JP2011219840A - Suspension wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension wire in which the reduction of tensile strength after soldering immersion and the reduction of wire diameter due to soldering erosion are less and which can be manufactured at low cost.SOLUTION: A mother wire of a Cu-Ni-Sn-based alloy is drawn by using a multi-stage wire drawing machine, and while back tension is applied to it, the drawn wire is passed through an electric furnace. After aging treatment is applied, tin plating is applied. No bad influence is given to environment and health because it uses no beryllium copper. The reduction of tensile strength after soldering immersion and the reduction of wire diameter due to soldering erosion are less than that of a suspension wire using copper-silver alloy. Furthermore, this suspension wire can be manufactured at lower cost than one using tungsten or rhenium-tungsten.

Description

  The present invention relates to a suspension wire, and more particularly, to a suspension wire that can be manufactured at a low cost with a reduction in tensile strength after immersion in solder and a reduction in wire diameter due to solder erosion.

  Conventionally, a suspension wire using beryllium copper has been used. However, since beryllium copper has an adverse effect on the environment and health, a suspension wire using a copper-silver alloy has been proposed (see, for example, Patent Document 1). In addition, a suspension wire using tungsten or rhenium-tungsten has been proposed (see, for example, Patent Document 2).

JP 2003-168229 A JP 2007-234711 A

The conventional suspension wire using the copper-silver alloy has a problem in that the tensile strength after solder immersion is reduced and the wire diameter is greatly reduced due to solder erosion.
In addition, the conventional suspension wire using tungsten or rhenium-tungsten has a problem of high cost.
SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension wire that can be manufactured at a low cost with a small decrease in tensile strength after solder immersion and a small decrease in wire diameter due to solder erosion.

In a first aspect, the present invention provides a suspension wire comprising a Cu—Ni—Sn alloy.
Since the suspension wire according to the first aspect does not use beryllium copper, there is no adverse effect on the environment and health. Further, the decrease in tensile strength after solder immersion and the decrease in wire diameter due to solder erosion are smaller than that of a suspension wire using a copper-silver alloy. Furthermore, it can be manufactured at a lower cost than a suspension wire using tungsten or rhenium-tungsten (the raw material cost is about 1 / 2.5 of tungsten and about 1/7 of rhenium-tungsten).

  According to the suspension wire (100) of the present invention, output stability can be improved.

1 is a perspective view showing a suspension wire 1 according to Embodiment 1. FIG. It is a graph which shows the characteristic of time and tensile strength immersed in the solder of 320 degreeC. It is a graph which shows the characteristic of time and tensile strength immersed in 350 degreeC solder. It is a graph which shows the characteristic of time and tensile strength immersed in the solder of 380 degreeC. It is a graph which shows the characteristic of time and wire diameter immersed in the solder of 320 degreeC. It is a graph which shows the characteristic of the time and wire diameter which were immersed in 350 degreeC solder. It is a graph which shows the characteristic of time and wire diameter immersed in the solder of 380 degreeC.

  Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.

Example 1
A. Wire Drawing Process A 0.3 mm diameter bus bar of a Cu-Ni-Sn alloy (trade name Toughmet 3: Brush Wellman) was drawn to 0.100 mm using a multistage wire drawing machine. The cross-sectional area reduction rate per die is 16%, and the drawing speed is 400 m / min. The straightness at this time is about 10 to 30 cm in radius of curvature.

B. Tension annealing process A back tension of 50 g to 100 g was added to the wire after the wire drawing process, and it was run in an electric furnace in a furnace temperature of 475 ° C., a furnace length of 3 m, and an inert atmosphere at a linear speed of 10 m / min. The straightness after this step is 0.07 or less (the warp height when the sample length is 40 mm). The tensile strength was 1400 N / square mm.

C. Aging treatment process The wire after the tension annealing process was passed through an electric furnace in a furnace temperature of 400 ° C., a furnace length of 3 m, and an inert atmosphere at a linear speed of 10 m / min. Further, an aging treatment was performed at a low temperature of 200 ° C. for 3 hours. The tensile strength after this step was improved by 2%. This improvement in tensile strength is due to the spinodal decomposition of the alloy components. In addition, the twist was reduced.

D: Tin plating process Tin plating was performed in order to improve solderability.

FIG. 1 is a perspective view of the manufactured suspension wire 1.
This suspension wire 1 has Ni: 14.5 to 15.5 parts by weight, Sn: 7.5 to 8.5 parts by weight, Pb: 0.02 parts by weight or less, Cu: remaining part by weight of Cu—Ni—Sn It is made of an alloy and has a tensile strength of 1380 N / square mm and a finished outer diameter of 0.101 mm.

FIG. 2 is a graph showing a decrease in tensile strength and time when the suspension wire is immersed in 320 ° C. solder (trade name Eco Solder M20: Senju Metal Co., Ltd.).
a is a suspension wire made of a Cu—Ni—Sn alloy. b is a suspension wire made of beryllium copper. c is a suspension wire made of phosphor bronze. Both have tin plating on the surface.

FIG. 3 is a graph showing a decrease in tensile strength and time when the suspension wire is immersed in 350 ° C. solder.
a is a suspension wire made of a Cu—Ni—Sn alloy, b is a suspension wire made of beryllium copper, and c is a suspension wire made of phosphor bronze, both of which are tin-plated.

FIG. 4 is a graph showing the time when the suspension wire is immersed in solder at 380 ° C. and the decrease in tensile strength.
a is a suspension wire made of a Cu—Ni—Sn alloy, b is a suspension wire made of beryllium copper, and c is a suspension wire made of phosphor bronze, both of which are tin-plated.

  The suspension wire of the present invention has a relatively small decrease in tensile strength after solder immersion.

FIG. 5 is a graph showing the time during which the suspension wire is immersed in 320 ° C. solder and the reduction in the finished outer diameter.
a is a suspension wire made of a Cu—Ni—Sn alloy, b is a suspension wire made of beryllium copper, and c is a suspension wire made of phosphor bronze, both of which are tin-plated.

FIG. 6 is a graph showing the time during which the suspension wire is immersed in the solder at 350 ° C. and the reduction in the finished outer diameter.
a is a suspension wire made of a Cu—Ni—Sn alloy, b is a suspension wire made of beryllium copper, and c is a suspension wire made of phosphor bronze, both of which are tin-plated.

FIG. 7 is a graph showing the time during which the suspension wire is immersed in solder at 380 ° C. and the reduction in the finished outer diameter.
a is a suspension wire made of a Cu—Ni—Sn alloy, b is a suspension wire made of beryllium copper, and c is a suspension wire made of phosphor bronze, both of which are tin-plated.

  The suspension wire of the present invention has a relatively small reduction in the finished outer diameter after solder immersion.

  The suspension wire of the present invention can be used for an optical pickup, a camera lens module, and the like.

  1 Suspension wire

Claims (1)

  A suspension wire comprising a Cu-Ni-Sn alloy.

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