| dc.description.abstract | ABSTRACT
Recently, materials such as aluminum nitride have become very popular in the application of electronic materials. The main reasons for their exploration are their high thermal conductivity, low dielectric constant and dielectric loss, and good electrical insulation. The range of applications is quite wide. , With great potential to gradually replace other ceramic substrate materials. We first conduct data review and analysis of the current status of the industry to understand the current development and application of the heat dissipation substrate industry, which is helpful to clarify the technology development strategy and R & D direction.
In the second part of the discussion, we discuss the forming and sintering of aluminum nitride substrates, using a blade forming method to make a green substrate with a certain thickness, and then gluing and sintering to produce a dense laminated aluminum nitride mature embryo substrate. As a result, it can be found that a longer degumming time can effectively increase the density of single-layer aluminum nitride mature embryos, reaching an apparent density of 3.275 g / cm3 and a thermal conductivity of 163.8W / mK.
The third part is to study the heat dissipation system of the aluminum nitride substrate package and discuss the low-temperature bonding solder material used for solid crystal bonding between the aluminum nitride substrate and the chip package. Through the observation of the crystal phase and microstructure, the material selection can effectively reduce the solid crystal package. Thermal resistance. Using low temperature bonded tin-bismuth solder (170℃), applied to GaN LED, the thermal resistance value of aluminum nitride substrate solid crystal package can reach 7.3℃ / W. In addition, the adhesion strength of the device wafers encapsulated by the die bonding process of different wafers was found. It was found that the bismuth in the die bonding layer of higher pressure will gather in the low-pits of the aluminum nitride surface to reduce the pores and increase the contact area because of the aggregation The contact of the intermetallic compound layer is increased, the obstruction of the heat flow path is reduced, and the packaged device has a lower thermal resistance value.
The fourth part observes the phenomenon of making metallized circuits on aluminum nitride substrates, and adopts the method of metal (Ti) interlayer to reduce the generation of thermal expansion stress. In addition, screen printing (metal copper ink formulation) and process conditions are controlled. During the high-temperature reduction experiment of metal oxides, a solid eutectic phase interface can be formed at the eutectic temperature of ceramics and metals, and pressurized with positive force. Strengthen circuit adhesion and complete the production of metallized ceramic substrates. | en_US |