JP2001126925A - Laminate inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate inductor, with which packaging property is improved and further the Q-factor is made large. SOLUTION: A coil 4 is embedded in an element body 1, further drawing parts 5 and 6 are connected to the coil 4, these drawing parts 5 and 6 are bonded with electrodes 2 and 3, and a winding axis Z of the coil 4 crosses the electrodes 2 and 3. At this time, when the film thickness of the coil 4 is defined as L7 and the thickness of the electrodes 2 and 3 is defined as L6, the condition 1.5<(L6÷L7)<7.0 is established.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer inductor used for electronic equipment having a high-frequency circuit and the like.

[0002]

2. Description of the Related Art At present, inductors used in high-frequency circuits and the like include: (1) a laminated inductor in which a coil is formed using a laminated pattern; and (2) a conductive film formed on an insulator or a magnetic material. Chip inductors in which spiral grooves are formed in a conductive film (3) Inductors in which a winding is wound around a core are generally used.

[0003] With the downsizing of electronic devices, downsizing and high characteristics of inductors have been demanded, and various improvements have been made.

In particular, a so-called laminated inductor in which a plurality of laminated sheets each having a conductive pattern such as a semicircle formed on a sheet is so developed as to have little change in characteristics even when mounted in any direction. Have been done. As a preceding example, see Japanese Patent Application Laid-Open No. H11-26241.
JP, JP-A-8-55726, JP-A-10-9
No. 2691, JP-A-11-260644 and the like.

[0005]

However, in the above configuration, in the directional inner laminated inductor,
Since the size of the inductor itself and the size of the inductor itself are extremely reduced, problems such as poor bonding with the circuit board, occurrence of an element standing phenomenon, and deterioration of the Q value have occurred.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a multilayer inductor which is less affected by directionality and has improved mountability.

Another object is to provide a laminated inductor having a large Q value.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a laminated inductor in which a winding axis of a coil section and an electrode intersect, wherein the film thickness of the coil section is L6 and the thickness of the electrode is L7. , 1.5 <L6 ÷ L7 <7.0.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an element body, a coil part embedded in the element body, and a pair of a coil part embedded in the element body and electrically connected to the coil part. A lead portion, comprising a pair of electrodes provided at both ends of the element body and electrically connected to the lead portion, a laminated inductor such that the winding axis of the coil portion and the electrode intersect, When the film thickness of the coil portion is L7 and the electrode thickness is L6, 1.5 <L6 ÷ L7 <7.0. Is not thin, the bonding strength with the land formed on the circuit board or the like is improved, and if L6 ÷ L7 is 7.0 or more, the probability that the electrodes are rounded and the element standing phenomenon occurs will occur. Get higher. In the invention according to claim 2, the element body has a columnar shape,
2. An electrode is formed at both ends and a side surface of the element body, and when the length of the electrode on the side surface is L4, L4 ÷ L1 ≦ 0.25. By using the laminated inductor described above, the mountability can be improved, and the mounting density on the circuit board can be improved. According to the third aspect of the present invention, each of the protrusion amounts of the electrodes provided on the side surface of the element body is set to 20 μm.
The multilayer inductor according to claim 1, wherein the thickness is set to m to 120 μm, it is possible to further suppress an element standing phenomenon and to improve the bonding property with a circuit board or the like. In the invention according to claim 4, the length of the element body is L1, and the length of one of the pair of lead portions is L1.
5. The laminated inductor according to claim 1, wherein L5 ÷ L1 ≦ 0.3 when 5.
As compared with the case where L5 ÷ L1> 0.3, characteristics such as the Q value can be improved. The invention according to claim 5 is
The electrode has at least one of a corrosion-resistant film and a bonding film, whereby the laminated inductor according to claim 1 can improve the bonding property between the electrode and a land, and the like. The weather resistance of the electrode can be improved. According to a sixth aspect of the present invention, a laminated sheet in which a conductive layer is formed on a sheet is laminated to form a coil portion, whereby the number of sheets is adjusted by using the laminated inductor according to the first aspect. Thus, the number of turns can be changed, so that the inductance value can be easily changed.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a perspective view showing a laminated inductor according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an element body, in which a coil portion (to be described later) is embedded. Electrodes 2 and 3 are provided at both ends of the element body 1, respectively. The electrodes 2 and 3 are provided on the end surfaces 1a and 1b and on a part of the side surface 1c, respectively.

It is advantageous for miniaturization, strength of the element, etc. to satisfy the following conditions with the length L1, height L2, and width L3 of the element body 1.

0.5 mm ≦ L 1 ≦ 1.7 mm 0.2 mm ≦ L 2 ≦ 0.9 mm 0.2 mm ≦ L 3 ≦ 0.9 mm By defining the size of the element body 1 as described above,
Even when the elements are mounted on a circuit board or the like, the mounting area on the circuit board can be reduced, and the size of the circuit board and the size and thickness of an electronic device on which the circuit board is mounted can be reduced.

By defining the size as described above, the number of turns of the coil portion can be secured to some extent, and the inductance value and the like can be matched with the characteristics of the circuit.

A feature of the multilayer inductor element configured as described above is that the axis of the coil portion embedded in the element body 1 intersects the end faces 1a and 1b of the element body 1 (particularly preferably, the axis Z). And the end faces 1a and 1b intersect substantially perpendicularly). With such a configuration, even if any one of the four side surfaces 1c is brought into contact with or opposed to the circuit board, the change in the characteristics of the multilayer inductor becomes extremely small, and the directionality of the multilayer inductor can be eliminated. The performance is improved.

In this embodiment, since the element body 1 is formed in a prismatic shape and L2 = L3, the mountability is further improved. May be a prism having a regular polygonal cross section.

The corners of the element body (side surface 1c and side surface 1c)
, Etc., or where the side surfaces intersect with the end faces 1a, 1b)
By performing chamfering, chipping and cracking of the element body 1 can be prevented. The specific degree of chamfering is preferably 0.03 mm or more. If the chamfering is smaller than 0.03 mm, burrs and the like are likely to occur at corners, and chipping of the element body 1 and the like occur.

Further, it is preferable that the protruding length L4 of the portion protruding from the side surface 1c of each of the electrodes 2 and 3 is L4ＬL1 ≦ 0.25 based on the length L1 of the element body 1. When L4 ÷ L1 is larger than 0.25, when the element body 1 is mounted on a circuit board, a bonding material such as solder largely protrudes to the side of the element body 1, and the mounting density can be improved. Can not. Further, when L4 ÷ L1 is larger than 0.25, the interval between the electrodes 2 and 3 becomes narrow, and the possibility that the electrodes 2 and 3 are short-circuited when mounted on a circuit board or the like increases. Note that L4 ÷ L1 = 0 means that the end faces 1a,
This shows that only electrodes 1b are provided with electrodes 2 and 3, respectively.

Next, the coil section will be described.

FIG. 2 is a sectional view showing a laminated inductor according to an embodiment of the present invention.

In FIG. 2, reference numeral 4 denotes a coil portion, and the coil portion 4 is buried in the element body 1. As described above, the winding axis Z of the coil portion 4 and the end faces 1a and 1b (or the electrodes 2 and 3) of the element body 1 are configured to intersect (particularly preferably to intersect substantially vertically). Further, lead portions 5 and 6 are electrically connected to both ends of the coil portion 4, respectively, and the lead portions 5 and 6 are respectively connected to the electrodes 2 and 3. The coil unit 4 is configured by laminating sheets as shown in FIG.
In FIG. 3, reference numerals 7 to 10 denote laminated sheets, and laminated sheets 7 to 10 are basically made of a dielectric material, a magnetic material,
Conductive layers 7a to 10a are formed by patterning a conductive material such as a conductive metal such as copper, silver or gold or a conductive alloy on a sheet made of an insulating material or the like.

More specifically, the laminated sheets 7 to 10
The number of windings is determined by the number of the laminated sheets 8 and 9 alternately laminated. For example, laminated sheet 8
The laminated sheet 9 is stacked thereon such that the conductive layers 8a and 9a are not directly opposed. In order to conduct the conductive layer 8a and the conductive layer 9a, the point 8c and the point 9c are electrically connected. As a connection method at this time, for example, a through hole is provided at point 9c of the laminated sheet 9 to the back surface (so that the point 8c of the conductive layer 8a is exposed), and a conductive member is provided in the through hole. Points 8c and 9
c is electrically connected. In this way, the laminated sheet 8 and the laminated sheet 9 are laminated to form one turn of the coil section 4. The number of turns of the coil section 4 is determined by setting the above-mentioned two laminated sheets 8 and 9 as one set. It is adjusted depending on the lamination. At both ends of the coil portion 4, laminated sheets 7 and 10 are provided, respectively, points 7b and 10b are electrically connected to one of the laminated sheets 8 and 9, respectively, and points 7c and 10c are connected to the drawing portions 5 and 6 respectively. Connected to either.

The thickness of each conductor layer is 5 μm to 1 μm.
When the thickness is 5 μm, good conductivity is exhibited, and it is suitable for miniaturization.

The length L5 of the drawers 5, 6 shown in FIG.
Is L5 の 長 L1 ≦ 0.3 based on the length of the element body 1.
(Preferably 0.2, more preferably 0.15). By satisfying this condition, the Q value of the multilayer inductor can be improved. There is also a case where L5 ÷ L1 is 0, and in this case, there is an embodiment in which the drawers 5 and 6 do not exist. In this case, the electrodes 2 and 3 are directly formed on the exposed laminated sheets in a state where the laminated sheets 7 to 10 are exposed on the end surfaces of the element body 1.

Next, the drawers 5, 6 will be described.

As shown in FIG. 4, the lead portions 5, 6 are formed by laminating one or a plurality of laminated sheets in which the conductive layer 11 is sandwiched between members made of an insulating material or the like.

As shown in FIG. 5, as the structure of the lead-out portions 5, 6, a through-hole 12 is formed in one sheet or a laminated body in which a plurality of sheets are stacked, and a conductive material is embedded in the through-hole 12. Alternatively, a method of forming a film of a conductive material on the inner wall in the through hole 12 is considered. The through holes 12 are formed by laser processing or the like.

Next, the relationship between the extraction portions 5 and 6 and the electrodes 2 and 3 will be described.

As shown in FIG. 6, by providing a recessed portion from the end face of the element body 1 in the lead-out portions 5 and 6 and by inserting the electrodes 2 and 3 into the recessed portion, the electrodes 2 and 3 are connected to each other. The bonding area with the extraction portions 5 and 6 is increased so that the electrodes 2
3, the contact area between the electrodes 2, 3 and the extraction portions 5, 6 can be increased, so that the conduction between the electrodes 2, 3 and the extraction portions 5, 6 is good. Can be prevented from deteriorating characteristics (the above structure is
4 and 5 (structure in which conductive material is emphasized in through-hole 12)
Corresponding to the structure shown).

As shown in FIG. 7, when the lead portions 5 and 6 are formed by forming a conductive film on the inner wall in the through hole 12, a part of the electrodes 2 and 3 is formed in the through hole 12. As described above, the bonding strength and good conduction between the electrodes 2 and 3 can be obtained as described above.
Corresponding to the structure shown).

Further, as shown in FIG. 8, by forming the lead-out portions 5 and 6 so as to protrude from the end face of the element body 1, it is possible to obtain the same bonding strength and good conduction as described above (the above-described structure has 4 and 5 (corresponding to the structure shown in FIG. 4 (a structure in which conductive material is emphasized in the through hole 12)).

Next, the relationship between the electrodes 2 and 3 and the coil section 4 will be described.

In FIG. 2, the thickness of the conductive layer constituting the coil section 4 is L7, and the thickness of each of the electrodes 2 and 3 is L7.
Assuming that 6, it is 1.5 <L6 ÷ L7 <7.0. With this configuration, for example, when L & １．５L7 is 1.5 or less, the protruding amounts of the electrodes 2 and 3 on the end faces 1a and 1b become small, and the probability of poor connection due to poor connection with lands or the like is extremely high. If L6 ÷ L7 is 7.0 or more, the corners of the electrodes will be rounded, and the probability of the element standing phenomenon will be extremely high.

In the present embodiment, in general, increasing the thickness L7 of the conductive layer of the coil section 4 tends to increase the outer shape of the element body and the weight of the element body 1, In order to reduce the size of the body, attention is paid to the fact that the thickness of the conductive layer of the coil portion 4 tends to be reduced.
関係 Specified the relationship of L7.

Specifically, when the thickness L7 of the conductive layer is 7 μm (case 1), the thickness L6 of each of the electrodes 2 and 3 needs to be set to 10.5 μm to 49 μm. By setting in this way, the above-described effects can be obtained. When the thickness L7 of the conductive layer is 12 μm (Case 2), the thickness L6 of the electrodes 2 and 3 is 18 μm or less.
It is 84 μm. That is, in general, in the case 1, the shape of the element body 1 can be made smaller than in the case 2, so that the thickness of the electrodes 2 and 3 is at least 10.5 μm.
With m, a sufficient amount of protrusion of the electrode can be obtained, and the bonding strength with a circuit board or the like can be improved. In addition,
In case 2, the minimum thickness is 10.5 μm, as in case 1. In general, case 2 has a larger element body 1 than case 1, and electrodes 2 and 3 A sufficient amount of protrusion from 1a and 1b cannot be secured, and sufficient bonding strength cannot be obtained.

Conversely, in case 1, when the thickness L6 of each of the electrodes 2 and 3 is set to the maximum film thickness of 84 μm in case 2, the electrodes 2 and 3 are rounded. The case 1 has a small element body and is lightweight, so that the element standing phenomenon is remarkably exhibited.

The thickness L7 of the conductive layer constituting the coil portion 4 is the average of the thicknesses of at least five different points, and the thickness of the electrodes 2 and 3 is also the average of the thicknesses of at least five points.

In the electrode 2, at least 5
When the average of the film thicknesses at the points and the average of the film thicknesses of at least five different points in the electrode 3 are different, the average value of both film thicknesses is added and the result is divided by 2 to obtain L6.

Next, the electrodes 2 and 3 will be described.

It is preferable that the protruding amount P1 of the electrodes 2 and 3 on the side surface of the element body 1 be 20 to 120 μm. If the protrusion amount is less than 20 μm, the bonding property is deteriorated, the mountability is not so much improved, and the probability that the element stand-up phenomenon occurs increases. If the protrusion amount exceeds 120 μm, the film deposition time becomes longer, and the productivity is increased. become worse.

The specific structure of the electrodes 2 and 3 is, for example, a structure in which a paste of a conductive material such as silver is baked, or a corrosion-resistant film having a corrosion resistance of nickel or the like is formed on the baked conductive portion. Alternatively, a bonding film made of solder, lead-free solder, or the like may be provided on the corrosion-resistant film from above the conductive portion.

The electrodes 2 and 3 include: only a conductive portion formed by baking a conductive material or the like; a bonding film provided on the conductive portion; a bonding film provided on the conductive portion; a corrosion-resistant film provided on the conductive portion. , And a specific structure such as providing a bonding film thereon.

[0044]

The present invention relates to a laminated inductor in which the winding axis of the coil section and the electrode intersect, and when the thickness of the coil section is L6 and the thickness of the electrode is L7, <L
By setting 6 ÷ L7 <7.0, the mountability and the like can be improved. When L6 ÷ L7 is 1.5 or less, the thickness of the electrode is not particularly reduced, so that the bonding strength with a land formed on a circuit board or the like is improved.
Is 7.0 or more, the electrode is rounded, and the probability of the element standing phenomenon increases.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a laminated inductor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a multilayer inductor according to an embodiment of the present invention.

FIG. 3 is a plan view showing a laminated sheet constituting the laminated inductor according to one embodiment of the present invention.

FIG. 4 is a view showing a lead portion of the multilayer inductor according to the embodiment of the present invention;

FIG. 5 is a diagram showing another lead portion of the multilayer inductor according to the embodiment of the present invention;

FIG. 6 is a partial cross-sectional view showing a laminated inductor according to one embodiment of the present invention.

FIG. 7 is a partial cross-sectional view showing a laminated inductor according to an embodiment of the present invention.

FIG. 8 is a partial cross-sectional view showing a laminated inductor according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Element body 1a, 1b End surface 1c Side surface 2, 3 Electrode 4 Coil part 5, 6 Lead-out part 7, 8, 9, 10 Laminated sheet 7a, 8a, 9a, 10a Conductive layer 11 Conductive film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsumi Sasaki, Inventor: 1006, Kazuma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. Terms (reference) 5E043 AA09 AB09 5E070 AA01 AB01 AB06 AB10 BA12 CB13 CB17 CB18 CB20 DB02 EA01 EB03

Claims (6)

[Claims] 1. An element body, a coil part embedded in the element body, a pair of lead-out parts embedded in the element body and electrically connected to the coil part, and both ends of the element body And a pair of electrodes electrically connected to the lead portion provided in the laminated inductor, wherein the winding axis of the coil portion and the electrode intersect, the film thickness of the coil portion is L7,
When the thickness of the electrode is L6, 1.5 <L6 ÷ L7 <
A laminated inductor, characterized in that the inductor is 7.0. 2. An element body having a columnar shape, electrodes formed on both end portions and side faces of the element body, and when the length of the electrode on the side face part is L4, L4 ÷ L1 ≦
2. The multilayer inductor according to claim 1, wherein the value is 0.25. 3. The multilayer inductor according to claim 1, wherein each of the protrusions of the electrodes provided on the side surface of the element body is set to 20 μm to 120 μm. 4. When the length of the element body is L1 and one of the pair of lead portions is L5, L5ＬL1 ≦ 0.3.
2. The multilayer inductor according to claim 1, wherein: 5. The multilayer inductor according to claim 1, wherein the electrode has at least one of a corrosion-resistant film and a bonding film. 6. The multilayer inductor according to claim 1, wherein a laminated portion having a conductive layer formed on the sheet is laminated to form a coil portion.