Electricity: conductors and insulators – Conduits – cables or conductors – Preformed panel circuit arrangement
Reexamination Certificate
1999-10-18
2002-09-17
Cuneo, Kamand (Department: 2827)
Electricity: conductors and insulators
Conduits, cables or conductors
Preformed panel circuit arrangement
C174S262000, C174S263000, C361S768000, C361S771000
Reexamination Certificate
active
06452112
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic circuit unit suitable for use in portable telephones or the like, and a method of manufacturing the same.
2. Description of the Related Art
The conventional electronic circuit unit will be explained with reference to FIG.
6
and
FIG. 7. A
circuit board
21
has a plurality of cutout sections
21
b formed on the end faces
21
a
thereof and conductive patterns
22
formed on the upper side thereof, and on the cutout sections
21
b
are formed end-face electrodes
23
that are connected to the conductive patterns
22
.
Further, electronic components (not illustrated) such as resistors, capacitors, and the like are mounted on the circuit board
21
in a state that the electronic components are connected to the conductive patterns
22
, and thus an electronic circuit unit
24
is configured with the one circuit board
21
.
Further, as shown in
FIG. 7
, a printed board
25
serving as a mother board includes conductive wiring patterns
26
formed on the surface thereof and a plurality of lands
27
for soldering, which are formed on the ends of the conductive wiring patterns
26
.
And, as shown in
FIG. 7
, the electronic circuit unit
24
is mounted on the printed board
25
as the mother board of the portable telephone or the like, and the end-face electrodes
23
provided on the circuit board
21
of the electronic circuit unit
24
are bonded onto the lands
27
provided on the printed board
25
through solders
28
, whereby the electronic circuit unit
24
is connected to the conductive wiring patterns
26
on the printed board
25
, and at the same time it is mounted to the printed board
25
.
With regard to the method for mounting the electronic circuit unit
24
to the printed board
25
, first, cream solders (not illustrated) are applied on the lands
27
, as shown in FIG.
7
.
Next, the electronic circuit unit
24
is mounted on the printed board
25
in a state that the end face electrodes
23
are located on the cream solder, and the printed board
25
having the electronic circuit unit
24
mounted in this state is carried into a heating furnace, whereby the cream solder is melted to bond the end face electrodes
23
to the lands
27
through the solder
28
.
However, in these mounting structure and method, since the soldering is made with the cream solder applied on the lands
27
on the printed board
25
, this method is difficult to make sufficient buildup of the solders
28
, and also difficult to secure good wettability of the solders
28
to the end-face electrodes
23
.
Further, when the circuit board
21
is warped due to a temperature variation, aged deterioration, or the like, both ends of the circuit board
21
are lifted up as shown in
FIG. 7
; and especially in such a warped circuit board
21
, the cream solder is difficult to wet the end face electrodes
23
.
Thus, in the conventional electronic circuit unit, since the soldering is made with the cream solder applied on the lands
27
on the printed board
25
, sufficient buildup of the solder
28
is difficult to be made, so that good wettability of the solders
28
to the end face electrodes
23
cannot be achieved, which is a problem to be solved.
Further, with regard to the circuit board
21
having a warp, the wettability of the cream solder to the end face electrodes
23
becomes still worse, which is another problem.
SUMMARY OF THE INVENTION
In a first embodiment to solve the foregoing problem, the electronic circuit unit of the present invention assumes a configuration containing a circuit board having conductive patterns on one face thereof and conductive lands connected to the conductive patterns on the other face thereof, in which electronic components such as resistors and capacitors, etc., connected to the conductive patterns are mounted on one face of the circuit board, a solder resist is provided on the other face of the circuit board, the lands are made up with broad width lands exposed from the solder resist and one or more thin width lands tied with the broad width lands in a state of being exposed from the solder resist, and the broad width lands have solder buildup formed thereon.
in a second embodiment to solve the problem, the electronic circuit unit of the present invention takes on circular broad width lands.
Further, as a third embodiment to solve the problem, the electronic circuit unit of the present invention takes on a configuration such that the broad width lands are formed near the end faces of the circuit board.
Further, as a forth embodiment to solve the problem, in the method of manufacturing an electronic circuit unit of the present invention, the electronic circuit unit is configured with a circuit board having conductive patterns on one face thereof and conductive lands connected to the conductive patterns on the other face thereof, in which electronic components such as resistors and capacitors, etc., connected to the conductive patterns are mounted on the one face of the circuit board, a solder resist is provided on the other face of the circuit board, and the lands are made up with broad width lands exposed from the solder resist and one or more thin width lands tied with the broad width lands in a state of being exposed from the solder resist. With this configuration, the method of the present invention comprises the steps of: applying cream solder on the broad width lands and the solder resist surrounding thereof, and on the thin width lands and the solder resist surrounding thereof, thereafter, at least heating the cream solder, and forming solder buildups on the broad width lands.
Further, as a fifth embodiment to solve the problem, the method of the present invention takes on circular broad width lands.
Further,as a sixth embodiment to solve the problem, the method of the present invention takes on a configuration such that the broad width lands are formed near the end faces of the circuit board.
REFERENCES:
patent: 4790894 (1988-12-01), Homma et al.
patent: 5724728 (1998-03-01), Bond et al.
patent: 1565748 (1980-04-01), None
patent: 05206606 (1993-08-01), None
patent: Hei 5-327156 (1993-12-01), None
patent: 06 334064 (1994-12-01), None
patent: 07 122846 (1995-05-01), None
patent: 07212104 (1995-08-01), None
Harada Hiroshi
Terashima Kiminori
Alps Electric Co. ,Ltd.
Cuneo Kamand
LandOfFree
Electronic circuit unit useful for portable telephone, etc.,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electronic circuit unit useful for portable telephone, etc.,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic circuit unit useful for portable telephone, etc.,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2848094