Electricity: conductors and insulators – Conduits – cables or conductors – Preformed panel circuit arrangement
Reexamination Certificate
1999-03-25
2001-06-19
Gaffin, Jeffrey (Department: 2841)
Electricity: conductors and insulators
Conduits, cables or conductors
Preformed panel circuit arrangement
C174S015100, C174S260000
Reexamination Certificate
active
06248957
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a system board device and, more particularly, to a printed-circuit board reinforcing member for reinforcing a printed-circuit board and a system board device using such a printed circuit board.
A large-scale computer is provided with a system board device comprising a mother bard and a plurality of daughter boards mounted on the mother board. A plurality of RAMs are mounted on each of the daughter boards. Additionally, a plurality of multi-chip modules, each of which has a pin grid-array structure, are mounted on the mother board. The multi-chip module having the pin grid-array structure is mounted on the mother board by a plurality of pins being soldered to respective terminals formed on the mother board. Such a multi-chip module has a relatively large vertical cross section having a side of which length is as long as 100 mm. Accordingly, if the mother board is warped, a displacement of the pins from the mother board is large. Thus, there is a problem in that a reliability of mounting is decreased. Additionally, In the system board device, the mother board is modified if necessary. Accordingly, the system board device preferably has a structure in which replacement of the multi-chip module and modification of the mother board are considered.
2. Description of the Related Art
FIG. 1
is a perspective view of a conventional system board device
10
. In
FIG. 1
, the system board device
10
includes a mother board
11
, a mother-board reinforcing member
12
having a square-frame shape and a multi-chip module
20
. The mother-board reinforcing member
12
is fixed to a front surface of the mother board
11
in an area in which the multi-chip module
20
is placed. The mother-board reinforcing member
12
is fixed to the mother board
11
by screws
13
provided on each corner of the mother-board reinforcing member
12
. Accordingly, the multi-chip module
20
having a pin grid array is located inside the mother-board reinforcing member
12
. Since the mother-board reinforcing member
12
is fixed by screws
13
at each corner portion of the mother-board reinforcing member
12
, an area in which the multi-chip module
20
is positioned is reinforced by the mother-board reinforcing member
12
. In such a structure, the mother board
11
is hardly warped when a thermal stress is generated in the mother board
11
. Thereby, soldered portions between the pins of the multi-chip module
20
and the terminals formed on the front surface of the mother board
11
are positively prevented from being destroyed.
FIG. 2
is a perspective view of another conventional system board device
30
. The system board device
30
comprises the mother bard
11
, a mother-board reinforcing member
31
having a square-frame shape and the multi-chip module
20
having pins
21
to be soldered to the terminals of the mother board
11
. Unlike the mother-board reinforcing member
12
shown in
FIG. 1
, the mother-board reinforcing member
31
is fixed to a back surface of the mother board
11
. The mother-board reinforcing member
31
is located in an area in which the multi-chip module
20
is mounted, and is fixed by screws
32
at each corner portion of the mother-board reinforcing member
31
. That is, the mother-board reinforcing member
31
is fixed to the mother board
11
in a position opposite to the multi-chip module
20
. As shown in an enlarged view in
FIG. 2
, each of the pins
21
is connected to the respective terminal
33
of the mother board
11
by a solder
34
.
In the system board device
10
shown in
FIG. 1
, a space
41
is needed between the multi-chip module
20
and the mother-board reinforcing member
12
that surrounds the multi-chip module
20
so that a nozzle
40
having a square-frame shape can be inserted between the multi-chip module
20
and the mother-board reinforcing member
12
so as to blow hot air to melt a solder. Accordingly, the size of the mother-board reinforcing member
12
is increased. Thus, if a plurality of multi-chip modules
20
are mounted on the mother board
11
, a distance between the adjacent multi-chip modules
20
is increased, which results in a low efficiency of mounting.
Additionally, a wire
42
for modification of the mother board
11
must run over a top surface of the mother-board reinforcing member
12
, and it is difficult to fix the wire
42
to the mother board
11
. Accordingly, the wire tends to be unintentionally cut off when the multi-chip module
20
is removed from the mother board
11
by using the above-mentioned nozzle
40
.
On the other hand, in the system board device
30
shown in
FIG. 2
, since the mother-board reinforcing member
31
is mounted on the back surface of the mother board
11
, a plurality of multi-chip modules can be efficiently arranged on the mother board
11
. However, since the mother-board reinforcing member
31
protrudes in a direction opposite to the multi-chip module
20
, an overall height H of the system board device
30
is larger than an overall height of the system module device
10
shown in FIG.
1
. This is not preferable when the system board device
30
must be accommodated in a small and restricted space of a large-scale computer. Additionally, since the mother-board reinforcing member
31
is mounted on the back surface which is opposite to the front surface on which the multi-chip module
20
is mounted, a capability for restricting a warp due to a thermal stress is lower than that of the mother-board reinforcing member
12
which is mounted on the same surface on which the multi-chip module
20
is mounted. Thus, a reliability of the soldered connection between the pins
21
of the multi-chip module
20
and the terminals
33
formed on the mother board
11
is decreased.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful printed-circuit board reinforcing member in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a printed-circuit board reinforcing member which can reduce a space to be provided between an electronic part mounted on a printed-circuit board and a printed-circuit board reinforcing member fixed to the printed-circuit board.
Another object of the present invention is to provide a printed-circuit board reinforcing member which guides an electronic part to be placed at an appropriate position inside the printed-circuit board reinforcing member.
A further object of the present invention is to provide a printed-circuit board reinforcing member which can prevent a wire extending from inside the printed-circuit board reinforcing member to outside the printed-circuit board reinforcing member in a state in which the printed-circuit board reinforcing member is fixed on a printed circuit board.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a printed-circuit board reinforcing member adapted to be mounted on a surface of a printed-circuit board for reinforcing a part of the printed-circuit board, the printed-circuit board reinforcing member having a square frame shape having four side members, an electronic part having a square shape being mounted on a part of the surface of the printed-circuit board so that the part of the surface of the printed-circuit board is surrounded by the printed-circuit board reinforcing member, the printed-circuit board reinforcing member comprising:
an inlet port formed on a top surface of each of the side members;
an outlet port formed on an inner surface of each of the side members; and
a fluid passage provided in each of the side members so as to connect the inlet port to the outlet port,
wherein heated fluid introduced into the inlet port is discharged from the outlet port so as to heat connecting parts between the electronic part and the printed-circuit board.
According to the above-mentioned invention, since the printed-circuit board reinforcing member has the nozzle st
Morita Yoshihiro
Murakami Hajime
Armstrong Westerman Hattori McLeland & Naughton LLP
Fujitsu Limited
Gaffin Jeffrey
Norris Jeremy
LandOfFree
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