JP2001196239A - Low chip type coil element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low chip type coil element wherein there are so eliminated the penetrating clearances of fluxes and fused solders even when it is mounted on a circuit pattern printed with a cream solder and is heated by passing it through a reflow furnace that its quality is stabilized and not deteriorated. SOLUTION: A low-elevation chip type coil element has a case core 40 having a bottomed unpierced recessed hole 41 and a coil 50, wherein a winding 52 is wound around a drum core 51 and a plurality of winding terminals 52a, 52b are derived from the winding 52. On the upper and lower surfaces orthogonal to the recessed hole 41 of the case core 40, there are provided respectively electrodes 43a, 44a and electrodes 43c, 44c for external connections which are extended continuously via electrodes 43b, 44b on both the opposite sidewalls of the case core 40. After inserting the coil 50 into the recessed hole 41, the winding terminals 52a, 52b are so interposed respectively between the electrodes 43a and a metallic fastening piece 60A and between the electrode 44a and a metallic fastening piece 60B as to subject them to heat fusions. Then, the top surfaces of both the case and drum cores 40, 51 and the metallic fastening pieces 60A, 60B are all coated with a coating material 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-profile, low-profile, low-profile chip-type coil element of a chip-type electronic component, and more particularly to a backlight (EL) used in watches, mobile phones, and the like. The present invention relates to a low-profile chip type coil element suitable for use as a step-up coil element for driving.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No.
JP-A-176659 discloses a low-profile chip type coil element as shown in FIGS. 4, 5 and 6, which is wound around a magnetic case core 1 having a through hole 2 and a magnetic drum core 6 having flanges at both ends. A coil 5 provided with a wire 7;
And a connecting member 9 for fixing the fixing member 4 to the case core 1. The case core 1 is provided with a plurality of electrodes including a fixing electrode 4 on an upper surface orthogonal to the through hole 2. The fixing electrode 8 is provided on the end face, the coil 5 is inserted into the through-hole 2, and the connection is metal-welded to both the case core 1 and the fixing electrodes 4, 8 on the drum core 6 side. The drum core 6 is fixed to the case core 1 by a member 9, and at least one set of the plurality of electrodes on the case core 1 side extends continuously to the lower surface via the side surface of the case core 1. An external connection electrode 3 is formed, and winding terminals 7a and 7b of the coil 5 are connected to the external connection electrode 3. The low-profile chip-type coil element is mounted on a circuit pattern on a printed circuit board surface. I It is intended to connect the external connection electrode 3 and the circuit pattern by soldering.

[0003]

The above-mentioned conventional low-profile chip type coil element is mounted on a circuit pattern on a printed circuit board, and the external connection electrode 3 is connected to the circuit pattern by soldering. Generally, cream solder is printed in advance on a circuit pattern on a printed circuit board surface, a low-profile chip-type coil element is mounted on the circuit pattern on which the cream-solder is printed, and a low-profile chip-type coil element is mounted. The printed circuit board is passed through a reflow furnace and heated to connect the external connection electrode 3 and the circuit pattern by soldering. However, the low-profile chip type coil element in the prior art is
A coil 5 having a magnetic drum core 6 provided with a winding 7 is inserted into the through hole 2 of the magnetic case core 1, and the drum core 6 is fixed to the case core 1 by a connecting member 9. The electrode 3 is in contact with the circuit pattern on the printed circuit board surface on the opposite side where the connecting member 9 is fixed to the case core 1, in other words, on the side where the through hole 2 of the case core 1 and the drum core 6 have the gap 10, When heated by passing through a reflow furnace, the molten solder easily enters the gap 10 and sometimes causes solder balls to occur. Also, the flux used for the solder penetrates deep into the gap 10 and is removed. Is difficult, and there may be a problem that characteristics of the low-profile chip type coil element are deteriorated.

[0004] An object of the present invention is to solve the above problem by first providing a low-profile chip type coil element having a structure in which there is no gap between a through hole and a drum core on the side in contact with a circuit pattern, and a reflow furnace. A low-profile chip type that prevents the formation of solder balls and prevents the formation of solder balls without the molten solder penetrating into the interior even when heated through It is an object to provide a coil element. Next, in the process of assembling the low-profile chip-type coil element, insert a coil having a drum core wound into the hole of the case core, and hold the winding terminal of the coil with an external connection electrode and a metal fixing piece. Although the metal is welded, when the drum core is vacuum-sucked and inserted into the hole of the case core, the external connection electrode and the metal fixing piece are short, so that it is difficult to hold the winding end easily. The purpose is to facilitate the automation of

[0005] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a magnetic case core having a concave hole having a bottom and not penetrating, and a flange at both ends. And a coil having a plurality of winding terminals provided on the magnetic drum core having a plurality of winding terminals. The case core is provided with a plurality of electrodes on an upper surface orthogonal to the concave holes, and the coil is formed in the concave shape. A low-profile chip-type coil element, wherein the coil terminals are inserted into the holes and the winding ends of the coil are respectively connected to the electrodes.

According to a second aspect of the present invention, the plurality of electrodes of the case core extend continuously to the lower surface via side surfaces of the case core, and can be connected to an external circuit at the lower surface. The low-profile chip-type coil element according to claim 1 constituting an electrode.

According to a third aspect of the present invention, the case core includes the electrode provided to have substantially the same width as the case core, and a metal fixing piece having a size substantially covering an upper surface portion of the electrode. The low-profile chip-type coil element according to claim 1 or 2, wherein the winding end is sandwiched between the metal fixing pieces and heat-fused together.

According to a fourth aspect of the present invention, at least three projections for positioning the drum core are formed on the inner peripheral surface of the concave hole in the case core or the outer peripheral surface of the flange in the drum core. The low-profile chip type coil element described in 1, 2, or 3.

According to a fifth aspect of the present invention, a coating material is provided to cover both the upper surface of the case core and the drum core and the metal fixing piece, and the drum core is narrowed with respect to the case core by the bottom of the concave hole. The low-profile chip-type coil element according to claim 1, 2, 3 or 4, wherein the coating material is held and held, and the upper surface of the coating material is a flat surface capable of being held by vacuum suction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a low-profile chip type coil element according to the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of a low-profile chip type coil element according to the present invention. FIG. 1 is a front sectional view of a completed state, FIG. 2 is an exploded perspective view of each component, and FIG. FIG. 4 is a perspective view of a state where a drum core is fixed to a case core.

As shown in FIGS. 1 to 3, the low-profile chip type coil element according to the present invention is a substantially rectangular parallelepiped magnetic case core 4 having a concave hole 41 having a bottom at the center and not penetrating.
0 and a winding 5 on a magnetic drum core 51 having flanges at both ends.
2 and the coil ends 50a, 5b with the coil 50 inserted into the recess 41 of the case core 40.
2b, which have metal fixing pieces 60A and 60B for holding down the metal 2b.

The substantially rectangular parallelepiped magnetic case core 40 is made of a high-resistance magnetic material such as a high-resistance ferrite. As shown in FIG. An angle projection 42 for positioning 51 is formed. That is, when the dimensional difference between the outer diameter of the drum core 51 and the inner diameter of the concave hole 41 of the case core 40 is extremely small, it becomes difficult to insert the drum core 51 into the concave hole 41. If the angled projection 42 is provided instead, the backlash of the drum core 51 in the concave hole 41 is prevented, and by positioning the drum core 51 substantially at the center of the concave hole 41, the variation in inductance is prevented. The inner peripheral surface of the concave hole 41 has a chevron 42.
The same effect can be obtained by providing the projection at a position at least substantially equally divided into three on the outer peripheral surface of the flange of the drum core 51 instead of providing the same.

As shown in FIGS. 1 to 3, the substantially rectangular parallelepiped magnetic case core 40 is provided with electrodes 43 and 44 on both sides opposed to each other with a recess 41 as a center. The electrodes 43 and 44 are arranged on the upper and lower flat surfaces of the substantially rectangular parallelepiped, and are part of both lateral side surfaces including a circular corner from the side surface. To form an external connection electrode. The drum core 51 has flanges at both ends, and the outside of the flange forms flat upper and lower end surfaces of the drum core 51. The electrodes 43 and 44 are formed of an electrode layer in which a metal paste such as silver is formed by printing and baking and then subjected to electrolytic plating or electroless plating of copper, nickel, tin or the like to improve solderability.

The metal fixing piece 60 shown in FIG.
A and 60B are for holding and fixing the winding terminals 52a and 52b of the coil 50, and are also made of a material having good solderability. The electrodes 43 and 60B are provided so as to cover the side surfaces of the substantially rectangular parallelepiped. A coil 50 in which the winding 52 is applied to the drum core 51 in the concave hole 41 of the case core 40 in the assembling process in such a size that the electrodes 43 and 44 substantially cover the portions provided on the upper and lower surfaces of the substantially rectangular parallelepiped according to When the coil 50 is inserted, the coil 50 is inserted into the concave hole 41 where the winding terminals 52a and 52b are located above the upper surface portions 43a and 44a of the electrodes 43 and 44 provided in the substantially rectangular parallelepiped case core 40, respectively. Are winding terminals 52a, 52 on both sides.
In a posture where b is positioned above the electrodes 43 and 44, the end face of the drum core 51 can be automatically inserted into the end face of the drum core 51 by vacuum suction and holding. Even if you can hold your posture accurately,
The winding terminals 52a and 52b protruding on both sides are wires and it is difficult to maintain a constant posture.
44 and the metal fixing pieces 60A and 60B are obtained up to substantially the same width as the above-described rectangular parallelepiped.
The range in which the winding ends 52a, 52b are pressed by the metal fixing pieces 60A, 60B can be widened and easily held.

As can be seen from FIGS. 2 and 3, the coil 50 having the winding 52 applied to the drum core 51 is
0, and is placed on the bottom of the concave hole 41. At the same time, the winding terminals 52a, 52
b is the upper surface portion 43 of the pair of external connection electrodes 43 and 44.
a, metal fixing pieces 60A, 60B positioned above 44a
And fix the metal fixing pieces 60A and 60B to the upper surface portion 43.
a, 44a by metal welding to form upper surface portions 43a, 44a.
a. Specifically, the metal fixing pieces 60A and 60B are welded to the electrodes by heat fusion (soldering) with a paste alloy (cream solder) containing tin or lead. The metal fixing piece 60
A, 60B play the role of reinforcing the winding terminals 52a, 52b and preventing rough contact, and as shown in FIG. 1, the side portions 43b, 44 of the external connection electrodes 43, 44.
The b and the bottom portions 53c and 44c are used as external connection terminals for connection to a circuit pattern on the printed circuit board surface.

The sectional view of FIG. 1 is a completed assembly view. The side of the case core 40 on which the metal fixing pieces 60A and 60B are provided is covered with an insulating coating material 70 such as an insulating resin or an insulating film. 40 and the drum core 51 are fixed, and the upper surface of the insulating coating material 70, that is, the upper surface of the low-profile chip-type coil element according to the present invention can be vacuum-sucked and held. There is a plane that can be used.

[0019]

As described above, according to the present invention,
An external connection electrode provided in the magnetic case core by inserting a coil having a plurality of winding ends formed by winding the magnetic drum core into a concave hole that is a hole that does not penetrate the bottom of the magnetic case core. The winding end is sandwiched between metal fixing pieces and connected by heat fusion together, and a low-profile chip type coil element is configured with a magnetic case core, a magnetic drum core, and a covering material covering both the metal fixing pieces. Place the low-profile chip coil element on the circuit pattern printed with cream solder,
Even if it is passed through a reflow oven and heated, there is no gap for the molten solder to enter, and no solder balls are generated.Flux used for solder does not enter the inside of the low-profile chip-type coil element. However, it is possible to realize a low-profile chip-type coil element with stable quality without deterioration of characteristics or deterioration of characteristics over time. further,
To insert the coil with the winding on the magnetic drum core into the concave hole that has a bottom and does not penetrate, and to fix the coil with the bottom of the concave hole and the covering material, the fixing electrodes and connecting members that were conventionally required It is not necessary, the number of components is reduced, the number of assembling steps is omitted, and the cost can be reduced as a whole even if the magnetic drum core is slightly complicated. Further, the magnetic material case core is provided with an external connection electrode having substantially the same width as the case core, and the winding terminal is sandwiched by a metal fixing piece having a size substantially covering the upper surface portion of the external connection electrode. Can be easily inserted and the automation of assembly can be facilitated. As described above, it is possible to provide an inexpensive low-profile chip-type coil element which is stable in quality, easy to automate in assembly, and inexpensive.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a completed state of a low-profile chip type coil element according to the present invention.

FIG. 2 is an exploded perspective view of each component except a covering of the element.

FIG. 3 is a perspective view of a completed state of the device excluding a coating.

FIG. 4 is a front sectional view of a completed state of a conventional low-profile chip type coil element.

FIG. 5 is an exploded perspective view of each constituent member excluding a conventional element covering.

FIG. 6 is a perspective view of a completed state of the conventional device excluding a coating.

[Explanation of symbols]

 1, 40 case core 2 through hole 3, 43, 44 external connection electrode 4, 8 fixing electrode 5, 50 coil 6, 51 drum core 7, 52 winding 7a, 7b, 52a, 52b winding terminal 9 connecting member 10 Gap 41 Concave hole 42 Angle projection 60A, 60B Metal fixing piece 70 Insulation coating material

Claims (5)

[Claims] 1. A magnetic case core having a concave hole which has a bottom and is not penetrated, and a coil having a plurality of winding terminals formed by winding a magnetic drum core having flanges at both ends. The case core is provided with a plurality of electrodes on an upper surface orthogonal to the concave holes, the coil is inserted into the concave holes, and winding terminals of the coils are respectively connected to the electrodes. Low profile chip type coil element. 2. The external connection electrode, wherein the plurality of electrodes of the case core extend continuously to a lower surface via a side surface of the case core to form an external connection electrode connectable to an external circuit on the lower surface. The low-profile chip-type coil element described in the above. 3. The electrode having the case core having substantially the same width as the case core, and a metal fixing piece having a size substantially covering an upper surface of the electrode. 3. The low-profile chip-type coil element according to claim 1, wherein the coil ends are heat-sealed together. 4. The drum core according to claim 1, wherein projections for positioning the drum core are formed at least at three positions on an inner peripheral surface of the concave hole in the case core or on an outer peripheral surface of the flange in the drum core. Low-profile chip type coil element. 5. A coating material is provided to cover both the upper surfaces of the case core and the drum core and the metal fixing piece,
5. The case core is held by holding the drum core with the bottom of the concave hole, and the upper surface of the coating material is a flat surface that can be held by vacuum suction.
The low-profile chip-type coil element described in the above.