KR20140063032A - High current power inductor for set-top box and manufacturing method of it - Google Patents

Abstract

The present invention relates to a high current power inductor for a set-top box. The high current power inductor for a set-top box includes a lead frame (10) having electrodes (12) receiving an electrical signal by being connected to external terminals of the upper part and the lower part and a winding guide unit (13) at the facing end area of the electrodes; a coil (20) which is wound around the winding guide unit (13) of the electrode (12) and of which the ends are individually connected to the electrode (12); and a block-shaped inductor body (30) which is integrally sintered and formed with a magnetic powder in order to enclose a portion of the electrode (12) and the coil (20) so that the wound coil is located inside.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-current power inductor for a top-box and a method of manufacturing the same. BACKGROUND OF THE INVENTION [0002]

The present invention relates to a high current power inductor for a top box and a method of manufacturing the same. More particularly, the present invention relates to a high current power inductor for a top box, The present invention relates to a high current power inductor for a top box and a method of manufacturing the same.

The term "set-top box" refers to a device that restores a compressed signal transmitted from a video server through a digital network to an original video and audio signal, and transmits the digitized information to the server It turns the screen back to the screen at home and is an essential device for realizing video on demand (VOD).

Such a set-top box is a device that makes television an Internet user interface. It is a special computer that can actually send and receive data through the Internet. It also has a protocol such as a web browser and TCP / IP. Recently, set-top boxes can be used for services such as telephone line or cable TV line for Web TV service.

This set-top box also accelerates the miniaturization, high capacity, and high efficiency of electronic devices, so that the components are integrated in a narrow space, and the influence of electromagnetic waves between the integrated electronic components also increases, so that the importance of the inductors is increasing.

A power inductor is a high efficiency inductor that has less capacitance (inductance) change than a normal inductor when a direct current is applied. It is mainly used at the power stage of a set-top box to suppress sudden change of current.

The types of power inductors are divided into a winding coil in which a metal coil is wound inside and a stacked type (chip inductor) in which a plurality of magnetic materials are stacked.

An example of a method for manufacturing a wound type power inductor is to manufacture a coil by winding a coil on a core of a cylindrical bobbin or ferrite core made of insulating resin to make a coil and then joining the end of the coil to the terminal pin. The coil thus manufactured is used as a single component.

In addition, in order to manufacture a wound type power inductor in a hermetically sealed type, a detachable case is coupled to the outside, or the outside is molded with resin to be cured. Recently, it is a trend to use a closed mold using a method of compression molding using a metal powder in order to improve current control and electromagnetic wave shielding efficiency.

The winding type power inductor manufactured by the above method requires a bobbin or a core separately and requires a process of joining the terminal pin to the bobbin or core.

Another example of a method for manufacturing a wound type power inductor is to provide a coil winding portion on an electrode without using a bobbin or a core to join the end portion of the coil to the electrode and then to harden the outer portion by molding. This method is applied by the present applicant Korean Registered Patent No. 10-1111999 (entitled POWER INDUCTOR AND METHOD FOR MANUFACTURING THE SAME).

At this time, the inductor body for molding the outside may be manufactured using a magnetic material, and may include a magnetic powder, a binder and an epoxy, and may further include an insulating filler and a lubricant, Lt; / RTI >

The manufacturing method does not require a process of joining the terminal pin to the bobbin or core without separately manufacturing the bobbin or the core, and thus the manufacturing process is simple.

However, no mention is made of the constituent components of the inductor body.

All of the existing power inductor products manufactured using the above methods have a structure in which only the electrode terminal is positioned at the bottom of the bottom to seal only about 70%, and about 30% can not be sealed. Therefore, current control of the inductor, The efficiency of the apparatus is deteriorated.

Accordingly, the present invention improves the strength of the inductor body and improves the hermeticity, thereby compensating for the disadvantage that current control, which is the net function of the inductor, is inferior in electromagnetic wave (EMI) shielding efficiency, A high current power inductor is required to be developed.

Japanese Unexamined Patent Publication No. 2010-153459 (published on July 7, 2010) Japanese Patent Application Laid-Open No. 2010-050216 (published on March 3, 2010) Japanese Patent Application Laid-Open No. 2009-290076 (published on December 10, 2009) JP-A-2009-290034 (published on December 10, 2009) Japanese Patent Application Laid-Open No. 2008-159964 (published on July 10, 2008) Japanese Patent Application Laid-Open No. 5-315176 (published on November 26, 1993) Korean Patent Laid-Open No. 10-2010-0101479 (published on September 17, 2010) Korean Patent Laid-Open Publication No. 10-1998-0037278 (published on 1998.08.05) Korean Patent Laid-Open No. 10-1994-0007909 (published on April 24, 1994) Korean Registered Patent No. 10-1111999 (Registration date: Jan. 27, 2012) Korean Patent Publication No. 10-2008-0022679 (published on March 12, 2008).

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to improve the strength of the inductor body and improve the hermeticity thereof, A high current power inductor for a top box, and a method of manufacturing the same, which are excellent in electrical characteristics and can reduce manufacturing costs.

In order to accomplish the above object, the high current power inductor for a top box of the present invention includes H-shaped grooves 11 formed in a strip-shaped metal plate so as to be spaced apart at regular intervals in the longitudinal direction of a metal plate, A lead frame 10 having electrodes 12 connected to external terminals to receive an electrical signal, and a winding guide portion 13 formed at an opposite end region of the electrodes; A coil (20) wound on a winding guide portion (13) of the electrode (12) and having an end connected to the electrode (12), respectively; An inductor body 30 in the form of a block, which is integrally sintered and formed by using a magnetic powder to enclose a part of the electrode 12 and the coil 20 so that the coil wound inside is positioned; The distance from the electrode 12 to the upper end of the inductor body 30 and the distance from the electrode 12 to the lower end of the inductor body 30 during sintering molding of the inductor body 30, And a distance ratio of 6 to 8: 4 to 2.

The powder composition of the inductor body 30 is composed of 98.0 to 99.5 wt% of Cabonyl Fe powder, 0.01 to 0.15 wt% of C powder, 0.2 to 0.8 wt% of O powder, 0.01 to 0.05 wt% of N powder, 0.25 to 1.20 wt%.

The mixing ratio of the powder and the binder for sintering the inductor body 30 is 90 to 95: 5 to 10, and the composition of the binder is 90 to 96 wt% of an epoxy resin, 1 to 4 wt% of a DDS resin, 1 to 4 wt%, and the acetone resin is 1 to 3 wt%.

In addition, the inductor body 30 has a sintering temperature of 180 to 200 ° C and a sintering time of 60 to 100 minutes.

Also, the sintering pressure of the inductor body 30 is 40 to 70 MPa, the number of wash water per minute is 10 to 20, and the powder filling rate is 180 to 230%.

According to the present invention, as described above, the coil and the coil are welded to the electrode terminal, and the terminal and the coil are integrally formed by using the powder molding to improve the airtightness so that current control, current noise suppression, electromagnetic interference Can be improved, the electrical characteristics are excellent, the strength of the inductor body is improved, and the manufacturing cost can be reduced.

In addition, powder sintering of the inductor body using the high permeability Cabonyl Fe powder can reduce the heat generation and increase the efficiency of the module in which the inductor is used because the hysteresis loss is smaller than that of the conventional inductor .

1A to 1F are diagrams illustrating a manufacturing process of a high-current power inductor for a top-box according to the present invention.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-
3 is a graph showing the permeability of each sample.

Hereinafter, a high current power inductor for a top box and a method of manufacturing the same will be described in detail with reference to the drawings.

FIGS. 1A to 1F are views showing a manufacturing process of a high-current power inductor for a top-box according to the present invention, and FIG. 2 is a flowchart showing a manufacturing process of a high-current power inductor for a top-

The high current power inductor for a top box according to the present invention includes electrodes 12 connected to external terminals at upper and lower parts to receive an electrical signal, and a winding guide part 13 formed at an opposite end area of the electrodes A lead frame 10; A coil (20) wound on a winding guide portion (13) of the electrode (12) and having an end connected to the electrode (12), respectively; An inductor body 30 in the form of a block, which is integrally sintered and formed by using a magnetic powder to enclose a part of the electrode 12 and the coil 20 so that the coil wound inside is positioned; .

The high current power inductor for a top box according to the present invention is manufactured by the following method.

First, as shown in FIG. 1 (a), H-shaped grooves 11 are drilled in a band-shaped metal plate so as to be spaced apart at regular intervals in the longitudinal direction of the metal plate. Thus, the electrodes 12 are formed on the upper and lower sides, respectively. At this time, the electrodes 12 are connected to the external terminals at the upper and lower parts, respectively, and receive the electric signals.

In addition, a winding guide portion 13 to be wound with the coil 20 is formed in the end regions of the electrodes 12 formed on the upper and lower portions. At this time, the winding guide part 13 is preferably formed by burring. The coil 20 is wound on the winding guide portion 13 thus formed.

After the H-shaped groove 11 is formed in the metal plate to form the electrode 12 and the winding guide portion 13, the coil 20 is wound on the winding guide portion 13 as shown in Fig. 1B. At this time, the coil 20 may be formed by winding the wire on the winding guide portion 13, or the coil 20 wound in advance may be coupled so that the outside of the winding guide portion 13 is inserted.

After the coils 20 are wound, the end portions of the coils are bonded to the electrodes 12 as shown in Fig. 1C. At this time, the bonding can be performed by soldering, but in order to improve the bonding strength, the bonding is performed by high frequency welding or laser welding.

After the end of the electrode 12 and the coil 20 are connected to each other, a part of the electrode 12 and the coil 20 are enclosed so that the coil 20 wound inside is positioned, In order to form the body 30, the entire lead frame 10 in which the coil 20 is wound is inserted into the powder sintering machine and powder sintered and molded.

The powder composition for forming the inductor body 30 is composed of 98.0 to 99.5 wt% of Cabonyl Fe powder, 0.01 to 0.15 wt% of C powder, 0.2 to 0.8 wt% of O powder, 0.01 to 0.05 wt% of N powder, 0.25 To 1.20 wt%.

As described above, the present invention can improve the current characteristics and the electromagnetic wave shielding efficiency by forming the powder into powder having high permeability mainly composed of Cabonyl Fe powder.

At this time, the size of the powder is preferably 3.5 to 5.0 microns in diameter.

If the size of the powder is too large, the moldability is good but the strength is lowered. If the size of the powder is too small, the strength is increased, but the moldability is poor.

At this time, a binder for maintaining the binding force with the powder is mixed in the mixed powder to form the inductor body 30.

The mixing ratio of the powder and the binder for sintering the inductor body 30 is 90 to 95: 5 to 10 by volume.

The composition of the binder is preferably 90 to 96 wt% of an epoxy resin, 1 to 4 wt% of a DDS resin, 1 to 4 wt% of a phenol resin, and 1 to 3 wt% of an acetone resin.

Epoxy resin has excellent acid resistance, alkali resistance, and water resistance. It has high chemical resistance, high adhesive strength and heat resistance, and is suitable for structural metal adhesion.

DDS (Dlamino diphenyl sulfone) resin is a kind of aromatic amine, which is an epoxy resin hardening agent and has a property of maintaining strength at high temperature.

The phenolic resin has the property of promoting the curing of the epoxy resin, and the acetone resin is used as the solvent.

In addition, the sintering temperature of the inductor body 30 is preferably 180 to 200 ° C, which is a curing point of the binder, and the sintering time is 60 to 100 minutes.

If the sintering temperature is excessively higher than 200 ° C. or the sintering time is excessively longer than 100 minutes, evaporation of the binder occurs and the role as a binder is lowered, so that the degree of bonding between the powders is reduced and the strength is lowered.

If the sintering temperature is less than 180 ° C or the sintering time is too short to less than 60 minutes, the binder is not uniformly distributed among the powders, resulting in a decrease in the degree of bonding of the powders, resulting in deterioration of moldability and strength. Therefore, it is preferable to sinter the sintered body while maintaining an appropriate sintering temperature and sintering time.

In addition, the sintering temperature of 180 to 200 ° C is the temperature at which the sintering is performed in the state where the mixed powder is solid, and the required strength characteristics can be obtained without densification as compared with the liquid phase sintering.

Also, it is preferable that the sintering pressure of the inductor body 30 is 40 to 70 MPa, the water repellency per minute is 10 to 20, and the powder filling rate is 180 to 230%.

Also, the sintering pressure of the inductor body 30 is 40 to 70 MPa, the number of wash water per minute is 10 to 20, and the powder filling rate is 180 to 230%.

At this time, if the sintering pressure for compressing the powder is too low to less than 40 MPa, the water repellency per minute is less than 10, or the powder filling rate is too small to less than 180%, the powder density becomes low and the formability is deteriorated, The bubbles may be present in the bubbles and the strength is lowered. On the other hand, if the sintering pressure is too high, the sintering pressure is excessively high, the water repellency per minute is excessively high, or the powder filling rate is excessively high, exceeding 230%, the powder density is increased to improve moldability and strength, The phenomenon becomes large and the accuracy and dimensional stability become poor. Therefore, it is preferable to sinter at an appropriate sintering pressure, water repellency per minute, and powder filling rate.

The distance X from the electrode 12 to the upper end of the inductor body 30 and the distance from the electrode 12 to the lower end of the inductor body 30 during sintering the inductor body 30 (Y) of 6 to 8: 4 to 2 is preferable.

Conventional products have a disadvantage in that the efficiency of current control and electromagnetic shielding is inferior due to the structure that the electrode terminal is located at the bottom of the bottom to seal only 70% and 30% is not sealed.

In order to compensate for this, the inductance value and the current value are improved by positioning the electrode 12 between the lower end of the inductor body 30 and the center of the height of the inductor body 30.

The electrode 12 is protruded from the inductor body 30 and the electrode 12 is bent to the upper portion of the inductor body 30 so that the electrode 12 is formed on the upper end of the inductor body 30. [ The electrode 12 is cut so as to have a length corresponding to the position where the electrode can be inserted into the electrode insertion groove 31 to separate the inductor body 30 from the lead frame 10 as shown in FIG.

The electrode 12 protruded from the separated inductor body 30 is bent to be inserted into the electrode insertion groove 31 to produce an article as shown in FIG.

2 is a flowchart showing a manufacturing process of a high current power inductor for a set top box according to the present invention.

The lead frame 10 having the electrode 12 and the winding guide portion 13 is fabricated by drilling so as to form the H-shaped groove 11 in the band-shaped metal plate. Then, the coil 20 is wound on the winding guide portion 13 of the manufactured lead frame 10. Then, After winding the coil 20, the respective ends of the coil 20 are bonded to the respective electrodes 12. After the coil 20 is bonded, the lead frame 10 is inserted into the sintering furnace and powder sintering is performed so as to form the inductor body 30 by receiving the coil 20 and a part of the electrode 12. [ After the powder sintering is completed, the electrode 12 is cut so that the electrode 12 protrudes from the inductor body 30 to separate the inductor body 30 from the lead frame 10. Subsequently, the electrode 12 protruding from the inductor body 30 is bent to be inserted into the electrode insertion groove 31 to complete the manufacture of the high current power inductor for a set-top box.

(Example)

1. Powder production

The powder for sintering the inductor body was prepared, and the components are shown in Table 1 below.

[Table 1] shows the results of comparative analysis of the magnetic powder of the present invention and the powders of other companies.

The Fe content of the other powders was low, and the magnetic powder of the present invention had a high cabonyl Fe content, showing a high permeability.

[Table 1] Comparison between the magnetic powder of the present invention and the powders of other companies

The inductance values of Carbonyl Fe series, Fe NiCu mixed series and Fe NiZn series were measured using Impedance Analyzer (HP4192A), and the results are shown in Table 2 below. The Carbonyl Fe series powder, which is used for manufacturing the inductor body of the present invention, has the highest value of 4.7uH, which is considered to be influenced by the magnetic material.

[Table 2] Measurement results of inductance value of each material

2. Comparison between the inductor body of the present invention and existing products

The inductor body of the present invention was fabricated by low-temperature firing (at about 200 ° C or less for about 90 minutes) using the powder thus prepared. The distance X from the electrode 12 to the upper end of the inductor body 30 and the distance X from the electrode 12 to the inductor body 30 during sintering molding of the inductor body 30, (Y) to the lower end of the substrate (30) was 8: 2. In the existing product, the position of the electrode is located at the bottom of the inductor body.

The high current power inductor of the present invention thus manufactured and the characteristics of the conventional product were compared and measured, and the measurement results are shown in Table 3.

Measurement result The high current power inductor for the top box of the present invention showed higher inductance value and current value than the conventional one.

[Table 3] Comparison of the characteristics of the high current power inductor of the present invention and the existing product

3. Binder

Table 4 shows the results of the experiment with consideration of the bondability of the magnetic powder to the main function or the properties (current, permeability etc.) and mechanical properties (hardness, molding, sintering) Of the epoxy resin series was the best and most suitable.

[Table 4] Comparison of properties of binder

The powders prepared by using the third and fourth binders of Table 4 were mixed and powdered and sintered to form the inductor body, and the permeabilities of the samples were compared. The results are shown in Table 5 and FIG. Here, Hc denotes a magnetic field, Ms denotes a saturated magnetic permeability, and Mr denotes a magnetic permeability. As shown in Table 5, the samples manufactured using the fourth binder of Table 4 showed the highest permeability compared to the other samples. It can be seen that the inductance value is higher than other samples at the same turn number, and has a lower resistance value at the same inductance.

[Table 5] Comparison of permeability per sample

[Table 6] shows the hardness test results after mixing the magnetic powder and the third and fourth binder in Table 4 for mechanical satisfaction.

In the case of applying the third binder (tertiary) of Table 4, the highest hardness was shown but the workability was poor. When the third binder (fourth) of Table 4 was applied, the hardness was 90 Hv or more And workability.

[Table 6] Hardness measurement results per sample

The technical idea should not be construed as being limited to the above-described embodiment of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, such modifications and changes are within the scope of protection of the present invention as long as it is obvious to those skilled in the art.

10: Lead frame
11: Home
12: Electrode
13: Winding guide section
20: Coil
30: Inductor body
31: electrode insertion groove

Claims (6)

H-shaped grooves 11 are formed in a strip-shaped metal plate so as to be spaced apart from each other at regular intervals in the longitudinal direction of the metal plate. Electrodes 12 to be connected to external terminals at upper and lower parts, , A lead frame (10) having a winding guide part (13) formed at an opposite end region of the electrodes;
A coil (20) wound on a winding guide portion (13) of the electrode (12) and having an end connected to the electrode (12), respectively;
An inductor body 30 in the form of a block, which is integrally sintered and formed by using a magnetic powder to surround a part of the electrode 12 and the coil 20 so that the coil 20 wound inside is positioned;
And,
The distance from the electrode 12 to the upper end of the inductor body 30 and the distance from the electrode 12 to the lower end of the inductor body 30 during sintering molding of the inductor body 30 is in the range of 6 to 8: 4. The high-current power inductor for a set-top box according to claim 1,
The method according to claim 1,
The powder composition of the inductor body 30 is composed of 98.0 to 99.5 wt% of Cabonyl Fe powder, 0.01 to 0.15 wt% of C powder, 0.2 to 0.8 wt% of O powder, 0.01 to 0.05 wt% of N powder, 0.25 to 1.20 wt% of Si powder, Wherein the high-current power inductor is a high-current power inductor.
3. The method of claim 2,
The mixing ratio of the powder and the binder for sintering the inductor body 30 is 90 to 95: 5 to 10, and the composition of the binder is 90 to 96 wt% of an epoxy resin, 1 to 4 wt% of a DDS resin, 4 wt%, and acetone resin is 1 wt% to 3 wt%.
4. The compound according to any one of claims 1 to 3,
Wherein the inductor body (30) has a sintering temperature of 180 to 200 DEG C and a sintering time of 60 to 100 minutes.
5. The method of claim 4,
Wherein the inductor body (30) has a sintering pressure of 40 to 70 MPa, a water repellency per minute of 10 to 20, and a powder filling rate of 180 to 230%.
H-shaped grooves 11 are formed in a strip-shaped metal plate so as to be spaced apart from each other at regular intervals in the longitudinal direction of the metal plate. Electrodes 12 to be connected to external terminals at upper and lower parts, , Fabricating a lead frame (10) in which winding guide portions (13) are formed in opposite end regions of the electrodes;
Winding the coil (20) on the winding guide portion (13) of the electrode (12);
Bonding each end of the wound coil (20) to each electrode (12);
The lead frame 10 is inserted into the sintering furnace and the coil 20 and a part of the electrode 12 are received to form the inductor body 30. The electrode insertion groove 31 is formed in the upper end of the inductor body 30 Sintering to form powder sintering;
Separating the inductor body (30) from the lead frame (10) by cutting the electrode (12) so that the electrode (12) protrudes from the powder sintered inductor body (30);
Bending the electrode (12) protruded from the separated inductor body (30) to be inserted into the electrode insertion groove (31);
Wherein the high-current power inductor is a high-current power inductor.

Images