Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – With provision for cooling the housing or its contents
Reexamination Certificate
1999-06-04
2001-09-11
Picardat, Kevin M. (Department: 2822)
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
With provision for cooling the housing or its contents
C257S675000, C257S713000, C257S717000
Reexamination Certificate
active
06288444
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a semiconductor device and a method of producing the semiconductor device. More particularly, the present invention relates to a semiconductor device suitable for mounting a semiconductor chip which generates heat during an operation and to a method producing such a semiconductor device.
2. Description of the Related Art
As the density of a semiconductor chip has increased in recent years, the number of terminals in a semiconductor chip has increased accordingly. Also, there is a growing tendency for a semiconductor chip to consume a large amount of electric power and to generate a large amount of heat.
In the meantime, electric devices mounted with semiconductor chips have rapidly become smaller, and there is a demand for smaller semiconductor chips. Therefore, it is necessary to develop a semiconductor chip which is small and thin, even if the number of terminals is large.
FIG. 1
illustrates a conventional fine-pitch type semiconductor device
1
. This semiconductor device
1
has a package structure called FBGA (Fine-pitch Ball Grid Array). This structure includes a semiconductor chip
2
, a wiring board
3
, solder balls
7
, and a sealing resin
8
.
The semiconductor chip
2
has a high density, and is fixed with an adhesive
5
onto the upper surface of the wiring board
3
, which functions as an interposer. The wiring board
3
is a printed wiring board or a flexible printed board (in
FIG. 1
, a flexible printed board is shown). The wiring board
3
has a wiring layer
4
formed on a polyimide tape. The wiring layer
4
and the semiconductor chip
2
are electrically connected by a wire
6
.
An opening is formed in a predetermined position of the polyimide tape, and the solder balls
7
are bonded to the wiring layer
4
through the opening. Thus, the semiconductor chip
2
is electrically connected to the solder balls
7
as external connecting terminals via the wiring layer
4
.
The sealing resin
8
is molded to cover the semiconductor chip mounting surface of the wiring board
3
, so as to protect the semiconductor chip
2
, the wiring layer
4
, and the wire
6
.
In the semiconductor device
1
shown in
FIG. 1
, a fine pitch is obtained by arranging the solder balls
7
in a grid pattern on the wiring board
3
, so that the semiconductor device
1
is compatible with the large number of terminals.
As a semiconductor chip has a higher density, the semiconductor chip generates a larger amount of heat. In the semiconductor device
1
, the only heat releasing passage for the heat generated from the semiconductor chip
2
is the sealing resin
8
or the wiring board
3
. However, the resin material used for the sealing resin
8
and the wiring board
3
is poor in thermal conductivity. The heat releasing efficiency of the semiconductor device
1
is low, and the heat generated from the semiconductor chip
2
stays inside the device. As a result, the semiconductor chip
2
is overheated, and causes a faulty operation.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a semiconductor device and a method of producing the semiconductor device, which semiconductor device is smaller than a conventional semiconductor device while maintaining high heat spreading properties.
The object of the present invention is achieved by a semiconductor device including a semiconductor chip, a heat spreading plate, a wiring board, and a sealing resin. The semiconductor chip is mounted on the heat spreading plate having a stage portion. The sealing resin seals the semiconductor chip and the heat spreading plate so that the stage portion is exposed from the sealing resin.
In this structure, heat generated from the semiconductor chip can be efficiently released through the stage portion to the outside, so that the semiconductor chip can be efficiently cooled to avoid faulty operations.
The object of the present invention is also achieved by a method of producing a semiconductor device which includes the following steps of: forming a wiring board having a first wiring layer and an opening portion; forming a heat spreading plate having a fixed portion and a stage portion; temporarily fixing the heat spreading plate to the wiring board so that the stage portion facing the opening portion; mounting a semiconductor chip onto the stage portion; forming a sealing resin for permanently fixing the heat spreading plate to the wiring board so that the stage portion is exposed from the sealing resin; and cutting collectively the heat spreading plate, the wiring board, and the sealing resin, to form individual semiconductor devices.
By this method, the heat spreading plate formed in the heat spreading plate forming step is temporarily fixed to the wiring board formed in the wiring board forming step, so that the heat spreading plate and the wiring board can be collectively assembled. In this manner, the workability is improved compared with a method in which the heat spreading plate and the wiring board are handled and assembled separately.
The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5102829 (1992-04-01), Cohn
patent: 5345106 (1994-09-01), Doering et al.
patent: 5442234 (1995-08-01), Liang
patent: 5583377 (1996-12-01), Higgins, III
patent: 5659200 (1997-08-01), Sono et al.
patent: 5691567 (1997-11-01), Lo et al.
patent: 5703398 (1997-12-01), Sono et al.
patent: 5783426 (1998-07-01), Suzuki et al.
patent: 5869889 (1999-02-01), Chia et al.
patent: 5972736 (1999-10-01), Malladi et al.
patent: 8-125051 (1996-05-01), None
patent: 8-250529 (1996-09-01), None
patent: 84110800 (1997-11-01), None
Abe Mitsuo
Hamano Toshio
Hayakawa Michio
Inoue Hiroshi
Katoh Yoshitsugu
Armstrong Westerman Hattori McLeland & Naughton LLP
Fujitsu Limited
Picardat Kevin M.
LandOfFree
Semiconductor device and method of producing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor device and method of producing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device and method of producing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2524712