Taiyo Yuden Co., Ltd.

Koichi Iguchi

Takahiro Samata

Tomoo Kashiwa

Hideharu Suzuki

Katsutoshi Kuroiwa

Masaki Okamoto

Takanori Yoshizawa

Yoshinari Nakada

Takayuki Maruyama

A wire wound electronic part includes a core having a wire wound core and flanges formed on both ends thereof, a coil conductor wound around the wire wound core and terminal electrodes disposed at the bottom of the flange, in which both ends of the coil conductor are conductively connected to the terminal electrodes by a solder, wherein a pair of grooves are formed at the bottom crossing the wire wound core of one of the flanges. The groove has a bottom and side walls disposed being slanted on both sides thereof, in which the vertical height for the side wall is formed larger than the length for the bottom of the side wall. The terminal electrodes are contained in the groove, and edge portion in the lateral direction of the terminal electrode is restricted by the side wall of the groove. The edge portion in the lateral direction of the terminal electrode is restricted by the side wall of the groove, which makes the lateral size stable and suppresses the movement of the molten solder in the lateral direction of the groove, thereby preventing unstable height and attitude of the wire wound electronic part upon mounting to a circuit substrate.

Wire wound electronic part

One inventive aspect relates to a low back type loop type coil part which may facilitate confirmation of quality of soldering. The loop type coil part comprises a core including a spool arranged vertically to a mounting side and a plate-like flange provided at an end of the spool to come in contact with the mounting side. A coil lead is wound around the spool, and an end of the coil lead is soldered and fixed to a terminal electrode of a bottom surface of the flange. A protruding part is provided at a part of a side surface of the flange in a length direction. A recess is formed in the bottom surface of the flange so as to be in contact with the protruding part of the side surface and a non-protruding part adjacent to the protruding part. The terminal electrode is provided to be continuous across an inner wall surface of the recess, a bottom surface of the protruding part, and a bottom surface of the non-protruding part. Accordingly, by using the protruding size of the flange, the fillet to facilitate confirmation of quality of soldering can be formed without increasing the thickness size of the flange of the core and the height size of the core.

Loop type coil parts

A surface-mounting choke coil has a resin coating material with magnetic powder which is filled a space between the upper flange and the lower flange of a drum-type ferrite core, while covering the circumferential of the winding. The resin coating material with magnetic powder has a glass transition temperature Tg of about &#x2212;20&#xb0; C. or lower, more preferably about &#x2212;50&#xb0; C. or lower in a course of transferring from a glass state to a rubber state during changing of shear modulus with respect to temperature as a physical property when hardening, and the thickness of the upper flange of the drum-type ferrite core is about 0.35 mm or less, and a value of a ratio L/Lof an outer diameter Lof the upper flange to a diameter Lof the winding core of the drum-type ferrite core is about 1.9 or more.

Surface-mounting coil component and method of producing the same

Growing community of inventors

Gunma, Japan

Koichi Iguchi