Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
2002-01-02
2003-11-04
Arbes, Carl J. (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S829000, C029S846000, C029S825000, C029S885000
Reexamination Certificate
active
06640430
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a printed circuit board that can be suitably used in electronic devices including video cameras.
2. Description of the Prior art
To describe a printed circuit board according to the prior art and its manufacturing method with reference to FIG.
9
through
FIG. 12
, an insulating board
21
consisting of a flexible substrate or the like has a rectangular base
22
provided with fixed contacts (not shown) or the like and a drawn part
23
having a substantially L-shaped overall form.
This drawn part
23
is substantially L-shaped to stay away from electrical parts or (not shown) or fitting members (not shown) arranged within the electronic device, and has insulating board angled parts
23
a
bent in an L shape or the like, cables
23
b
connected to both sides of, and formed in a width equal to, these insulating board angled parts
23
a,
and leaders
23
c
formed at an end of the cables
23
b.
A plurality of wiring patterns
24
made of silver have conductive pattern bent parts
24
a
shaped in an L or the like, linear wiring parts
24
b
connected to both ends of, and having a pattern with equal width to, these conductive pattern bent parts
24
a,
and linear connecting parts
24
c
provided at an end of the wiring parts
24
b.
The plurality of wiring patterns
24
are formed in parallel by screen printing over the drawn part
23
in a state wherein the conductive pattern bent parts
24
a
are arranged over the insulating board angled parts
23
a
of the drawn part
23
of the insulating board
21
, the wiring parts
24
b
are arranged over the cables
23
b
and the base
22
, and further the connecting parts
24
c
are arranged over the leaders
23
c.
The wiring parts
24
b
formed over the base
22
are connected to fixed contacts (not shown) formed of an electroconductive pattern over the base
22
.
The wiring patterns
24
are so designed that the pitch of the patterns in the conductive pattern bent parts
24
a
be equal to the pitch of the patterns of the wiring parts
24
b
positioned close to and on both sides of the conductive pattern bent parts
24
a,
and that the gap width between the conductive pattern bent parts
24
a
be equal to the gap width between the wiring parts
24
b
positioned close to and on both sides of the conductive pattern bent parts
24
a.
On such a printed circuit board, the connecting parts
24
c
provided in leaders
23
c
are connected to a connector (not shown), so that a current from outside is entered into the printed circuit board via the connecting parts
24
c
or a current from the printed circuit board is supplied outside via the connecting parts
24
c.
By a manufacturing method for such a printed circuit board according to the prior art by screen printing, as shown in
FIG. 11
, after the insulating board
21
is mounted on a mount
25
, a meshed printing mask
26
is mounted over the insulating board
21
.
Next, after painting or otherwise applying silver paste
27
over the printing mask
26
, a squeegee
28
is moved in the direction of arrow A to form the plurality of wiring patterns
24
over the insulating board
21
by printing.
Thus, as shown in FIG.
9
and
FIG. 10
, the squeegee
28
is moved in the direction of arrow A, and first the conductive pattern bent parts
24
a
are formed by printing, followed by the formation of the wiring parts
24
b
by printing.
The reason why the squeegee
28
is moved in the direction of arrow A is that the formation of the wiring patterns
24
by printing in a state in which their orthogonal intersections with the squeegee
28
are minimized results in minimization of the running or blurring of patterns. In particular, minimization of orthogonal intersections between the wiring parts
24
b
having large pattern areas and the moving path of the squeegee
28
serves to reduce the running or blurring of the patterns of the wiring parts
24
b.
However, while the conductive pattern bent parts
24
a
are printed earlier in an orthogonally crossing state than the wiring parts
24
b
by the movement of the squeegee
28
in the direction of arrow A, the silver paste
27
flows from the peak toward the trough of the ink permeating part of the printing mask
26
for the formation of the conductive pattern bent parts
24
a
during the printing of these conductive pattern bent parts
24
a.
If, then, the printing conditions lose balance, slight quantities of the silver paste
27
may get caught between the printing mask
26
and the insulating board
21
in corners of the trough of the ink permeating part, and create running parts
24
d
as shown in FIG.
10
.
As a result, these running parts
24
d
would often short-circuit the wiring patterns
24
among themselves.
Or if in the conventional printed circuit board and its manufacturing method the squeegee
28
is moved in the direction of arrow B first to form the connecting parts
24
c
by printing and then the conductive pattern bent parts
24
a
are formed by printing after the wiring parts
24
b
are printed as shown in
FIG. 12
, blurred parts
24
e
of the silver paste
27
(see
FIG. 12
) may be caused to occur and possibly invite wire breaking in the conductive pattern bent parts
24
a
by stagnant air or the like gathering in the corners at the top of the ink permeating part of the printing mask
26
for forming the conductive pattern bent parts
24
a.
As printed circuit boards are required to be reduced in size along with the advance in the size compression of electronic devices in which they are to be used, the wiring patterns
24
are more narrowly spaced between one another and also reduced in width, running parts
24
d
and blurred parts
24
e
would give rise to the risks of short-circuiting and wire breaking in the resultant narrower conductive pattern bent parts
24
a.
In the conventional printed circuit board and its manufacturing method, since gaps between the conductive pattern bent parts
24
a
of the wiring patterns
24
are designed to be as wide as gaps between the wiring parts
24
b
positioned near their two sides and screen printing is carried out in the direction of arrow A, running parts
24
d
arise in the trough of the conductive pattern bent parts
24
a
, making the wiring patterns
24
susceptible to short-circuiting between each other.
Or if screen printing is carried out in the direction of arrow B, blurred parts
24
e
may arise at the top of the conductive pattern bent parts
24
a
, giving rise to the risk of inviting wire breaking.
SUMMARY OF THE INVENTION
In view of these problems, the present invention is intended to provide a more reliable printed circuit board less susceptible to short-circuiting or wire breaking in the conductive pattern bent parts of wiring patterns, and its manufacturing method.
According to a first aspect of the invention, the problems noted above are solved with a configuration having an insulating board and a plurality of wiring patterns formed over this insulating board by screen printing and provided with first conductive pattern bent parts and wiring parts linked to these first conductive pattern bent parts, gaps between adjoining first conductive pattern bent parts are formed wider than those between those of the wiring parts positioned close to and on both sides of the first conductive pattern bent parts.
According to a second aspect of the invention, a pitch of patterns in the first conductive pattern bent parts is formed greater than that of the patterns of those of the wiring parts positioned close to and on both sides of the first conductive pattern bent parts.
According to a third aspect of the invention, a pattern width in the first conductive pattern bent parts is greater than that of the patterns of those of the wiring parts positioned close to and on both sides of the first conductive pattern bent parts.
According to a fourth aspect of the invention, wiring patterns are screen-printed in such a printing direction that the first conductive pattern bent parts are formed by printing e
Alps Electric, Ltd.
Arbes Carl J.
Beyer Weaver & Thomas
Nguyen Tai
LandOfFree
Method of manufacturing a printed circuit board does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing a printed circuit board, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing a printed circuit board will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3147414