Wafer-Level 3D Integration Based on Poly (Diallyl Phthalate) Adhesive Bonding

Three-dimensional integration technology provides a promising total solution that can be used to achieve system-level integration with high function density and low cost. In this study, a wafer-level 3D integration technology using PDAP as an intermediate bonding polymer was applied effectively for integration with an SOI wafer and dummy a CMOS wafer. The influences of the procedure parameters on the adhesive bonding effects were determined by Si–Glass adhesive bonding tests. It was found that the bonding pressure, pre-curing conditions, spin coating conditions, and cleanliness have a significant influence on the bonding results. The optimal procedure parameters for PDAP adhesive bonding were obtained through analysis and comparison. The 3D integration tests were conducted according to these optimal parameters. In the tests, process optimization was focused on Si handle-layer etching, PDAP layer etching, and Au pillar electroplating. After that, the optimal process conditions for the 3D integration process were achieved. The 3D integration applications of the micro-bolometer array and the micro-bridge resistor array were presented. It was confirmed that 3D integration based on PDAP adhesive bonding is suitable for the fabrication of system-on-chip when using MEMS and IC integration and that it is especially useful for the fabrication of low-cost suspended-microstructure on-CMOS-chip systems.

A Novel Method for Integration of Online Educational Resources via Teaching Information Remote Scheduling

The traditional online education resource integration technology ignores the calculation of the characteristic variance contribution rate of online educational resources, and the evaluation of educational resources is biased, which leads to the low ability of resource integration. Therefore, the online education resource integration technology based on remote scheduling of teaching information is proposed. Based on the theory of remote scheduling of teaching information, the quantitative value of online educational resources integration is obtained. By calculating the integration probability of online educational resources, the influencing factors of online educational resources in the process of integration are determined. The principle of teaching information remote scheduling is integrated into the feature vector extraction of online educational resources, and the contribution rate of feature variance of online educational resources is calculated. By extracting the number of main factors of the online educational resources feature vector, the feature vector of online educational resources is decomposed. Taking the wavelet entropy of online educational resources as the fusion weight of online educational resources, the integration result of online educational resources is obtained through wavelet transform. The experimental results show that the online education resource integration technology based on remote scheduling of teaching information has ideal application performance in integration probability, the goodness of fit, and robustness.

Integration Technology for Wafer-Level LiNbO3 Single-Crystal Thin Film on Silicon by Polyimide Adhesive Bonding and Chemical Mechanical Polishing

An integration technology for wafer-level LiNbO3 single-crystal thin film on Si has been achieved. The optimized spin-coating speed of PI (polyimide) adhesive is 3500 rad/min. According to Fourier infrared analysis of the chemical state of the film baked under different conditions, a high-quality PI film that can be used for wafer-level bonding is obtained. A high bonding strength of 11.38 MPa is obtained by a tensile machine. The bonding interface is uniform, completed and non-porous. After the PI adhesive bonding process, the LiNbO3 single-crystal was lapped by chemical mechanical polishing. The thickness of the 100 mm diameter LiNbO3 can be decreased from 500 to 10 μm without generating serious cracks. A defect-free and tight bonding interface was confirmed by scanning electron microscopy. X-ray diffraction results show that the prepared LiNbO3 single-crystal thin film has a highly crystalline quality. Heterogeneous integration of LiNbO3 single-crystal thin film on Si is of great significance to the fabrication of MEMS devices for in-situ measurement of space-sensing signals.