Dispensing – Molten metal dispensing – Flow controllers or assists
Reexamination Certificate
2000-05-23
2002-02-26
Kastler, Scott (Department: 1742)
Dispensing
Molten metal dispensing
Flow controllers or assists
C222S591000
Reexamination Certificate
active
06349861
ABSTRACT:
FIELD OF THE INVENTION
This 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 mounted with electronic parts by feeding molten solder ejected through jet nozzles to the substrate while letting the substrate be conveyed in a prescribed direction.
Jet solder feeding devices of this type include the one which comprises: a first jet nozzle
1
for feeding molten solder J 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 J having been fed to the substrate P, as shown in
FIGS. 6 and 7
. 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 J accumulated in a solder melting bath
5
. This jet solder feeding device is designed to eject molten solder J from the first jet nozzle
1
and the second jet nozzle
2
toward a substrate-conveying path
10
by rotationally driving 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. The ejecting ports
8
are provided, for example, in three rows relative to the direction A in which the substrate P is conveyed, and all the ejecting ports
8
are formed at a prescribed pitch M relative to the direction B perpendicular to the direction A in which the substrate P is conveyed in such a manner that more than one ejecting ports
8
are in each row, as shown in
FIGS. 8
a
,
8
b
. As for the direction B perpendicular to the substrate-conveying direction A, these ejecting ports
8
are staggered in a top view in such a manner that each ejecting port
8
in the row next to the first or second row is located right at a midpoint of the adjacent ejecting ports in the above first or second row which are lined up laterally along the direction B perpendicular to the substrate-conveying direction A.
In this jet solder feeding device, the substrate P is designed to improve wettability of solder in such a manner as to apply flux thereto before soldering.
In the above described conventional jet solder feeding device, however, molten solder J ejected from 4 adjacent ejecting ports
8
, in a top view, flows right into the midpoint of the above 4 adjacent ejecting ports
8
while keeping a balanced relationship among the force and direction Fs of its flow, as shown in FIG.
9
. Accordingly, when the substrate P is conveyed to a position facing each ejecting port
8
of the first jet nozzle
1
and comes in contact with the molten solder J, gas of vaporized flux or air Q or the like may accumulate in the midpoint of the 4 adjacent ejecting points
8
under the bottom surface of the substrate P. This causes poor wetting since there arise portions where the molten solder J does not come in contact with the substrate P.
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 enable the prevention of poor wetting due to the accumulation of gas, air or the like under the bottom surface of the substrate caused when the substrate is conveyed to a position where it is fed with molten solder.
DISCLOSURE OF THE INVENTION
In order to solve the above problem, the present invention is a jet solder feeding device for feeding molting solder to a substrate conveyed in a prescribed conveying direction by ejecting the molten solder from multiple ejecting ports toward a the substrate, wherein, in at least one part of the area including the above multiple ejecting ports, the ejecting ports are provided in more than one rows relative to the substrate-conveying direction, including an upstream row and a downstream row and arranged at a second prescribed pitch in lines substantially along multiple inclined lines which are inclined to the substrate-conveying direction and, being arranged at a first prescribed pitch in the direction perpendicular to the substrate-conveying direction, the above first prescribed pitch being set to be larger than the above second prescribed pitch.
The jet solder feeding device having this configuration enables the prevention of poor wetting due to the accumulation of gas, air or the like under the bottom surface of the substrate caused when the substrate is conveyed to a position where it is fed with molten solder.
The invention in one embodiment is a jet solder feeding device for feeding molten solder to a substrate conveyed in a prescribed conveying direction by ejecting the molten solder from multiple ejecting ports toward the substrate, wherein, in at least one part of the area including the multiple ejecting ports, the ejecting ports are provided in more than one rows relative to the substrate-conveying direction, including an upstream row and a downstream row and arranged at a second prescribed pitch in lines substantially along multiple inclined lines which are inclined to the substrate-conveying direction, and being arranged at a first prescribed pitch in the direction perpendicular to the substrate-conveying direction, the above first prescribed pitch being set to be larger than the above second prescribed pitch.
According to this configuration, since the first prescribed pitch is larger than the second prescribed pitch, the balance of the flowing force of molten solder from each ejecting port is lost between the midpoint of adjacent ejecting ports arranged at the first prescribed pitch and the midpoint of adjacent ejecting ports arranged at the second prescribed pitch. As a result, molten solder flows from the point where its flowing force is larger to the point where its flowing force is smaller. Accordingly, the flow of molten solder passing through midway between adjacent groups of ejecting ports is created positively; therefore when the substrate is conveyed to the position where it is fed with molten solder, even if gas of vaporized flux is generated or air is admixed, the gas generated or the air admixed under the bottom surface of the substrate is satisfactorily discharged along the above described flow to the outside. This means no occurrence of poor wetting.
The invention in another embodiment is a jet solder feeding device for feeding molten solder to a substrate conveyed in a prescribed conveying direction by ejecting the molten solder from multiple ejecting ports toward the substrate, wherein, in at least one part of the area including the above multiple ejecting ports, the ejecting ports are provided in more than one rows relative to the substrate-conveying direction, including an upstream row and a downstream row and arranged in lines substantially along multiple inclined lines which are inclined to the substrate-conveying direction, and being arranged at a prescribed pitch in the direction perpendicular to the substrate-conveying direction, said ejecting ports further being arranged in such a manner that overlap dimensions relative to the direction perpendicular to the substrate-conveying direction of an ejecting port in the most upstream row and an ejecting port in the most downstream row of adjacent groups of ejecting ports are smaller than overlap dimensions relative to the direction perpendicular to the substrate-conveying direction of the adjacent ejecting ports of one group of ejecting ports arranged along the same inclined line.
The invention in another embodiment is a jet solder feeding device for feeding molten solder to a substrate conveyed in a prescribed conveying direction by ejecting molten solder from multiple ejecting ports toward the substrate, wherein, in at least one part of
Koshi Masuo
Onobayashi Takeshi
Sugimoto Tadahiko
Todoroki Kenichirou
Kastler Scott
Matsushita Electric - Industrial Co., Ltd.
Parkhurst & Wendel L.L.P
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