JPS63205939A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the generation of a hollow and a weld line at a resin- molding part by a method wherein a first cavity and a second cavity are formed and a resin is injected into said cavities via a gate part formed at the second cavity. CONSTITUTION:A semiconductor device is mounted on a die pad at a lead frame part this assembly is resin-molded by using a pair of metal molds 25. The following three are formed at the metal molds 25: a first cavity 27 accommodating the semiconductor device; a second cavity 29 which is continuous via a narrow-width part 28 and which is used to form a frame part 14 between leads; a gate part 30 which is formed at the second cavity 29. A molten resin flows through the route of the gate part 30, the second cavity 29 and the narrow-width part 28, and reaches the first cavity 27 the semiconductor device is molded; at the same time, the frame part 14 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device in which an IC chip or the like is molded.

SUMMARY OF THE INVENTION] The present invention provides a method for manufacturing a semiconductor device formed by molding, for example, an IC chip, which includes: a first cavity that accommodates a semiconductor element; the first and second cavities through a gate provided in the second cavity;
By injecting resin into the cavity, it is possible to prevent cavities and weld lines from forming in the resin-molded part of the semiconductor device, to protect the semiconductor element well, and to effectively display the characteristics of the element. be.

[Prior Art] Conventionally, as a method for manufacturing this type of semiconductor device, there is a method in which, for example, a flat pack type semiconductor device as shown in FIG. 11 is molded using a molding die 25 as shown in FIG. 13. .

In the figure, symbol a indicates a semiconductor device, and this semiconductor device is made by mounting an IC chip on a well-known lead frame, wire bonding it, and then transfer-molding it with epoxy resin or the like using a molding die 25. After the portion 1 is formed, it is manufactured by cutting or etching so that each lead 2 becomes independent.

[Problem to be Solved by the Invention 1] However, in such a conventional example, during molding, due to factors such as the cross-sectional area of the cavity 31 being too large compared to the cross-sectional area of the gate 30, There have been problems in that weld lines and wire deformation are likely to occur due to cavities being formed in the wire and insufficient fluidity of the molten resin.

The present invention was devised in view of these problems, and aims to provide a novel method for manufacturing semiconductor devices with good element characteristics by preventing defects in resin molded parts. be.

[Means for Solving the Problems] Therefore, the present invention has a first cavity that accommodates a semiconductor element, a second cavity that is continuous with the first cavity via a narrow portion, and has a first cavity that accommodates a semiconductor element. The structure is such that resin is injected into the first and second cavities through a gate provided in the second cavity.

[Function] The first cavity accommodates a semiconductor element and performs resin molding, and the second cavity forms a resin molded part surrounding the resin mold. At that time, the molten resin is
From the gate part, the conductor 2 passes through the cavity and the narrow part, and the first
reaches the cavity and surrounds the semiconductor element.

[Example 7] Details of the method for manufacturing a semiconductor device according to the present invention will be described below based on an example shown in the drawings.

First, prior to explaining the manufacturing method, a semiconductor device manufactured by applying this method will be disclosed.

1 and 2 are a plan view and a sectional view of a semiconductor device according to this embodiment, FIGS. 3 and 4 are plan views of a lead frame, and FIG. 5 is a partially enlarged view of a lead frame. 6th
The figure is a perspective view of a molding die, and FIG. 7 is an explanatory diagram showing a transfer molding process.

In the figure, A is a semiconductor device, and is an IC chip! a square prism-shaped mold part 12 containing l;
Intermediate leads 1 led outward from each of the four circumferential surfaces of
3 to 13, a frame part 14 surrounding the mold part 12 and provided integrally with the mold part 12 via the intermediate leads 13 to 13, and a frame part 14 extending outward from the outer surface of the frame part 14. The external lead 15 protrudes and is sequentially electrically connected to the intermediate leads 13 to 13.

The mold part 12 and the frame body part 14 are formed by molding resin such as epoxy or silicone by the present method,
As shown in FIG. 2, the mold part 12 includes an IC chip 1
1 is mounted on Guipat 16 and intermediate lead 13~
The inner end of 13 is integrally molded. In addition, in the figure, 19 indicates a honding wire.

Here, the above-mentioned Guipat 16. The intermediate lead 13° external lead 15 and the bent portion 18 that connects the intermediate lead 13 and the external lead 15 are formed by etching or other processing on a single lead frame 17 as shown in FIG. be. Figure 4 shows such a lead frame 1.
7 shows a state in which the mold part 12 and the frame body part 14 are provided.

Further, the frame portion 14 is molded so as to enclose the bent portion I8, and has a substantially square shape along the molded portion 12. Reinforcement plates 20 to 20 in the shape of a sketch are integrally provided on the inner surface of the corner of the frame portion 14, with two adjacent side edges biting into each other. Further, the reinforcing plate 20 is provided with a detection hole 20a for use in positioning, etc. in a transfer molding process, an assembly process, etc. to be described later. In addition, the reinforcing plate 20
Of course, it is possible to provide an unevenness or other detected portion in place of the detection hole 20a. By arranging such a reinforcing plate 20, deformation of the frame body portion 14 can be prevented, and for example, distortion of the intermediate lead 13 can be prevented from occurring when external force is applied during transportation.

Furthermore, the pitch of the external leads 15-15 is changed at the bending part 18 so that it becomes longer than the pitch of the intermediate leads 13-13, and as shown in FIG. is set to the same value (L) as the pitch of. Therefore, no matter how short the pitch between the intermediate leads 13 to 13 is, the measuring device 6 can measure and inspect element characteristics and the like. Also, in this way, external leads 15 to 1
Since the pitch of 5 can be long, soldering work to printed circuit boards etc. is easy.

Moreover, as mentioned above, when the external leads 15 to 15 are not used for connection to a printed circuit board, etc., the frame body part 1
Of course, it is also planned to cut the intermediate leads 13 to 13 at a position closer to the inside of the semiconductor device 4 and use it as a shape similar to that of a conventional semiconductor device. In this case, the mold part 12
is considerably smaller than the conventional one, and measurements can be carried out reliably even if the pitch of the intermediate leads 13 to 13 is short. It would be possible to obtain semiconductor devices.

When used by cutting at the inside position of the frame body part 14 in this way, as shown in the modified example of FIGS. 9 and 10, an intermediate lead is used! 3 to 13 near the frame body 14 with a narrow width (
By forming the interval C between the intermediate leads 13 to have a length <L (L, <L), it is possible to prevent so-called solder bridges from occurring during soldering.

Next, the lead frame 17 will be explained based on FIGS. 3 and 5.

The lead frame 17 is usually made of multi-wire iron-nickel plate. It is formed by cutting, etching, etc. so as to leave the lead portion etc. As shown in FIG. 3, in the lead frame 17 according to this embodiment, a square-shaped guide pad 16 is disposed in the center of an area corresponding to one semiconductor device A, and a square guide pad 16 is arranged diagonally outward from the four corners of the guide pad 16. A support par 21 is extended in the direction.

The tip of this support par 21 is connected to the lead frame mother plate 17.
a, and the corresponding support) <-21
The middle portion of the plate serves as the reinforcing plate 20.

Then, an IC chip 1 is placed on the side edge of the Guipad 16.
A plurality of terminals of the lead portion 22 wire-bonded to the lead portion 1 face each other.

Each lead extends outward from the plurality of terminals of the lead portion 22 so that the pitch gradually increases,
An intermediate lead 13 is located on the inside, and an external lead 15 is located on the outside, with the bent portion 18 located between the leads.

Two parallel tie bars 23A are attached to the plurality of intermediate leads 13 to 13 on each side edge side of the Guipad 16.
, 23B are horizontally mounted.

Both ends of the tie bars 23 A and 23 B are formed continuously to the reinforcing plate 20 . On the other hand, another tie bar 24 is horizontally formed in the intermediate part of the external leads 15 to 15, and both ends of the tie bar 24 are formed so as not to protrude beyond the edges of the external leads 15A, 15A located on both sides. has been done.

Next, a method for manufacturing this semiconductor device A will be explained.

First, the IC chip 11 is assembled into the guide pad 16 of the lead frame 17 as shown in FIG. The molds are matched from above and below, and molten resin is injected into the molds 25, 25 and solidified.

The molding die 25 has a first cavity 27 that accommodates the IC chip 11 when the molds are matched, and a second cavity 29 that is continuous with the narrow portion 28 and forms the frame portion 14. The resin can be injected into the first and second cavities through a gate portion 30 provided in the second cavity 29. Therefore, there is no need to separately inject resin into the mold part 12 and the frame part 14,
The mold is easy to maintain and manage. Furthermore, as shown in FIG. 7, a plurality of molds 25 may be provided on both sides of the runner 26 to perform transfer molding. Further, since the structure of the semiconductor device A is composed of the mold section 12 and the frame section 14 surrounding the mold section 12, it is possible to set the gate section 30 at any position of the frame section 14.

Here, the molten resin that has passed through the gate part 30 passes through the second cavity 29, passes through the narrow part 28, and reaches the first cavity 27, and the molten resin that passes through the relatively long and narrow cavity is Due to the mold structure, cavities and wire deformation are less likely to occur within the molded part, and weld lines are also less likely to occur.

The state in which the mold part 12 and the frame body part 14 are formed in this way is as shown in FIG. The gap between 15 and 15 is also injected. but,
As described above, the tie bar 23B is provided on the outside of the mold portion 18, and the tie/bar 23A is provided on both sides of the frame portion 14.
, 24, further resin outflow is prevented.

Next, in a cutting process, the semiconductor device A is cut out from the lead frame motherboard 17a, and the intermediate leads 1
The tie bars 23A, 23B, and 24 formed horizontally on the external leads 15 and 15 are cut or etched to form the intermediate leads 13. The external leads I5 are separated and further cut from the bottom bar 21 at the corner of the mold part 12 to obtain a completed semiconductor device.

In addition, the tie bars 23A and 23B are formed in the molding process.

The paris part that has flowed out to 24 and solidified can be easily removed by sandblasting or the like.

Although the embodiments have been described above, various other design changes are possible. For example, in the above embodiments, the second cavity 29 may go around the first cavity 27 that accommodates a semiconductor element such as an IC chip. Is it formed?
the first and second cavities are continuous via the narrow portion 28;
However, as long as the gate portion 30 is provided in the second cavity 29, it is possible to obtain the same effect with other structures.

Further, in the above embodiment, the first cavity 27 is formed as a rectangular recess, but it goes without saying that the present invention can be applied to other shapes as well.

[Effects of the Invention] As is clear from the above description, in the method for manufacturing a semiconductor device according to the present invention, the molten resin that has passed through the gate portion passes through the narrow portion through the second cavity. The molten resin that passes through the relatively long and narrow cavity is less likely to cause cavities or wire deformation in the molded part, and is less likely to cause weld lines. This has the effect of forming a good molded part and maintaining good characteristics of the semiconductor device.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the method for manufacturing a semiconductor device according to the present invention, FIG. 2 is a sectional view of the same, FIGS. 3 and 4 are plan views of a lead frame, and FIG. 5 is a plan view of a lead frame. 6 is a perspective view of the mold, FIG. 7 is an explanatory diagram showing the transfer molding process, FIG. 8 is a perspective view of the measuring device, and FIG. 9 is a plan view showing a modified example of the semiconductor device. 10 is an enlarged view of a modified example, FIG. 11 is a perspective view showing a conventional example, FIG. 12 is a sectional view showing a conventional mounting state, and FIG. 13 is a perspective view showing a conventional molding die. be. A...Semiconductor device, 11...IC chip, 12...
- Mold part, 13... Intermediate lead, 14... Frame body part, 15... External lead, 17... Lead frame, 25... Molding die, 27... First cavity, 28 ...Narrow part, 29...Second cavity, 3
o...Gate part. 11 right-hand pages, 11 pages, 11 right-hand pages.

Claims (1)

[Claims] It has a first cavity that accommodates a semiconductor element, and a second cavity that is continuous with the first cavity through a narrow part, and the first cavity that is connected to the first cavity through a gate part provided in the second cavity. and a method for manufacturing a semiconductor device, comprising injecting a resin into the second cavity.