Coil-type electronic component
A coil-type electronic component having a coil inside or on the surface of a base material is characterized in that the base material of the coil-type electronic component is constituted by a group of soft magnetic alloy grains inter-bonded via oxide layers, multiple crystal grains are present in each soft magnetic alloy grain, and the oxide layers preferably have a two-layer structure whose outer layer is thicker than the inner layer.
1. A coil-type electronic component having a coil inside or on the surface of a base material, wherein the base material is constituted by a group of inter-bonded grains consisting of soft magnetic alloy grains and oxide layers covering the soft magnetic alloy grains, some of said grains being inter-bonded via the oxide layers whereas some of said grains being directly inter-bonded without involving any oxide layer, and multiple in-grain crystal grains having different orientation axes are present within each soft magnetic alloy grain, said multiple in-grain crystal grains having different orientation axes being such grains formed in an oxygen ambience where the temperature is raised to 500 to 900° C. at a rate of 30 to 300° C./hour.
2. A coil-type electronic component according to claim 1 , wherein the soft magnetic alloy contains iron, chromium, and silicate as its main ingredients.
3. A coil-type electronic component according to claim 1 , wherein the soft magnetic alloy contains iron, aluminum, and silicate as its main ingredients.
4. A coil-type electronic component according to claim 1 , wherein the oxide layers have a two-layer structure where an outer layer is thicker than an inner layer.
5. A coil-type electronic component according to claim 1 , wherein the surface of the outer layer of the oxide layer not inter-bonding the soft magnetic alloy grains has irregularities.
6. A coil-type electronic component according to claim 1 , wherein the average size of the soft magnetic alloy grains is 5 to 30 μm in equivalent average grain size d50% (arithmetic mean).
7. A coil-type electronic component according to claim 4 , wherein the main component of the inner layer is chromium oxide or aluminum oxide and the main component of the outer layer is iron-chromium oxide or iron-aluminum oxide.
8. A coil-type electronic component according to claim 1 , wherein the grains are inter-bonded only by the oxide layers and the direct bonding.