JPS61272339A - Lead material for electronic parts excelled in repeated bendability and its production - Google Patents

Abstract

PURPOSE:To manufacture lead material for electronic parts excelled in various characteristics required of lead material by subjecting a Cu alloy containing additive elements such as Ni, Sn, Zn, etc., to hot rolling, cold rolling, including annealing treatment and temper rolling under specific conditions. CONSTITUTION:An ingot of Cu alloy containing, by weight, 1.0-3.5% Ni, 0.2-0.9% Si, 2.0-4.5% Sn, 0.1-5.0% Zn, 0.02-1.0% Mn and 0.0005-0.02% of 1 or >=2 elements among Mg, Cr, Ti and Zr is prepared. After subjected to facing of its surface, the ingot is hot-rolled to form a plate of about 10mm thickness, which is water-cooled from >=600 deg.C at >=5 deg.C/sec cooling rate to undergo surface descaling, cold-rolled to 0.43mm thickness and annealed at 400-600 deg.C for 5sec-4hr. In this way, the lead material for electronic parts excelled in repeated bendability, spring characteristic, heat resistance, thermal peeling resistance of tinning film and solder, and stress corrosion resistance can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention is applicable to fluorescent tube display tubes, liquid crystal display panels, hybrid IC
Regarding lead materials such as clip terminals used in electronic parts such as
This invention relates to a lead material for electronic components that has excellent spring properties, heat resistance, heat peeling properties of plated tin and solder, and stress corrosion cracking resistance, and a method for producing the same.

[Prior art 1] Phosphor bronze, which has excellent repeated bendability, has traditionally been widely used as a lead material used in electronic components, but phosphor bronze is generally difficult to hot-roll, so cold rolling is Since it is manufactured by repeating rolling and annealing many times, there is a problem that the process is complicated and the cost is extremely high.However, the most important property for lead material is repeated bendability. We have developed a copper-based material that comprehensively satisfies the properties essential for lead materials, such as excellent strength, elasticity, heat resistance, peeling resistance of plated tin and solder, and resistance to stress corrosion and cracking. Therefore, a copper-based material that has both the above characteristics is desired.

[Problem to be Solved by the Invention 1] The present invention has been made in view of the prior art described above, and as a result of the inventor's intensive research, it has been found that the present invention has excellent repeated bendability, stiffness, elasticity, and heat resistance. , excellent peeling resistance and stress corrosion cracking resistance of plated tin and solder;
We have developed a lead material for electronic components that allows the necessary hot working, has less complicated manufacturing processes than phosphor bronze, is inexpensive, and has excellent repeated bendability, and a method for manufacturing the lead material.

[Means for Solving the Problems 1] The lead material for electronic components having excellent repeated bending properties and the manufacturing method thereof according to the present invention are as follows: (1) Ni1. O~3.5wt%, Si0.2~0.9
wt%, Sn2. O~4.5wt%, Zn 0.1-
5.0 wt%, Mn 0.02 to 1.0 wt%, and further contains one or two selected from Mg5Cr, Ti%Zr.
A first invention provides a lead material for electronic components having excellent repeated bending properties, characterized in that the lead material contains 0.0005 to 0.02 wt% of Ni or more, and the remainder substantially consists of Cu, (2) Ni 1. O~3.5wt%, S i 0.
2 to 0.9 wt%, Sn 2. O~4゜5wt%, Zn
0.1-5. (but%, Mn 0.02~1.0w
t%, and further contains one or two selected from M8, Cr, Ti%Zr.
After hot rolling a copper alloy ingot containing 0.0005 to 0.02 wt% of Cu and the remainder substantially Cu,
After cooling at a rate of 5°C/sec or more from a temperature of 10°C or higher, and after cold working, annealing at a temperature of 400 to 600°C for 5 minutes to 4 hours, followed by temper finish rolling. , 300
This invention consists of two inventions, the second invention being a method for manufacturing a lead material for electronic components with excellent repeated bending properties, characterized by performing annealing at a temperature of 600° C. for 5 seconds to 4 hours.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lead material for electronic components having excellent repeated bending properties and a method for manufacturing the same according to the present invention will be described in detail below.

First, the components and component ratios of the lead material for electronic components having excellent repeated bending properties according to the present invention will be explained.

Ni is an element that contributes to strength, heat resistance, and repeated bendability, and the content is 1. If less than Out%, Si
The content is 0.2-0. ht% range, strength, heat resistance, and repeated bendability do not improve, and
If the content exceeds 3.5 u+t%, hot workability will be reduced and it will be uneconomical. Therefore, the Ni content is 1.
The content is 0 to 3.5 wt%.

Si is an element that contributes to strength, heat resistance, and repeated bendability together with Ni, and if the content is less than 0.2 wt%, even if the Ni content is in the range of 1.0 to 3.5 wt%. Strength, heat resistance, and 1) cyclic bendability are not improved, and if the content exceeds 0.9 wt%, hot workability is reduced. Therefore, the Si content is 0.2~
It is set to 0.9u+t%.

It is desirable that the content of Ni and Si be in at% ratio close to the ratio of Ni:5i=2:1, and if the ratio deviates significantly from this ratio, the amount of precipitation of Ni and Si compounds will decrease. However, the effects of improving strength, heat resistance, and repeated bending properties as explained above are reduced, and the peeling resistance of plated tin and solder is reduced.

Sn is an element that contributes to improving repeated bendability and springiness, and if the content is less than 2.0 wt%, these effects will be small, and if the content exceeds 4.5 wt%, the heat resistance, Reduces hot workability and peeling resistance of plated tin and solder.

Therefore, the Sn content is set to 2.0 to 4.5u+L%.

Zn is an element that significantly improves the peeling resistance of plated tin and solder. If the content is less than 0.1 wt%, this effect will be small, and if the content exceeds 5.0 wt%, soldering will be impaired. Sexuality deteriorates. Therefore, Zn content 1i
0.1-5.0 IIlt% tosle.

Mn is an element that improves hot workability, and the content is 0.
．． If it is less than 0.02u+t%, this effect will be small, and 1.
If the content exceeds 0 wt%, the flowability during agglomeration will deteriorate and the agglomeration yield will decrease. Therefore, the Mn content is 0.
02-1, 0 wt%.

M8, Cr, Ti, and Zr are all elements that improve hot workability, and if the content is less than 0.0005 wt%, this effect will be small, and if the content exceeds 0.02 wt%, it will be difficult to form an agglomerate. The flow of the molten metal deteriorates and the yield of agglomerates decreases. Therefore, the M8, Cr, Ti, and Zr contents are 0.0
0.005 to 0.02-t%. In addition, M8, Cr, Z
Even when two or more types of r are contained, the total content is set to 0.0005 to 0.02 wt% for the same reason as explained above.

Next, a method for manufacturing a lead material for electronic components having excellent repeated bendability according to the present invention will be described.

After hot rolling a copper alloy ingot with the above-mentioned ingredients and proportions, the purpose is to cool it from a temperature of 600°C or more at a rate of 5°C/second or more for the purpose of solution treatment. 6
When cooling from a temperature below 00℃, the cooling rate is 5℃
/ seconds or more, precipitation has already occurred before cooling begins, making it impossible to obtain a sufficient solution treatment effect and worsening subsequent cold workability. Even in this case, if the cooling rate is less than 5°C/sec, precipitation will occur during cooling, a sufficient solution treatment effect will not be obtained, and subsequent cold workability will deteriorate.

Next, after cold working, annealing is performed at a temperature of 400 to 600°C for 5 minutes to 4 hours to precipitate Ni and Si compounds, and at a temperature below 400°C, annealing is performed for 5 minutes to 4 hours. The precipitation of Ni and Si compounds is insufficient even if the temperature exceeds 600°C, and precipitation does not occur at temperatures exceeding 600°C.
Most of i, Si remains in solid solution, and in any case, the solid solution of Ni and Si seriously reduces the heat peeling properties of plated tin and solder, so the annealing temperature is 4.
It is necessary to set the annealing temperature to 00 to 600°C, and if the annealing time is less than 5 minutes, the precipitation is insufficient, and if it exceeds 4 hours, it is uneconomical, so it is preferable to set the annealing time to 5 minutes to 4 hours.

Furthermore, after performing temper finish rolling, 300 to 600
The reason why annealing is performed at a temperature of 5 seconds to 4 hours at a temperature of 300 °C is to recover the elongation decreased by rolling, improve repeat bendability, and restore springiness. Even after 4 hours of annealing, this effect is insufficient, and at temperatures exceeding 600°C, the precipitated Ni and Si compounds re-dissolve, resulting in the deterioration of the required mechanical properties. So the annealing temperature is 300~600℃
Furthermore, if the annealing time is less than 5 seconds, the above effect is insufficient, and if it exceeds 4 hours, it is uneconomical, so the annealing time is preferably 5 seconds to 4 hours.

[Example 1] An example will be described regarding a lead material for electronic components having excellent repeated bendability and a method for manufacturing the same according to the present invention.

Example Copper alloys having the components and component ratios shown in Table 1 No. 1 to No. 5 were melted in the atmosphere under charcoal coating using a Kryptor melting furnace, and then melted in a cast iron book mold to a size of 45 m + n t x 80 w x 200 mm. After casting an ingot of 1 lb, the front and back sides of the ingot were rolled 2.5n+m each, and then hot rolled at a temperature of 850°C to 10mm, and then rolled at a speed of 30°C/30°C from a temperature of 600°C or higher. After cooling with water,
After removing scale and cold rolling to 0.429 mmt, annealing was performed at a temperature of 500'C for 120 minutes,
Thereafter, it was cold rolled into a plate material of 0.3n+nt, and further annealed at a temperature of 450°C for 120 minutes. N
Comparative examples No. 0, 6, No. 7, and No. 7 used commercially available phosphor bronze types 2 and 3 with a plate thickness of 0.3 mmt.

Table 2 shows the test results for the samples produced in this way.

The test method is as explained below.

(1) Tensile test was conducted using JIS13 cut perpendicular to the rolling direction.
No. test piece All test pieces Hardness was measured using a micro Vickers hardness tester.

(2) Repeated bendability is determined by punching out a 0.5m+n width lead using a press as a test piece, bending it back and forth in one direction by 90 degrees with a 250g weight hanging from one end, and measuring the number of times it takes to break. It was counted as one time and was calculated as the average value of test piece 5.

The bending axis is parallel to the rolling direction.

(3) Heat resistance was determined by measuring the hardness after heating at each temperature for 5 minutes using a saltpetre furnace and a salt bath furnace, and determining the temperature at which the hardness reached 80% of the hardness before heating.

(4) Stress corrosion cracking resistance is D, H, Thomps
on [Materials Res, &5tds, 1
(1961) = 108-111], and the presence or absence of cracking was determined after being held in an ammonia atmosphere for 8 days.

(5) For heat-resistant peeling of solder, use weakly activated 7 lux.
The soldered sample was held at a temperature of 150°C for 500 hours in a 5n60-Pb40 solder bath at a temperature of 230°C, and then bent 90' to examine the adhesion of the solder.

(6) The spring limit value was measured using a moment tester using a test piece cut at right angles to the rolling direction.

As is clear from Table 2, it can be seen that Examples 1 to 4 of the present invention have overall excellent performance as lead materials for electronic components.

Compared with Comparative Examples 5 to 7, improvements were made as described below.

Inventive Examples 1 to 4 have significantly improved repeat bendability than Comparative Example 5 because they contain Sn, and also have superior heat resistance and electrical conductivity compared to Comparative Example 6.7. , compared to Comparative Example 7, the peeling resistance of plated tin and solder is superior, and while phosphor bronze is generally difficult to hot work, 1 to 4 of the present invention have good hot workability. is excellent.

[Effect of the Invention 1] As explained above, the lead material for electronic components having excellent repeated bending properties and the method for manufacturing the same according to the present invention has the above-mentioned configuration, and therefore has excellent repeated bending properties.
Moreover, it has overall excellent spring properties, heat resistance, peeling resistance of plated tin and solder, stress corrosion cracking resistance, etc., and also has excellent hot workability. It is.

Claims (2)

[Claims] (1) Ni1.0-3.5wt%, Si0.2-0.9
wt%, Sn2.0-4.5wt%, Zn0.1-5.
0wt%, Mn0.02-1.0wt%, and further contains 0.0005-0.02wt% of one or more selected from M_8, Cr, Ti, and Zr, and the remainder is substantially A lead material for electronic components that is characterized by being made of Cu and has excellent repeated bending properties. (2) Ni1.0-3.5wt%, 5i0.2-0.9
wt%, Sn2.0-4.5wt%, Zn0.1-5.
0 wt%, Mn 0.02 to 1.0 wt%, and further contains 0.0005 to 0.02 wt% of one or more selected from M_8, Cr, Ti, Zr,
After hot rolling a copper alloy ingot with the remainder substantially consisting of Cu,
Cooling from a temperature of 600°C or more at a rate of 5°C/second or more,
After cold working, annealing is performed at a temperature of 400 to 600°C for 5 minutes to 4 hours, followed by temper finishing rolling, and then
A method for producing a lead material for electronic components having excellent repeated bendability, characterized by annealing at a temperature of 0 to 600°C for 5 seconds to 4 hours.