from the package surface.

Therefore, an object of the present invention is to provide a technique capable of suppressing displacement of the chip position during resin sealing of a semiconductor device having a tab shape smaller than the chip area.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0008]

The outline of the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, the chip is mounted on a tab smaller than the chip area, toward the cavity on the chip mounting surface side of the lead frame set in the resin sealing mold,
The sealing resin is injected.

[0009]

According to the above-mentioned means, the resin pressure at the time of resin injection is received from the chip mounting surface, so that there is no gap between the leads supporting the chip and the tab and the chip position is stable.
It is possible to suppress the displacement of the chip position during resin sealing. Therefore, stable quality can be secured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partial plan view of a lead frame 3 used in the present invention. The lead frame 3 includes a tab 4 on which a semiconductor chip is mounted, a tab lead 5 for supporting the tab 4, and an inner lead 6 for external connection for electrically connecting to an external device (for example, a mounting board or a measuring device).
And an outer lead 7, and a dam lead 8 connecting a plurality of leads for external connection. The tab 4 is formed smaller than the area of the chip to be mounted, and the lead frame is shared so that the tab 4 can be mounted regardless of the size of the chip. By using such a lead frame, the contact area between the chip and the sealing resin is increased, and package cracks can be prevented.

FIG. 2 is a view showing an assembly using the lead frame 3. The semiconductor chip 2 is mounted on the tab 3, and the tip portion of the inner lead 6 and the electrode pad (not shown) of the semiconductor chip 2 are electrically connected by the bonding wire 15. The semiconductor chip 2 is fixed to the tab 3 with a conductive or non-conductive adhesive (not shown), and the adhesive is applied only to the tab 3.

Next, a method of manufacturing the semiconductor device 1 will be described.

First, the lead frame 3 is prepared. The lead frame 3 is obtained by machining a normal process, for example by pressing or etching, QFP (Q uad F la
t P -ackage) type semiconductor device. Next, the lead frame 3 is transferred to a chip (die) bonding process, and the semiconductor chip 2 is bonded to the tab 4 as shown in FIG. At that time, the adhesive is applied only to the tab 4, and the semiconductor chip 2 is fixed only by the tab 4. As a result, the exposed silicon area of the semiconductor chip 2 is increased, so that the contact area between the semiconductor chip 2 and the sealing resin 14 is increased. Therefore, the sealing resin 14 and the semiconductor chip 2 by the subsequent heat treatment
It is possible to suppress the generation of voids between and, and to prevent the generation of package cracks. Next, the electrode pads (not shown) on the semiconductor chip 2 and the tips of the inner leads 6 are electrically connected by a bonding wire 15 made of a conductor such as gold or aluminum. The lead frame 3 on which the wire bonding is completed is, as shown in FIG. 3, a resin encapsulation mold for encapsulating the semiconductor chip 2, the inner leads 6, the bonding wires 15 and the like with a thermosetting encapsulating resin. Set to 10. In the resin-sealing die 10, a gate 12 for injecting the sealing resin into the cavity 11 is formed on the semiconductor chip 2 mounting surface side when the lead frame 3 is set. As a result, the sealing resin 14 injected from the gate 12 is filled from the mounting surface of the semiconductor chip 2 first, and pressure is not applied from the back surface side of the tab 4. Therefore, a gap is not formed between the leads supporting the chip and the tab, and the chip position is stable, so that the displacement of the chip position during resin sealing can be suppressed.

After the encapsulation resin filled in the cavity 11 of the resin encapsulation mold 10 and encapsulating the semiconductor chip 2, the inner leads 6, the bonding wires 15, etc. is thermally cured, the lead frame 3 is encapsulated with the resin. Take out from the mold 10 for the frame, frame frame 9, dam lead 9 to outer lead 7
To separate each semiconductor device. Then, each outer lead 7 is formed into a desired shape, for example, as shown in FIG.
In the QFP as shown in FIGS. 3A and 3B, the semiconductor device 1 is formed by molding into a gull wing shape.

The effects of the present invention will be described below.

(1) By injecting the sealing resin toward the side of the lead frame on which the semiconductor chip is mounted, the resin pressure at the time of resin injection is received from the chip mounting surface, so that the chip and the tab are supported. There is no gap between the leads,
Since the chip position is stable, displacement of the chip position during resin sealing can be suppressed. Therefore, it is possible to reduce defective sealing and improve reliability.

(2) Since the injection port of the sealing resin when the assembly is set in the resin sealing die is provided on the side of the lead frame on which the semiconductor chip is mounted, the sealing resin is Since it is filled from the chip mounting surface side, the chip position is stable and displacement of the chip position during resin sealing can be suppressed.

(3) Since the adhesive is applied only to the tab, the exposed silicon area of the semiconductor chip increases, so that the contact area between the semiconductor chip and the sealing resin increases. Therefore, it is possible to suppress the generation of voids between the sealing resin and the semiconductor chip due to the heat treatment, and it is possible to prevent the generation of package cracks.

The invention made by the inventor of the present invention has been specifically described based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. In the above embodiment, the gate, which is the injection port of the sealing resin, is provided on the semiconductor chip mounting surface side, but the present invention can be realized by providing it on the side opposite to the semiconductor chip mounting surface as in the conventional case. For example,
As shown in FIGS. 5 and 6, a through hole 24 for allowing the sealing resin 30 to pass is provided at the gate position of the lead frame 17, and the semiconductor chip mounting is performed from the gate 28 on the side opposite to the semiconductor chip mounting surface of the lead frame 17. The sealing resin 30 is injected into the surface side. According to such a method, the present invention can be realized by using a conventional resin sealing mold.

[0020]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

That is, by injecting the sealing resin toward the side of the lead frame on which the semiconductor chip is mounted, the resin pressure at the time of resin injection is received from the chip mounting surface, so that the leads supporting the chip and the tab are supported. Since there is no gap between them and the chip position is stable, displacement of the chip position during resin sealing can be suppressed. Therefore, it is possible to reduce defective sealing and improve reliability.

[0022]

[Brief description of drawings]

FIG. 1 is a partial plan view of a lead frame used in the present invention.

FIG. 2 is a diagram showing a state in which a semiconductor chip is mounted on a lead frame used in the present invention.

FIG. 3 is a diagram showing a resin sealing method for a semiconductor device according to an embodiment of the present invention.

FIG. 4A is a plan sectional view of a semiconductor device formed according to the present invention. (B) is a II sectional view of (a).

FIG. 5 is a partial plan view of a lead frame used in another embodiment of the present invention.

FIG. 6 is a diagram showing a resin sealing method for a semiconductor device according to another embodiment of the present invention.

FIG. 7 is a diagram showing a conventional resin sealing method for a semiconductor device.

[Explanation of symbols] 1 ... Semiconductor device, 2 ... Semiconductor chip, 3 ... Lead frame, 4 ... Tab, 5 ... Tab lead, 6 ... Inner lead, 7 ... Outer lead, 8 ... Dam lead, 9: Frame frame, 10: Resin sealing mold, 11
... cavity, 12 ... gate, 13 ... runner, 1
4 ... Sealing resin, 15 ... Bonding wire, 16
…… Package, 17 …… Lead frame, 18 …… Tabs, 19 …… Tab leads, 20 …… Inner leads, 2
1 …… Outer lead, 22 …… Dam lead, 23 ……
Frame frame, 24 ... Passage hole, 25 ... Semiconductor chip,
26 ... Resin sealing mold, 27 ... Cavity, 28 ...
… Gate, 29 …… runner, 30 …… sealing resin, 31
...... Semiconductor chip, 32 …… Lead frame, 33 ……
Tab, 34 ... Tab lead, 35 ... Mold for resin encapsulation,
36 ... cavity, 37 ... gate, 38 ... runner, 39 ... sealing resin

Claims (4)

[Claims] 1. A semiconductor chip, a tab for mounting the semiconductor chip, which is smaller than the area of the semiconductor chip, a tab lead for connecting the tab and a lead frame, and a tip near the periphery of the tab. A resin-sealing mold is provided with an assembly consisting of a plurality of connecting leads in which parts are arranged, and a bonding wire for electrically connecting the electrode pad on the semiconductor chip and the corresponding external lead-out. A method of manufacturing a semiconductor device, comprising setting and injecting a sealing resin into the resin sealing mold to form a package, wherein the sealing resin is mounted on the semiconductor chip of the lead frame. A method for manufacturing a semiconductor device, characterized in that the semiconductor device is injected from the side where it is placed. 2. The injection port of the sealing resin when the assembly is set in the resin sealing mold is provided on the side of the lead frame on which the semiconductor chip is mounted. The method for manufacturing a semiconductor device according to claim 1. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the adhesive is applied only to the tab. 4. A semiconductor chip, a tab for mounting the semiconductor chip, a tab lead for mounting the semiconductor chip and connecting the tab and the lead frame, and a tip portion near the periphery of the tab. An assembly consisting of a plurality of connecting leads arranged and a bonding wire for electrically connecting the electrode pad on the semiconductor chip and a corresponding external lead-out is set in a resin sealing mold. A method for manufacturing a semiconductor device, wherein a package is formed by injecting a sealing resin into the resin sealing die, wherein the sealing resin is mounted on the semiconductor chip of the lead frame. A method for manufacturing a semiconductor device, characterized in that it is injected from the side.