因應全球智慧化節能潮流，無線通訊及可攜式行動裝置產品要求高效能及低功耗設計，因此電源模組內部負責儲能轉換及整流濾波之功率電感扮演重要節能元件角色，電源模組內DC-DC轉換器應用需要小尺寸，低直流電阻，高飽和電流和高電感感量，Fe-Si-Cr合金具有較高的飽和磁化強度和較低的高頻磁損耗，具有更好的直流疊加特性，於功率電感中已廣泛採用，目前一體成型Fe-Si-Cr合金功率電感技術相對成熟，雖然廣泛應用於合金功率電感中，但因需高壓成型，不利於小型化的需求；合金積層晶片功率電感具有易於小型化、優異飽和電流性質及低製程成本優勢，已開始受到產業界的重視及投入研發。在Fe-Si-Cr合金積層電感的生產過程中，Fe-Si-Cr合金粉末表面上高溫熱處理形成富鉻層，因為Cr比Fe和Si更容易被氧化，在高溫熱處理過程中，容易沿著晶界擴散到表面，與氧離子反應，在表面生成富氧化鉻層，進而與Ag內電極反應，形成大量片狀AgCrO2；AgCrO2為一種p-type半導體，導致合金積層電感元件失效或短路等嚴重問題。本研究探討不同熱處理溫度與氣氛對Fe-Si-Cr薄帶與Ag電極間反應特性之影響，設計實驗研究其生成機制，找出抑制AgCrO2生成的方法，並將此方法，實際應用於Fe-Si-Cr合金積層電感的製作。
本研究實驗結果顯示，在大氣環境下熱處理，O2不僅會促使Ag大量揮發並擴散，更使Ag與Fe-Si-Cr的熱氧化層(Thermal grown oxide layer, TGO layer) Cr2O3以類似於化學氣相沉積的反應生成大量片狀AgCrO2，在溫度低於650 ˚C時，Ag與Fe-Si-Cr 合金的熱氧化層Cr2O3會先反應生成Ag2CrO4，再與Cr2O3反應生成AgCrO2；Ag2CrO4熔點658 ˚C低於燒結溫度750 ˚C，在接近熔點的溫度，容易揮發沿著粉末間的孔隙移動，與持續揮發的Cr2O3反應，藉由氣相反應，在粉末間的孔隙與產品表面，生成大量的六角片狀物AgCrO2。以N2作為熱處理氣氛，則可有效降低Ag的擴散情形，抑制AgCrO2生成，使Ag線路的連續性提高，再經過空氣氛熱處理，提高Fe-Si-Cr 合金粉末表面的電阻，提升電感的特性；
另外利用玻璃等對Fe-Si-Cr 合金粉末進行表面處理，抑制易揮發之TGO生成，也可提高合金材料的電阻及崩潰電壓，並提高電感的特性。

In the multilayer Fe-Si-Cr alloy power inductors, a chromium-rich layer is formed onto the Fe-Si-Cr alloy powder surface after annealing because Cr is more easily oxidized than Fe and Si and tends to diffuse to the surface along the grain boundaries to react with oxygen ions. It is resulted in the reaction between Ag and Fe-Si-Cr thermally grown oxide (TGO) layer, Cr2O3, to form a large amount of flaky AgCrO2. Since AgCrO2 is a p-type semiconductor with delafossite structure and the resistivity is about 4.5 × 103 Ω∙m. The conversion efficiency of inductor is reduced by the increasing of eddy current loss. In air atmosphere, O2 not only enhances the volatilization and diffusion of Ag, but also resulted in the reaction between Ag and Cr2O3, to form a large amount of flaky AgCrO2 via the mechanism of chemical vapor deposition (CVD). When the temperature is lower than 650 ̊C, the Ag will react with the Cr2O3 to form Ag2CrO4, and then react with Cr2O3 to form AgCrO2. When the annealing temperature is near the melting point, Ag2CrO4 volatilizes easily along the pores between the alloy powders, and reacts with the volatile Cr2O3 continuously. And it will result a large amount of hexagonal flaky AgCrO2 between the pores of alloy powder and the surface of product. In nitrogen atmosphere, the diffusion of Ag can be effectively reduced, the formation of AgCrO2 can be suppressed. The electrical characteristics of the inductors can be improved also.

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