JPS59215445A - High-strength cu-fe alloy for electric conduction - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy having superior mechanical properties, drawability and solderability without remarkably reducing the electric conductivity by cold working a Cu-Fe alloy contg. a specified amount of Fe after hot working and by carrying out precipitation treatment. CONSTITUTION:A Cu-Fe alloy contg. 5-15% Fe is subjected to precipitation treatment at 500 deg.C for 100min, and it is cold worked at 50% working rate to obtain an electrically conductive Cu alloy having >=55% electric conductivity in IACS unit, >=60kg/mm.<2> tensile strength, and >=80% expansion rate on the basis of JIS with respect to solderability. When a Cu-Fe alloy contg. 6-12% Fe, 0.02-0.1% misch metal and 0.3-0.6% Mg2Si is used in place of said Cu-Fe alloy, an electrically conductive Cu-Fe alloy having further improved castability, cold workability and >=62kg/mm.<2> tensile strength is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high strength Cu--Fe alloy for electrical conductivity.

ICs currently make up electronic products such as converters.

For lead frame materials such as B81, we use Cu-Fe alloys that have a four-voltage conductivity and are inexpensive, such as CDA1g4.

A Fe--Ni alloy is used, which has a slightly lower conductivity but is highly durable. In recent years, with the remarkable development of the electronics industry, there has been a demand for alloys with contradictory properties such as higher strength, higher strength, and higher electrical conductivity than these alloys.

The present invention is based on an inexpensive Cu-B'' alloy which has high conductivity and has a higher conductivity than the CJJA194 alloy.

The aim is to develop an alloy with high strength and poor electrical conductivity by adding additional elements such as persimmons.

In the present invention, the target value of 1 alloy property is tensile strength 60kg/
Repeated tests and research were carried out with the conductivity set at mm2 or more and conductivity at 1AC3 units''c55% or more. The sample used to determine the range of Fe addition is 2.5% strength up to 50 cm.

After hot working and cold working, it was subjected to 100% analysis treatment at 500°C to measure tensile strength and conductivity.
As shown in the table (it was found that 15% or less of Fe reached the target value. This is the point of cost reduction and strength increase which are the objectives of the present invention), z, s, s, which are close to the prior art. o%;2
Excluding Cu -ii ~12%] I'e B Based on gold, the influence of other additive elements was investigated. Next, we conducted a tensile test on a plate material that is more suitable for practical use, and also tested other properties that are necessary for lead frame materials, such as bendability, solderability, and heat resistance ◇ Table 1 500℃ Relationship between Fe (%), tensile strength, and electrical conductivity σ) of a sample subjected to 55 mm cold working after 100 ml precipitation treatment.

This is to give an overview of Cu-Fe alloys.

The phase diagram on the Cu side of the Cu-Fe system that has the pressure relationship of the present invention is shown in the first diagram.
Shown in the figure. The solubility of Fe in the ε phase on the Cu side is determined by the peritectic temperature 1
, 4.0% at 094℃, 2.6% at 1,000℃, 90
At 0℃ it is 1.4 more, and at 700℃ it decreases sharply to about 0.3%.
″r: It is said that there is.The primary solid solution ε phase on the Cu side is 4
゜0% Fe is the peritectic point, and the peritectic temperature [1,094℃
''e(υ+Liq+:'(,:u(represents the peritectic reaction.

Regarding electrical conductivity, which is the most important characteristic among the properties that are the object of the present invention, the solubility of k''e decreases dramatically as the temperature drops, so by performing a precipitation treatment.

The 6 phases on the Cu side are close to pure copper! It can be expected to increase the conductivity by 1:1, and it is possible to easily increase the conductivity to 55% in units of lAC3.

Generally, the tetraelectricity is better when li'e is dispersed and precipitated in the Cu (ε phase) matrix than when it is supersaturated (mainly) dissolved in the Cu (ε phase) matrix. Therefore, the temperature is relatively low (450~b). Looking at the mechanical strength, Cu-2.5%Fe has a second phase of
Because of the small amount of ゛e(r), we cannot expect much work strengthening, but in the case of Cu-6~12%Fe alloys, the second phase increases, and by working, the strength increases as shown in Figures 2a and 2b. - It can be seen that it is fiber-reinforced. However, in order to use it as a conductive structural member for electrical and electronic equipment, elongation and bending workability are required.

1. These electrical and electronic devices are often joined by electrical markings and other σ) components, so soldering itself can easily be done in one piece. It is improved in resistance to corrosion that occurs and progresses during use in temperature conditions, and also in the joint strength of soldered parts.

The present invention is superior to conventional Cu-2,5% Fe yarn!
Even if the electrical conductivity is reduced to a certain extent, the mechanical properties are maintained by increasing the amount of 5% to 15%, preferably 6% to 12%.

The goal is to develop an alloy with good malleability and soldering properties. Therefore, the range of components that can satisfy these characteristics has been confirmed through experiments, and measurements of currently used CDAl94 have shown the following results at 50% potassium nitride.

IACS tensile strength elongation 11RB6
5% 49-53 2-4 73-76 Components are within the following ranges.

Cu 1! ' e P Z
n97, θ~97.8 2.1~2.6 0.015~
0.04 0.05~0.2 This? As you can see, the tensile strength ζ6θkg / [+1111' sword/ra] about 7 to 10 kg/sword 2 required today is not very good, and the plating properties, solderability, and bendability are satisfactory. approved and used.

The newly developed alloy has a 1 weight standard''r: Fe of 5 to 15
%.

Preferably, a Cu-Fe binary alloy containing 6 to 12 mm, and 0.02 to 0.0 mm of Minos metal (M, M, , ) is added thereto.
An alloy containing 1%, My, Si 0.2-10, 6% has a CS of 55 or more, a tensile strength of 60kg/2 or more, and solderability, bendability, corrosion resistance, and heat resistance. The performance is also comparable to CIJA194, and the test results will be described below as examples.

First, the trial melting is carried out. It is said that if the carbon content of the main thread alloy exceeds 0.02, it will separate into two phases and a sound TC ingot will not be obtained. Short time in furnace
Made it dissolve. At first, a magnesia crucible was used, but later a graphite crucible was lined with alumina.

Effects of Additive Elements Fifteen types of alloys shown in Table 2 were melted and processed into layered materials (1.0 m+nφ, 1.50 mmφ) using the following processing method.

Ingot (23X100X200+nm) → Cut Wr (20
X20X 130nin) → Hot processing (500℃,
12.5 x 12.5 x 330++nn) 4
Yakina'EL (500℃, 10111 j rl)-
＞Cold rolling −+1.5+Tl]nφ and 1, Oon
++φ → Precipitation 3f (500°C) → Cold rolling (55-chi processing) → Electrical conductivity foot → Tensile strength measurement.

As a result of the above, the tensile strength and conductor ratio are as shown in Table 3. That is, Cu-10Fe-o, lp alloy, ell-
2,5Fe-0,lHe-0,18i, Cu-2,5
Fe-o, 3Mg-o, 3s i.

To u-2,51! 'e-0,6Mg2S i-0,11
' It can be seen that the alloy in the door has reached the target value.

Table 3 Note: 500°C''C: Sample subjected to 55% cold working after precipitation treatment for 100 minutes. Precipitation treatment temperature: 450℃
, it takes 1000 minutes (approximately 16.7 hours)
This method was excluded because it is not suitable for actual industrial situations.

Table 4 shows Cu-Fe base metal 2P, (,:,a, Minosh metal (Δ1.ΔL), Ca-8i, 8"g2"
''': ((g) The conductivity, tensile strength, and elongation of the wire subjected to 55% cold IHJ processing after precipitation treatment were shown.
It can be seen that the lick phase with 0.1% added exceeds L1 and 1[L(), and furthermore, the elongation is improved.

The cold-processed Aya/old board material was ranked number 1 with arrow work pay. Ingot (23x
100X200 mn) → Hot rolling (10 books) →? jr
Inter-rolling (2nrm) → 97i cabinet 500℃+
30rnin) - + cold rolling (0, 8, 0, 57, 0,
5,0,,47ml+) → Precipitation treatment 1ffl(50
0°C, 100rn ln) -47 with pressure screw (Q
, 4 nun: In this 1, the force d power factor is 15°20,
30.50%σ>0.4 fence θ) The alloys using O that obtained the temporary phase are Cu-2,5F'e, Cu-10Fe, Cu-2,
A specific softness test was conducted on three base metals of 5Fe-0,6Mg2Si.

The results are shown in Table 5 below.

Table 5 Tensile test results As can be seen from the results of the tensile test, the tensile strength of the 2.5Fe alloy (hereinafter simply referred to as 2,5Fe alloy 1-) is 5.
Compared to 54kg/m2 for 0-chi processed material* Cu-1
o%Fe alloy (hereinafter referred to as H in B'e alloy) has the same <50 strips processed material with 59 to 8/P'', Cu-2,s
F'e-0,6D, 1g2S + Alloy T60~62
k+= /+mc'' i0 [shown, there were 4 to 5 requests for 1 in A1.

For the W-curve, each test sample is shaped into a predetermined shape (0-4X 5 X401111+
1) Processed.

Fig. 3 ζ = Showing - Jig ￥ +'l (loaded by Deco-type tensile testing machine, 4j 300 times J] = ￥) Usage'CiiJ Gere 7
';L::-1.1. Depending on the condition of the 1:1 ratio of the 1:1 ratio, the product was graded into 4 grades: A: Good, ii: Small wrinkles, B: Medium wrinkles, and D: Large wrinkles.

In addition, the tip y+ia of the edge part of the jig is machined to have two radii r, and the σ) double radius - hour r is r=Q・2~1
- The bending strength was changed by changing between On and +n.

An alloy sample was processed according to the experimental method (1.4 mm).
0.6.0.8° and 1. ootm) 'a: Bending tests were conducted in two directions, parallel and perpendicular to the rolling direction of the sample. The results are shown in Table 6. The evaluation is A, B.

The four ranks of C1D were adopted, and the evaluation criteria are shown in Figs. 4a to 4d. This criterion was relatively determined by classifying the test specimens yA to D of 2,5Fe alloy, which are comparative materials.

From Table 6, it can be seen that for each sample, the smaller the radius of curvature, the more '! As the degree of cold working increases,
The rank of ifllllII is decreasing. The difference depending on the processing direction is that 10,000 times in average is better than in the vertical direction.
h 2-5 Comparison with Fe alloy L Te2. sFe 10.6Mg, Si and 10Fe alloys are evaluated well. As a cause 2. sFe+o, 6Mg, Si alloy LLMg,
This is because the toughness is the same as above due to the addition of Si, and Cu-1
As mentioned in the section on the W bending test, the strength of the 0rue alloy is thought to be due to the composite reinforcement of the primary crystal 1i''e.

A: Good B: Small wrinkles C: Medium wrinkles] J = wrinkled solderability test method As a solderability test, JIS-Z-3197, resin flux test method for soldering was used as a reference, A: Spreading. Test, B: Corrosion test was conducted, and C: Tensile test was conducted. The solder used here has a composition of 60% Sn -40%
” BB shape 1.6 diameter rod-shaped resin-filled ones were used.

A: Spread test JIS-Z-A 191m standard sale') VC, (
Polish a 1,4×30×30×11 test piece with steel wool.

Cleaned with methanol. After oxidizing in the air at 150°C for 1 hour and cooling, soldering was carried out in an electric furnace at 250°C (1,3F solder 7a:').After the solder spread sufficiently on the test piece, it was removed. After that, the flux was removed with alcohol, and the maximum value of the solder thickness was measured with a micrometer, and the linear equation D: 0.3
Diameter when there are 7 solder balls of y (nIITl) H: Maximum value of solder thickness on test piece (control) B: 0.4X 30 according to the regulations of $Motsu 1 town test J l5-Z-3] 97
Polish the test piece with steel wool (-, wash with methanol, dry thoroughly, test piece with 0.3
The solder from No. 2 was applied and placed in an air oven at 250°C, and after the solder had spread, it was held for 5 seconds and then taken out. 4 test pieces each
One piece is used as a standard test piece at a temperature of 72°C (20°C).
The remaining three samples were kept in an atmosphere of 40° C. and a humidity of 90% or more at 72:13], and after the test, the appearance changes were visually observed and compared.

C: Tensile test 0.4 x 5 x 30 x 30oIm (7) A test piece was polished with steel wool, washed with methanol and oxidized at 150° C. for 1 hour in a hot water bath. This is Tsumugi<:ip
L wire Q, 85nnnψ is overlapped by 5mIn to make a joint shape,
Soldering was performed using a soldering iron with a soldering iron tip temperature of 350°C, and a tensile test was conducted using this. Solderability test results A: Spreading test The experimental results are shown in Section 7.

According to the JIS standard, Zuba and 1oFe alloys, which all pass the test because their spread rate exceeds 8oφ, seem to be somewhat inferior to the other two. The cause of this seems to be that the solder is slightly repelled when the iron is removed, and it is thought that this caused the first shift to fail. Since the results were obtained under fairly severe conditions with the surface made hostile before the test, all alloys are recognized as having good solderability in practical terms.

B: Corrosion experiment results The experimental results are shown in Figures 5a to 50. In the symbols directly below each sample 1-0, a: standard test piece, b: test piece left in a 90% humidity atmosphere for 72 hours. .

As shown in Figs. 5a to 50, no clear corrosion phenomenon was observed when compared with a and b. For the L2,5 Fe, 2,5Fe-4-o, 6Mg, and Si alloys, black discoloration was observed around the soldering area. No such discoloration was observed in the -10,000,1OFe alloy. This is considered to be due to the influence of P contained in the 10F'e alloy. From the above* 2.51”e+0.6Mg2
It is thought that the corrosion resistance of Si alloy VC also improves when Pk is added. On the other hand, the conductivity decreases.
Figures a to 6C are sketches of the above figures 5a to 50. 1 Heat Resistance Test Two types of heat resistance tests were conducted: A: constant time; B: constant temperature.

A: When the time is constant, the test piece of 0.4 x 10 x ]Om is 0.300,
Salt bath [KN Os+N a (N Ut
) t ] for 5 minutes, then washed with 0.1% nitric acid aqueous solution, polished with emery paper to ensure a level surface, and then checked for hardness at room temperature after being held at each temperature. The hardness was measured using a micro-Vickers hardness meter to examine changes in hardness due to differences in heating temperature.

B: When the temperature is constant, a 0.4 x 10 x 10 mm test piece is placed in a 500°C salt bath at 0°2.3, 6.10.30, 60,100,
It was held for 300, 600, and 1000 seconds, and then washed with a 0.1% nitric acid aqueous solution.

Ensure the surface is level with emery paper. Thereafter, the hardness after holding for each time was measured using a micro Vickers hardness meter, and changes in hardness due to changes in heating time were investigated.

Heat resistance test results A: For constant time (isochronous heating) After processing the sample into a predetermined large explosion, heat treatment is performed.

After treatment, the hardness at room temperature was measured using a Vickers hardness meter, and the results are shown in Table 8 and FIG.

These results show that 2. ryh'e
The alloy is softening at the lowest temperature. Furthermore, 2.5Fe
10, 6Mg, 8i alloy and 1oFe,! l:
A comparison shows that the hardness of the 2°5Fe+0.6Mg2Si alloy in cold working is higher than 1gFe, but the hardness decreases rapidly when a certain heating temperature is reached. In comparison, lol'e alloy softens slowly at any working degree.

These causes include 2.51"'e -1-0゜6
In Mg and Si alloys, the matrix is independent due to the added elements.

It is basically considered to be the same as the 2゜51゛e alloy. Therefore, even if the softening temperature is increased by adding All, it is thought that once this softening temperature is lowered, the material softens rapidly. L sword/shi101: In the ''e alloy, primary Fe exists in the Cu matrix, and when processed, it becomes a ribbon shape and contributes to 1 strengthening, so C up to the softening temperature of Fe.
Even if the u-matrix softens, it is thought that the softening progresses slowly into a sword due to the ribbon-like reinforcement of Fe.

B: When the temperature was constant, the alloy sample was processed to the required size, subjected to a prescribed heat treatment, and then its hardness was measured using a Vickers hardness tester. The results are shown in Table 9 and FIG.

From Table 9, IOI”e, 2.5i”e+Q, 6Mg2
Both the 8i and 2°5Fe alloys have a longer softening time than the 2°5Fe alloy. For all alloys, the softening time becomes longer as the degree of working increases. 10B'e and 2.5Fe+
0.6Δ'g2" Itt 2゜51 compared to gold
! 'e + 0, 6Mg2Si alloy has a higher initial hardness, but has a faster softening time. The reason for this is as mentioned in A, 2゜5Fe-4-o, 6N1g2
This is thought to be due to the difference in the strengthening mechanism of Si and 10Fe alloys. ・Tensile test of the soldering part A tensile test was conducted on a test piece with soldered copper fat at 6.1 weight 160mm, but all the results were that of copper wire. It was broken in some parts. In this test, even though the surface of the test piece was soldered after being made into
J (7) There was no change. Furthermore, even when this portion was bent, no peeling occurred during the 5 bends. From the above results, it was confirmed that all alloy samples had high reliability regarding the strength of the solder joint.

To summarize the above results, for Cu-10%Fe, which is a typical component of the alloy of the present invention, the target value of conductivity is IAeS.
It was found that the unit was 55% or more, the tensile strength was 60 kg/stroke 2 or more, and the L force was also excellent in bendability, solderability, heat resistance, and corrosion resistance near soldering. N of the receiving body in history
1. M f O, 02-0.1%, Ntg2SjkO6
It has been found that addition of 2 to 0.6% improves strength and elongation, making it an inexpensive and high-performance lead frame material.

[Brief explanation of the drawing]

Figure 1 is an equilibrium phase diagram showing mainly the mesh side of a copper-iron (Uu-F'e) binary alloy, and Figures 23 and 2b are rolling diagrams of the alloy of the present invention containing Fe1 after 50φ cold working. Optical microscopic structure photograph (X200
), Figure 3 is a side view showing the shape and dimensions of the test suite for the W song, and Figures 4a to 4d show the evaluation criteria for the test results for the W song. ), Figures 5a to 5C are photographs showing the surface condition of the sample after the corrosion test, Figures 6a to 6
Figure 0 is a sketch of Figures 5a to 5c, Figure 7 is an isochronous heating curve in a heat resistance test, and Figure 8 is a curve showing changes in hardness depending on holding time during isothermal heating at 500°C. . Agent Patent Attorney Isao Fujimoto Agent Patent Attorney Takeo Goto Naka 1 Figure 3 Kasumi Figure 2a Rolled surface Figure 2b Rolled parallel cross section Figure 4a Evaluation A Figure '4B Evaluation 13
4th (: Figure Evaluation C Figure 4d Evaluation Figure 5a 2.5"Fe Figure 5b 2::':""5'Fcto0',:,6
M&S i Figure 5a 1oFe Procedural Amendment (Method) September 28, 1980 Commissioner of the Japan Patent Office 1. Indication of the case 1986 Patent Application No. 86684 2. Name of the invention High strength Cu-top for conductive use e Alloy 6, Relationship with the person making the amendment Patent applicant address Chiba Prefecture Chiyo City Chiyo Taipei 5-4-8 Name
Hisato Watanabe 4, agent 106 phone 05-274-! 1466 Address No. 2 Parker Building Annex, 2-16 So, Nihonbashi, Chuo-ku, Tokyo August 10, 1981 (Delivery date B/60, 1981, Detailed description of the invention in the specification to be amended) Column, Column for brief explanation of drawings, Drawing Z Contents of amendments Contents of amendments as shown in the attached sheet (1) [-C, JJ
The following four ranks were decided. "of[
It was ranked as 4 ranks: 'C and IJ. The evaluation criteria was determined by visually comparing test specimens of 2 and 51'e alloys, which were used for comparison, into four grades, A and IJ.'' (2) In the same No. 19 Tei lines 15 to 17 (same page Shimoba et al. lines 4 to last line), "experimental results... clearly" should be replaced with r experimental results. 1 shown in Figures 4a, 4b, 5a, 5b, 6a and 6b, 2.5i'e, 2.5Fe + 0.6 Mg2Si, respectively.
Figures 4b, 5b and 6b are standard specimens of 10Fe alloy.
e10.6Mg2Si OJ:10Fe alloy with humidity 9
It's clear that you're in the same state as if you were left alone in a 0%) atmosphere for 72 hours.'' (3) On page 20, lines 7 to 9, “On the other hand,...
...is shown. ” will be deleted. (4) "Figure 7" at the end of page 21 of the same page I' 73.71
), Figure 70”. (5) Change “Figure 8” in the second line of page 24 to “Figure 88.8b.”
and Figure 80”. (6) "It is a curved line indicating the shape dimension" in the 16th line to the 27th line 2nd line on page 26. Side view showing the "shaped dimension", No. 4a, 4b , 5a, 5b, Oa and 6
Figure b is a sketch diagram showing the surface condition of the sample after the corrosion test.
Figures 7a, 7'b and 7c are isochronous υ1 thermal curves in the heat resistance test, and Figures 8a, 81] and 80 are also based on the holding time of isothermal heating at 500°C. 1 is a curve showing changes in hardness. ” he corrected. (7) Figures 4a, it), 4C14d, and 5a, 5b, and 50 of the drawings attached to this application are deleted. (8) Figures 28.2b and 6a- in the drawings attached to this application
Figures 2a, 2b, 4d, 4b, 5a, 5b attached to Amendment 4 of this procedure, all of Figure 60, Figure 7, and Figure 8.
Figures 6a, 6b, 7a, 7b, 7c and 88.8
b, g Replace with figure c. (Note) Reference photos 1a, 1b, 1c, xcl and reference photos 2a, 2b, 2c should be submitted as separate sheets. Figure 22 Figure 40 Figure 4b Figure 5o Figure 5b Figure 6o Figure 6b

Claims (1)

[Scope of Claims] (1) Fe5-ts% by weight, the balance being Cu and unavoidable impurities, having an electrical conductivity of 1Aesss or higher after 50% cold working after precipitation treatment, and a tensile strength. is 6
0kg/I[12 or more soldering characteristic 75K J 18
A high-strength Cu-Fe alloy for conductive use, characterized by a standard spreading rate of 80% or more. (2. In the alloy according to claim 1, F
A gravity Cu-Fe alloy for electrical conduction, characterized in that e is 6-12% and the conductivity IACS is 60% or more. (3) An alloy according to claim 1, characterized in that castability and cold workability are improved by further containing 0.02 to 0.1% of mitsch metal. Turtle cylinder force Cu-Fe alloy. (4) An alloy for conductivity according to claim 2, further containing 3 to 0.6% My2SiqO and having a tensile strength of 62 kg/rr++n2 or more. force Cu-F'e alloy.