Improved Mechanical And Dielectric Properties Of EP Composites By ATP Hybrids

Epoxy resins（EP）was widely used in the field of electronic packaging because its unique properties.However,with the continuous development of microelectronics industry,electronic devices tend to be miniaturized and applied at a high-frequency,which imposes more requirements on the dielectric,mechanical and dynamic thermo-mechanical properties of EP composites.The introduction of modified attapulgite（ATP）into the EP matrix can improve the mechanical and dynamic mechanical properties of EP composites for further enhanced mechanical properties,reduced relative dielectric constant and lower loss of EP composites to expand its applications in the field of electronic packaging.The ATP-Al₂O₃hybrids and ATP-SHS（Silica hollow sphere,SHS）hybrids were prepared,following which the ATP hybrids were introduced into EP matrix to prepare ATP-Al₂O₃/EP and ATP-SHS/EP composites.Firstly,the hybrids（ATP-Al₂O₃）composed of modified ATP and modified Al₂O₃were prepared under the premise of ATP content of 3 wt%,following which the EP composites reinforced with ATP-Al₂O₃hybrids were synthesized.The results show that the Al₂O₃particles are uniformly dispersed on the surface of rod-like ATP while the ATP-Al₂O₃hybrids are uniformly dispersed in the EP matrix.The mechanical and dynamic mechanical properties of the fabricated ATP-Al₂O₃/EP composites are enhanced by doping ATP-Al₂O₃hybrids into EP.The impact and flexural strength of 3 wt%ATP-3wt%Al₂O₃/EP composites are 27.88 k J/m~2and 157.04 MPa,respectively,which are significantly higher compared to the impact strength（5 k J/m~2）and flexural strength（83.56 MPa）of pure EP.Compared with pure EP,the glass transition temperature and dielectric strength of ATP-Al₂O₃/EP composites are increased,at the same time,the relative dielectric constant is decreased.While the dielectric loss showed no significant change.The surface functional groups on the ATP-Al₂O₃hybrids react with the EP matrix during curing as the chemical bonds generated between the two phases.As the result,the interface effect is enhanced,and the stress conduction is achieved in a more effective way.After the SHS were fabricated by improved St?ber method,the hybrids（ATP-SHS）composed of modified ATP and modified SHS were prepared.Then the ATP-SHS hybrids were introduced into the EP matrix to prepare ATP-SHS/EP composites.The results show that the impact and flexural strength of 3 wt%ATP-3wt%SHS/EP composites are 24.62 k J/m~2and 136.86 MPa,respectively,which are significantly higher compared to the impact strength（5 k J/m~2）and flexural strength（83.56 MPa）of pure EP.Compared with pure EP,the relative dielectric constant of ATP-SHS/EP composites are greatly decreased.While dielectric strength and glass transition temperature are obviously increased.At the same time,the dielectric loss is not changed significantly.As the defects of EP matrix are compensated,the deformability is suppressed,so the interfacial combination and stress transfer efficiency of ATP-SHS/EP composites are enhanced by the addition ATP-SHS hybrids.As the result,the mechanical properties of the ATP-SHS/EP composites are greatly improved by the addition ATP-SHS hybrids.Meanwhile,the relative dielectric constant of the ATP-SHS/EP decreases as more air is introduced into the composites by adding SHS.The practical application of EP composites may be expanded through improved mechanical and dielectric properties accompanied with higher glass transition temperatures.