This article investigates a novel approach to the integration of multilayer, thin film magnetics embedded in printed circuit board (PCB) for Power Supply in a Package (PwrSip) applications. A solenoid inductor structure is formed by sandwiching a multilayer CZTB magnetic sheet between two distinct PCBs with copper tracks on each which form the upper and lower windings of the device. A solder reflow process utilizing solder balls mounted on the exposed NiAu pads of one of the PCBs is used to create the electrical connection between the two boards, hence, forming closed current loops for the windings of the inductor. This novel inductor structure enables the use of about 4 oz ( $140~\mu \text{m}$ ) of copper to enclose the multilayer CZTB magnetic sheet, and hence demonstrates very low $R_{\text {dc}}$ . The multilayer CZTB magnetic sheet is characterized by using a Ryowa permeameter. The magnetic sheet exhibited a permeability of 367. The manufactured flip-chip inductor was electrically characterized by using a vector network analyzer (VNA). The device has a footprint of 7.25 mm ² and has an inductance of 52 nH. The fabricated PCB embedded inductor achieved a peak quality factor of 23 at 40 MHz.

中文翻译：

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高 问多层CZTB磁性片的Factor PCB嵌入式倒装片式电感器，用于封装式电源（PwrSiP）

本文研究了一种新颖的方法，用于集成封装在印刷电路板（PCB）中的多层薄膜磁性材料，以用于封装电源（PwrSip）应用。螺线管电感器结构是通过将多层CZTB磁性片夹在两个不同的PCB之间而形成的，该两个PCB上均带有铜迹线，从而形成了设备的上，下绕组。利用安装在其中一个PCB的裸露NiAu焊盘上的焊球的焊锡回流工艺可用于在两块板之间建立电连接，从而形成用于电感器绕组的闭合电流环路。这种新颖的电感器结构可以使用约4盎司（ $ 140〜\ mu \ text {m} $ ）铜封装多层CZTB磁性片，因此显示出非常低的 $ R _ {\ text {dc}} $ 。多层CZTB磁性片的特征在于使用了Ryowa磁导计。磁性片的磁导率为367。使用矢量网络分析仪（VNA）对制得的倒装芯片电感器进行电学表征。该器件占地面积为7.25 mm ²，电感为52 nH。制成的PCB嵌入式电感器在40 MHz时的峰值品质因数为23。