Metal fusion bonding – Process – Applying or distributing fused filler
Reexamination Certificate
2000-05-23
2001-07-10
Dunn, Tom (Department: 1725)
Metal fusion bonding
Process
Applying or distributing fused filler
C228S261000, C228S006200, C228S037000
Reexamination Certificate
active
06257482
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a jet solder feeding device for feeding molten solder to a substrate by ejecting the molten solder from ejecting ports, and to a method for soldering the same.
BACKGROUND OF THE INVENTION
Jet solder feeding devices are already known in which soldering is carried out for a substrate having surface mounted parts and discrete parts (parts with lead legs) consolidated thereon by feeding molten solder ejected from jet nozzles to the substrate while letting the substrate being conveyed.
Jet solder feeding devices of this type include the one which comprises: a first jet nozzle
1
for feeding molten solder satisfactorily to a substrate P mounted with electronic parts in the whole area of the surface to be soldered and a second jet nozzle
2
for removing excess molten solder having been fed to the substrate P, as shown in
FIGS. 3 and 4
. The first jet nozzle
1
and the second jet nozzle
2
are connected to a duct
3
for the first nozzle and a duct
4
for the second nozzle, respectively, both of which are soaked in molten solder accumulated in a solder melting bath
5
. This jet solder feeding device is designed to eject molten solder from the first jet nozzle
1
and the second jet nozzle
2
toward a substrate-conveying path
10
by rotationally driving jet impellers
6
and
7
arranged to face each of the openings at one end of the duct
3
and at one end of the duct
4
, respectively.
On the upper end portion of the first jet nozzle
1
, a corrugated plate
9
with multiple open ejecting ports
8
is mounted. As shown in
FIGS. 5
a
and
5
b
, the ejecting ports
8
have the same bore diameter and the same round shape and are provided, for example, in three rows in the direction B perpendicular to the direction A in which the substrate P is conveyed: ejecting ports
8
A in an upstream row, ejecting ports
8
B in an intermediate row and ejecting ports
8
C in a downstream row, and all the ejecting ports
8
are formed in different locations relative to the direction B perpendicular to the direction A in which the substrate P is conveyed. Each of the wall portions surrounding each ejecting port
8
on the corrugated plate
9
is designed to be flat.
The substrate P warps to some degree when heated by the molten solder, and when piles of molten solder ejected from ejecting ports
8
A become low, portions are created on the surface of the substrate P or the electronic parts intended to be soldered which the molten solder will not come in contact with. This causes poor wetting.
One of the conventional techniques to possibly deal with this problem is such that the piles of the molten solder are made higher by increasing the number of revolutions of the jet impellers
6
and
7
.
In the above described conventional jet solder feeding device, however, although the average height, on a time basis, of the piles of the molten solder becomes higher by increasing the rpm of the jet impellers
6
and
7
, the height is very unstable since it varies with time. Accordingly, when the piles of molten solder ejected from ejecting ports
8
temporarily become low, portions may be created on the surface of the substrate P or the electronic parts intended to be soldered which the molten solder will not come in contact with; consequently, poor wetting is caused in some part of the substrate.
There is an alternative in which ejecting pressure is increased by decreasing the bore diameter of each ejecting port
8
. In this case, however, since the cross-sectional area of the ejection from each ejecting port
8
becomes smaller, the area of the contact surface of the substrate P also becomes smaller, and there is still a possibility of causing poor wetting.
The present invention has been made to solve the above problem. Accordingly, the object of the present invention is to provide a jet solder feeding device and a method for soldering which make it possible to keep the molten solder ejected from ejecting ports at a desired height in a more stable manner.
SUMMARY OF THE INVENTION
In order to solve the above problem, the present invention is a jet solder feeding device for feeding molten solder to a substrate by ejecting the molten solder from multiple ejecting ports formed on a corrugated plate, in which each wall portion surrounding each ejecting port on the corrugated plate is designed to project upward forming a conical surface.
According to this configuration, the molten solder ejected from ejecting ports can be kept at a desired height in a stable manner.
The invention according to a first embodiment is a jet solder feeding device for feeding molten solder to a substrate by ejecting the molten solder from multiple ejecting ports formed on a corrugated plate, wherein a wall portion surrounding each ejecting port on the corrugated plate is projected upward the walls forming a conical surface.
According to this configuration, molten solder introduced under a corrugated plate is satisfactorily guided by the wall portion which surrounds each ejecting port and is projected upward; accordingly, the molten solder ejected from the ejecting ports can be kept at a desired height, in addition, its state is satisfactorily maintained in a stable manner.
The invention according to a second embodiment is the jet solder feeding device, wherein the wall portion surrounding each ejecting port and being projected upward is formed by extrusion.
According to this configuration, projecting upward the wall portion surrounding each ejecting port can be achieved easily, and the production cost can be held lower.
The invention according to a third embodiment is the jet solder feeding device, wherein the jet solder feeding device comprises a first nozzle for feeding molten solder to a substrate and a second nozzle for removing excess solder having been fed to the substrate, and the ejecting ports are provided on the first nozzle.
According to this configuration, molten solder can be satisfactorily fed to a substrate from the multiple ejecting ports provided on the first nozzle.
A method for using the device includes soldering a substrate by ejecting molten solder from multiple ejecting ports formed on a corrugated plate to feed the molten solder to the substrate, wherein a wall portion surrounding each ejecting port on the corrugated plate is projected upward, whereby soldering is carried out for a part to be connected on the substrate with the molten solder ejected from each of the above described ejecting ports.
According to this method, molten solder introduced under a corrugated plate is satisfactorily guided by the wall portions surrounding each ejecting port and being projected upward; accordingly, the molten solder ejected from the ejecting ports can be kept at a desired height, in addition, its state is satisfactorily maintained in a stable manner. Thus soldering is satisfactorily achieved for the substrate conveyed above the corrugated plate.
REFERENCES:
patent: 5192582 (1993-03-01), Leidke et al.
patent: 5779971 (1998-07-01), Pan et al.
patent: 40435619 (1998-05-01), None
Koshi Masuo
Nakayama Hiroaki
Sugimoto Tadahiko
Todoroki Kenichirou
Cooks Colleen
Dunn Tom
Matsushita Electric - Industrial Co., Ltd.
Parkhurst & Wendel L.L.P
LandOfFree
Jet solder feeding device and soldering method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Jet solder feeding device and soldering method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Jet solder feeding device and soldering method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474620