铂薄膜电阻温度传感器玻璃密封材料的稳定性能研究

Stability of Glass Seals for Pt Thin-film Resistance Temperature Detector

针对铂薄膜电阻温度传感器中绝缘封装过程中存在的气密、绝缘等性能问题,研究了两种玻璃与铂薄膜温度传感器氧化铝基底间浸润性、气密性、绝缘性及热循环稳定性等性能,优选性能最佳的玻璃密封材料应用在铂薄膜温度传感器中。研究结果表明,热稳定性存在差异SiO_(2)-Ba O-Al_(2)O_(3)-CaO系微晶玻璃与SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系微晶玻璃在800℃~1000℃间与氧化铝基底均具有良好的浸润性。SiO_(2)-Ba O-Al_(2)O_(3)-CaO系玻璃与SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃密封材料在800℃、通气压力在20.7 k Pa下的漏气率分别约为0.0073 sccm·cm^(-1)和0.0065 sccm·cm^(-1),绝缘电阻率分别约为21.6×106Ω·cm和31.1×106Ω·cm。此外,在30℃~800℃热循环500次后,两种玻璃表面出现尺寸不一的孔洞,其中,SiO_(2)-Ba O-Al_(2)O_(3)-CaO玻璃经历500次热循环后孔洞尺寸由0.13μm增至15.62μm,而SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃孔洞尺寸变化较小,表面形貌较为致密。以上研究结果表明,SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃具有更加优异的密封性能、高温绝缘性能及热循环稳定性,更适合用于铂薄膜电阻温度传感器的封装工艺。

Noting the airtight,insulation and other performance issues of platinum thin-film resistance temperature sensors in the insulation encapsulation process,two kinds of glass and platinum thin-film temperature sensors were evaluated,focusing on the infiltration of the performance,airtightness,insulation and thermal cycling stability,so as to optimize the performance of the glass sealing materials for the platinum thin-film temperature sensors.The two glass-ceramics,SiO_(2)-BaO-Al_(2)O_(3)-CaO glass and SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO glass,with different thermal stability,have high wettability with the alumina substrate at 800–1000℃.At 800℃,the air leakage rates were about 0.0073 sccm·cm−1 and 0.0065 sccm·cm−1,at the vent pressure of 20.7 kPa,while the insulation resistivities were about 21.6×106Ω·cm and 31.1×106Ω·cm,respectively.In addition,the size of holes on the surfaces of the two types of glass appeared to be different after 500 thermal cycling from 30 to 800℃.Specifically,the pore size of the SiO_(2)-BaO-Al_(2)O_(3)-CaO glass increased from 0.13μm to 15.62μm after 500 thermal cycles,whereas that of the SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO glass showed a smaller change and the surface morphology was more denser.It is therefore concluded that the SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO glass has more excellent sealing performance,high-temperature insulation performance and thermal cycle stability,and hence is more suitable for the encapsulation process of platinum thin-film resistance temperature sensors.