U.S. patent application number 14/473406 was filed with the patent office on 2015-03-05 for metal ball fabricating apparatus.
The applicant listed for this patent is MK Electron Co., Ltd.. Invention is credited to Eung Jae KIM, Hak Song LEE, Jeong Tak MOON, Yong Suk OH, Su Yong RYU, Jae Yeol SON, Hyung Jin SUNG.
Application Number | 20150064293 14/473406 |
Document ID | / |
Family ID | 52583590 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150064293 |
Kind Code |
A1 |
MOON; Jeong Tak ; et
al. |
March 5, 2015 |
METAL BALL FABRICATING APPARATUS
Abstract
Provided is a metal ball fabricating apparatus for fabricating a
metal ball by melting a material. The metal ball fabricating
apparatus includes: a fabricating unit configured to fabricate a
metal ball; and a collecting unit configured to collect the metal
ball. The fabricating unit includes: a chamber configured to
receive and store a material; a heating unit configured to apply
heat to melt the material in the chamber; an orifice disposed at a
lower portion of the chamber to which a metal ball droplet drops; a
piston disposed over the orifice to generate a metal ball droplet;
and a purifying system configured to remove a foreign substance
from the material.
Inventors: |
MOON; Jeong Tak;
(Gyeonggi-do, KR) ; SON; Jae Yeol; (Gyeonggi-do,
KR) ; KIM; Eung Jae; (Daegu, KR) ; RYU; Su
Yong; (Incheon, KR) ; SUNG; Hyung Jin;
(Daejeon, KR) ; OH; Yong Suk; (Daejeon, KR)
; LEE; Hak Song; (Chungcheongnam-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MK Electron Co., Ltd. |
Gyeonggi-do |
|
KR |
|
|
Family ID: |
52583590 |
Appl. No.: |
14/473406 |
Filed: |
August 29, 2014 |
Current U.S.
Class: |
425/6 |
Current CPC
Class: |
B22F 2009/0888 20130101;
B22F 2009/0816 20130101; B22F 9/08 20130101; B22F 2009/0892
20130101 |
Class at
Publication: |
425/6 |
International
Class: |
B22F 9/08 20060101
B22F009/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2013 |
KR |
10-2013-0104511 |
Claims
1. A metal ball fabricating apparatus for fabricating a metal ball
by melting a material, the metal ball fabricating apparatus
comprising: a fabricating unit configured to fabricate a metal
ball; and a collecting unit configured to collect the metal ball,
wherein the fabricating unit comprises: a chamber configured to
receive and store a material; a heating unit configured to apply
heat to melt the material in the chamber; an orifice disposed at a
lower portion of the chamber to which a metal ball droplet drops; a
piston disposed over the orifice to generate a metal ball droplet;
and a purifying system configured to remove a foreign substance
from the material.
2. The metal ball fabricating apparatus of claim 1, wherein the
purifying system comprises a discharge pump configured to discharge
a vaporized foreign substance in a heating atmosphere.
3. The metal ball fabricating apparatus of claim 1, wherein the
purifying system comprises a vacuum pump configured to adjust a
vacuum level of the chamber to below about 10.sup.-1 torr.
4. The metal ball fabricating apparatus of claim 1, wherein the
purifying system comprises a temperature control unit configured to
adjust a heating atmosphere temperature of the chamber in a range
of about 500.degree. C. to about 800.degree. C.
5. The metal ball fabricating apparatus of claim 1, wherein the
piston and the orifice are disposed to have a gap of about 0 mm to
about 0.5 mm therebetween.
6. The metal ball fabricating apparatus of claim 5, wherein the
fabricating unit comprises a gap control unit configured to control
the gap between the piston and the orifice.
7. The metal ball fabricating apparatus of claim 1, wherein the
orifice comprises a graphite material.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn.119
to Korean Patent Application No. 10-2013-0104511, filed on Aug. 30,
2013, in the Korean Intellectual Property Office, the disclosure of
which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] One or more embodiments relate to metal ball fabricating
apparatuses, and more particularly, to a metal ball fabricating
apparatus for fabricating a metal ball by melting a material.
BACKGROUND
[0003] An orifice having an inner diameter of about 50 .mu.m or
less is used to fabricate a micro metal ball having size of about
100 .mu.m, but an oxide of molten solder may block the orifice due
to a small inner diameter of the orifice.
[0004] In many cases, a purifying operation for purifying a raw
material in an alloying process is performed to solve the problem
of orifice blockage.
[0005] However, since an oxide layer exists on a lumpy surface of a
lump of a raw material generated in the alloying process, oxides
may be again mixed in the molten solder, at the time of being input
into fabrication equipment.
[0006] Therefore, there is a need to solve the problem of orifice
blockage by incorporating a raw material purifying system, which is
used in an alloying process, into a metal ball fabricating
apparatus.
SUMMARY
[0007] One or more embodiments include metal ball fabricating
apparatuses for fabricating metal balls by melting materials.
[0008] Additional aspects will be set forth in part in the
description which follows and, in part, will be apparent from the
description, or may be learned by practice of the presented
embodiments.
[0009] According to one or more embodiments, a metal ball
fabricating apparatus for fabricating a metal ball by melting a
material includes: a fabricating unit configured to fabricate a
metal ball; and a collecting unit configured to collect the metal
ball, wherein the fabricating unit includes: a chamber configured
to receive and store a material; a heating unit configured to apply
heat to melt the material in the chamber; an orifice disposed at a
lower portion of the chamber to which a metal ball droplet drops; a
piston disposed over the orifice to generate a metal ball droplet;
and a purifying system configured to remove a foreign substance
from the material.
[0010] The purifying system may include a discharge pump configured
to discharge a vaporized foreign substance in a heating
atmosphere.
[0011] The purifying system may include a vacuum pump configured to
adjust a vacuum level of the chamber to below about 10.sup.-1
torr.
[0012] The purifying system may include a temperature control unit
configured to adjust a heating atmosphere temperature of the
chamber in a range of about 500.degree. C. to about 800.degree.
C.
[0013] The piston and the orifice may be disposed to have a gap of
about 0 mm to about 0.5 mm therebetween.
[0014] The fabricating unit may include a gap control unit
configured to control the gap between the piston and the
orifice.
[0015] The orifice may include a graphite material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and/or other aspects will become apparent and more
readily appreciated from the following description of the
embodiments, taken in conjunction with the accompanying drawings in
which:
[0017] FIG. 1 illustrates an overall structure of a metal ball
fabricating apparatus according to an embodiment;
[0018] FIG. 2 illustrates a fabricating unit of a metal ball
fabricating apparatus according to an embodiment;
[0019] FIG. 3 illustrates a graph comparing wettability test
results before and after purification is performed by using a
purifying system of a metal ball fabricating apparatus according to
an embodiment;
[0020] FIG. 4 presents a table comparing wettability test results
before and after purification is performed by using a purifying
system of a metal ball fabricating apparatus according to an
embodiment;
[0021] FIG. 5 illustrates a state of the material for fabricating a
metal ball when the purification temperature is about 300.degree.
C. according to an embodiment;
[0022] FIG. 6 illustrates a state of the material for fabricating a
metal ball when the purification temperature is about 800.degree.
C. according to an embodiment;
[0023] FIG. 7 illustrates a state of the material when the vacuum
level is about 10.sup.-1 torr according to an embodiment;
[0024] FIG. 8 illustrates a state of the material when the vacuum
level is about 10.sup.-3 torr according to an embodiment;
[0025] FIG. 9 illustrates a comparison of the test dimension and
result for each material of the orifice provided in a fabricating
unit of a metal ball;
[0026] FIG. 10A illustrates a droplet when a metal orifice is
used;
[0027] FIG. 10B illustrates a droplet when a ceramic orifice is
used;
[0028] FIG. 10C illustrates a droplet when a graphite orifice is
used;
[0029] FIG. 11A illustrates a comparison between results when a
metal nozzle is used;
[0030] FIG. 11B illustrates comparison between results when a
ceramic nozzle is used;
[0031] FIG. 11C illustrates a comparison between results when a
graphite nozzle is used;
[0032] FIG. 12 is a table illustrating an overall comparison
between results when each of the vacuum level, the purification
temperature, and the fabrication temperature is changed; and
[0033] FIG. 13 illustrates a graph comparing uniformities of metal
ball sizes depending on gaps between a piston and the orifice
provided in a fabricating unit of a metal ball fabricating
apparatus according to an embodiment.
[0034] FIG. 14 presents a table comparing uniformities of metal
ball sizes depending on gaps between a piston and the orifice
provided in a fabricating unit of a metal ball fabricating
apparatus according to an embodiment.
DETAILED DESCRIPTION
[0035] Reference will now be made in detail to embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to like elements throughout.
In this regard, the present embodiments may have different forms
and should not be construed as being limited to the descriptions
set forth herein. Accordingly, the embodiments are merely described
below, by referring to the figures, to explain aspects of the
present description. As used herein, the term "and/or" includes any
and all combinations of one or more of the associated listed
items.
[0036] Exemplary embodiments will now be described in detail with
reference to the accompanying drawings. However, these embodiments
are not limited thereto.
[0037] The effects and features of the embodiments and the
accomplishing method thereof will become apparent from the
following description of the embodiments, taken in conjunction with
the accompanying drawings. The invention may, however, be embodied
in many different forms and should not be construed as being
limited to the embodiments set forth herein; rather, these
embodiments are provided such that this disclosure will be thorough
and complete, and will fully convey the concept of the invention to
one of ordinary skill in the art.
[0038] Spatially relative terms, such as "above," "upper,"
"beneath," "below," "lower," and the like, may be used herein for
ease of description to describe one element or feature's
relationship to another element(s) or feature(s) as illustrated in
the drawings. It will be understood that the spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation
illustrated in the drawings. For example, if the device in the
drawings is turned over, elements described as "below" or "beneath"
other elements or features would then be oriented "above" the other
elements or features. Thus, the exemplary term "above" may
encompass both an orientation of above and below. The device may be
otherwise oriented (rotated about 90 degrees or at other
orientations) and the spatially relative descriptors used herein
may be interpreted accordingly.
[0039] The terminology used herein is for the purpose of describing
the embodiments only and is not intended to be limiting of the
embodiments. As used herein, the singular forms "a," "an" and "the"
are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprise" and "comprising" used herein specify the
presence of stated elements, steps, operations, and/or devices, but
do not preclude the presence or addition of one or more other
elements, steps, operations, and/or devices.
[0040] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which the
embodiments belong. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0041] FIG. 1 illustrates an overall structure of a metal ball
fabricating apparatus 1 according to an embodiment. FIG. 2
illustrates a fabricating unit 10 of the metal ball fabricating
apparatus 1 according to an embodiment. FIGS. 3 and 4 illustrate a
comparison between wettability test results before and after
purification is performed by using a purifying system 30 of the
metal ball fabricating apparatus 1 according to an embodiment.
FIGS. 5 and 6 illustrate a comparison between results when
purification is performed under different purification temperatures
by using the purifying system 30 of the metal ball fabricating
apparatus 1 according to an embodiment. FIGS. 7 and 8 illustrate a
comparison between results when purification is performed under
different vacuum levels by using the purifying system 30 of the
metal ball fabricating apparatus 1 according to an embodiment.
FIGS. 9 to 11 illustrate a comparison between results when an
orifice 150 provided in the fabricating unit 10 of the metal ball
fabricating apparatus 1 according to an embodiment is formed of
different materials. FIG. 12 is a table illustrating an overall
comparison between results when each of the vacuum level, the
purification temperature, and the fabrication temperature is
changed. FIGS. 13 and 14 illustrate a comparison between
uniformities of metal ball (S) sizes depending on gaps between a
piston 130 and the orifice 150 provided in the fabricating unit 10
of the metal ball fabricating apparatus 1 according to an
embodiment.
[0042] The metal ball fabricating apparatus 1 according to an
embodiment is a metal ball fabricating apparatus 1 for fabricating
a metal ball S by melting a material. The metal ball fabricating
apparatus 1 includes: a fabricating unit 10 configured to fabricate
a metal ball S; and a collecting unit 20 configured to collect the
metal ball S. The fabricating unit 10 includes: a chamber 110
configured to receive and store a material; a heating unit 120
configured to apply heat to melt the material in the chamber 110;
an orifice 150 disposed at a lower portion of the chamber 110 to
which a metal ball (S) droplet drops; a piston 130 disposed over
the orifice 150 to generate a metal ball (S) droplet; and a
purifying system 30 configured to remove a foreign substance from
the material.
[0043] The metal ball fabricating apparatus 1 is configured to
include the fabricating unit 10 and the collecting unit 20.
[0044] The fabricating unit 10 includes various devices configured
to receive a material, which is a raw material of the metal ball S,
and fabricate the metal ball S, and substantially constitutes a
body of the metal ball fabricating apparatus 1. The metal ball S
may be a metal ball S used in a wire bonding package and may be
spherical; however, embodiments are not limited thereto.
[0045] The material used to fabricate the metal ball may be, for
example, an alloy including various metals such as copper (Cu),
nickel (Ni), aluminum (Al), and cobalt (Co), and a chemical
additive may be added thereto; however, embodiments are not limited
thereto.
[0046] The material is stored in the chamber 110. In one
embodiment, the chamber 110 is configured to have a predetermined
strength to endure a high temperature and a high pressure
difference, and has an appropriate capacity.
[0047] The heating unit 120 is provided to heat the material in the
chamber 110. The heating unit 120 may heat the chamber 110 by, for
example, an electrical resistance to melt the material in the
chamber 110, but its configuration and shape are not limited
thereto.
[0048] The orifice 150 is provided at a lower portion of the
chamber 110 so that the material in the chamber 110 may be heated
and melted and the melted material may drop in the shape of
droplets. The orifice 150 has the shape of a minute pipe and has an
appropriate shape and configuration for forming a metal ball (S)
droplet of a desired size and controlling the metal ball (S)
droplet. Since the orifice 150 may be damaged when the melted metal
ball (S) droplet drops, the orifice 150 may be attached/detached
to/from the chamber 110 so that the orifice 150 may be replaced
when necessary; however, embodiments are not limited thereto. The
orifice 150 may be configured to include a graphite material.
[0049] The piston 130 is disposed over the orifice 150. The piston
130 is spaced apart from the orifice 150 by a predetermined gap and
is configured to perform a piston movement so that the melted
material forms the metal ball (S) droplet. Accordingly, the piston
130 may be configured to perform a vertical piston movement, and
the gap between the piston 130 and the orifice 150 and the movement
period of the piston 130 may be adjusted appropriately. A power
applying unit 140 may be provided so that the piston 130 may
perform a piston movement.
[0050] The purifying system 30 is provided to remove a foreign
substance from the material stored in the chamber 110. The
purifying system 30 may include a device constituting a portion of
the fabricating unit 10 of the metal ball fabricating apparatus 1.
The purifying system 30 may be any member or device that may serve
to remove a foreign substance from the material. It may also be
understood that, when the purifying system 30 constitutes a portion
of the fabricating unit 10, the purifying system 30 may be
incorporated into the fabricating unit 10 to remove a foreign
substance from the material in a fabrication process. The purifying
system 30 will be described later.
[0051] In addition to the above-described units or members, an
inert gas injecting unit 160, various pipe structures, and valve
units 162 and 172 may be provided to supply an inert gas to
maintain an atmosphere suitable for fabricating the metal ball S;
however, embodiments are not limited thereto.
[0052] The collecting unit 20 is provided to collect the metal ball
S fabricated by the fabricating unit 10. The collecting unit 20 may
include a collecting valve 24, a collecting chamber 26, and a
cooling chamber 22 configured such that the metal ball (S) droplet
dropping through the orifice 150 may be cooled and solidified in a
dropping process.
[0053] The cooling chamber 22 may be extended with a vertical
height such that the metal ball (S) droplet may be cooled in the
dropping process.
[0054] The collecting chamber 24 is a member for collecting the
dropped metal ball (S). A sieve may be provided in the collecting
chamber 24 to load the metal ball S. The sieve may be extracted by
a transport unit to discharge the metal ball S to outside.
[0055] The collecting unit 20 may include various transport devices
for collecting the metal ball S and a valve serving to collect the
metal ball S, and the configuration of the collecting unit 20 is
not limited thereto.
[0056] Hereinafter, the purifying system 30 will be described in
detail.
[0057] The purifying system 30 may include any device that is used
to remove a foreign substance from the material and may also
include any device that may serve to remove a foreign substance
from the material.
[0058] For example, when the material is heated to a predetermined
temperature to remove the foreign substance, the heating unit 120
heating the material may serve to remove the foreign substance, but
the heating unit 120 may also be used to melt the material that is
used to fabricate the metal ball S. As another example, a gas
injecting unit and a pump serving to discharge a vaporized foreign
substance may serve to remove the foreign substance and constitute
a portion of the purifying system 30. However, since the gas
injecting unit and the pump may also serve to adjust an atmosphere
in the chamber 110, melt the material, and fabricate the metal ball
S, they may also be included in a component other than the
purifying system 30.
[0059] Thus, according to some embodiments, the purifying system 30
should not be regarded as a separate device that is independent of
other members or devices in the fabricating unit 10, and may be
regarded as a portion constituting the fabricating unit 10.
[0060] The purifying system 30 includes a discharge pump 170
configured to discharge the foreign substance in a heating
atmosphere.
[0061] When the chamber 110 is heated in a predetermined atmosphere
to a temperature that is equal to or higher than a melting
temperature, the material in the chamber 110 is melted into liquid.
In this case, oxygen and a foreign substance, such as various
oxides, which are contained in the liquid material, may be floated
on a surface thereof, and the foreign substance may be removed by
the operation of the discharge pump 170.
[0062] In this case, the atmosphere in the chamber 110 may be a
near-vacuum atmosphere, and the discharge pump 170 may include a
vacuum pump. By the operation of the discharge pump 170, air in the
chamber 110 may flow toward the vacuum pump to be discharged to
outside, and a relatively light foreign substance such as the oxide
may be discharged according to the air flow. In this case, the
vacuum level of the chamber 110 may be low and may be adjusted to
about 2.0.times.10.sup.-2 torr or less.
[0063] The purifying system 30 may include a temperature control
unit (not illustrated) configured to adjust a heating atmosphere
temperature of the chamber 110 in a range of about 500.degree. C.
to about 900.degree. C.
[0064] The temperature control unit may control the operation of
the heating unit 120 and adjust the temperature of the chamber 110
so that the foreign substance may be easily separated while the
material is easily melted. In this case, the temperature control
unit may control the temperature of the chamber 110 from about
500.degree. C. to about 900.degree. C., for example, or to about
800.degree. C. Accordingly, the temperature control unit may
include a temperature sensor and a control unit controlling the
operation of the heating unit 120.
[0065] As described above, according to the one or more of the
above embodiments, since the purifying system 30 is included in the
fabricating unit 10, the metal ball fabricating apparatus 1 may
fabricate the metal ball S by a pure material alone by removing a
foreign substance from the material used to fabricate the metal
ball S. Also, since a material purifying operation is performed in
a melting process for fabrication, a separate independent purifying
unit may not be necessary and the purified material may be
prevented from being contaminated again by being exposed to outside
when supplied into the chamber 110.
[0066] Thus, the higher-quality metal ball S may be fabricated, and
the efficiency of the fabrication process may be improved and the
fabrication cost may be reduced, since the blockage of the orifice
150, to which the metal ball (S) droplet drops, is prevented.
[0067] In one embodiment, the piston 130 and the orifice 150 are
disposed to have a gap of about 0 mm to about 0.5 mm
therebetween.
[0068] The piston 130 is spaced apart from the orifice 150 by a
predetermined gap and performs a piston movement so that the melted
material may drop in the form of droplets through the orifice 150.
In this case, in order to form a metal ball (S) droplet of a
desired size, the piston 130 and the orifice 150 may have a gap
therebetween and the gap between the piston 130 and the orifice 150
may be adjusted to about 0 mm to about 0.5 mm. Herein, the gap
between the piston 130 and the orifice 150 represents a gap at
which the piston 130 is advanced to maximum and is most adjacent to
the orifice 150.
[0069] A gap control unit 142 may be provided to adjust the gap
between the piston 130 and the orifice 150.
[0070] The gap control unit 142 may be provided to adjust the gap
between the piston 130 and the orifice 150, and may be, for
example, a device that changes the initial position of the piston
130. By the gap control unit 142, the gap between the piston 130
and the orifice 150 may be changed and the size of the metal ball
(S) droplet may also be changed appropriately. Thus, the metal
balls S of various sizes may be fabricated according to purposes,
and the general purpose of the metal ball fabricating apparatus 1
may be improved.
[0071] Hereinafter, the effects of the metal ball fabricating
apparatus 1 according to an embodiment will be described with
reference to the drawings.
[0072] FIGS. 3 and 4 illustrate a comparison between wettability
test results before and after purification is performed by using
the purifying system 30 of the metal ball fabricating apparatus 1
according to an embodiment.
[0073] It may be seen from FIGS. 3 and 4 that a wetting force is
increased and a zero-cross time is reduced after the purification
is performed.
[0074] That is, the zero-cross time is the time taken to balance
the water level of solder, and the zero-cross time may be short as
much as possible. In one embodiment, in order to reduce the
zero-cross time, the surface tension should be low. In general, as
the amount of interposer in a melted metal increases, the surface
tension increases and thus the zero-cross time increases.
[0075] According to some embodiments, the zero-cross time is
reduced after the purification, and this may be regarded as the
improvement of a fluid flow. Thus, it may be seen that the fluidity
of the melted material passing through the hole of the orifice is
improved by the purification of the material.
[0076] Also, as the surface tension decreases, the wetting force
increases. As seen from FIG. 4, the increase of the wetting force
after purification represents the decrease of the surface tension,
and this represents the improvement of the fluidity of the
material.
[0077] FIGS. 5 and 6 illustrate a comparison between results when
purification is performed under different purification temperatures
by using the purifying system 30 of the metal ball fabricating
apparatus 1 according to an embodiment. FIGS. 7 and 8 illustrate a
comparison between results when purification is performed under
different vacuum levels by using the purifying system 30 of the
metal ball fabricating apparatus 1 according to an embodiment.
[0078] FIG. 5 illustrates a state of the material when the
purification temperature is about 300.degree. C., and FIG. 6
illustrates a state of the material when the purification
temperature is about 800.degree. C. It may be seen that the oxide
layer formed on the surface of the material may be further reduced
in the case where the purification temperature is about 800.degree.
C., in comparison with the case where the purification temperature
is about 300.degree. C.
[0079] FIG. 7 illustrates a state of the material when the vacuum
level is about 10.sup.-1 torr, and FIG. 8 illustrates a state of
the material when the vacuum level is about 10.sup.-3 torr. It may
be seen that the oxide layer formed on the surface of the material
may be further reduced in the case where the vacuum level is about
10.sup.-3 torr, in comparison with the case where the vacuum level
is about 10.sup.-1 torr.
[0080] As described above, it may be seen that the purification of
the material is further improved by the removal of the oxide when
the material is melted while the high temperature and the low
vacuum level are maintained.
[0081] FIGS. 9 to 11 illustrate a comparison between results when
the orifice 150 provided in the fabricating unit 10 of the metal
ball fabricating apparatus 1 according to an embodiment is formed
of different materials.
[0082] FIG. 9 illustrates the test dimension and result for each
material of the orifice 150, FIG. 10 illustrates each orifice 150,
and FIG. 11 illustrates the uniformity of droplets generated
through each orifice 150.
[0083] FIG. 10A illustrates a droplet when a metal orifice 150 is
used, FIG. 10B illustrates a droplet when a ceramic orifice 150 is
used, and FIG. 10C illustrates a droplet when a graphite orifice
150 is used.
[0084] It may be seen from FIGS. 9 to 11 that, when the orifice 150
is formed of graphite having excellent slippage characteristics,
most stable and uniform droplets are formed even when a small
orifice 150 is used.
[0085] FIG. 12 is a table illustrating an overall comparison
between results when the vacuum level, the purification
temperature, and the fabrication temperature are changed. It may be
seen from FIG. 12 that the fabrication result is varied when each
of the vacuum level, the purification temperature, and the
fabrication temperature is changed.
[0086] FIGS. 13 and 14 illustrate a comparison between uniformities
of metal ball (S) sizes depending on gaps between the piston 130
and the orifice 150 provided in the fabricating unit 10 of the
metal ball fabricating apparatus 1 according to an embodiment.
[0087] As illustrated in FIGS. 13 and 14, it may be seen that the
size of the fabricated metal ball S and the deviation of the size
increase as the gap between the piston 130 and the orifice 150
increases in the piston movement having the same frequency.
[0088] As described above, since the gap control unit 142 is
provided to adjust the gap between the piston 130 and the orifice
150, the gap between the piston 130 and the orifice 150 may be
adjusted, and the piston 130 and the orifice 150 may be adjusted to
have an optimum gap therebetween in the fabrication process.
Therefore, the metal balls S may be fabricated to have a uniform
size.
[0089] As described above, according to the one or more of the
above embodiments, since the purifying system 30 is included the
fabricating unit 10, the metal ball fabricating apparatus 1 may
fabricate the metal ball S by a pure material alone by removing a
foreign substance from the material used to fabricate the metal
ball S. Also, since a material purifying operation is performed in
a melting process for fabrication, a separate independent purifying
unit may not be necessary and the purified material may be
prevented from being contaminated again by being exposed to outside
when supplied into the chamber 110.
[0090] Thus, the higher-quality metal ball S may be fabricated, and
the efficiency of the fabrication process may be improved and the
fabrication cost may be reduced, since the blockage of the orifice
150, to which the metal ball (S) droplet drops, is prevented.
[0091] Also, since the gap control unit is provided to adjust the
gap between the piston 130 and the orifice 150, the gap between the
piston 130 and the orifice 150 may be changed and the size of the
metal ball (S) droplet may also be changed appropriately. Thus, the
metal balls S of various sizes may be fabricated according to
purposes, and the general purpose of the metal ball fabricating
apparatus 1 may be improved.
[0092] Also, even when a small orifice including a graphite
material is used, stable and uniform metal ball droplets may be
formed.
[0093] It should be understood that the exemplary embodiments
described herein should be considered in a descriptive sense only
and not for purposes of limitation. Descriptions of features or
aspects within each embodiment should typically be considered as
available for other similar features or aspects in other
embodiments.
[0094] While one or more embodiments have been described with
reference to the figures, it will be understood by those of
ordinary skill in the art that various changes in form and details
may be made therein without departing from the spirit and scope as
defined by the following claims.
* * * * *