Interconnection of Amorphous Alloys by Cleaning and Activating their Surfaces

本文首次研究了Pd_<40>Ni_<40>P_<20>金属玻璃中过冷液体的粘度，为互连实验提供了基础数据。发现过冷液体的粘度可以用arrhenius型方程表示，在578 K的玻璃化温度下，粘度为3X10^<10> Pa s。在2 ^< 10 ~ 9> Torr的高真空条件下，用5kV和40ma的氩离子蚀刻3hr的金属玻璃，在50 MPa的压力下加热到玻璃化转变温度，将金属玻璃互连。通过保留玻璃相，实现了金属玻璃之间的互连。然而，结合状态不够强，不足以检测结合强度。理由可以考虑如下。1)由于样品加热时间较长，经氩离子蚀刻的清洁表面在互连前再次受到污染。2)灯加热器加热真空室内部，导致气体析出，这是由于真空室表面吸附的气体释放所致。因此，在互连之前，清洗过的表面再次被污染。3)由于载荷导致金属玻璃的整体变形，因此没有在表面上施加足以实现表面之间完全接触的压力。为了解决上述问题，我们正在对设备进行如下改进。1)加热方式由灯加热器改为感应加热器，实现快速加热和单独加热样品。2)我们正在生产模具，其中样品的一侧受到约束，以便通过加载实现表面的完全接触。我们将继续进行非晶合金互连实验。

We have at first investigated the viscosity of the supercooled liquid in a Pd_<40>Ni_<40>P_<20> metallic glass, which is fundamental data in experiments of interconnection. It was found that the viscosity of the supercooled liquid can be expressed by the Arrhenius-type equation and was 3X10^<10> Pa s at the glasstransition temperature of 578 K.The metallic glasses that were etched by argon ions at 5kV and 40 mA for 3 hr under a high vacuum of 2x^<1O-9> Torr, were interconnected by heating up to the glass transition temperature under a pressure of 50 MPa. An interconnection between the metallic glasses was achieved with retaining the glassy phase. However, the bonding state was not enough strong to examine the bonding strength. The reason was considered as follows. 1) The cleaned surfaces, which were etched by argon ions, were contaminated again before the interconnection because it took long time to heat the samples. 2) The lamp heater heated the inside of the vacuum chamber and leaded to gas evolution that resulted from release of gas adsorbed on the surface of the vacuum chamber. Accordingly, the cleaned surfaces were contaminated again before the interconnection. 3) The pressure, which was sufficient to achieving the full contact between the surfaces, was not applied on the surfaces, because the loading resulted in the over-all deformation of metallic glasses. In order to resolve the problems described above, we are improving the apparatus as follows. 1) The method of heating is being changed from lamp heater to induction heater to achieve rapid heating and to heat the samples alone. 2) We are producing die sets in which the side of samples is under constraint so that full contact of the surfaces is achieved by loading. We will continue the experiments of interconnection in amorphous alloys.