Semiconductor device

Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package

Reexamination Certificate

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Details

C257S666000, C257S787000, C257S694000, C257S696000, C257S690000, C257S692000

Reexamination Certificate

active

06323545

ABSTRACT:

TECHNICAL FIELD
The present invention relates to the structure of a resin-encapsulated semiconductor device.
BACKGROUND ART
FIG. 7
is a perspective view showing the structure of a memory module used for memory expansion in a personal computer etc.
In the drawing, the reference character
17
denotes a module substrate,
18
denotes electrodes, and
19
denotes semiconductor devices for use as memory.
When expanding memory in a personal computer, the memory module shown in
FIG. 7
is inserted in a memory expansion socket attached to the personal computer.
In the memory module, as shown in
FIG. 7
, a plurality of semiconductor memory devices are mounted on the module substrate
17
and the electrodes
18
for making external connections are arranged along the edge of the memory module substrate
17
.
The electrodes
18
are inserted in a memory expansion socket in the body of the personal computer to make contact with the contact pins in the memory expansion socket, thus making electric connection.
However, with the recent increase in memory capacity of the semiconductor memory devices, it is not always necessary to pack a plurality of semiconductor memory devices
19
in the memory module as shown in FIG.
7
.
For the packaging, low-price resin-encapsulation packages are used for the semiconductor memory devices
19
.
Typical packages include the TSOP (Tin Small Outline Package) shown in FIG.
8
and SOJ (Small Outline Jleaded Package) shown in
FIG. 9
, for example.
These packages have gull-wing-like or J-shaped external leads
20
extending along the outer sides of the body so that they can be mounted with solder on a mounting substrate (the module substrate
17
, for example).
These packages have the leads extending on the outside of the package body; when the electrodes
18
of the module substrate on which semiconductor memory devices using these packages are mounted as shown in
FIG. 7
are inserted in a socket in a personal computer, the external leads
20
may be deformed unless handled carefully enough.
However, since expansion memories for personal computers etc. are for use by common users, they must be so constructed that they can be attached easily without suffering deformation of the external leads even if they are handled somewhat roughly, but the conventional package structures as shown in FIG.
8
and
FIG. 9
do not satisfy this requirement sufficiently.
For semiconductor device packaging suitable for insertion into sockets, there is the LCC (Leadless Chip Carrier) which has a body made of ceramic, and which makes external connections by means of metal printed as terminals on sides of the body, but it requires extremely high packaging cost.
SUMMARY OF THE INVENTION
The present invention has been made to solve these problems, and an object of the invention is to provide a low-cost resin-encapsulated semiconductor device which can be easily inserted into a socket in the body of a personal computer etc. without suffering deformation of the external connections and which can surely make contact with contactors in the socket.
Another object is to enable size reduction of the resin-encapsulated semiconductor device above.
DISCLOSURE OF THE INVENTION
Semiconductor element having a plurality of electrodes formed in its periphery; a plurality of leads for external connection which are provided in correspondence with the plurality of electrodes and respectively connected to the plurality of electrodes through wires; and a package body in which the semiconductor element and the plurality of leads are encapsulated with a resin material, wherein the plurality of leads extend toward a bottom of the package body on the side to be inserted in a socket and bent alternately in raised shape and recessed shape, with tops of the raised parts and bottoms of the recessed parts exposed in surfaces of the package body, and therefore the parts serving as the external connection electrodes (i.e. the tops of the raised parts and the bottoms of the recessed parts) are arranged at a large pitch, so that the area of the external connection electrodes can be enlarged to enhance the reliability of the contact.
Alternatively, the external connection electrodes
2
can ensure required area even with a small lead pitch, and reducing the lead pitch enables the package to be downsized.
According to a semiconductor device of the invention, the plurality of leads extend toward the bottom of the package body on the side to be inserted in the socket and bent alternately in raised shape and recessed shape, with the tops of the raised parts and the bottoms of the recessed parts exposed in the surfaces of the package body, and the plurality of leads terminate in the vicinity of the middle of the bottom of the package body, and therefore the package body can be easily manufactured with a die through resin molding using an injection molding.
According to a semiconductor device of the invention, the semiconductor element mounted has the plurality of electrodes formed approximately in the middle of its surface, and the plurality of leads provided in correspondence with the plurality of electrodes of the semiconductor element have their respective ends on one side extended to the vicinity of the plurality of electrodes and connected to the corresponding electrodes through the wires, and therefore it is possible to reduce the dimension in the height direction of the entirety of the packaged semiconductor device to reduce the size of the semiconductor device.


REFERENCES:
patent: 5105261 (1992-04-01), Ueda et al.
patent: 5172214 (1992-12-01), Casto
patent: 5446317 (1995-08-01), Sato et al.
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patent: 5760471 (1998-06-01), Fujisawa et al.
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patent: 7-22567 (1995-01-01), None
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patent: 4-243155 (1992-08-01), None

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