JPS61199608A - Printed coil - Google Patents

Abstract

PURPOSE:To facilitate such structures as multilayer printed coils, large size coils, or other fine pattern coils by forming a flat coil and a central insular iron core section electrically insulated from the coil both on an insulating sheet by etching a ferromagnetic member such as an iron foil. CONSTITUTION:A single insular pattern 2 furnishing an iron core is formed in the central part of one surface of an insulating sheet member 1, and a spiral flat coil 3 satisfying a required number of winding turns, insulated from the pattern 2, and having the starting end 3A and the terminal end 3B is formed in the manner to surround the pattern 2. Such a printed coil is obtained at a low cost and with high efficiency by applying a photoetching means to a 'flexible laminar material' which has been prepared, in advance, by pasting a ferromagnetic foil member, e.g., iron foil uniformly to the sheet member 1 to form the insular iron pattern 2 and the flat coil 3.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a thin film printed coil that can be used as a coil for a motor or a transformer, and in particular, it relates to a thin film printed coil that can be used as a coil for a motor or a transformer, and in particular, it relates to a thin film printed coil that can be used as a coil for a motor or a transformer. Regarding printed coils that are made of a ferromagnetic material such as iron and a flat coil formed in the same way.

``Prior Art'' Sheet-shaped printed coils, in which coils are formed by adhering a conductor such as copper foil in a spiral shape on an insulating sheet member, are currently available in various structures as coils for flat motors, etc. Are known. These conventional printed coils are generally used as printed coils for so-called coreless motors, etc., because they are formed by forming a coil conductor of copper or the like into a spiral shape using an error step.

Printed coils of this type are also employed in various thin film impedance means.

"Problems to be Solved by the Invention" Conventional printed coils as described above generally have a structure that only has a coil part. If an etching method is used to manufacture the coil, the core will be made of the same material as the coil conductor, such as copper, at the same time.

However, if the iron core is made of a good conductor such as copper,
Since it increases the magnetic resistance, it poses a practical problem as an iron core structure.

``Means for Solving the Problems'' The present invention provides a flat coil to be formed on an insulating sheet, and an island-like pattern that is electrically insulated from the coil and becomes an iron core portion in the center using a strong material such as iron foil. The present invention provides a printed coil configured to be formed by etching a magnetic material, and the printed coil with such a structure is laminated in a multilayer structure, and the flat coils of each layer are connected in series, and each island pattern as an iron core part is connected in series. can also be configured to be magnetically connectable to each other. Therefore, the magnetic resistance of the island pattern that functions as the iron core can be configured to a sufficiently low value, while the flat coil surface should be appropriately coated with a good conductive material such as copper or silver to increase conductivity. This enables the construction of multilayer printed coils, large fills, or other finely patterned coils.

"Example" Figures 1 and 2 show a conceptual plan view and a cross-sectional view of a printed coil constructed according to an example of the present invention, and 1 indicates various types of electrically insulating plastic films, etc. It is an insulating sheet member consisting of an insulating sheet member, which has a single island-like pattern 2 serving as an iron core in the central part of one side, and an outer part of the insulating sheet member that is electrically insulated from the island-like pattern 2. A spiral flat coil 3 having a starting end 3A and a terminal end 3B is formed with a required number of turns so as to surround the coil. Such a printed coil is produced by photo-etching a so-called flexible laminated material in which a ferromagnetic foil member such as iron foil is uniformly adhered to an insulating sheet member 1 in advance to form an iron core island pattern 2 and a flat coil 3. can be formed at low cost and with high efficiency. Of course, the island pattern 2 and the flat fill 3 can be appropriately formed in a desired pattern form on both the front and back surfaces of the insulating sheet member 1 by using a flexible double-sided layered material or the like.

FIG. 3 shows an example of a multilayer printed coil in which a single-sided printed coil and a double-sided printed coil are laminated as described above.
can be provided with an electrical and magnetic connection structure 4, for example each flat coil 3 has its starting end 3A and its terminal end 3
B can be configured to be connected in series using a through-hole conduction structure, etc., and each island pattern 2 can also be magnetically connected to each other by using a through-hole conduction means or an iron bottle or the like. can.

As mentioned above, the flat coil 3 is formed of the same ferromagnetic material as the iron core island pattern 2, but when configuring a multilayer printed coil, a large printed coil, a printed coil with a high density or fine pattern, etc. for,
The electrical resistance of the fill increases, making it difficult to obtain a printed coil with good characteristics. In order to solve this problem, the embodiment shown in FIG. 4 is constructed so that a good conductor 5 such as copper or silver is deposited on the surface of the flat coil 3 by means of plating or vapor deposition. Iron core island pattern 2
In order to maintain low magnetic resistance, good conductors such as those mentioned above are not deposited on the surface. In the printed coil having this structure, the flat coil 3 is thicker than the island pattern 2 by an amount equivalent to the amount of the good conductor 5 deposited thereon, and this difference in thickness may cause problems in applications such as multilayer coils. Therefore, in the embodiment shown in FIG. 5, the iron core island pattern 2 is removed and only the flat coil is further etched to form a thin flat coil 3C, and the above-mentioned good conductor 5 is coated on the surface of the flat coil. The thickness of the pattern 2 is the same as that of the pattern 2. The printed coils shown in FIGS. 4 and 5, which are constructed by coating a flat coil with a good conductor, can achieve both low impedance in the coil portion and low magnetic resistance in the iron core island pattern 2, and have improved characteristics. We can provide good printed coils.

"Effects of the Invention" As described above, the printed coil of the present invention has an island-like pattern formed in the center of the coil, which functions as an iron core, independently of a flat coil, and these coil parts and island-like patterns are made of iron. It is made of ferromagnetic material such as foil, and has a structure that allows a good conductor to be applied to the flat coil part as necessary, so the coil part can be used as a printed coil such as a multilayer coil, large coil, or fine pattern fill. It has the advantage of being able to provide products with excellent both impedance characteristics of the iron core and magnetoresistance characteristics of the iron core at low cost using flexible circuit board techniques.

[Brief explanation of the drawing]

FIG. 1 is a conceptual plan configuration diagram of a printed coil according to an embodiment of the present invention, FIG. 2 is a cross-sectional explanatory diagram of the printed coil of FIG. 1, and FIG. 3 is a lamination of printed coils of the present invention. Fig. 4 is a conceptual cross-sectional diagram of the multilayer printed coil obtained by the above method; FIG. 2 is a similar cross-sectional explanatory view of a printed coil having a structure in which the printed coil is further improved to make the thickness of the flat coil with a good conductor and the thickness of the iron core island pattern equal to each other. l: Insulating sheet member 2: Iron core island pattern 3; Flat coil 4: Connection part 5: Adhering good conductor Applicant: Nippon Mektron Co., Ltd.? "r": Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] (1) In a printed coil in which a spiral flat coil is formed on an insulating sheet member, the flat coil is formed of a conductor made of ferromagnetic material, and the flat coil is formed of a conductor made of ferromagnetic material. 1. A printed coil characterized in that a ferromagnetic island pattern is provided in the center of the coil to be electrically insulated from the coil and to act as an iron core. (2) The printed coils having the above structure are laminated in multiple layers, and the flat coils between each layer are connected in series, and the island patterns are magnetically connected to each other. Printed coils listed in ). (3) The printed coil according to claim (1) or (2), wherein a conductive member is attached on the surface of the flat coil. (4) The printed coil according to claim (3), wherein the thickness of the flat coil to which the conductive member is attached is equal to the thickness of the island pattern.