JPS63145734A - Copper alloy for electronic apparatus and its production - Google Patents

Abstract

PURPOSE:To obtain a copper alloy for electronic apparatus having excellent strength and electrical conductivity, by subjecting an alloy ingot which is specified in the content and compounding ratio of Ni and Ti and into which Sn, etc., are incorporated to a homogenization treatment at a specific temp. and cooling the ingot right after hot rolling. CONSTITUTION:The alloy which contains Ni and Ti at Ni/Ti larger than 4 within the range of 0.4-3.0wt% Ni and 0.1-0.7% Ti, contains 0.1-6.0% Sn, 0.005-3.0% in total >=1 kinds among Zn, Mn, Mg, mischmetal, B, Sb, Te, Si, Co, Zr, Al, Fe, V, P, Ga, In, Ag, Y, Ga, and Pb, and <=20ppm O2, <=5mum deposit particles and consists of the balance inevitable impurities is cast. Such alloy ingot is subjected to the homogenization treatment for 0.5-15hr at 750-960 deg.C and is cooled right after the ingot is hot rolled at 700-880 deg.C. Semiconductor apparatus are reduced in thickness and size if this copper alloy is used as a material for said apparatus.

Description

[Detailed description of the invention] (Industrial application field) The present invention
)<Excellent, with good workability and plating density, and good interface strength with the hanger Ti. 1. This relates to a copper alloy for electronic devices that does not cause deterioration and a method for producing the same.

(Prior art) Semiconductor equipment in general, for example? The following 13↑j1 or sacred water is placed on the r conductor glue frame.

(1) High strength and good heat resistance, (2) Heat dissipation,
In other words, it must have high thermal conductivity (electrical conductivity), (3) Bending and forming after forming the frame.
4) Good adhesion and bonding properties with 61 resin, (5) No deterioration over time of the joint with the hanger, and lead frames of conventional electronic devices mainly use 42 alloy (F). e
-42wt%Ni> is used.

This alloy has a tensile strength of 63 KFj/rrvA and a heat resistance of 67
Although it exhibits excellent properties at 0°C (the temperature at which the strength reaches 70% of the initial strength after heating for 30 minutes), the electrical conductivity is only 3% lAC.
There is C, which is inferior to about 3.

In recent years, semiconductor devices have been required to have higher reliability as well as increased integration and miniaturization, and the form of semiconductor devices is also changing from the conventional DIP type 1G to the chip kitria type and PGA type.

For this reason, lead frames for semiconductor devices are also thin.

At the same time, it became necessary to have characteristics that are equivalent to those of 42 alloy. In other words, we need to improve the strength of the components to prevent the strength from decreasing due to thinning of the walls, and the collection and! To increase i degree, J, rudan = t'l increase, same as thermal conductivity 1! J'PI
(In the direction of certain conductivity, history has excellent t14 thermal properties and ゛1'
- Fixing the conductor on the frame and bonding from the semiconductor to the wiring at the leg part of the lead frame.Metsu on the surface of the lead frame as a pretreatment - Tij [and plating density, mold with 141 resin 1 ( In terms of reliability, it is desired that there be no deterioration of the solder joint strength between the frame and the board over time (1,1).

[Problem that the invention seeks to solve]

The 42 alloy mentioned above has a low conductivity of 3% AC3 and has the disadvantage of poor heat dissipation, but if a copper alloy is used instead, the conductivity can be dramatically improved to 50-30% AC3. However, it is difficult for alloy 42 to have the same properties as alloy 42.

[Problem 4 - Means for Solving] In view of this, the present invention has been developed as a result of various studies, and has been developed to provide a copper alloy for electronic devices and a method for manufacturing the same, which has a strength equal to or higher than alloy 42 and far superior conductivity. It was developed by Shino.

The alloy of the present invention contains Ni0.4-3, Owt% (hereinafter referred to as 1;
(NVt% is abbreviated as %), contains Ni and Ti in a range of Ti0.1 to 0.7% so as to be larger than Ni/Tih14, and further contains 3n0.1 to 6.0% and 7n.

Mn, Mg, Missile Metal (hereinafter abbreviated as MM), B
, Sb, Tc, Si, Co, Zr.

AJ! , Fe, V, P, Ga, In, A9. Y.

One or more of Ca and Pb in total 0.005
~3.0%, and α-containing CtN of 20 ppm or less,
It is characterized in that the precipitate particles are 5 μm or less, and the remainder consists of CU and unavoidable impurities.

Further, in the manufacturing method of the present invention, Ni is 0.4 to 3.0%.

io, Ni and Ti within the range of 1 to 0.7% Ni/T
Including so that i is larger than 4, and further including 3nO, 1 to 6
．． 0% and Zn, Mn, Mg, MM.

B, Sb, Te, 3i, Co, Zr, A1°Fe, V
, P, Ga, In, A9. Y, Ca.

A combination of any one or two or more of pb i10.005 to 3
．． 0%, the α content is 20 ppm or less, the precipitate particles are 5 II In or more, and the balance is CLI and unavoidable impurities.
~ 15Ti, after i level 7'i treatment, 700
It is a sign that hot rolling from ~880''C followed by immediate cooling is recommended.

(Function) In the present invention, the addition of Ni and Ti is to achieve excellent strength and conductivity due to the synergistic effect of both elements. ' + 3i 1 piece to 0
．． The lower limit was set at 1% to 0.7%. No. 1 shows no improvement in the 15 properties, and if the upper limit is exceeded, the castability, workability and bending formability are significantly reduced, and production becomes a national disaster. Also Ni and 1i/! -Ni/1 is limited to be greater than 4 because of its superior conductivity compared to 42 alloy, its small size, and Ni? Ni/T! This is because when N is less than 4, it has an excellent electrical conductivity of 39 and cannot have an intensity greater than 10, and is preferably N! / -1-! It is desirable that the culm degree is 4 to 10.

The addition of 3n leads to solid solution of 3n in the matrix and Cu-3
As a precipitate of n-Ni-1"i or 3n-Ni-1°i, it improves strength and bending workability,
and hot rolling conditions (starting temperature.

The reason for limiting the sn content to 0.1 to 6.0% is to suppress variations due to finishing temperature, cold TJI speed, etc. Below the lower limit, the effect is poor, and above the upper limit, the processability is reduced. This is because manufacturing becomes difficult.

Zn, Mn, M9. MM, B, Sb, Tc.

S i, Co, Zr, Aj! , Fc, V, P, Ga.

In, A9. Addition of one or more of Y, Ca, and Pb improves castability due to deoxidizing effect, and the average
Prevents reheat cracking during alpha embedding and rolling cracking during hot rolling,
Furthermore, in order to strengthen the plating adhesion and the joint interface with solder and suppress the deterioration of J: Re-solder joint strength]14, the content of these anatomical M was limited to 0.005 to 3.0%. If it is less than the lower limit, the effect will be weak, and if it exceeds the upper limit, the castability, plating adhesion, and bending formability will deteriorate.

02 Contains right ((i is ur) 20pp in molten metal
The reason why the value is less than m (S) or less than 10 p pIII is that if it exceeds this value, it will become a melt field J as an oxide, and it will become a lithium slag, making it difficult to solve the Ti component. 1 eyebrow ^↑ Not only does it worsen Ti, but it also impairs plating adhesion and hang bonding. Also, the size of the precipitate particles was set to 5μ7n or less because if the particle size exceeds this, the surface condition of the plating will become denser and the hang wettability will be greatly affected. 4.

Next, in the manufacturing method of the present invention, the alloy Vifoni with the above composition is made into 750
After uniform 1'I treatment at 960 DEG C. for 0.5 to 1504 hours, hot rolling is carried out from 700 DEG C. to 880 DEG C., and then immediately cooled to 15 degrees Celsius. It is an alloy component] °i
It has a high activity of ν, and is popular and easily becomes an oxide, which generates slag and causes component defects. But Arl”
i'fT F/'/ >l in a non-oxidizing atmosphere such as Nz
i 3 times (1) makes it possible to cover this and greatly improves productivity. Also, the cold 7JI speed in semi-continuous or continuous casting is 100
℃,/sec or more is desirable; if it is less than that, precipitates will be generated due to groove formation, coarsening will occur during homogenization flooding before hot rolling, and subsequent properties and manufacturability will be adversely affected.

Furthermore, the reason why the homogenization treatment was limited to 0.5 to 15 hours at 750 to 960 °C is because below the lower limits, the effect of Ti homogenization cannot be seen, and when the upper limits are exceeded, reheating cracks may occur and production costs may worsen. Preferably at 800-880°C for 2
It is desirable to set it to 8 clear days. In addition, the hot rolling start temperature was set to 7.
The reason why it is limited to 00 to 880 °C is because hot rolling tends to occur when outside this range, and J, preferably 7
It is desirable to start at 50-850°C.

Due to the effect of 3N addition, cooling of hot Nobutoshi can be done at any cooling speed, but especially at 500°C.
/minute or more is desirable. In addition, according to the manufacturing method of the present invention, after hot working, cold working 77Ti1 and 400-800
Repeated annealing at ℃ for 10 seconds to 360 minutes), and finally 2
By combining temper annealing at 00 to 500°C, a tensicon leveler, etc., better 1:1 properties can be achieved.

[Rei/Ii! ! example〕

Atmosphere temperature W (using a furnace, melt and cast a copper alloy with the cutter blade composition shown in Table 1 in Ar gas, thickness 50 mm, +1''120
In+Ti. An ingot with a length of 200 mm is '+'-1.

L:, 'l'L? : Surface cutting, 850℃T-3T
i, t RJ uniform v1 processing L/j knee i! , 830
CU hot rolling was carried out, and this was water-cooled to make a tentative piece with a piece size of 10 mnI.

Cold ff rolling and intermediate annealing (N in Table 1)
O1-21 at 570°C for 1 hour, ~o, 22 at 700°
1) at a final processing rate of 40%.
A plate with 9 lengths and 251 depths was plated and annealed at 300°C for 0.5 hours, and test pieces were cut out to determine the tensile strength, bending formability (R/l), Plating density: 1: U:
- The root ↑J (oxide film removability) was investigated. The results are shown in Table 2. The 1° tensile strength is based on JIS-12241, and the electrical conductivity is J
Measured based on 1S-Ti0505. Bending j1°!
・j') (R/() is tested based on the block method of JIS-Z22/18, and the minimum bending radius < R) that prevents cracks on the test piece surface is applied to the test piece. υ]
It is shown as a value.

After cleaning the surface of a 30 x 30 yml test piece, conduct Ag plating, heat it in the air, and observe the swelling of the plated surface afterward.
After heating at ℃r for 5 minutes, the sample 'b' with no visible IN bleed is marked Q, and the sample 1b where swelling is observed is marked X. In addition, the oxide film removability was measured on Ti0X50 test pieces after surface cleaning treatment.
After heating at 420° C. for 1 minute in the atmosphere, a peel test was conducted using a Cedar dip, and those with almost no peeling were marked with a Q mark, while those with peeling were marked with an X mark.

Regarding the solder joint strength, a 5 x 507 g test piece was joined to an oxygen-free copper plate of the same shape using a 60/40 hang, and after an accelerated heating test at 150°C for 500 n; y, a tensile test was performed to determine the strength. 8 before the accelerated test
0% or more is indicated by ◯, 50 to 80% is indicated by Δ, and less than that is indicated by X.

As is clear from the i'Ti and i'12 tables, Kizagoaki Alloy No. It can be seen that equivalent bending forming +4, hang joint strength, plating density practice 1 and 7 - lead PI are obtained.

On the other hand, comparative alloy N0 with less l-i containing tr 27i
19 and Comparative alloy No. 22, which contains less Ni and one item, showed an improvement in strength.
, 20 has difficulty in hot rolling]1, and comparative alloys containing a large amount of Ni ~O, 21 not only have poor solder joint strength but also poor plating density and moldability. In addition, comparative alloy No. 23, which has a large amount of 3n, has a hot-rolled temperature of 1, which is the same as comparative alloy No. 20.
Comparative alloy No. 24.25, which has a high content of other elements, not only has poor 39 electrical properties, but also has poor plating density Ti and bending formability. Comparative alloy No. 26, in which the α-containing e-i ratio exceeds 20 ppm, and comparative alloy No. 27, in which the σ precipitate grain size exceeds 5 μTn, both have a low solder joint strength and plating crystallization of 1.
(I can see that [is inferior.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a copper alloy with excellent conductivity, 2 strong, 1 poor, bending formability, hang bondability, etc.
It can be used as a semiconductor device such as lead frames, and has remarkable industrial effects such as making it possible to make them thinner and smaller.

Claims (2)

[Claims] (1) Ni0.4-3.0wt%, Ti0.1-0.7
It contains Ni and Ti within the range of wt% so that Ni/Ti is greater than 4, and further contains Sn0.1 to 6.0wt% and Z.
n, Mn, Mg, misch metal (MM), B, Sb,
Te, Si, Co, Zr, Al, Fe, V, P, Ga,
Contains a total of 0.005 to 3.0 wt% of any one or more of In, Ag, Y, Ca, and Pb, the O_2 content is 20 ppm or less, the precipitate particles are 5 μm or less, and the balance is Cu. A copper alloy for electronic devices that contains unavoidable impurities. (2) Ni0.4-3.0wt%, Ti0.1-0.7
It contains Ni and Ti within the range of wt% so that Ni/Ti is greater than 4, and further contains Sn0.1 to 6.0wt% and Z.
n, Mn, Mg, misch metal (MM), B, Sb,
Tc, Si, Co, Zr, Al, Ic, V, P, Ga,
Contains one or more of In, Ag, Y, Ca, and Pb in total of 0.005 to 3.0 wt%, O_2 content is 20 ppm or less, precipitate particles are 5 μm or less, and the remainder is Cu and unavoidable. An alloy ingot consisting of impurities of 750 to 9
After homogenization treatment at 60°C for 0.5-15 hours, 700-
A method for producing a copper alloy for electronic devices, characterized by hot rolling from 880°C and cooling immediately thereafter.