3 results about "Field cooling" patented technology

The application discloses a copper-embedded multilayer board defect detection method and system based on eddy current thermal imaging and impedance spectrum fusion, relates to the technical field of multilayer board defect detection, and comprises the following steps: applying a high-frequency alternating pulse magnetic field to a copper-embedded multilayer board to be detected; continuously collecting thermal field cooling sequence images after pulse excitation, then extracting thermal diffusion coefficients of copper-embedded regions a and thermal field isotheral line distribution characteristics; using test probes of an automatic machine to contact copper-embedded blocks and corresponding network test points on the copper-embedded multilayer board to be detected, injecting a wideband sweep signal, obtaining impedance spectrum and extracting characteristic parameters; and a , thermal field isotheral line asymmetry, Z LF , R HF and Δ θ are constructed into a multi-dimensional feature vector, input into a fusion judgment model, and a judgment result of the copper-embedded multilayer board defect is output according to a preset multiple threshold. The application realizes non-destructive defect detection, and the micro-crack detection rate is about 97%, and the copper-embedded offset and interlayer short-circuit detection rate is 100%.

The application discloses a kind of synergistically improves SrFeO 3‑δ Method of cubic perovskite structure spontaneous exchange bias effect relates to functional material preparation technical field.The method of the present application is by high-temperature solid-phase sintering,Er ions are doped in the Sr site of SrFeO 3‑δ Gradient magnetic Co ions are doped in the Fe site of SrFeO 3‑δ SrFeO 3‑δ Cubic perovskite structure with improved spontaneous exchange bias effect;The preparation process of the application is simple, the production cost is low, and the SrFeO 3‑δ Cubic perovskite structure prepared still can be offset along the magnetic field axis under zero magnetic field cooling condition, can realize stable unidirectional pinning effect without complex multilayer film structure or field cooling treatment, and is important to expand SrFeO 3‑δ Cubic perovskite oxide application field, improve device performance and promote the development of related scientific research.