U.S. patent application number 16/262167 was filed with the patent office on 2019-05-30 for copper alloy wire and manufacturing method thereof.
The applicant listed for this patent is METAL INDUSTRIES RESEARCH & DEVELOPMENT CENTRE. Invention is credited to Tung-Chen CHENG, Chen-Hsueh CHIANG, Chia-Hao HSU.
Application Number | 20190161841 16/262167 |
Document ID | / |
Family ID | 62193530 |
Filed Date | 2019-05-30 |
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United States Patent
Application |
20190161841 |
Kind Code |
A1 |
CHENG; Tung-Chen ; et
al. |
May 30, 2019 |
COPPER ALLOY WIRE AND MANUFACTURING METHOD THEREOF
Abstract
A copper alloy wire and a manufacturing method thereof are
provided. The copper alloy wire includes: by weight percentage of
components, 0.3 to 0.45 of silver (Ag), 0.01 to 0.02 of titanium,
and a remaining part that is formed by copper and unavoidable
impurities. The method for manufacturing the copper alloy wire is
performing two-phase vacuum melting: first performing vacuum
electric arc melting into a copper-titanium mother alloy, and then
performing vacuum induction melting with remaining components into
a copper alloy wire material by means of continuous casting; then
drawing the copper alloy wire material into a copper alloy fine
wire by a non-slip wire drawing device in a material even-flow wire
drawing manner, and finally performing thermal treatment on the
copper alloy fine wire by using argon as a protection gas, so as to
complete a process of the copper alloy wire.
Inventors: |
CHENG; Tung-Chen;
(Kaohsiung, TW) ; CHIANG; Chen-Hsueh; (Kaohsiung,
TW) ; HSU; Chia-Hao; (Kaohsiung, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
METAL INDUSTRIES RESEARCH & DEVELOPMENT CENTRE |
Kaohsiung |
|
TW |
|
|
Family ID: |
62193530 |
Appl. No.: |
16/262167 |
Filed: |
January 30, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15361620 |
Nov 28, 2016 |
|
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16262167 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 9/00 20130101; C22F
1/08 20130101; B21C 1/003 20130101; C22C 1/02 20130101 |
International
Class: |
C22F 1/08 20060101
C22F001/08; C22C 1/02 20060101 C22C001/02; C22C 9/00 20060101
C22C009/00 |
Claims
1. A method for manufacturing a copper alloy wire, comprising:
performing a vacuum melting step: melting titanium, silver, and
copper into a molten copper alloy; performing a continuous casting
step: manufacturing the molten copper alloy into a copper alloy
wire material; performing a wire drawing step: drawing the copper
alloy wire material into a copper alloy fine wire; and performing a
thermal treatment step: performing thermal treatment on the copper
alloy fine wire under a condition that an annealing temperature is
ranged from 580.degree. C. to 700.degree. C.
2. The method for manufacturing a copper alloy wire according to
claim 1, wherein the copper alloy wire comprises: by weight
percentage of the copper alloy wire, 0.3 to 0.45 of silver, 0.01 to
0.02 of titanium, and a remaining part that is formed by copper and
unavoidable impurities.
3. The method for manufacturing a copper alloy wire according to
claim 1, wherein in the vacuum melting step, two-phase melting is
performed in a vacuum manner and comprises steps of: first melting
a total share of titanium and a partial share of copper into a
copper-titanium mother alloy by means of electric arc melting, and
then melting the copper-titanium mother alloy with a total share of
silver and a remaining share of copper together into the molten
copper alloy by means of induction melting.
4. The method for manufacturing a copper alloy wire according to
claim 3, wherein the partial share of copper uses copper with a
purity greater than 4N.
5. The method for manufacturing a copper alloy wire according to
claim 3, wherein the remaining share of copper uses copper with a
purity greater than 4N.
6. The method for manufacturing a copper alloy wire according to
claim 1, wherein a wire diameter of the copper alloy wire material
ranges between 4 mm and 8 mm.
7. The method for manufacturing a copper alloy wire according to
claim 1, wherein a wire diameter of the copper alloy fine wire
ranges between 10 .mu.m and 20 .mu.m.
8. The method for manufacturing a copper alloy wire according to
claim 1, wherein the copper alloy wire material is drawn into the
copper alloy fine wire by a wire drawing device.
9. The method for manufacturing a copper alloy wire according to
claim 8, wherein the wire drawing device comprises a non-slip wire
drawing device.
10. The method for manufacturing a copper alloy wire according to
claim 9, wherein in the wire drawing step, the non-slip wire
drawing device comprises a tension control apparatus and an eye
mold, and the tension control apparatus is configured to increase a
back drawing force of the copper alloy wire material behind the eye
mold.
11. The method for manufacturing a copper alloy wire according to
claim 9, wherein the non-slip wire drawing device performs a wire
drawing process on the copper alloy wire material at a speed of 100
to 1000 m/min at room temperature.
12. The method for manufacturing a copper alloy wire according to
claim 8, wherein coarse drawing, medium drawing and fine drawing of
the wire drawing device are performed on the copper alloy wire
material into the copper alloy fine wire.
13. The method for manufacturing a copper alloy wire according to
claim 1, wherein the thermal treatment for annealing time of
greater than 0.1 second is performed on the copper alloy fine
wire.
14. The method for manufacturing a copper alloy wire according to
claim 1, wherein a protection gas is used in the thermal treatment
process.
15. The method for manufacturing a copper alloy wire according to
claim 14, wherein argon is used as the protection gas in the
thermal treatment process.
16. The method for manufacturing a copper alloy wire according to
claim 1, wherein the copper alloy wire, only consisting of the
following elements: by weight percentage of components, 0.3 to 0.45
of silver, 0.01 to 0.02 of titanium, and a remaining part that is
formed by copper and unavoidable impurities.
17. A method for manufacturing a copper alloy wire, comprising:
melting titanium, silver, and copper under a vacuum manner into a
molten copper alloy; manufacturing the molten copper alloy into a
copper alloy wire material; drawing the copper alloy wire material
into a copper alloy fine wire; and performing a thermal treatment
on the copper alloy fine wire under an annealing temperature.
18. The method for manufacturing a copper alloy wire according to
claim 17, wherein the annealing temperature is ranged from
580.degree. C. to 700.degree. C.
19. The method for manufacturing a copper alloy wire according to
claim 17, wherein the step of melting titanium, silver, and copper
comprises steps of: first melting a total share of titanium and a
partial share of copper into a copper-titanium mother alloy by
means of electric arc melting, and then melting the copper-titanium
mother alloy with a total share of silver and a remaining share of
copper together into the molten copper alloy by means of induction
melting.
20. The method for manufacturing a copper alloy wire according to
claim 17, wherein the copper alloy wire material is drawn into the
copper alloy fine wire by a wire drawing device.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Division of application Ser. No.
15/361,620, filed on Nov. 28, 2016, the prior application is
herewith incorporated by reference in its entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to a method manufacturing a
copper alloy, and in particular, to a copper alloy wire and a
manufacturing method thereof.
Related Art
[0003] In recent years, because the price of gold rises, gold wires
that are conventionally used as semiconductor encapsulation wires
have begun to be replaced with other metal wires, and developing
wires for semiconductor encapsulation wires by means of material
components or innovative structures has become a main development
direction of the field.
[0004] Therefore, copper metal, which has advantages in both
conductivity and costs, is also used as a main alternative material
to develop wires. However, although the copper metal has good
conductivity and ductility as well as low price, in actual
application, the attribute that the copper metal is easily oxidized
affects the conduction function and greatly shortens life of copper
wires. Therefore, improving the problem of copper wire oxidization
by means of component, process or structural improvement has also
become one of subjects to be researched in the field.
[0005] For example, in the patent document (Patent No. TW I509089),
a profile construction of a pure copper alloy wire is disclosed;
the wire is formed by at least one base metal of 40 to 100 ppm
titanium, zirconium, zinc, or tin, and the remaining part is formed
by copper; the profile construction of the wire is a machined
surface, which is radially shrinked due to a process of a diamond
wire drawing eye mold, and an organic carbon layer with a total
organic carbon content of 50 to 3000 .mu.g/m.sup.2 is formed on a
surface of the wire.
[0006] The technology of the foregoing patent document (TW I509089)
mainly lies in making base metal elements easily oxidized and
contained in a copper base metal first perform inner oxidization
with oxygen atoms so as to inhibit copper oxides on a surface of a
copper wire from deteriorating into spots. Next, in a period in
which most copper oxides on the surface oxide layer are
nonsaturated copper oxides, an organic layer that does not make the
oxide layer reduced is formed on the surface of the wire by means
of a diamond drawing die, so as to obtain redox equilibrium of the
copper oxide layer, thereby preventing generation of spot-shaped
copper oxides on the surface; however, when the copper wire of the
patent document is actually welded with an aluminum pad,
weldability may be poor owing to ratios of components.
[0007] Further, in the patent document (Patent No. TW I512121), a
bonding wire is disclosed, wherein the bonding wire includes: a
core that has a surface and uses copper as a main component, where
a total share of content of copper is at least 97%, and 0.5% to 3%
of palladium and 45 to 900 ppm silver (Ag) are further included;
the technology of the patent document lies in that a coating is
combined outside the core, and the coating includes at least one of
Pd, Au, Pt, or Ag as the main component. If an annealing
temperature is selected as a variable parameter, and annealing time
is set as a constant value, then it is particularly beneficial to
select the annealing temperature as an annealing temperature value
greater than a maximum ductility; specifically, a size of an
average grain of the wire may be adjusted to a size of a large
grain by means of the manufacturing principle, and other
properties, for example, wire softness, and ball bonding behaviors
may be affected in a positive manner.
[0008] However, in actual application, because a surface coating of
the bonding wire of the foregoing patent document (TW I512121)
includes at least one of Pd, Au, Pt, or Ag as a main component, the
bonding wire of the foregoing patent document (TW I512121) has high
manufacturing costs and a ballability that is poorer than that of a
bonding wire without a surface coating.
[0009] In view of the above, the present disclosure develops a
copper alloy wire having specific components to not only improve an
oxidization problem thereof, but also keep and improve weldability
thereof.
SUMMARY
[0010] The main problem to be resolved by the present disclosure
lies in limitation of the attribute that copper alloy wires are
easily oxidized in application of semiconductor encapsulation.
Therefore, the present disclosure adds silver (Ag) and titanium as
components, and improves a manufacturing method thereof, so as to
overcome the problem that copper alloy wires are easily oxidized as
well as improve weldability thereof.
[0011] To achieve the foregoing objective, the present disclosure
discloses a copper alloy wire, which is mainly formed by copper,
silver (Ag), and titanium, and is melted in a vacuum manner in the
following weight percentage: 0.3 to 0.45 of silver (Ag), 0.01 to
0.02 of titanium, and a remaining part of copper.
[0012] However, the copper alloy wire of the present disclosure is
manufactured in the following way: after two-phase melting is
performed in vacuum state, manufacturing a copper alloy wire
material by means of continuous casting, and then performing
drawing on the copper alloy wire material by a wire drawing device
into a copper alloy fine wire, and finally performing thermal
treatment at an annealing temperature of 580 to 700.degree. C.
(annealing time is greater than 0.1 second) to complete the copper
alloy wire.
[0013] In the vacuum melting step, two-phase melting is divided
into first-phase vacuum electric arc melting and second-phase
vacuum induction melting, and description is stated as follows:
[0014] 1. Vacuum electric arc melting: melting a total share of
titanium and a partial share of copper into a copper-titanium
mother alloy having a low melting point by means of vacuum electric
arc melting; and
[0015] 2. Vacuum induction melting: melting the copper-titanium
mother alloy with a total share of silver (Ag) and a remaining
share of copper together into a molten copper alloy by means of
induction melting.
[0016] Next, the evenly molten copper alloy is casted into the
copper alloy wire material with a wire diameter ranging between 8
mm and 4 mm by means of continuous casting, and then is drawn into
the copper alloy fine wire with a wire diameter ranging between 10
.mu.m and 20 .mu.m by a non-slip wire drawing device at a speed of
100 to 1000 m/min at room temperature.
[0017] Finally, thermal treatment is performed on the copper alloy
fine wire by using argon as a protection gas at an annealing
temperature of 580.degree. C. to 700.degree. C. (annealing time is
greater than 0.1 second), so as to complete the copper alloy wire,
so that the oxidization problem of the copper alloy wire is
obviously improved, and better weldability is achieved, and a
function of overall mechanical property optimization is
obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The disclosure will become more fully understood from the
detailed description given herein below for illustration only, and
thus are not limitative of the disclosure, and wherein:
[0019] FIG. 1A is a schematic diagram of main components and
first-phase melting of the present disclosure;
[0020] FIG. 1B is a schematic diagram of main components and
second-phase melting of the present disclosure;
[0021] FIG. 2A is a flowchart of steps of a manufacturing method of
the present disclosure;
[0022] FIG. 2B is a flowchart of a vacuum melting step of the
present disclosure;
[0023] FIG. 2C is a flowchart of a wire drawing step of the present
disclosure;
[0024] FIG. 2D is a flowchart of a thermal treatment step of the
present disclosure; and
[0025] FIG. 3 is a schematic diagram of a non-slip wire drawing
device of the present disclosure.
DETAILED DESCRIPTION
[0026] First, referring to FIG. 1A and FIG. 1B at the same time,
FIG. 1A and FIG. 1B are components and a melting manner of a copper
alloy wire of the present disclosure, and the copper alloy wire of
the present disclosure is manufactured in a vacuum melting manner
using the following weight percentage of components: copper, silver
(Ag), and titanium: 0.3 to 0.45 of silver (Ag), 0.01 to 0.02 of
titanium, and a remaining part of copper.
[0027] Because a melting point of titanium metal is 1668.degree.
C., which is higher than a melting point of 1085.degree. C. of
copper and a melting point of 961.8.degree. C. of silver (Ag) by
almost 600 to 700.degree. C., to prevent titanium metal from being
unevenly distributed in the molten copper alloy for casting owing
to incomplete melting. Two-phase melting is used in a vacuum
melting phase: first, as shown in FIG. 1A, a total share of
titanium A and a partial share of copper B1 are melted to a
copper-titanium mother alloy 100' having a low melting point by
means of vacuum electric arc melting; and then as shown in FIG. 1B,
the copper-titanium mother alloy 100', a total share of silver (Ag)
C and a remaining share of copper B2 are melted together to a
molten copper alloy 100 by means of induction melting. The
foregoing partial share of copper B1 and the remaining share of
copper B2 both use copper with a purity greater than 4N.
[0028] However, the copper alloy wire of the present disclosure is
manufactured in the following steps: manufacturing a copper alloy
wire material by means of continuous casting in a vacuum melting
manner shown in FIG. 2A, and then performing drawing on the copper
alloy wire material by a wire drawing device into a copper alloy
fine wire, and finally performing thermal treatment to complete a
process of the copper alloy wire, and the steps are as follows:
[0029] step S10: perform two-phase melting in vacuum state (e.g.,
melting titanium, silver, and copper under a vacuum manner into a
molten copper alloy);
[0030] step S20: manufacture the molten copper alloy into a copper
alloy wire material by means of continuous casting;
[0031] step S30: perform drawing the copper alloy wire material to
obtain a copper alloy fine wire by a wire drawing device; and
[0032] step S40: perform thermal treatment on the copper alloy fine
wire under an annealing temperature (e.g., the annealing time is
greater than 0.1 second, and the annealing temperature is ranged
from 580 to 700.degree. C.
[0033] According to FIG. 2B, it can be further known that
"two-phase melting" mentioned in step S10 is divided into step S11
in a first phase and step S11 in a second phase, and description is
stated as follows.
[0034] Step S11: melt a total share of titanium and a partial share
of copper into a copper-titanium mother alloy having a low melting
point by means of vacuum electric arc melting. In detail, when
titanium having a melting point of 1668.degree. C. is put into a
copper metal liquid having a melting point of 1085.degree. C., the
copper metal liquid cannot make titanium metal completely melted
therein, and therefore in step S11, titanium to be melted and
partial copper are first placed in a crucible, which is vacuumized,
so that a pollution source in air is reduced in a melting process.
Then, titanium and copper in the crucible are directly heated and
melted by electric arcs generated by a stun rod, so that copper and
titanium are first melted into a copper-titanium mother alloy
having a melting point closer to that of copper. An objective of
this step lies in preventing titanium metal having a high melting
point from being melted into a copper alloy wire with remaining
components in state of incomplete melting or uneven melting, and
consequently, distribution of titanium metal in the copper alloy is
uneven, resulting in a case in which inoxidizability of the copper
alloy is unsatisfactory.
[0035] Step S12: melt the copper-titanium mother alloy with a total
share of silver (Ag) and a remaining share of copper together into
a molten copper alloy by means of induction melting.
[0036] In step S20 (as shown in FIG. 2A), the molten copper alloy
is casted from the even molten copper alloy into a copper alloy
wire material with a wire diameter ranging between 8 mm and 4 mm by
means of continuous casting; in this step of melting into a wire
material, based on physical characteristics, casting costs and
convenience of the wire material, a continuous casting process that
directly pours the copper alloy molten liquid into a constantly
vibrated and cooled casting die body to generate continuous wire
materials is used.
[0037] Next, in step S30, coarse drawing, medium drawing, and fine
drawing are performed on the copper alloy wire material with the
wire diameter ranging between 8 mm and 4 mm by the wire drawing
device at a speed of 100 to 1000 m/min at room temperature into a
copper alloy fine wire with a wire diameter ranging between 10
.mu.m and 20 .mu.m.
[0038] In an embodiment, the "non-slip wire drawing device" in step
S31 shown in FIG. 2C can be used to perform wire drawing on the
copper alloy wire material. For example, referring to FIG. 3, in
the wire drawing step, the non-slip wire drawing device 300
includes a tension control apparatus 301 and an eye mold 302, and
the tension control apparatus 301 (for example, a tension rod) is
configured to increase a back drawing force of the copper alloy
wire 303 behind the eye mold 302, so that flowing uniformity of a
wire central material is improved to a better mechanical property,
and common broken wire problems derived from sector defects in
general wire drawing are reduced.
[0039] In step S40: after wire drawing, thermal treatment at an
annealing temperature of 580 to 700.degree. C. for annealing time
of greater than 0.1 second is performed on the copper alloy fine
wire, so as to complete a process of the copper alloy wire. Grains
on a surface of the copper alloy fine wire drawn by the non-slip
wire drawing device can still maintain arrangement with both even
sizes and even distribution, and therefore, flowing uniformity in
the wire after thermal treatment is good, and mechanical properties
of the wire may be optimized to make the wire have better ductility
to facilitate encapsulation welding work. Upon measurement
verification, a breaking level (B.L.) and an elongation level of
the copper alloy wire of the present disclosure can be increased.
In an embodiment, a problem that a copper alloy wire is easily
oxidized can be improved by using argon in place of common nitrogen
as a protection gas in thermal treatment in step S41 shown in FIG.
2D.
[0040] Referring to table I, table I lists examples 1 to 4 with
different ratios of components of the present disclosure, and
components by weight percentage are as follows:
TABLE-US-00001 TABLE I Silver (Ag) Titanium (Ti) Copper (Cu)
Example 1 0.45 0.02 Remaining part Example 2 0.45 0.01 Remaining
part Example 3 0.3 0.01 Remaining part Example 4 0.3 0.02 Remaining
part
[0041] The present disclosure adds titanium in components, so as to
improve an antioxidant capacity of the copper alloy wire, thereby
improving easy oxidization in use, which leads to lack of wire
attributes, of the copper wire. The present disclosure adds silver
(Ag) in components, so as to improve weldability of a pure copper
wire. The conventional pure copper wire into which silver (Ag) is
not added has cases in which ballability is poor and a copper ball
easily detaches, but the claimed copper alloy wire into which
silver (Ag) metal is added can form an intermetallic compound (IMC)
layer having high welding strength in welding, and has performances
better than the conventional pure copper wire in the breaking level
(B.L.) and the elongation level (E.L.).
[0042] Referring to table II, table II is a table of differences
between examples 1 to 4 of the present disclosure and a 6N pure
copper wire in the breaking level (B.L.) and the elongation level
(E.L.), and the differences are listed below:
TABLE-US-00002 TABLE II Presentation data of a 6N pure copper wire
in the breaking level (B.L.) and the elongation level (E.L.)
Breaking level (B.L.) Elongation level (E.L.) 4.34 g 9.87% 4.23 g
8.69% 4.14 g 9.08% 4.24 g 9.21% Presentation data of the present
disclosure in the breaking level (B.L.) and the elongation level
(E.L.) Breaking level (B.L.) Elongation level (E.L.) Example 1 6.07
g 11.76% Example 2 5.60 g 12.18% Example 3 5.82 g 12.02% Example 4
5.83 g 12.01%
[0043] Based on the above, the present disclosure can achieve the
following effects:
[0044] 1. Adding silver (Ag) and titanium in trace elements, so as
to improve weldability and an antioxidant capacity of a copper
wire;
[0045] 2. Performing vacuum continuous casting on a manufacturing
device, and making a wire have good quality and high cleanness in
combination with a wire drawing process of a non-slip wire drawing
device; and
[0046] 3. Optimizing mechanical properties of the copper wire
itself under thermal treatment conditions at a specific temperature
for specific time.
[0047] The foregoing implementation manners or examples of the
technical means used in the present disclosure are not intended to
limit the implementation scope of the present patent for invention.
Equal variations and modifications that accord with literary
content of the patent application scope of the present disclosure
or that are made according to the scope of the present disclosure
patent are covered by the scope of the present disclosure
patent.
* * * * *