Magneto-impedance sensing device method and manufacturing method thereof

Abstract

An electromagnetic impedance sensing device includes a substrate, a first patterned conductive layer, a second patterned conductive layer, a magneto-conductive wire and an encapsulation layer. The substrate has a surface and a trench extending into thereof. The first patterned conductive layer is formed on the surface, as well as a bottom and sidewalls of the trench. The magneto-conductive wire is disposed in the trench. The second patterned conductive layer extending across the trench and electrically in contact with the first patterned conductive layer is formed on the first patterned conductive layer to make the magneto-conductive wire sandwiched between the first and the second patterned conductive layers. The magneto-conductive wire is encapsulated by the encapsulation layer to make the magneto-conductive wire electrically isolated from the first and second patterned conductive layers. At least one coil circuit surrounding the magneto-conductive wire is formed by the first and second patterned conductive layers.

Description

technical field [0001] The invention relates to a semiconductor element and its manufacturing method, and in particular to an electromagnetic impedance sensing element and its manufacturing method. Background technique [0002] Due to the emergence of consumer electronic products such as mobile phones and electronic compasses, coupled with traditional products such as motors and brakes, the demand for electromagnetic impedance sensing devices is increasing. [0003] At present, most electromagnetic impedance sensing elements are based on ceramic substrates. The magnetic wires are fixed on the ceramic substrate through the interlaced stacking of multi-layer patterned conductive layers, patterned insulating layers and magnetic wires, and the magnetic wires are the center. , forming an induction coil circuit surrounding the magnetic wire. However, when forming the sensing coil circuit, every step of forming the patterned conductive layer and the patterned insulating layer must...

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Problems solved by technology

However, when forming the sensing coil circuit, the formation steps of each patterned conductive layer and patterned insulating layer must be aligned with the magnetic wires, and the manufacturing process is complicated and time-consuming

In addition, the magnetic wire is not easy to fix, and the height difference between the magnetic wire and the ceramic substrate will cause uneven coating of the photoresist used to pattern the conductive layer and insulating layer, which is prone to the problem of out-of-focus exposure and development , so that the yield rate is not easy to improve

In addition, since the conductive layer and the insulating layer will fluctuate with the shape of the magnetic wire, it is not conducive to the subsequent electrode pad (Pad) production, making it more difficult to further miniaturize the critical dimensions of the electromagnetic impedance sensing element, so that the number of coils cannot be reduced. increase, which hinders the improvement of the sensitivity of the electromagnetic impedance sensing element

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