JPS5816041A - High-tensile fine au alloy wire - Google Patents

Abstract

PURPOSE:To enhance the strength of Au in the state of a fine wire by adding specified very small amounts of Ca and Si or Sn to Au. CONSTITUTION:In order to enhance the strength of a fine Au wire having <=0.05mm. diameter used as a lead wire of a semoconductor device, an Au alloy contg. 0.0003-0.0010% Ca and 0.0003-0.0050% Si and/or Sn is used as the material of the wire. The resulting fine Au alloy wire has higher strength and heat resistance than a fine pure Au wire, and it has superior performance as a lead wire of a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to a high tensile strength Au alloy fine wire that can withstand use with a cross-sectional diameter of Q, 051 fiφ or less.

Traditionally, it has been used for decoration or semiconductor devices (transistors,
It is well known that gold wire is used for lead wires (thin wires used to connect substrates and semiconductor elements) for ICs, LSIs, etc., but in recent years, gold wire has become more diverse in the decorative field. In addition, in the field of semiconductor devices, thinner (diameter: 0.05 mφ or less) and stronger (harder to break) gold wire is used from the viewpoints of economy, higher integration density, and faster connection. There is a growing demand for

Therefore, from the above-mentioned viewpoint, the present inventors determined that the diameter:
As a result of conducting research to obtain a thin gold wire with a diameter of 0.05 inφ or less that has high tensile strength (high strength) that can be used in the above-mentioned fields of use, we found that Oa: 0.
0003 to 0.0010%, and further contains one or two of Si and an: O, OOO3 to 0.0
050%, and the remainder consisting of Au and unavoidable impurities (weight percent) has high tensile strength (high strength) and good wire drawability, and thus has 1. Set the diameter to 0.05. They found that a thin wire with a diameter of 1φ or less exhibits a high tensile strength sufficient to withstand use.

This invention was made based on the above findings, and the reason why the component composition was limited as described above is as follows. That is, as a result of experiments conducted on various alloy components from the viewpoint of strength and heat resistance, it was found that when Oa and Si and/or Sn coexist, desired high strength (high tensile strength) and heat resistance (especially 300 It has been empirically found that the wire can be suppressed from softening at temperatures below 30°F (°C) and has good wire drawability. Therefore, either the content of Ca or Si (and/or Sn) is less than the above lower limit, that is, Oa: 0.0003%
Less than, Si (and/or Sn): 0,0003%
If the content is less than 0.0010%, the desired characteristics cannot be ensured, and on the other hand, if either Oa or Si (and/or Sn) has the above upper limit, that is, Oa: 0.0010%,
Si (and/or Sn): O, OO'50%
If the content exceeds Oa: 0.0003 to 0.0010%, Si and /l or Sn: It was set at 0.0003 to 0.0050 chi.

Next, the Au alloy fine wire of the present invention was prepared by a conventional melting method according to an embodiment of the present invention, and a molten Au alloy having the composition shown in Table 1 was prepared and cast. Au alloy thin wires 1 to 8 of the present invention each having a diameter of 0.02511φ were manufactured by rolling using a groove type rolling mill and subsequently drawing.

Next, the resulting thin Au alloy wires 1 to 8 of the present invention were subjected to a tensile test, and the breaking strength and elongation at room temperature and the breaking strength immediately after being held at 250°C for 30 seconds were measured. These measurement results are shown in Table 1 together with the same measurement values for pure gold thin wires of the same diameter.

From the results shown in Table 1, the Au alloy fine wires 1 to 8 of the present invention
It is clear that both have higher strength (higher tensile strength) than fine pure gold wire and also have heat resistance.

As mentioned above, the Au alloy thin wire of the present invention has high tensile strength and heat resistance, so it has excellent performance when used not only in the diversifying decorative field but also as lead wires for semiconductor devices. It demonstrates this.

Applicant: Mitsubishi Metals Corporation Agent Tomi, 1) Kazuo

Claims (1)

[Claims] Oa: Contains 0.0003 to 0.0010%, and further contains one or two of Sl and Sn: O, 0O
A high-tensile Au alloy thin wire characterized by having a composition (the above weight %) containing 0.03 to 0.0050%, and the remainder consisting of Au and unavoidable impurities.