KR102313650B1 - Transformer and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a transformer and comprises a main body (100) and a core (200) coupled to the main body (100). The main body (100) includes: a first bobbin (110) in which a first primary coil (120) is wound, a first terminal pin (125) connected to the first primary coil (120) is provided, and a first through hole (115) is formed in a central portion thereof; a second bobbin (130) in which a secondary coil (140) is wound, a second terminal pin (145) connected to the secondary coil (140) is provided, and a second through hole (135) is formed in a central portion thereof; and a third bobbin (150) in which a second primary coil (160) is wound, a third terminal pin (165) connected to the second primary coil (160) is provided, and a third through hole (155) is formed in a central portion thereof. The second bobbin (130) is fitted into the third through hole (155) of the third bobbin (150), and the first bobbin (110) is fitted into the second through hole (135) of the second bobbin (130), so the secondary coil (140) is disposed between the first primary coil (120) and the second primary coil (160). In accordance with the present invention, insulation between coils is secured, an insulation distance between terminal pins is secured, and efficiency can be improved by lowering the leakage inductance (Lk).

Description

Transformer and manufacturing method thereof

The present invention relates to a transformer, and more particularly, to a transformer and a method of manufacturing the same for improving the insulation effect by a simple process instead of applying the insulation method to the basic tube or tape epoxy and triple insulated copper wire.

A transformer is a power supply converter that converts electricity into a required value.

A transformer includes a primary coil and a secondary coil that are magnetically coupled, and the basic principle is that when current flows in the primary coil, current also flows in the secondary coil due to electromagnetic induction. The ratio of the voltage of the primary coil and the transmitted voltage of the secondary coil corresponds to the ratio of the number of turns winding the coil.

In such a transformer, a magnetic field surrounding the primary coil induces a voltage around the secondary coil, and the desired output voltage can all be obtained by changing the ratio of the number of turns wound around the coil.

In addition, the transformer may obtain different voltages by winding several primary coils or secondary coils in one transformer to obtain various types of output voltages, and combining the primary and secondary coils.

Transformers are classified by basic use, and there are resonant LCC power transformers and flyback transformers.

The resonant LCC power transformer (LLC Power Transformer) separates the primary and secondary coils for winding, and designs appropriate for the Lk value according to the distance between the bobbins and the number of turns of the coil. This resonant LCC power transformer has a bobbin for the primary coil and the secondary coil, so it is advantageous to secure a safe distance for insulation by design.

FlyBack Transformer reduces Lk by winding both primary and secondary coils on one bobbin. However, in the flyback transformer, it is difficult to secure a safe distance for insulation because both the primary and secondary coils must be wound on one bobbin. Therefore, there is a hassle of filling the primary and secondary coils with epoxy or applying as much as possible triple insulated copper wire, copper wire insulation tube and insulating tape, which increases the overall volume of the transformer, complicates the process, and requires manual manufacturing. There is a problem in that the manufacturing cost is increased due to the disadvantage of having to proceed with the high-priced copper wire such as triple insulated copper wire.

An object of the present invention is to provide a transformer and a method for manufacturing the same, which ensure insulation between coils while minimizing triple insulated copper wire, secure an insulation distance between terminal pins, and improve efficiency by lowering leakage inductance (Lk) will be.

According to a feature of the present invention for achieving the above object, the transformer of the present invention includes a main body and a core coupled to the main body.

The main body includes a first bobbin wound with a first primary coil and provided with a first terminal pin connected to the first primary coil, a first bobbin having a first through hole formed in a central portion thereof, and a second coil wound around the body and connected to the secondary coil A second bobbin having two terminal pins and a second through hole formed in a central portion thereof, a third terminal pin having a second primary coil wound thereon and connected to the second primary coil, and having a third through hole formed in a central portion thereof. 3 bobbins, wherein the second bobbin is fitted into a third through hole of the third bobbin and the first bobbin is fitted into a second through hole of the second bobbin, the first primary coil and the The secondary coil is disposed between the second primary coils.

Each of the first terminal pin and the third terminal pin is plural and arranged to be spaced apart from each other on one side of the main body.

The first terminal pin is disposed on the inside and the third terminal pin is disposed on the outside.

The third terminal pin is drawn out from an upper portion of the body than the first terminal pin.

A plurality of the second terminal pins are arranged to be spaced apart from each other on the other side of the main body.

One of the first terminal pins and one of the third terminal pins are electrically connected to each other on the substrate on which the transformer is mounted.

The two first primary coils are wound around the first bobbin, and each end thereof is connected to four first terminal pins.

One of the first primary coils wound on the first bobbin uses a triple insulated copper wire, and the remaining first primary coil, the second primary coil, and the secondary coil use a USTC copper wire.

The bobbin assembly to which the first bobbin, the second bobbin, and the third bobbin are coupled is molded by a molding unit.

A portion where the first primary coil and the first terminal pin are connected, a portion where the secondary coil and the second terminal pin are connected, and a portion where the second primary coil and the third terminal pin are connected are formed after soldering. part, and end portions of the first terminal pin, the second terminal pin, and the third terminal pin protrude to the outside of the molding part.

The first bobbin, the second bobbin, and the third bobbin include a winding portion on which a coil is wound, and an upper flange and a lower flange extending outward to support the coil with the winding portion interposed therebetween, respectively. The first bobbin and the second bobbin have a stepped surface formed along an edge on an upper surface of the upper flange, and the upper flange of the second bobbin and the third bobbin is formed between the second through hole and the second bobbin by the width of the stepped surface. A protruding rib protruding through the three through-holes is included, so that the step surface overlaps the protruding rib up and down.

In the second bobbin, a stepped seating surface is further formed at a predetermined portion along the edge on the upper surface of the lower flange, and the lower surface of the lower flange of the third bobbin is seated on the seating surface.

The third bobbin includes a winding portion on which a coil is wound, and an upper flange and a lower flange extending outwardly to support the coil with the winding portion interposed therebetween, and a taper inclined downward toward the edge on the upper surface of the upper flange. An addition is formed.

A method of manufacturing a transformer includes winding a first primary coil on a first bobbin having a first terminal pin, soldering an end of the first primary coil to the first terminal pin, and bonding a second terminal pin. winding a secondary coil on a second bobbin and soldering an end of the secondary coil to the second terminal pin; winding a second primary coil on a third bobbin having a third terminal pin; The steps of soldering an end to a third terminal pin and coupling the first bobbin, the second bobbin and the third bobbin, and the bobbin to which the first bobbin, the second bobbin and the third bobbin are coupled and insert-injecting the assembly into a mold to form a body including a molding part.

In the step of coupling the first bobbin, the second bobbin, and the third bobbin, the second bobbin is fitted into a third through hole formed in the central portion of the third bobbin, and the second bobbin is inserted into the central portion of the second bobbin. The first bobbin is fitted into the formed second through-hole so that the secondary coil is disposed between the first primary coil and the second primary coil.

In the present invention, since three bobbins are applied to form a sandwich structure of the first primary coil, secondary coil, and second primary coil, the leakage inductance between the first primary coil and the secondary coil and between the secondary coil and the second primary coil is greatly reduced. can have an effect.

In addition, in the present invention, since each of the three bobbins has a terminal pin, the coils of the first bobbin and the third bobbin can be connected on the board without connecting the coils to each other, thereby facilitating manufacturing.

In particular, the present invention winds a coil on each bobbin, solders the coil and terminal pin to complete self-completion, and then fitting each other and injecting the molding part to complete the manufacturing, so automatic winding and automatic wiring are possible, so that the manufacturing is easy. have.

In addition, in the present invention, since the first terminal pin and the third terminal pin are arranged in a line, the first terminal pin is disposed on the inside and the third terminal pin is disposed on the outside, so that the combination of the first bobbin and the third bobbin is easy and After the first bobbin and the third bobbin are combined, a safe distance can be secured by separating the terminal pins from each other, and it is easy to connect the first terminal pin and the third terminal pin on the board.

In addition, the present invention has an effect that is easy and stable to be coupled during inter-fitting since a step overlapping up and down is formed on the upper flange or the lower flange of each bobbin, and it is easy to form thinly and uniformly when forming the molding part to be proceeded thereafter.

In addition, the present invention has an effect of improving the insulation effect through a simple process instead of applying the basic tube or tape epoxy and triple insulated copper wire for the insulation method between the coils by applying three bobbins combined in a sandwich structure.

1 is a perspective view showing an upper side of a transformer according to an embodiment of the present invention.
2 is a perspective view showing a lower side of a transformer according to an embodiment of the present invention.
3 is a perspective view showing a state in which a core is coupled to a main body of a transformer according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view AA of the main body of FIG. 3 ;
5 is a cross-sectional view of the body of FIG. 4 separated into a first bobbin, a second bobbin, and a third bobbin;
6 is a perspective view showing a first bobbin according to an embodiment of the present invention.
7 is a perspective view showing a second bobbin according to an embodiment of the present invention.
8 is a perspective view showing a third bobbin according to an embodiment of the present invention.
9 is a view showing a terminal pin and a connection relationship of a transformer according to an embodiment of the present invention.
10 is a flowchart illustrating a method of manufacturing a transformer according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing an upper side of a transformer according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a lower side of a transformer according to an embodiment of the present invention.

1 and 2 , the transformer 10 according to an embodiment of the present invention includes a body 100 and a core 200 coupled to the body 100 .

The body 100 includes a coil inside and terminal pins 125 , 145 , and 165 connected to the coil outside.

A plurality of terminal pins 125 , 145 , and 165 are provided on one side and the other side of the main body 100 , and each of the terminal pins 125 , 145 , 165 is spaced apart from each other and arranged side by side. In the embodiment, the terminal pins 125 and 165 arranged on one side of the main body 100 are input terminals, and the terminal pins 145 arranged on the other side of the main body 100 are output terminals.

3 is a perspective view showing a state in which a core is coupled to a main body of a transformer according to an embodiment of the present invention.

As shown in FIG. 3 , the main body 100 is provided with molding flanges 101 formed on both sides thereof, and a core coupling portion 102 is formed therebetween. The molding flange 101 is a portion formed by enclosing the bobbin assembly 100 ′, which will be described later, with the molding unit 170 having a predetermined thickness. The core coupling portion 102 is a stepped portion between the molding flanges 101 on both sides. The core coupling portion 102 is formed with a first through hole 115 penetrating up and down in the central portion. The core 200 is coupled to the core coupling portion 102 and the first through hole 115 . The width and length of the core coupling portion 102 are designed in advance in consideration of the size of the core 200 coupled to the core coupling portion 102 .

The core 200 includes an upper core 210 and a lower core 220 . The upper core 210 is coupled to the upper portion of the body 100 , and the lower core 220 is coupled to the lower portion of the body 100 . The upper core 210 and the lower core 220 coupled at the upper and lower portions of the main body 100 surround the coil included in the main body 100 to form a magnetic path, thereby controlling the electric flow of the coil. As an example, the main body 100 includes primary coils 120 and 160 and secondary coils 140 , and the high voltage flowing into the primary coils 120 and 160 generates an induced electromotive force in the adjacent secondary coil 140 to reduce the voltage to a low voltage. can be output.

The upper core 210 and the lower core 220 are formed in a shape including a flat plate part (a), both side leg parts (b) and a center leg part (c). Specifically, in the upper core 210 and the lower core 220 , both leg parts b are formed to protrude vertically from both sides of the flat plate part a, and the central leg part c is formed between the both leg parts b. It is formed in an E-shaped cross-sectional shape that protrudes vertically from the

The upper core 210 and the lower core 220 have a flat plate portion (a) in close contact with the upper or lower surface of the core coupling portion 102, and both leg portions (b) in close contact with both sides of the core coupling portion 102 in the width direction. and the central leg portion c is coupled to the main body 100 in such a way that it is inserted into the first through hole 115 . The first through hole 115 is a portion substantially formed in a first bobbin (reference numeral 110 in FIG. 6 ) to be described later.

The upper core 210 and the lower core 220 are formed of a magnetic material. The magnetic material is made of a ferromagnetic material capable of obtaining a strong magnetic flux, and a ferrite core with low loss at high frequencies can be used. As an example, the magnetic material may use a Mn-Zn ferrite core.

The coil included in the body 100 has a sandwich structure of the first primary coil NP, the secondary coil NS, and the second primary coil NP. Hereinafter, the structure of the sandwich coil included in the body 100 will be described in detail.

FIG. 4 is a cross-sectional view taken along line A-A of the main body of FIG. 3 , and FIG. 5 is a cross-sectional view illustrating the main body of FIG. 4 separated into a first bobbin, a second bobbin, and a third bobbin.

As shown in FIGS. 4 and 5, the body 100 uses three bobbins 110, 130, and 150, coils 120, 140, and 160 are wound on each bobbin 110, 130, 150, and then the first primary coil NP is coupled to each other. ) (120)-secondary coil (NS) 140-second primary coil (NP) 160 forms a sandwich structure. The primary coils 120 and 160 and the secondary coil 140 are insulated with bobbins 110 , 130 , 150 to reduce leakage inductance Lk between the primary coils 120 and 160 and the secondary coil 140 . That is, between the first primary coil 120 and the secondary coil 140 and between the secondary coil 140 and the second primary coil 160 are insulated with bobbins 110 , 130 , and 150 , so that the first primary coil 120 and the secondary coil 120 are insulated. The leakage inductance between the coils 140 and between the secondary coil 140 and the second primary coil 160 is reduced.

Specifically, the body 100 includes a first bobbin 110 , a second bobbin 130 , and a third bobbin 150 .

The first bobbin 110 is provided with a first terminal pin 125 protruding downwardly on one side, and a first through hole 115 is formed in the central portion. The upper core 200 and the lower core 200 are coupled to the first through hole 115 . The first bobbin 110 is wound with the first primary coil 120 . An end of the first primary coil 120 wound on the first bobbin 110 is connected to the first terminal pin 125 by soldering. For example, the end copper wire of the first primary coil 120 wound on the first bobbin 110 may be wound and connected to the first terminal pin 125 and then fixed by soldering.

The second bobbin 130 is provided with a second terminal pin 145 protruding downward on the other side, and a second through hole 135 is formed in the central portion. The first bobbin 110 is fitted into the second through hole 135 from the bottom to the top. The secondary coil 140 is wound around the second bobbin 130 . An end of the secondary coil 140 wound on the second bobbin 130 is connected to the second terminal pin 145 by soldering. For example, the end copper wire of the secondary coil 140 wound on the second bobbin 130 may be wound and connected to the second terminal pin 145 and then fixed by soldering.

The third bobbin 150 is provided with a third terminal pin 165 protruding downwardly on one side, and a third through hole 155 is formed in the central portion. The second bobbin 130 is fitted into the third through hole 155 from the bottom to the top. The third bobbin 150 is wound around the second primary coil 160 . An end of the second primary coil 160 wound on the third bobbin 150 is connected to the third terminal pin 165 by soldering. For example, the end copper wire of the second primary coil 160 wound on the third bobbin 150 may be wound and connected to the third terminal pin 165 and then fixed by soldering.

The second bobbin 130 is fitted into the third through hole 155 of the third bobbin 150 , and the first bobbin 110 is fitted into the second through hole 135 of the second bobbin 130 , , a sandwich structure in which the secondary coil 140 is disposed between the first primary coil 120 and the second primary coil 160 .

The bobbin assembly 100 ′ to which the first bobbin 110 , the second bobbin 130 , and the third bobbin 150 are coupled is molded by the molding unit 170 . The molding part 170 is formed of an insulating material to insulate the primary coils 120 and 160 and the secondary coil 140 from the outside, and protect the coil from moisture resistance.

Specifically, the first primary coil 120 wound on the first bobbin 110 and the secondary coil 140 wound on the second bobbin 130 are insulated by the second bobbin 130, and the second bobbin ( The secondary coil 140 wound around 130 and the second primary coil 160 wound around the third bobbin 150 are insulated by the third bobbin 150 , and finally connected to the outside by the molding unit 170 . Insulated.

In the embodiment, the portion where the first primary coil 120 and the first terminal pin 125 are connected, the portion where the secondary coil 140 and the second terminal pin 145 are connected, and the second primary coil 160 and the second The portion to which the three-terminal pin 165 is connected is molded by the molding part 170 after soldering and is not exposed to the outside, and the first terminal pin 125 , the second terminal pin 145 and the third terminal pin 165 are not exposed. ) may protrude to the outside of the molding unit 170 to be mounted on the substrate.

Referring to FIG. 4 , in a state in which the first bobbin 110 , the second bobbin 130 and the third bobbin 150 are coupled, the third terminal pin 165 protrudes above the first terminal pin 125 . and ends of the first terminal pin 125 and the third terminal pin 165 are located on the same line. As a result, after molding, the third terminal pin 165 is drawn out from the upper portion of the body 100 rather than the first terminal pin 125 .

6 is a perspective view showing a first bobbin according to an embodiment of the present invention, FIG. 7 is a perspective view showing a second bobbin according to an embodiment of the present invention, and FIG. 8 is a third bobbin according to an embodiment of the present invention. is the perspective view shown.

4 to 8 , the first bobbin 110 , the second bobbin 130 , and the third bobbin 150 interpose the winding parts 111 , 131 , 151 on which the coil is wound, and the winding parts 111 , 131 , 151 . It includes upper flanges 113, 133, 153 and lower flanges 114, 134 and 154 extending outwardly to support the coil, respectively. The first bobbin 110 , the second bobbin 130 , and the third bobbin 150 are made of an insulating material, and are preferably made of plastic injection molding.

The first bobbin 110 , the second bobbin 130 , and the third bobbin 150 are formed with a step overlapping up and down on the upper flanges 113 , 133 , 153 or the lower flanges 114 , 134 , 154 so that they can be well coupled when they are fitted together. do.

Specifically, the first bobbin 110 and the second bobbin 130 have stepped surfaces 113a and 133a formed along the edges on the upper surfaces of the upper flanges 113 and 133 . In addition, the upper flanges 113 and 133 of the second bobbin 130 and the third bobbin 150 pass through the second by the width of the stepped surfaces 113a and 133a formed on the first bobbin 110 and the second bobbin 130 . The ball 135 and the protruding ribs 133b and 153b protruding into the third through hole 155 are included. The protrusion ribs 133b and 153b of the second bobbin 130 and the third bobbin 150 are formed in which upper flanges 133 and 153 further protrude into the second through hole 135 and the third through hole 155 . Accordingly, when the first bobbin 110 is fitted to the second bobbin 130 and the second bobbin 130 is fitted to the third bobbin 150, the stepped surfaces 113a and 133a are formed between the protruding ribs 133b and 153b. It overlaps with the bottom surface up and down, so it is easy to fit and stable (see FIG. 4).

In addition, the first bobbin 110 is further formed with a stepped portion 113b perpendicular to the stepped surface 113a to be in close contact with the end of the protruding rib 133b of the second bobbin 130 .

The second bobbin 130 further has a stepped seating surface 134a formed at a predetermined portion along the edge on the upper surface of the lower flange 134 , and the lower flange 154 of the third bobbin 150 is formed on the seating surface 134a. ), the lower surface is seated. In addition, the first bobbin 110 is further formed with a stepped seating surface 114a at a certain portion along the upper edge of the lower flange 114, and the lower flange of the second bobbin 130 on the seating surface 114a ( 134) is seated.

4 and 5 , when the first bobbin 110 is fitted into the second through hole 135 of the second bobbin 130 , the step surface of the upper flange 113 of the first bobbin 110 . 113a and the stepped portion 113b overlap the bottom surface and the end of the protruding rib 133b of the upper flange 133 of the second bobbin 130, and the lower flange 114 of the first bobbin 110 is seated The surface 114a is vertically overlapped with a portion of the bottom surface of the lower flange 134 of the second bobbin 130 so that the first bobbin 110 and the second bobbin 130 are easily and stably fitted.

In addition, when the second bobbin 130 coupled to the first bobbin 110 is fitted into the third through hole 155 of the third bobbin 150 , the upper flange 133 of the second bobbin 130 is The stepped surface 133a is vertically overlapped with the protruding rib 153a of the upper flange 153 of the third bobbin 150, and the seating surface 134a of the lower flange 134 of the second bobbin 130 is 3 The lower flange 154 of the third bobbin 150 overlaps up and down with the bottom surface of the second bobbin 130 and the third bobbin 150 is easily and stably fitted.

In addition, the third bobbin 150 is inclined downward toward the edge on the upper surface of the upper flange 153 to form a relatively thin tapered portion 153a. The tapered portion 153a is a portion that secures the thickness of the molding portion 170 by forming a thin outer portion of the upper flange 153 of the third bobbin 150 to strengthen the overall structure of the body 100 . That is, since the thickness of the molding portion 170 is secured as much as the space of the tapered portion 153a, the bonding strength between the bobbin assembly 100 ′ and the molding portion 170 becomes stronger.

In the bobbin assembly 100 ′ to which the first bobbin 110 , the second bobbin 130 , and the third bobbin 150 are coupled, the first terminal pin 125 and the third terminal pin 165 are the bobbin assembly 100 . '), and the second terminal pin 145 is arranged on the other side of the bobbin assembly 100'.

In addition, the third terminal pin 165 is drawn out from the upper portion of the main body 100 than the first terminal pin 125 .

After the first bobbin 110, the second bobbin 130, and the third bobbin 150 are coupled, the bobbin assembly 100' is molded by the molding unit 170, and then the upper core 210 and the lower core ( 220) is combined to produce a transformer (10).

9 is a view showing a terminal pin and a connection relationship of a transformer according to an embodiment of the present invention.

As shown in FIGS. 6 to 9 , a plurality of first terminal pins 125 and third terminal pins 165 are arranged side by side in a line on one side of the body 100 to be spaced apart from each other, and the first terminal pins ( 125 is disposed on the inside and the third terminal pin 165 is disposed on the outside.

That is, since the size of the third bobbin 150 is relatively large compared to the size of the first bobbin 110 , in order to arrange the first terminal pin 125 and the third terminal pin 145 side by side in a line, the third The terminal pins 165 are disposed on the outermost side and the first terminal pins 125 are disposed therebetween.

The above structure allows the first terminal pin 125 and the third terminal pin 165 to be connected to each other on the board, thereby eliminating the need to connect copper wires between bobbins and facilitating manufacturing.

For example, two first primary coils 120 may be wound around the first bobbin 110 , and each end may be connected to four first terminal pins 125 . In addition, two secondary coils 140 may be wound around the second bobbin 130 , and each end may be connected to four third terminal pins 165 . In addition, one second primary coil 160 may be wound around the third bobbin 150 , and each end may be connected to two third terminal pins 165 .

Specifically, the first terminal pin 125 includes pins 2, 3, 4, 5, and 6, the third terminal pin 165 includes pins 1 and 7, and pins 1 to 7 are They are arranged side by side at a predetermined interval on one side of the body 100 .

In addition, the transformer 10 shorts pins 1 and 2 from the board, and the leakage inductance Lk at pin 3 connected to pin 2, pin 2, pin 1, and pin 7 connected to pin 1 ) can be configured to measure The method of shorting the substrate as described above is easy to manufacture because there is no need to remove the copper wire from the first coil 120 of the first bobbin 110 and connect it with the copper wire of the first coil 160 of the third bobbin 150 . There is an advantage.

In addition, one of the first primary coils 120 wound on the first bobbin 110 uses a triple insulated copper wire, and the primary coils 120 and 160 wound on the remaining first bobbin 110 and the third bobbin 150 . ) and the secondary coil 140 wound on the second bobbin 130 may use USTC copper wire.

Triple insulated copper wire has three layers of external insulation formed on the outside of the copper wire, and USTC copper wire uses enameled wire and twisted in a uniform shape to connect nylon, cotton, and Nomax to the outside of the wire. It is externally insulated, etc. For example, the triple insulated copper wire may have a diameter of 0.3mm and the number of cores may be two, and the USTC copper wire may have a diameter of 0.1mm and 50 to 60 cores and a diameter of about 1.0 to 1.15mm.

Triple insulated copper wire has excellent insulation effect, but has the disadvantage of being expensive. USTC copper wire is low-priced, but it has the disadvantage that it is necessary to fill in epoxy or use an insulation tube and insulation tape as much as possible for insulation. In addition, the triple insulated copper wire has a thick insulating film, so the number of turns increases and the space increases when used a lot, so there is a limit in lowering the leakage inductance (Lk).

The insulation problem between triple insulated copper wire and USTC copper wire is solved with three bobbins and a molding part. However, in consideration of the high voltage of the primary side, it is preferable to use a triple insulated copper wire for one of the first primary coils 120 wound around the first bobbin 110 .

In the transformer 10, one end of the first primary coil 120 wound on the first bobbin 110 is connected to the first terminal pins 125 of No. 2 and No. 3, and the other end is connected with No. 5 and No. It may be connected to No. 6 first terminal pin 125 . For example, two types of first primary coils 120 are wound on the first bobbin 110 , and one first primary coil is connected to the first terminal pins 125 of No. 2 and No. 3 using a USTC copper wire, and The other first primary coil 120 is connected to the first terminal pins 125 of Nos. 5 and 6 using a triple insulated copper wire. No. 4 first terminal pin 125 may be a dummy pin.

An end of the second primary coil 160 wound on the third bobbin 150 is connected to the third terminal pins 165 of No. 1 and No. 7 . For example, one second primary coil 160 is wound on the third bobbin 150 , and one second primary coil 160 is connected to the third terminal pins 165 of Nos. 1 and 7 using USTC copper wire. Connected.

One end of the secondary coil 140 wound on the second bobbin 130 is connected to the second terminal pins 145 of No. 8 and No. 9, and the other end of the second terminal pin of No. 11 and No. 12 ( 145) is connected. For example, two secondary coils 140 are wound on the second bobbin 130, one secondary coil uses USTC copper wire, is connected to the second terminal pins 145 of No. 8 and No. 9, and the other secondary coil ( 140) uses a USTC copper wire and is connected to the second terminal pins 145 of No. 11 and No. 12. No. 10 second terminal pin 145 may be a dummy pin.

The above-described transformer 10 can insulate between the primary coils 120 and 160 and the secondary coil 140 with the three bobbins 110, 130, and 150 and the molding part 170 and insulate it from the outside, and the three bobbins 110, 130, and 150 There are terminal pins 125, 145, and 165, respectively, so that the coils of the innermost first bobbin 110 and the outermost third bobbin 150 can be connected from the board through the terminal pins, and the first primary coil-secondary coil- The second primary coil may have a sandwich structure to lower the leakage inductance Lk.

10 is a flowchart illustrating a method of manufacturing a transformer according to an embodiment of the present invention.

As shown in FIG. 10 , in the transformer manufacturing method, a first primary coil 120 is wound on a first bobbin 110 having a first terminal pin 125 , and an end of the first primary coil 120 is removed. A step (S1) of soldering and bonding to the first terminal pin 125, winding the secondary coil 140 on the second bobbin 130 having the second terminal pin 145, and attaching the end of the secondary coil 140 A step (S2) of soldering to the second terminal pin 145 and coupling the second primary coil 160 to the third bobbin 150 having the third terminal pin 165, and the second primary coil ( A step (S3) of soldering the end of 160 to the third terminal pin 165 and coupling (S3), and a step of coupling the first bobbin 110, the second bobbin 130, and the third bobbin 150 (S4) And, the first bobbin 110, the second bobbin 130, and the third bobbin 150 are combined bobbin assembly 100 ' is put into a mold and insert injection into the body 100 including the molding part 170 and forming (S5).

In the step (S3) of coupling the first bobbin, the second bobbin, and the third bobbin, the second bobbin 130 is fitted into the third through hole 155 formed in the central portion of the third bobbin 150, and the 2 The secondary coil 140 between the first primary coil 120 and the second primary coil 160 by fitting the first bobbin 110 into the second through hole 135 formed in the central portion of the bobbin 130 . ) is placed in a sandwich structure.

The first bobbin 110 , the second bobbin 130 , and the third bobbin 150 are formed with a step overlapping up and down on the upper flanges 113 , 133 , 153 or the lower flanges 114 , 134 , 154 so that they can be well coupled when they are fitted together. Since the fitting is easy and stable, the formation of the molding part 170 to be performed is easy and structural stability is also secured.

In the step of coupling the first bobbin, the second bobbin, and the third bobbin, the first terminal pin 125 and the third terminal pin 165 are plural and are arranged side by side on one side of the bobbin assembly 100'. , the first terminal pin 125 is disposed on the inside and the third terminal pin 165 is disposed on the outside, the second terminal pin 145 is plural and arranged side by side on the other side of the bobbin assembly 100' make it

The sandwich structure of the first primary coil-secondary coil-second primary coil using three bobbins secures insulation between coils, secures external insulation, and secures an insulation distance by separating terminal pins to lower leakage inductance. For example, the distance between the terminal pins may be in the range of 4.5 to 5 mm, and the diameter of the terminal pins may be 0.8 mm.

After the step of forming the body including the molding unit 170 , the first terminal pin 125 , the second terminal pin 145 , and the third terminal pin 165 protrude to the outside of the molding unit 170 , The first terminal pin 125 and the third terminal pin 165 are connected to the board on which the transformer 10 is mounted.

It further includes the step of coupling the core 200 to the body 100 manufactured by the above-described process. The core 200 is coupled in such a way that it is inserted into the first through hole 115 while in close contact with the core coupling portion 102 of the body 100 , and the surface in contact with the core 200 and the body 100 is epoxy bonded to the core. (200) is fixed to the state coupled to the body (100). Epoxy bonding improves waterproofness and minimizes fragments in case of breakage, making it easier to check cracks.

Table 1 below shows an application example of the transformer of the present invention.

coil Terminals Wire TURNS L uH L/K uH CURRENT bobbin S F at 100kH at 100kH 100℃/20% Primary (NP1) 3 2(7) USTC 0.1×60P 8 180 10 5 first bobbin Primary (NP2) 6 5 TIW 0.3×2P 3 Secondary (NS1) 9 8 USTC 0.1×50P 18 2nd bobbin Secondary (NS1) 12 11 USTC 0.1×50P 6 Primary (NP3) One 7 USTC 0.1×60P 7 3rd bobbin

As shown in Table 1, the first primary coil wound on the first bobbin is USTC copper wire and triple insulated copper wire. USTC copper wire has a diameter of 0.1mm and has 60 cores, and after winding 8 turns on the first bobbin, connect both ends to the first terminal pins of No. 3 and No. 2, and triple insulated copper wire has a diameter of 0.3mm It is formed by winding a thing with two wires with three layers of insulating layers. After winding three turns on the first bobbin, both ends are connected to the first terminal pins of No. 5 and No. 6.

In addition, the secondary coil wound on the second bobbin is a USTC copper wire with a diameter of 0.1mm and 50 elements, and one is wound 18 turns on the second bobbin, and then both ends are connected to the second terminal pins of No. 8 and No. 9. The other one was wound on the second bobbin for 6 turns, and then both ends were connected to the second terminal pins of Nos. 11 and 12.

In addition, the first coil wound on the third bobbin was a USTC copper wire having a wire diameter of 0.1 mm and 60 elements, and 7 turns were wound on the third bobbin, and then connected to the third terminal pins of No. 1 and No. 7.

Then, the first terminal pin of No. 2 and the third terminal pin of No. 7 were short-circuited from the board, and leakage inductance (Lk) was measured at the terminal pins of No. 3, 2, 1 and 7.

As a result of the measurement, the leakage inductance (Lk) was measured to be 10uH or less.

From the above results, it is confirmed that the leakage inductance (Lk) can be lowered by manufacturing a transformer having a sandwich structure of a first primary coil, a secondary coil, and a second primary coil to which three bobbins and a molding part are applied.

In the present invention, three bobbins are applied to insulate between the coils and a molding part is applied to insulate from the outside, so insulation can be secured while minimizing triple insulated copper wires, and each bobbin has a terminal pin so that the inner coil and the outer The coil on the side can be connected from the board rather than inside, and the insulation distance between the terminal pins can be secured. , which can greatly reduce the leakage inductance and improve the efficiency.

The above-described transformer can be installed in a TV, monitor, LED drive power supply, PC power supply, etc. to enable stable power supply. In the embodiment, the number of first to third terminal pins and the number of turns of the coil have been arbitrarily determined and described, but the number of terminal pins and the number of turns of the coil can be changed according to design conditions.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is disclosed in the drawings and in the specification with preferred embodiments. Here, although specific terms have been used, they are used only for the purpose of describing the present invention and are not used to limit the meaning or the scope of the present invention described in the claims. Therefore, it will be understood by those skilled in the art that various modifications and equivalent other embodiments of the present invention are possible therefrom. Accordingly, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.

10: transformer 100: body
101: molding flange 102: core coupling portion
110: first bobbin 111: winding part
113: upper flange 113a: stepped surface
113b: stepped portion 114: lower flange
115: first through hole 120: first primary coil
125: first terminal pin 130: second bobbin
131: winding portion 133: upper flange
133a: stepped surface 133b: protruding ribs
134: lower flange 135: second through hole
140: secondary coil 145: second terminal pin
150: third bobbin 151: winding part
153: upper flange 154: lower flange
155: third through hole 160: second primary coil
165: third terminal pin 170: molding part
200: core 210: upper core
220: lower core a: flat portion
b: both leg parts c: central leg part

Claims (15)

main body; and
a core coupled to the body;
including,
the body is
a first bobbin on which a first primary coil is wound, a first terminal pin connected to the first primary coil is provided, and a first through hole is formed in a central portion;
a second bobbin on which a secondary coil is wound, a second terminal pin connected to the secondary coil is provided, and a second through hole is formed in a central portion thereof; and
a third bobbin on which a second primary coil is wound, a third terminal pin connected to the second primary coil is provided, and a third through hole is formed in a central portion;
includes,
The second bobbin is fitted into a third through hole of the third bobbin and the first bobbin is fitted into a second through hole of the second bobbin, between the first primary coil and the second primary coil The secondary coil is disposed on
The first bobbin, the second bobbin, and the third bobbin
a winding unit on which the coil is wound; and
and an upper flange and a lower flange extending outward to support the coil, respectively, with the winding portion interposed therebetween,
The first bobbin and the second bobbin are formed with a stepped surface along the edge on the upper surface of the upper flange,
The upper flanges of the second bobbin and the third bobbin include protruding ribs protruding through the second through hole and the third through hole as much as the width of the stepped surface, so that the stepped surface overlaps the protruding rib vertically. According to claim 1,
The first terminal pin and the third terminal pin are each in plurality, and are arranged to be spaced apart from each other at one side of the main body. 3. The method of claim 2,
The first terminal pin is disposed on the inside and the third terminal pin is disposed on the outside. 3. The method of claim 2,
The third terminal pin is drawn out from the upper portion of the main body than the first terminal pin. 3. The method of claim 2,
The plurality of second terminal pins is a transformer that is arranged to be spaced apart from each other on the other side of the main body. 3. The method of claim 2,
A transformer configured to electrically connect one of the first terminal pins and one of the third terminal pins on a board on which the transformer is mounted. According to claim 1,
A transformer in which the two first primary coils are wound around the first bobbin and each end is connected to four first terminal pins. 8. The method of claim 7,
One of the first primary coils wound on the first bobbin uses triple insulated copper wire, and the remaining first primary coil, the second primary coil and the secondary coil use USTC copper wire. According to claim 1,
wherein the bobbin assembly to which the first bobbin, the second bobbin and the third bobbin are coupled is molded by a molding unit. 10. The method of claim 9,
The portion where the first primary coil and the first terminal pin are connected, the portion where the secondary coil and the second terminal pin are connected, and the portion where the second primary coil and the third terminal pin are connected are formed after soldering. molded by wealth,
End portions of the first terminal pin, the second terminal pin, and the third terminal pin protrude to the outside of the molding unit. delete According to claim 1,
The second bobbin is further formed with a stepped seating surface in a certain portion along the rim on the upper surface of the lower flange,
A transformer in which a lower surface of the lower flange of the third bobbin is seated on the seating surface. main body; and
a core coupled to the body;
including,
the body is
a first bobbin on which a first primary coil is wound, a first terminal pin connected to the first primary coil is provided, and a first through hole is formed in a central portion;
a second bobbin on which a secondary coil is wound, a second terminal pin connected to the secondary coil is provided, and a second through hole is formed in a central portion thereof; and
a third bobbin on which a second primary coil is wound, a third terminal pin connected to the second primary coil is provided, and a third through hole is formed in a central portion;
includes,
The second bobbin is fitted into a third through hole of the third bobbin and the first bobbin is fitted into a second through hole of the second bobbin, between the first primary coil and the second primary coil The secondary coil is disposed on
The third bobbin is
a winding unit on which the coil is wound; and
and an upper flange and a lower flange extending outward to support the coil, respectively, with the winding portion interposed therebetween,
A transformer in which a tapered portion inclined downward toward the edge is formed on the upper surface of the upper flange. delete delete

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