JP2925375B2 - Molding method for mold part in electronic component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a synthetic resin molded part for packaging a semiconductor chip in an electronic component having a semiconductor chip such as an IC.

[0002]

2. Description of the Related Art In general, this type of electronic component is well known in the art, and as shown in FIGS. 5 and 6, an island portion B is integrally formed on a lead frame A made of a thin metal plate. At the same time, a large number of narrow lead terminals C are integrally formed so that the inner leads C1 at the tips of the lead terminals C extend radially toward the island portions B, After mounting the semiconductor chip D on the upper surface of the semiconductor chip D
Wherein between each inner lead C _1, and wire bonding with a thin gold wires E and, then, the lead frame A, a pair of upper and lower molds F, pinched at G, the molds F, G Molding cavity C formed during
By injecting a synthetic resin in a molten state from a gate J provided along the lower surface of the lead frame A,
A mold section is formed.

[0003]

However, in the conventional molding method of the mold portion, when the lead frame A is sandwiched between a pair of upper and lower molds F and G, the island portion B and the respective inner leads C are formed. ₁ is suspended in the mold part forming cavity H, so that when the molten synthetic resin is injected into the cavity H from the gate J on the lower surface side of the lead frame A,
This molten synthetic resin, the island portion B and the inner leads C1 is displaced so as to be pushed upward from below, and the semiconductor chip D was mounted on the island portion B, between each inner lead C ₁ Since stress is applied to the gold wire E to be connected, the gold wire E is cut off in the middle, or the bonding portion of the gold wire E to the semiconductor chip D and the bonding portion to the inner lead C1 are disconnected. Has caused a problem that the rate of occurrence of defective products is considerably high when molding the molded part.

An object of the present invention is to provide a molding method of a mold part which can solve this problem.

[0005]

In order to achieve the above technical object, the present invention provides a semiconductor device having a semiconductor chip mounted and mounted.
Lead frame with lead terminals for semiconductor chips
A pair of upper and lower molds is used for the
The inner lead at the lead terminal is
Hold it so that it is located in the cavity for molding
In this state, the cavities in the two molds
Of the mold part to inject molten synthetic resin
In the forming method, the lead frame is placed between the two molds.
First, load the semiconductor chip so that it faces downward.
On the other hand, in the cavity of the two dies,
Melted by the molten synthetic resin injected into the tee
The spacer body made of synthetic resin that integrates with the spacer
On the underside of the semiconductor chip and each lead terminal.
To support the lower side of the inner lead,
In this state, the molten synthetic resin is placed in the cavity.
And characterized by injected from the gate provided on the upper surface side of the lead frame. Is the thing.

[0006]

[Work] In this manner, a downward pressing force acts on the semiconductor chip and each inner lead by the molten synthetic resin injected into the cavity for molding the molding portion. Since the lower surface side of each inner lead is supported by a synthetic resin spacer body previously inserted into the molding cavity, the downward displacement of the semiconductor chip and each inner lead is prevented. be able to.

On the other hand, the synthetic resin spacer body is partially melted by the molten synthetic resin injected into the cavity and integrated with the molten synthetic resin to form the semiconductor chip and the spacer. It becomes a part of a mold part for packaging each gold wire and each inner lead.

[0008]

As described above, according to the present invention, it is possible to prevent the semiconductor chip and each inner lead from being displaced by the molten synthetic resin at the time of molding the molded portion, so that the gap between the semiconductor chip and each inner lead can be prevented. It is possible to reliably reduce disconnection of the gold wire on the way and disconnection of the gold wire from the semiconductor chip and the inner lead, thereby significantly reducing the rate of defective products when molding the molded part. It has the effect of being able to be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the drawing, reference numeral 1 denotes a lead frame formed by punching a thin metal plate. In this lead frame 1, an island portion 4 is supported by a support bar 5 at a portion between both side frames 2 and 3. While being integrally formed in a state, a large number of lead terminals 6 are integrally formed such that inner leads 6 a at the tips of the respective lead terminals 6 extend radially toward the island portion 4. . A dam bar 7 is integrally formed between the lead terminals 6.

After the semiconductor chip 8 is die-bonded to the upper surface of the island portion 4 of the lead frame 1, a thin gold wire 9 is wire-bonded between the semiconductor chip 8 and each of the inner leads 6 a. Then, the lead frame 1 is connected to a pair of upper and lower molds 10,
11, the semiconductor chip 8 die-bonded to the island portion 4 of the lead frame 1 is inserted so as to face downward.
Is sandwiched between the molds 10 and 11, and then a molten synthetic resin is injected into a molding cavity 12 through a gate 13 provided along the upper surface of the lead frame 1, thereby forming a molding portion. Is molded.

Prior to the molding of the mold portion, the cavity 12 is provided with a lower surface side of the lead frame 1.
The spacer body 14 made of the same material as the mold part is inserted into the spacer body 14. An annular protrusion 14a is integrally provided on the upper surface of the spacer body 14, and each of the annular protrusions 14a is provided on the upper surface of the annular protrusion 14a. The inner lead 6a is configured so as to be in contact with the lower surface, and the center thereof has a protrusion 14b.
Are provided integrally so that the upper surface of the projection 14b contacts the semiconductor chip 8.

In this way, a downward pressing force acts on the island portion 4 with the semiconductor chip 8 and each inner lead 6a by the molten synthetic resin injected into the cavity 12 for molding. But,
Since the lower surfaces of the semiconductor chip 8 and the inner leads 6a are supported by the synthetic resin spacers 14 previously inserted into the molding cavity 12, the semiconductor chip 8 and the inner leads 6a are formed. 6a
Can be prevented from displacing in the downward direction.

On the other hand, the spacer body 14 made of synthetic resin is used.
The semiconductor chip 8 and the gold wires 9 are partially melted by the molten synthetic resin injected into the cavity 12 and integrated with the molten synthetic resin.
In addition, it becomes a part of a mold part for packaging a part of each inner lead 6a.

[Brief description of the drawings]

FIG. 1 is a plan view of a lead frame according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view when the lead frame is inserted between a pair of upper and lower molds.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a plan view of a lead frame in a conventional method.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead frame 2, 3 Side frame 4 Island part 5 Support bar 6 Lead terminal 6a Inner lead 7 Dam bar 8 Semiconductor chip 9 Gold wire 10, 11 Mold 12 Molding cavity 13 Gate 14 Spacer body 14a Annular projection 14b Projection

Claims (1)

(57) [Claims] A semiconductor chip is mounted and mounted on the semiconductor chip.
Frame with lead terminals for body chip
The semiconductor chip and the lead by a pair of upper and lower molds.
The inner leads at the terminals are
Sandwiched in the cavity for molding
In this state, in the cavity of both the molds
How to mold a mold part to inject molten synthetic resin
In the method, the lead frame is placed between the two dies by a semiconductor chip.
With the die facing down,
Into the cavity in the cavity
Synthesized by being melted and integrated with the molten synthetic resin
The resin spacer is connected to the semiconductor by the spacer.
Inner lead on the underside of the chip and each lead terminal
Insert to support the lower side of the
A method of molding a mold part in an electronic component , wherein the molten synthetic resin is injected into a cavity from a gate provided on an upper surface side of the lead frame.