JPS62182240A - Conductive high-tensile copper alloy - Google Patents

Abstract

PURPOSE:To develop a Cu alloy for electronic and electrical equipment parts excellent in strength, elongation, thermal and electric conductivities, solderability, plating suitability, adhesive strength of scales, and corrosion resistance, by adding specific elements to a Cu alloy containing Cr and Si in a specific ratio. CONSTITUTION:A Cu alloy prepared by incorporating, by weight, 0.1-5% Cr, 0.02-1% Si (Si content is regulated to Cr/5.6 or below, where Cr means a stoichiometric ratio of Cr), and <0.003% O2 and also incorporating 0.01-0.15%, each, of P, As, and Sb, 0.05-1.0%, each, of Ni, Co, and Al, 0.01-0.5%, each, of Zr, Mg, and Te, 0.01-1.0%, each, of Fe, Mn, Ta, Nb, Ag, misch metal, and Ti, and 0.01-3.0%, in total, of 1 or >=2 kinds among 0.05-0.3%, each, of Zn, Sn, and Be to Cu is used as a material for semiconductor lead frames, lead wires, various terminals, connectors, conductive springs, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to conductive high-strength copper alloys used for conductors, leads, conductive springs, terminals, etc. of electronic devices, and in particular, relates to conductive high-strength copper alloys used for conductors, leads, conductive springs, terminals, etc. of electronic devices, and in particular, for use in small and high-density semiconductor leads. It provides a copper alloy suitable for frames.

[Conventional technology]

Copper alloys are widely used for conductive springs in electronic devices, such as semiconductor leads, terminals for various type parts, connectors, switches, etc. Phosphor bronze in particular has a strength of 50 to 65 kg/- and excellent workability. It has become widespread since then.

However, since this alloy has a low electrical conductivity of 10 to 20%, it cannot be used for members that require electrical conductivity (thermal conductivity), and cannot be used particularly for miniaturized and highly integrated semiconductor applications. Therefore, CU-Fe series, Cu-Zr series, Cu-N
It is used in some alloys such as i-3i series.

(Problems to be solved by the invention) Cu-Fe alloys, such as C-194 (Cu-2,4w
t%Fe-0,12wt%Zn-P alloy) and C-1
95(Cu-1,5wt%-o, awt%Co-0,
6wt% Sn-p alloy) has a conductivity of 50-65″3
Although it exhibits properties of GIAC3 and strength of 45 to 55 Kg/mi, higher strength results in lower workability and solderability.

Although the CU-Cr alloy shows conductivity of about 80 to 90% rAcs, coarse Cr crystals are likely to precipitate, and Cr is 0.7
wt% (hereinafter W [% is abbreviated as %) or more and the strength is 55
If an attempt is made to increase the ratio to 3/IruA or more, the workability, homogeneity, and isotropy of the paulownia material will be impaired. Cu-Zr alloy is 90%
Although it exhibits a conductivity of lAC3 or more, its strength is as low as 40 Ky/- or less. CLJ-N i -3i alloy is N1zS
In alloys that precipitate 81, the electrical conductivity and solderability decrease depending on the combination of Ni and 81 and manufacturing conditions. That is, unreacted Ni,
3i, which inevitably reduces the strength of the solder joint,
This is a fatal flaw in normal mounting methods such as soldering to printed circuit boards.

In view of this, it has excellent mechanical properties such as strength and elongation, as well as thermal and electrical conductivity, as well as excellent solderability, plating properties, corrosion resistance such as scale 1 resistance and stress 13 corrosion resistance. There is a strong desire to develop alloys that are suitable for semiconductor REITs, for example, where advanced properties are required.

(Means for Solving the Problems) In view of this, the present invention has developed a conductive high-strength copper alloy suitable for small, high-density semiconductor lead frames as a result of various tests. 5% and 3i0.02~
Contains 1.0%, further p 0.01-0.15%, A
50.01-0.15%, Sb0.01-0.15%,
Ni0.05-1%, Co0.05-1%, Zro,
01-0.5%, Mq0.01-0.5%, Fe0.
01-1%, Zn0.05-3%, 3nO105-3%
, AJo, 05-1%, [3e0.05-0.3%, M
no, 01-1%, Ta0.01-1%, Nb0.01
~1%, Te0.01~1%, Ag0.01~1%, Mitshu Metal (hereinafter abbreviated as MM) 0.01~1%, T
It is characterized by containing any one type or two or more types within the range of i 0.01 to 1% in a total amount of i 10.01 to 3%, and the balance being Cu, especially S within the above tissue range.
I count is less than the stoichiometry of Cr, and the amount of 02 is 0.003
% or less.

The above alloys are easily manufactured by conventional methods and have the desired dimensions and mechanical properties. For example, an ingot that has been melted and cast is hot-worked and then rapidly cooled, then cold-worked, heat-treated at a temperature of 350 to 650°C, and then subjected to an aging precipitation treatment. Note that solution treatment at 800 to 950° C. and water quenching can also be performed during the manufacturing process.

[Effect]

The alloy of the present invention has the above composition range, and exhibits high strength and thermal and electrical conductivity due to the precipitation hardening effect caused by the precipitation of Cr3Si and Cr5Si2 compounds.
When the Cr content is X%, the stoichiometric amount of 3i is X/
5.6, the thermoelectric conductivity can be increased by minimizing the solid solution 5iffi by suppressing the S1 content to below the stoichiometric amount in 1 h. Furthermore, Cr-3i
In addition to the compound, Cr precipitates and strengthens and improves thermal and electrical conductivity. Coarse precipitates have a poor strengthening effect and impede workability and homogeneity. A dispersed precipitate is easily obtained. Therefore, the Cr content is 0.1 to 5%, particularly preferably 1 to 1%, and 3i
The content is 0.02 to 1.0%, particularly preferably 0.1 to 1.0%.
If the content is less than the lower limit, sufficient strength will not be obtained, and if the content exceeds the upper limit, the manufacturing processability will be reduced.

Also, P 0.01-0.15%, A S 0. O1~0
．． 15%, Sb 0.01-0.15%, Ni 0
．． 05~1%, CO0.05~1%, Z r0.01~
0.5%, Mg0.01~0.5%, Fe0.01~1
%, Zn0.05-3%, 3n0.05-3%, Al0
．． 05-1%, Be0.05-1%, Mn0101-1
%, Ta0.01-1%, Nb0. Old ~ 1%, “le
o, 01-0.5%, AQ 0.01-1%, M
M 0.01~1''6 z T i 0101~1%
(Hereinafter, these are abbreviated as Y, etc.) The reason why the total content of one or more of these is set at 0.01 to 3% is to improve the strength. , P behind these Y, etc. not only acts as a deoxidizing agent, but also precipitates compounds with Cr, producing highly dispersible precipitates, and eventually Cr.
Although the precipitation of 111 particles is oriented in the processing direction during manufacturing and processing and deforms into a linear shape, deteriorating the isotropic uniformity and plating properties of VI14, the addition of P prevents this. Mn, 3b, 7-n
Further, Mn acts as a deoxidizing agent and prevents deterioration of solder connection strength over time, and Mn inhibits oxidation and improves scale adhesion. Zr, MQ, [3e, Ta, and Nb further precipitate auxiliarily to refine the crystal grains and improve heat resistance and bendability, and Mg and BC, like Zn, suppress oxidation and adhesion of scale. Improve your sexuality. Δ1, Ni
, C0. Fe, Ti, etc. further act as auxiliary reinforcing components, &1~1, As further acts as crystal refinement,
Te, AcN; 1 further improves heat resistance. Furthermore, as a solid solution component, 3n reduces thermal and electrical conductivity, but increases the dispersibility of precipitates, and together with its solid solution strengthening effect, improves mechanical 1<r properties such as strength and elongation. If necessary, for example, 60 to 701/'-grade, or 0 if each or more
Contains 75-3'xO.

Melt. However, even if these additive elements are below the lower limit, they may not be included.
The above effect is also insufficient, and even if each additive element exceeds the limit, the thermal/electrical conductivity and processability decrease significantly even if the total amount exceeds the limit (). Become.

[Example] The alloys shown in Table 1 were blended and melted, and cast into a mold to a thickness of 2.
The surface side was prepared as j'J Bu with a width of 5 mm, a width of 110 mm, and a height of 300 mm. This was heated and hot-rolled at about 700'C or above to a thickness of 5m, cooled with water, pickled, then cold-rolled to a thickness of 0.811117I+, then heated at 350°C for 4 hours. processed, followed by a thickness of 0.3
It was cold rolled by 1 m/n.

The electrical conductivity, tensile strength, and elongation of the above board materials were measured, and they were bent using a press using a V-groove gouer with a base angle of 90° and a V-shaped bonder with various tip radii (R), and subjected to IJO processing.
A physical microscope was used to detect cracks in the bent portion. The bending was performed in the rolling direction and in a direction perpendicular to the rolling direction, and the ratio (R/l) between the plate thickness (1) and the tip radius (R) was determined. In addition, in order to check the solderability, after eutectic soldering of a lead copper wire to a 5 mm wide part,
After being left at 0°C for 500 hours, a pull test was performed. In addition, in order to check the adhesion of the scale,
The samples were treated on a pot plate of 'C for various times and a tape peeling test was conducted to determine the minimum oxidation thickness at which the scale would peel off on the adhesive tape.

The thickness of the oxide film was measured by a cathode reduction method. In order to further examine the plating properties, the surface was dissolved to a thickness of 0.1μ with Hz SO+ -1-1202 solution, neutralized with KCN solution, and then Ag plated to a thickness of 3μ, which was then heated to 475°C. The sample was heated for 5 minutes on Hot Play 1 to above, and then examined under a microscope to check for flakes. Stress corrosion cracking occurred in 30vo i% nitrate while applying a cart of 301 (ff/-).
The time was kept and the time of cracking Brahma was compared. C194 (Cu-
2,4%Fe-0,12%Zn-0,03P alloy), M
F202 (CU-2,1%3n-0,22%N i
-0,08% P alloy), C510 (Cu-5,2%
3n-0,15% alloy Alloy Cl-1-3,5%N i
-0,61%3i-〇,03P alloy) as shown in Table 2.

In addition, except for comparison alloy No. 26, the 07 content is 0.001~
It was 0.0025%.

　　　]j.

Table 1 (2) As is clear from Tables 1 and 2, the alloy of the present invention No.
Nos. 1 to 21 showed satisfactory results in all properties, and this is clear when compared with conventional alloys No. 30 to 33. That is, the alloy of the present invention has N 0.11,14
Except for the Or-excess compositions, all of them showed satisfactory properties, especially the invention alloys Nos. 3 to 4, which had a high 3n content.
Although the conductivity is low, the strength and workability are excellent, and the 3i
Excess inventive alloy No. 11.14 also has low conductivity but excellent other properties.

On the other hand, comparative alloy N, which is outside the composition range of the alloy of the present invention,
o, 22 to 30, it can be seen that one or more of the characteristics is inferior. That is, comparative alloy No. 22, 3 which does not contain Y etc.
Comparative alloy with low i content No. 0.23,02 Comparative alloy with high content of 26.3n Comparative alloy No. 0.27, comparative alloy with low Ni content No.
, 29 and comparative alloy with high Ni content No, 30
Comparative alloy N0.24 with a high 3i content and comparative alloy N0 with a high Sn content are inferior in workability and isotropy.
．． Comparative alloy No. 25 has poor conductivity, and comparative alloy No. 28 contains Zn and Mn in small amounts, and it can be seen that the solderability is poor in No. 28.

(Effects of the Invention) As described above, the present invention improves both strength and thermoelectric conductivity, which have been difficult to achieve in the past, and improves workability, which is essential for electronic and electrical equipment parts in which copper alloys are widely used.
Solder (= J-type solder with improved properties such as soldering properties and plating properties to a sufficiently satisfactory level, used for semiconductor lead frames, lead wires, various terminals, connectors, conductive springs, etc.)
This has a remarkable effect.

Claims (2)

[Claims] (1) Cr0.1-5wt% and Si0.02-1.0w
t%, further P0.01-0.15wt%, As0
．． 01-0.15wt%, Sb0.01-0.15wt
%, Ni0.05-1wt%, Co0.05-1wt%
, Zr0.01-0.5wt%, Mg0.01-0.5
wt%, Fe0.01-1wt%, Zn0.05-3w
t%, Sn0.05-3wt%, Al0.05-1wt
%, Be0.05-0.3wt%, Mn0.01-1w
t%, Ta0.01-1wt%, Nb0.01-1wt
%, Te0.01-0.5wt%, Ag0.01-1w
t%, misch metal 0.01-1wt%, Ti0.0
A conductive high-strength copper alloy containing 0.01 to 3 wt% of any one or more types within the range of 1 to 1 wt%, and the balance being Cu. (2) The conductive high-strength copper alloy according to claim 1, wherein the amount of Si is equal to or less than the stoichiometric ratio of Cr, and the amount of O_2 is equal to or less than 0.003 wt%.