JP2000243630A - Film inductor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film inductor together with its manufacturing method for good mounting efficiency on a circuit board. SOLUTION: A conductor film 14 is formed on the surface of an insulating base material 12 comprising such as ceramics or magnetic material wherein at least its surface is insulating, both ends of the base material 12 comprise electrodes 20 and 22, and the conductor film 14 between the electrodes 20 and 22 is provided with a conical groove 16 extending from one electrode 20 to the other electrode 22. A coil part 18 divided with the groove 16 is formed at the conductor film 14 on both sides of the groove 16, and a part of the coil part 18 is provided with a trimming part 24 for adjusting the inductance of the coil part 18 divided with the groove 16. The trimming part 24 is formed at one end part of the coil part 18 while contacting the electrode 20, which is sandwiched between one end part of the groove 16 and a division groove 26 extending from one side of the electrode 20 to the groove 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-type inductor having a coil pattern formed by a conductive layer film formed on the surface of an insulating substrate and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a film type inductor is disclosed in
As shown in JP-A-55321 and FIG. 10, a conductor film 3 is formed on the surface of a rectangular base material 1 made of an insulating magnetic material or at least a surface of an insulating material. The coil part 5 was formed by forming the groove 2. And
Electrodes 4 are provided at both ends of the coil portion 5, and are formed so as to be surface mountable on the surface of the circuit board.

[0003]

In the case of the prior art described above, the inductance of the coil portion 5 formed by the groove 2 cannot be adjusted, and a pattern for adjusting the inductance is formed on the circuit pattern on the surface of the circuit board. And adjust the inductance. In this case, since the pattern for trimming is formed on the surface of the circuit board, the mounting efficiency of the circuit board is reduced, which hinders the miniaturization of the circuit board. Further, since the trimming is performed with a laser or the like, there is a possibility that other components on the circuit board may be adversely affected.

Further, in the case of the above-mentioned conventional technology, if the shape of the chip base material is made small and thin due to the demand for miniaturization and thinning of the electronic equipment, the number of turns of the coil in the coil portion is small and the required performance as an inductor is obtained. There were no cases. Although thin-film inductors are also effective in reducing the thickness, sufficient performance such as inductance cannot be obtained.

The present invention has been made in view of the above-mentioned problems of the prior art, and a film-type inductor which can surely obtain a desired inductance, is easy to reduce in size, and has a high efficiency of mounting on a circuit board. And a method for manufacturing the same.

[0006]

The film-type inductor of the present invention comprises a conductor film formed on the surface of an insulating base material such as ceramics or a magnetic material having at least an insulating surface. There is an electrode, and the conductor film between the electrodes is provided with a spiral groove extending from the one electrode to the other electrode. The conductor film on both sides of the groove is divided by the groove to form a coil portion, and a coil type inductor is provided in which a trimming portion is provided in a part of the coil portion and is divided by the groove to adjust the inductance of the coil portion. is there. The trimming portion is formed at one end of the coil portion in contact with the electrode, and is sandwiched between the continuous groove and the partition groove extending from one of the electrodes in the spiral groove, and The conductive path length of the section can be adjusted.

Further, according to the present invention, a conductor film is formed on a surface of an insulating base material, and a spiral groove is formed in the conductor film to provide a coil portion. This is a method for manufacturing a film-type inductor provided with a trimming portion which is defined by a circle and adjusts the inductance. Then, a trimming groove is formed in the trimming portion to adjust the inductance of the coil portion.

The film-type inductor according to the present invention is provided with an insulating planar base material such as ceramics or a magnetic material having at least an insulating surface, and a plurality of pairs of through holes formed at predetermined intervals in the base material. A conductor pattern was provided between the through hole inner surface and the through hole, a spiral conductor pattern was formed between the through holes and the front and back surfaces of the base material, and electrodes were formed at both ends of the conductor pattern. Things. The conductor pattern is formed by forming a plurality of conductor patterns on the front and back surfaces of the substrate in a multi-spiral pattern so as to be alternated on the front and back surfaces of the substrate. The multi-helical conductor pattern is formed in a double spiral shape which is independent and insulated from each other. The double spiral conductor pattern has a different number of spiral turns.

According to a method of manufacturing a film-type inductor of the present invention, an insulating planar base material such as ceramics or a magnetic material having at least a surface insulated is provided, and a plurality of pairs of through-holes are formed in the base material at predetermined intervals. Then, a plating resist is provided on the surface of the base material except for the coil pattern forming portion and the electrode forming portion. At this time, each coil pattern forms a portion where no plating resist is provided so that independent coil patterns are formed in a multiple spiral shape. Thereafter, a conductor film is formed by plating on the through hole, the predetermined coil pattern forming portion and the electrode forming portion, and a multiple spiral conductor pattern is formed on the front and back surfaces of the base material.

Further, according to the method of manufacturing a chip inductor of the present invention, an insulating planar base material such as ceramics or a magnetic material having at least an insulating surface is provided, and a plurality of pairs of through holes are provided at predetermined intervals in the base material. And forming a conductive film on the surface of the base material including the inner surface of the through hole. Cover with an etching resist so that the conductive film remains in the vicinity between the through holes, and remove the conductive film other than the portion where the etching resist remains,
This is a method for manufacturing a chip inductor in which a coil pattern of a spiral conductive film is formed on the front and back surfaces of the base material.

The coil pattern is a multiple helical conductor pattern that alternately crosses the front and back surfaces of the base material. The etching resist is formed by printing. Further, a photoresist may be used as the etching resist.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a film-type inductor 10 according to a first embodiment of the present invention, in which an insulating film is applied to the surface of a magnetic material such as an insulating magnetic material or other insulating material such as ceramics or ferrite. It consists of 12. On the four side surfaces of the base material 12, conductor films 14 of a metal thin film formed by copper plating or the like are provided. The conductor film 14 is formed with a groove 16 having a depth that reaches the base material 12, and the adjacent conductor films 14 are separated from each other by the groove 16. The groove 16 is formed in a spiral shape from one end to the other end of the substrate 12, and the conductor film 14 partitioned by the groove 16 forms a coil 18 on the surface of the substrate 12. I have.

A coil portion 18 formed by a groove 16 in the base material 12
, Electrodes 20 and 22 are formed at both ends.
Assuming that four side surfaces of the film-type inductor are 4a, 4b, 4c, and 4d from the surface side, the side surface 4a at one end of the coil portion 18 is partitioned by a groove 16 and the coil portion 16
Is provided with a trimming unit 24 for adjusting the inductance. The trimming portion 24 is formed at one end of the coil portion 18 in contact with the electrode 20 side. In the portion where the trimming portion 24 is formed, one end of the groove 16 is formed so as to surround one side portion of the conductor film 14 by the trimming portion 24. The groove 16 has a trimming portion 24,
The side surface 4d of the base material 12 is branched and connected to the electrode 20 side, and the other of the grooves 16 reaches a corner of the base material 12. On the other side surface 4b of the base material 12, a continuous spiral groove 16 is formed.
Is formed by the partitioning groove 26 extending from one side surface of the electrode 20 to form a region where the conductive path length of the coil portion can be adjusted.

Therefore, as shown in FIG. 2, which is a development view of the side surface of the film type inductor 10, the groove 16 and the partitioning groove 2 are formed.
The region surrounded by 6 is connected to the electrode 20, but is divided by the grooves 16 and 26 and does not constitute the coil portion 18. On the other hand, on the surface side of the base material 12, a trimming portion 24 divided into two sides by a dividing groove 26 and a groove 16.
Are connected to the coil portion 18 which is the conductor film 14 connected to the electrode 22.

In the method of manufacturing a film-type inductor according to this embodiment, first, a ceramic material or the like is formed and fired to form a base material 12 having a desired shape. Then, a conductor film 14 is formed on each electrode 14 portion and side surface of the base material 12 by plating, vapor deposition, sputtering, or the like. Next, a spiral groove 16 reaching the substrate 12 is formed on the surface of the conductor film 14. Groove 1
6 divides the conductive films 14 with the groove 16 interposed therebetween. Thereby, the coil portion 18 is formed between the electrodes 20 and 22. The groove 16 can be formed by using a cutter or a grindstone disk in addition to the laser beam. When forming the groove 16,
One end 16a of the groove 16 is connected to the electrode 20, and a partitioning groove 26 connecting the electrode 20 and the groove 16 is formed on the side surface opposite to the one end 16a across the surface of the base material 12. As a result, a portion that is divided into two by the partitioning groove 26 and the groove 16 and connected to the coil portion 18 becomes the trimming portion 24. Further, the electrodes 20 and 22 at both ends of the base material 12 are plated with solder or the like so as to cover both ends of the conductor film 16. Further, the surface of the portion where the coil portion 18 is formed may be covered with a ferrite film which is an insulating ferromagnetic material. The coating method is performed by, for example, applying a magnetic paint containing a magnetic material.

After the film-type inductor 10 is surface-mounted on a circuit board, the partitioning groove 2 is formed in the trimming portion 24.
6, and a trimming groove 28 extending from one end of the groove 16 is formed to adjust the inductance. The trimming groove 28 is preferably formed from the side surfaces 4b and 4d to the side surface 4a, but may be formed only on the side surfaces 4b and 4d. The trimming groove 28 is formed at an appropriate position, shape and length in accordance with the adjustment amount of the inductance.

According to the film-type inductor 10 of this embodiment, since the trimming portion 24 is provided on the base 12, it is not necessary to provide a trimming portion for adjusting the inductance on the circuit board, and the mounting density can be increased. . Also,
Trimming can be performed by the inductor element itself, and the object to which the film-type inductor 10 is attached is not limited.

Next, a second embodiment of the film-type inductor according to the present invention and a method of manufacturing the same will be described with reference to FIGS. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. In the film-type inductor of this embodiment, one end 16a of the groove 16 is formed along the corner of the base material 12, and the trimming groove 28 is formed from the groove 16 at the corner.
Is formed. Similarly, the partitioning groove 26 is also formed at the other corner, and the trimming groove 28 is formed from this corner. This makes it easier to form the trimming groove 28.

Next, a third embodiment of the film-type inductor according to the present invention and a method of manufacturing the same will be described with reference to FIGS. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. The film-type inductor according to this embodiment includes a substrate-like base material 32 having an insulating film formed on the surface of a magnetic material such as an insulating magnetic material or other insulating material such as ceramics or ferrite. A conductor film 34 of a metal thin film formed by copper plating or the like is provided on both surfaces of the substrate 32, and a plurality of through holes 36 are formed along edges of the substrate 32 that are parallel to each other. The inside of the through hole 36 is also covered with the conductor film 34. The conductor film 34 is formed as a pattern parallel to each other so as to connect the through holes 36 on the front surface side of the base material 32, and the conductor film 34 similarly connects the through holes 34 on the back surface side of the base material 32 as shown in FIG. As shown in the figure, each of the conductor films 34 is formed in a double spiral shape that connects the through holes 36 and is insulated from each other. Each double helical conductor film 34 forms a coil pattern, and each double helical conductor film 34 has both ends connected to the electrodes 38 and 40 on the surface of the base material 32. The pair of electrodes 38 is connected to one coil pattern by the conductor film 34, and the other pair of electrodes 40 is connected to one coil pattern of the other conductor film 34. Also, the conductor film 34
Is covered with an insulating magnetic paint 42.

In the method of manufacturing the film-type inductor of this embodiment, a row of through holes 36 having a predetermined pitch is formed in the base material 32, and a plating resist is applied by printing to portions other than the coil pattern and the electrode forming portion. Alternatively, a photoresist material is applied to the entire surface except for the through holes 36, the electrodes and the coil pattern shape are exposed, and the resist material in the electrode and coil pattern shape portions is removed. By using a photoresist, a more precise and fine pattern can be obtained.

Thereafter, the base material 32 is immersed in an electroless plating solution, plated with copper, copper and nickel, and the like, and a conductive film 34 is formed by electrolytic plating. The electrodes 38 and 40 and the conductor film 34 of the coil pattern are immersed in a plating solution.
To form A conductor film is also formed in the through hole 36 by plating. Then, the magnetic paint 42 is printed or applied in a predetermined range and dried and cured.

As another manufacturing method, a conductive film 34 is formed on the entire surface of the base material 32 and the through hole 36, and a plating resist is printed or applied on the electrodes 38, 40 and the coil pattern portion to form the base material 32. Is immersed in an etching solution. Thus, the conductor film 34 having a desired pattern can be formed.

According to the film-type inductor of this embodiment, a multi-spiral coil pattern can be easily formed on the thin base material 32. After a large number of coil patterns are formed on the large base material 32 tablets, the coil pattern is divided. And the inductor can be formed efficiently. Further, since the coil portion of the inductor is formed in a double spiral shape, it can be used as a single-turn transformer or a multiple-turn transformer depending on the connection method of the electrodes 38 and 40 of the coil pattern. Mounting on a surface can be easily performed by surface mounting.

Next, a fourth embodiment of the film-type inductor according to the present invention and its manufacturing method will be described with reference to FIGS. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. The film-type inductor of this embodiment has the same structure as that of the above-described embodiment, in which a pair of electrodes 44 is formed on the surface side of the base material 32 and located at both ends of one coil pattern formed by the conductor film 34. ing. The electrodes 46 are located on the back side of the substrate 32, and are connected to both ends of the auxiliary coil pattern. In the film-type inductor of this embodiment, each helical coil of the double helical coil pattern is formed independently.

FIG. 8 shows a film type inductor according to this embodiment.
As shown in FIG. 7, the circuit board can be stacked and disposed between two circuit boards 50 and 52. Attachment to the circuit boards 50 and 52 may be connected to the circuit pattern 54 by a conductor paint 56 other than by soldering.

The method for manufacturing the film-type inductor of this embodiment is formed in the same manner as in the above-described embodiment. FIG. 8 is an enlarged view, and the film-type inductor of this embodiment can be mounted between multilayer substrates.

The same effects as those of the above embodiment can be obtained by the film-type inductor of this embodiment, and furthermore, mounting on a multilayer board is possible, and the mounting density can be further improved.

Next, a fifth embodiment of the film-type inductor according to the present invention and its manufacturing method will be described with reference to FIG. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. The film-type inductor of this embodiment has the same structure as that of the above-described embodiment, and the number of turns of the coil pattern between the electrodes is different. The coil pattern between the electrodes 58 on the front surface side of the substrate 32 has a small number of turns, and the coil pattern between the electrodes on the back side (not shown) has a large number of turns.

The number of turns of the coil pattern between the electrodes on the back side is increased by increasing the number of through holes 36 at one side edge of the base material 32 by using the through holes 60 formed at the center of the equipment 32. The number of windings is increased by folding back at the through hole 60.

Thus, the number of turns of the coil pattern between one of the electrodes can be increased without the conductor films 34 intersecting, and can be used for various inductor elements and transformers. The film-type inductor of this embodiment is the same as the above-described embodiment.

The present invention is not limited to the above embodiment, and the shape and the number of turns of the coil pattern can be set as appropriate, and the trimming method can be selected as appropriate. Also, the inductance may be adjusted after the coil portion having the multiple spiral structure is formed.

[0032]

According to the film-type inductor of the present invention and the method of manufacturing the same which are provided with the trimming portion, it is not necessary to provide a trimming pattern on the circuit board, the trimming can be easily performed, and the mounting density is improved. And the quality of the circuit can be improved.

Also, an inductor having a multi-spiral structure can form a different inductor circuit with one element depending on the connection method of the coil pattern, thereby increasing the mounting density of electronic equipment, facilitating component management, and improving the electronic components. Equipment manufacturing costs can also be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a film-type inductor according to a first embodiment of the present invention.

FIG. 2 is a schematic development view of a side surface of the film-type inductor according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a film-type inductor according to a second embodiment of the present invention.

FIG. 4 is a schematic development view of a side surface of a film-type inductor according to a second embodiment of the present invention.

FIG. 5 is a plan view showing a film-type inductor according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a film-type inductor according to a third embodiment of the present invention.

FIG. 7 is a plan view showing a film-type inductor according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a mounted state of a film-type inductor according to a fourth embodiment of the present invention.

FIG. 9 is a plan view showing a film-type inductor according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view showing a conventional film-type inductor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Film type inductor 12 Base material 14 Conductor film 16 Groove 18 Coil part 20, 22 Electrode 24 Trimming part 26 Sectioning groove 28 Trimming groove

Claims (9)

[Claims] 1. A conductive film is formed on a surface of an insulating base material, and electrodes are provided at both ends of the base material. The conductive film between the electrodes extends from the one electrode to the other electrode. A spiral groove is formed, the conductive film on both sides of the groove is divided by the groove to form a coil portion, and a trimming portion which is divided by the groove and adjusts inductance is provided in a part of the coil portion. Film type inductor. 2. The method according to claim 1, wherein the trimming portion is formed at one end of the coil portion in contact with the electrode, and is sandwiched between the continuous spiral groove and a partitioning groove formed from one of the electrodes. The film-type inductor according to claim 1, wherein the conductive path length of the coil portion is adjustable. 3. A conductor film is formed on a surface of an insulating base material, and a spiral groove is formed in the conductor film to provide a coil portion, and a part of the coil portion is defined by the groove. A method for manufacturing a film-type inductor, comprising: providing a trimming portion for adjusting an inductance; and forming a trimming groove in the trimming portion to adjust the inductance of the coil portion. 4. An insulating flat base material is provided, a plurality of pairs of through holes are formed at predetermined intervals in the base material, and a conductor pattern is provided between the inner surface of the through holes and the through holes. Form a spiral conductor pattern between the holes and the front and back of the substrate,
A film type inductor with electrodes formed at both ends of this conductor pattern. 5. The conductor pattern according to claim 4, wherein the conductor pattern is formed such that the conductor patterns are alternately formed on the front and back surfaces of the substrate, and the plurality of conductor patterns are formed on the front and back surfaces of the substrate in a multiple spiral shape. Film type inductor. 6. The film-type inductor according to claim 5, wherein the multi-helical conductor pattern is formed in a double spiral independent of each other. 7. The film-type inductor according to claim 5, wherein the double-helical conductor pattern has a different number of spiral turns. 8. An insulating planar base material is provided, a plurality of pairs of through holes are formed at predetermined intervals in the base material, and a plating resist is formed on the surface of the base material except for a coil pattern forming portion and an electrode forming portion. Manufacturing a chip inductor in which a conductive film is formed by plating on the through-hole, the predetermined coil pattern forming portion and the electrode forming portion, and a multi-spiral conductive coil pattern is formed on the front and back surfaces of the base material. Method. 9. An insulating planar base material is provided, a plurality of pairs of through holes are formed at predetermined intervals in the base material, and a conductive film is formed on the surface of the base material including an inner surface of the through hole. The conductive film on the surface of the substrate is coated with an etching resist so that the conductive film remains in the through holes and between the through holes and in a predetermined range of the substrate surface and between the through holes, A method for manufacturing a chip inductor, comprising: removing a portion of the conductive film other than a portion where an etching resist remains, thereby forming a spiral conductive coil pattern on the front and back surfaces of the substrate.