A base gel was prepared with bisphenol A epoxy resin E124 as the main resin, polymercaptan as the curing agent, and imidazole as the accelerator. A single component high thermal conductive structural adhesive was prepared by adding different proportions and sizes of spherical alumina and irregular alumina into the base gel. The effects of different filling content and different particle sizes of alumina on the thermal conductivity, bonding strength, viscosity, and thixotropy of the single component high thermal conductive structural adhesive were studied. The results show that when the mass ratio of base gel to the three different particle sizes of alumina is m(base gel)∶m(40 μm Al2O3)∶m(2 μm Al2O3)∶m(0.5 μm Al2O3) =15∶59.5∶25.5∶6, m(base gel)∶m(40 μm Al2O3)∶m(5 μm Al2O3)∶m(0.5 μm Al2O3) =15∶59.5∶25.5∶8, m(base gel)∶m(40 μm Al2O3)∶m(10 μm Al2O3)∶m(0.5 μm Al2O3)=15∶68∶17∶8, three kinds of high thermal conductive structural adhesives cured at 90℃ for 15 min can be obtained, their thermal conductivity is 2.73, 3.05, 2.85 W/(m·K), their bonding strength is 5.49, 5.55 and 5.31 MPa, and their viscosity is 145 000, 127 467 and 118467 mPa·s, respectively. The volume resistivity of the three kinds of high thermal conductive structural adhesives is above 1014 Ω·m, and the adhesive survival rate after high temperature and humidity, cold and thermal shock is more than 70% and 90%, respectively. The performance of the high thermal conductive structural adhesive meets the basic performance requirements of screen printing and heat dissipation materials for chip packaging.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |