Research On Preparation Of 3D Ceramic Substrate By Bonding Using Inorganic Binder

As electronic packaging technology gradually develops toward miniaturization,high reliability,and low cost,the industry has put forward higher requirements for package substrates.Ceramic substrates are widely used in power devices and high temperature electronic device packages due to their good heat resistance,thermal conductivity,insulation and high mechanical strength.The traditional planar ceramic substrate has a large processing size,which is difficult to meet the market demand.The industry proposes a three-dimensional ceramic substrate technical scheme containing electrical interconnection lines.Based on the analysis and summary of the existing three-dimensional ceramic substrate technology,Study on the preparation of three-dimensional ceramic substrates by inorganic bonding.The main research contents include:?1?Preparation of inorganic binder.Because the aluminosilicate inorganic binder has low temperature curing,good heat resistance and high bonding strength,the aluminosilicate inorganic binder is prepared by metakaolin and alkali activator,and its performance is tested and analyzed.Test items include zeta potential,thermogravimetry-differential heat,XRD and SEM electron micrographs.According to the experimental results,the aluminosilicate inorganic binder has excellent stability and compactness,can be cured at a low temperature,and the inorganic binder can withstand a high temperature of at least 500?.?2?A three-dimensional ceramic substrate is prepared by an inorganic binder bonding method.First,a planar ceramic substrate?DPC substrate?and a ceramic ring are prepared,and then an inorganic binder is uniformly coated on the ceramic ring,and then the DPC substrate is aligned with the ceramic ring,bonded,and cured at a certain temperature.In order to prevent the inner wall of the ceramic ring from being contaminated when the inorganic binder is applied,the silicone mold is used for protection to ensure the smoothness of the inner wall of the ceramic ring after the inorganic binder is applied.The prepared three-dimensional ceramic substrate has an alignment accuracy of<3?m.?3?Optimization of preparation process of three-dimensional ceramic substrate.The effects of inorganic binder layer thickness,curing temperature and bonding area?ceramic ring aperture?on the properties of three-dimensional ceramic substrates were investigated.Experiments show that when the thickness of the bonding layer is increased from 200?m to500?m,the shear strength of the dam layer first rises and then decreases,reaching a maximum value?18.77MPa?when the thickness is 350?m;when the curing temperature of the inorganic glue is raised from 50? to At 250?,the shear strength increases rapidly and then rises slowly after 150?.When the inner diameter of the ceramic ring increases from 3.2 mm to 4.0 mm,the shear strength increases from 5.14 MPa to 11.45 MPa,and the leak rate is 5.60×10^-10 Pa·m³/s is increased to 2.47×10^-8 Pa·m³/s.?4?Three-dimensional ceramic substrate performance test.The three-dimensional ceramic substrate was analyzed for high temperature resistance,thermal cycling,high temperature and high humidity.eight samples were selected before the reliability test,and the leak rate value and the shear strength value were tested as experimental control groups.The results show that the sample still maintains a high air tightness,and its shear strength also tends to increase,which may be due to further curing at high temperatures.Therefore,the inorganic binder bonded three-dimensional ceramic substrate prepared in this paper has good reliability and has broad application prospects in the field of electronic packaging.