Electricity: conductors and insulators – Conduits – cables or conductors – Preformed panel circuit arrangement
Reexamination Certificate
2001-04-04
2002-04-23
Cuneo, Kamand (Department: 2841)
Electricity: conductors and insulators
Conduits, cables or conductors
Preformed panel circuit arrangement
C361S786000, C361S790000, C361S791000, C439S067000, C439S493000, C174S260000, C174S261000
Reexamination Certificate
active
06376778
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a printed circuit board assembly, especially to a printed circuit board assembly wherein the printed circuit board stably contacts with a circuit membrane and can be used for keyboards and scanners.
BACKGROUND OF THE INVENTION
As computer becomes more and more important and omnipresent to modern society, people rely on keyboard to key in various data for computer or cash register. Therefore, the keyboards are under extensive research and the requirement for keyboards are strict. For example, the appearance, tactility, click sound and balance of the keyboards are demanding factors.
The conventional keyboard generally comprises a printed circuit board assembled with a circuit membrane. The circuit membrane is a silvery mesh film with extended ribbon cable connected to the rigid printed circuit board provides electrical connection between the printed circuit board and the circuit membrane.
FIG. 1
shows a prior art printed circuit board assembly composed of a printed circuit board
12
a
and a circuit membrane
10
a.
The circuit membrane
10
a
has an extended ribbon cable
11
a
electrically connected to the printed circuit board
12
a.
The prior art printed circuit board
12
a
is electrically connected to the ribbon cable
11
a
through a connection stage
13
a.
The connection stage
13
a
is arranged on the printed circuit board
12
a
and the ribbon cable
11
a
is inserted into the connection stage
13
a
such that the circuit membrane
10
a
is electrically connected to the printed circuit board
12
a.
The use of connection stage
13
a
can achieve stable connection. However, the cost of the connection stage
13
a
is high and the assembling thereof is time consuming.
FIGS. 2 and 3
show another prior art printed circuit board assembly for keyboard. The keyboard has a flexible pad
15
a
on the cover plate
14
a
thereof. The ribbon cable
11
a
of the circuit membrane is sandwiched between the flexible pad
15
a
and the printed circuit board
12
a.
Moreover, the printed circuit board
12
a
is fixed to the flexible pad
15
a
by screwing two screws
16
a
such that the ribbon cable
11
a
of the circuit membrane is clamped between the cover plate
14
a
and the printed circuit board
12
a.
The electric contacts of the printed circuit board
12
a
are in contact with the electric contacts of the ribbon cable
11
a
of the circuit membrane. However, the screws
16
are generally screwed at both lateral sides of the printed circuit board
12
a,
the stress exerted on the printed circuit board
12
a
is uneven. The center part of the printed circuit board
12
a
is protuberant and the electric contacts of the printed circuit board
12
a
have poor contact with the electric contacts of the ribbon cable
11
a.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a printed circuit board assembly. After screws screw the both sides of the printed circuit board, the stress can be uniformly distributed. Therefore, the electric contacts of the printed circuit board are in firm contact with the electric contacts of the circuit membrane.
It is another object of the present invention to provide a printed circuit board assembly, which has simple structure and the cost and assembling time is saved.
To achieve the above object, the present invention provides a printed circuit board assembly comprises a circuit membrane, a printed circuit board, a cover plate and two screws.
The circuit membrane has an extended ribbon cable with a plurality of electric contacts. The printed circuit board has a plurality of electric contacts corresponding to the electric contacts of the circuit membrane. The cover plate has an arch-shaped bump formed thereon and the location thereof being corresponding to the electric contacts of the circuit membrane and the printed circuit board. The screws penetrate through both sides of the printed circuit board and are screwed to the cover plate, thus fixing the printed circuit board to the cover plate and clamping the ribbon cable between the cover plate and the printed circuit board. The electric contacts of the printed circuit board are in contact with the electric contacts of the circuit membrane.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:
REFERENCES:
patent: 5263868 (1993-11-01), Renn et al.
patent: 6017244 (2000-01-01), Daane
patent: 6323437 (2001-11-01), Johnson
Cuneo Kamand
Rosenberg , Klein & Lee
Silitek Corporation
Vu Quynh-Nhu H.
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