The Research On Encapsulation Based On High-Performance Amorphous Strips And Magnetic-cores

Fe-based amorphous and magnetic-cores have superior soft magnetic properties, which are widely applied to electronic and electric industry. However its annealing embrittlement is rather great after the crystallization treatment of amorphous strips, so that destruction rates are very high, and the extensive application range is limited. It is imperative to develop a new kind encapsulation material.Firstly, the effect of the stress and testing temperature before and after amorphous strips been packed on their surfaces were systematically studied. The results showed that variation regular of stress with frequency, before and after amorphous strips been packed is basically the same, the law is that the changed impedance value increases with stress and testing frequency increasing, when frequency is 1MHz, the impedance value of amorphous strips is the largest; the change sensitivity of piezomagnetic of amorphous strips increases with testing temperature rising, especially when testing temperature rises from 30℃to 40℃,the amorphous strips have the best piezomagnetic properties.Secondly, Epoxy resin glue for electronic packaging has been developed. The effect of filler content, thixotropic agent content, solidifying agent content, coupling agent selection, secondary annealing on the soft magnetic properties of magnetic-cores was investigated. The results indicate that the inductance value decreased significantly after magnetic-cores being packing; the thixotropic agent and filler have significant effect on magnetic-cores inductance value, and proper proportion is conducive to the increase of inductance value. When polyamide resin(650#) content,calcium carbonate content,thixotropic agent content and titanate coupling agent content will occupy percent 100,percent 75,percent 60 and percent 3 of epoxy resin respectively, glue formula on porous epoxy resin for electronic packaging is optimal, the inductance value of magnetic-cores declined by percent 2.8 at 100 KHz. After cores being secondary annealed, expansion of packaging glue happen, which causes that the inductance value of magnetic-cores declined seriously, soft magnetic properties reduced.