JPH0799123A - Printed coil - Google Patents

Abstract

PURPOSE:To reduce an interval required for an insulation and miniaturize a device by a method wherein outer and inner peripheral connecting holes provided on a laminated conductive form surface are electrically connected between interlayers with respect to each other. CONSTITUTION:On each conductive form surface 54, outer peripheral connecting holes 51, 52 and an inner peripheral connecting hole 53 are provided in conductive patterns 55. The outer peripheral connecting holes 51, 52 and inner peripheral connecting hole 53 are connected relative to a function of each conductive form surface 54 and laminated. The outer peripheral connecting holes 51, 52 and inner peripheral connecting hole 53 provided on this laminated conductive form surface 54 are electrically connected between interlayers with respect to each other by a primary-side terminal 41, a secondary-side terminal 42, and an inner peripheral terminal 43. As described above, an insulated layer is interposed between the conductive patterns 55 of each conductive form surface 54 that are laminated, whereby an interval required for an insulation is just reduced to miniaturize a printed coil laminated body. Also, if the number of laminated coils is increased, an external signal line has only to be connected to an outer peripheral terminal and line-coupling works can be readily carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil structure suitable for use in transformers and choke coils used in electronic equipment and power supply devices, and particularly when used as a transformer, it has good magnetic coupling, low loss and high frequency characteristics. Of good equipment.

[0002]

2. Description of the Related Art A transformer is a magnetic component used in electronic equipment and power supplies, which insulates the primary side from the secondary side, and the voltage on the secondary side depends on the voltage on the primary side and the winding ratio. It has the property of being determined by FIG. 1 is a perspective view showing the structure of a conventional transformer using a bobbin, in which a main part is cut away. In the figure, the bobbin 1 is formed of an insulating resin or the like, and a ring-shaped collar portion 1b is provided at both ends of a tubular cylindrical portion 1a.
Are formed. The winding wire 2 is made of a conductive wire wound around the tubular portion 1a of the bobbin 1, and the primary winding wire 2a and the secondary winding wire 2b form two layers with the insulating tape 3 interposed therebetween. The barrier 4 is attached to the bobbin 1 in order to secure a gap between the winding 2 and the collar portion 1b and to meet a safety standard. For example, a tape-shaped insulator is wound in two layers with the insulating tape 3 interposed therebetween. Configure. The core 5 is an EE type core made of a magnetic material, and has a middle foot 5b penetrating the tubular portion 1a of the bobbin 1 and a middle foot 5b.
Has leg portions 5a located on both sides of. By combining two EE type cores 5, a closed magnetic circuit is formed, and the state of electromagnetic coupling of the transformer is improved.

However, in the conventional transformer, since the conducting wire 2 is wound around the cylindrical bobbin 1, the winding work becomes complicated, and the bobbin 1 occupies most of the volume of the transformer, resulting in a large apparatus. There was a problem. Further, in order to obtain the safety standard, it is necessary to secure sufficient insulation, and therefore the barrier 4 needs to be attached. The reason is that the circumference of the winding 2 is not covered with an insulator, so that the interval required for insulation increases.

Therefore, a simple winding operation is disclosed, for example, in Japanese Utility Model Laid-Open No. 4-46524 proposed by the present applicant. 2A and 2B are configuration diagrams of the apparatus disclosed in the publication, FIG. 2A is a sectional view, and FIG. 2B is a stacking bobbin 6
It is a perspective view showing a simple substance of. In the transformer, several bobbins 6 are stacked and the core 5 is mounted. A flat plate-shaped insulating barrier 7 is attached to the boundary between the primary side and the secondary side of the stacked bobbins 6. An insulating cover 8 is attached to the outside of the stacked bobbin 6.

Details of the stacked bobbin 6 include a plate 6a serving as a partition wall between the windings 2 and a cylindrical magnetic core portion 6b having a rectangular opening provided at the center of the plate 6a. The draw-out guide portions 6c hold the plate 6a in a fixed posture, and two pull-out guide portions 6c are provided on both sides of the lower end of the plate 6a. The pin portion 6d is the drawer guide portion 6c
The terminals are provided for soldering to a printed circuit board (not shown) and the winding 2 is connected. Plate 6
When a is overlapped, it is preferable that the drawer guide portions 6c have a nested structure so as not to interfere with each other. Winding 2
Is wound around the magnetic core portion 6b, and both ends thereof are connected to the pin portion 6d. Then, the middle leg of the core 5 penetrates the magnetic core portion 6b. According to this structure, the winding work may be performed along the plate 6a with the magnetic core portion 6b as the center, so that the work is simpler than the case where the conductor wire 2 is wound around the cylindrical bobbin 1.

[0006]

However, since the circumference of the winding wire 2 is not covered with an insulating material, the space required for insulation is increased, and the problem of increasing the size of the transformer remains. Also,
When the drawer guide portion 6c is nested, the pin portion 6d
Is increased according to the number of stacked bobbins 6, the winding may be wound around each pin 6d, or each pin 6d may be wound.
There is a problem that the work of wiring between each other becomes complicated.

Further, in the stacked bobbin 6, since the primary coil and the secondary coil are separated and laminated, the magnetic coupling surface of the primary and secondary windings is only one surface provided with the insulating barrier 7, and the leakage inductance is reduced. Is large, and the magnetic coupling of the primary and secondary windings deteriorates. Regarding the AC resistance, when there is a conductor in which current flows in the same direction at high frequencies, the effective resistance has a property of greatly increasing due to the so-called proximity effect.
Therefore, when the stacked bobbins 6 are assembled so that the current flows in the same winding direction in each plate, the resistance increases.

Further, regarding the stray capacitance, there is a problem between adjacent plates in the stacked bobbin 6. Now, assuming that a commercial power supply is connected to the primary side, the primary side voltage is 1
00V to 220V, and assuming that the secondary side is for driving a logic circuit, it becomes 5V to 15V, and the primary side voltage becomes higher than the secondary side voltage by about one digit. Since the electrostatic energy is proportional to the square of the voltage here, for example, the conversion ratio of the transformer is 1
If the ratio is 0: 1, the stray capacitance of the stacked bobbin 6 used as the primary coil is 10 times the stray capacitance of the secondary coil.
The value is 0 times.

It is a first object of the present invention to provide a small-sized and inexpensive device in which the winding can be filled with an insulating material and the distance required for insulation can be reduced. A second object of the present invention is to provide a device in which connection work to each terminal is easy even if the number of laminated coils is increased. A third object of the present invention is to provide a transformer having good magnetic coupling, low loss and good high frequency characteristics.

[0010]

According to the present invention for achieving the first to third objects, a conductor forming surface 54 on which a conductor pattern 55 having a number of turns of at least two is formed around a core insertion hole 56. However, in a plurality of printed coils laminated with an insulating layer sandwiched between them, outer peripheral connection holes 51 and 52 provided on the outer peripheral side of the conductor pattern and inner peripheral connection provided on the inner peripheral side are formed on each conductor formation surface. A plurality of holes 53 are provided, and the outer peripheral connection hole and the inner peripheral connection hole are connected to the conductor pattern of the conductor formation surface of itself according to the function of each conductor formation surface, and are laminated on the laminated conductor formation surface. And a connection coil 6 having a connection pattern 61 for connecting the outer peripheral connection hole and the inner peripheral connection hole.
0, and means 41 to 43 for electrically connecting the outer peripheral connection hole and the inner peripheral connection hole provided in the laminated conductor forming surface and the connection coil to each other between the layers.

[0011]

According to the structure of the present invention, the following effects are obtained. Both ends of each conductor pattern are connected to the outer peripheral connection hole and the inner peripheral connection hole, and in the connection coil, the inner peripheral connection hole is connected to the outer peripheral connection hole by a connection pattern. Then, it is connected to the wiring of the printed circuit board through the terminal mounted in the outer peripheral connection hole and the through hole. Here, since the conductor patterns are connected by the inner and outer connection holes of each flat plate coil, the degree of freedom in coil arrangement is improved, magnetic coupling is good, and low loss and high frequency characteristics can be achieved. . In addition, by selecting the connection pattern of the connection coil appropriately, even with the same plate coil,
Since a plurality of connection relationships between the conductor patterns can be realized, mass productivity is improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 3
FIG. 3 is a configuration perspective view of an assembled state showing an embodiment of the present invention. In the figure, the core 30 is a so-called EE type core,
Here, the both-sided core 31 has a rectangular cross section, and the midfoot core 32 has a circular cross section. The connecting portion 33 is a core material that connects the both side cores 31 and the middle foot core 32, and has a rectangular cross section.

The terminal 40 is used to connect the signal lines on the primary side and the secondary side when it is used as a transformer, and has a primary side terminal 41, a secondary side terminal 42 and an inner peripheral terminal 43. . Here, the number of the primary-side terminals 41 and the secondary-side terminals 42 needs to be at least two.
Increase according to the number of stacked layers. Further, the inner peripheral terminal 43 may be determined according to the number of laminated layers of the printed coil laminated body 50 and the connection type.
It is provided individually.

The flat coil print coil laminate 50 is
It has the function of the primary winding and secondary winding of the transformer,
The middle leg core 32 is inserted into the core insertion hole 56 provided at the center, and the outside is sandwiched by the both side cores 31 to form a magnetic circuit. Then, on the surface of the printed coil laminate 50, the connecting portion 33 of the core 30 is located in the center, and the primary side terminals 41 and the secondary side terminals 42 are located on both sides of this.

4A and 4B are configuration diagrams of the printed coil laminate 50. FIG. 4A is a top view and FIG. 4B is a sectional view taken along line BB in FIG. 4A. The printed coil laminate 50 is a flat coil 58.
Are laminated, the core insertion hole 56 is located at the center,
Five primary-side outer peripheral connecting holes 51 and five secondary-side outer peripheral connecting holes 52 are provided in a row at each of the left and right ends. Six inner peripheral connection holes 53 are provided near the core insertion hole 56. The interlayer connection hole 57 is provided in the vicinity of the primary side outer peripheral connection hole 51.
The flat coil 5 is provided in the inner peripheral connection hole 53.
8 Used when the interlayer connection is insufficient.

After stacking the flat coil 58, the primary side terminal 41 is soldered to the primary side outer peripheral connecting hole 51, the secondary side terminal 42 is soldered to the secondary side outer peripheral connecting hole 52, and the inner peripheral connecting hole 53 is attached. The inner peripheral terminal 43 is soldered. Here, the primary-side terminal 41, the secondary-side terminal 42, and the inner peripheral terminal 43 are made of a short rod made of a metal such as copper having good solderability, and the primary-side terminal 41 and the secondary-side terminal 42 are the printed circuit board 20. The length of the inner peripheral terminal 43 is about the thickness of the printed coil laminate 50. When the interlayer connection hole 57 is used, a terminal equivalent to the inner peripheral terminal 43 is also attached to this. The conductor forming surface 54 is a flat plate coil 58.
A spiral conductor pattern 55 is formed in a region sandwiched between the core insertion hole 56, the primary side outer peripheral connection hole 51, and the secondary side outer peripheral connection hole 52.

The conductor pattern 55 is formed on both sides or one side of the flat coil 58, and FIG. 4B shows the conductor pattern 55 on both sides. When the conductor pattern 55 is the primary side coil 10 having a function as a primary winding, one end is connected to the primary side outer peripheral connection hole 51 and the other end is connected to the inner peripheral connection hole 53. In the case where the flat coil 58 is the secondary coil 20 having a function as a secondary winding, one end is connected to the secondary outer peripheral connecting hole 52 and the other end is connected to the inner peripheral connecting hole 53. .

Next, the laminated state of the flat plate coil 58 will be described with reference to FIG. Here, the primary coil 10 is formed on both front and back surfaces of the base plate 12 by using the wiring pattern 14, and the secondary coil 20 is formed by using the wiring pattern 24 on both front and back surfaces of the base plate 22. Then, the two base plates 12 are laminated, and the base plate 22 is formed on the lower side of the two base plates 3.
The sheets are stacked. An insulating resin 26 is filled between the base plates 12 and 22, so that the wiring patterns 14 and 24 having the same function as that of the conventional winding are formed in the insulator 2.
Covered with 6. As a result, the interval required to obtain the safety standard can be shortened.

FIG. 5 is a sectional view showing a state in which the printed coil transformer is mounted on the printed board. In the figure, a printed board 20 is provided with a primary through hole 21 and a secondary through hole 22. Then, when the printed coil laminate 50 is mounted on the printed circuit board 20, the primary side terminals 41 and the secondary side terminals 42 are soldered to the primary side through holes 21 and the secondary side through holes 22, respectively. .

Here, the primary side terminal 41 and the secondary side terminal 42
In addition, with respect to the arrangement of the inner peripheral terminals 43, it is necessary to secure a sufficient space distance to the conductor pattern 55 on the conductor forming surface 54 and to secure an insulation distance required for obtaining a safety standard. Here, in the outer peripheral portion and the inner peripheral portion of the spiral conductor pattern 55,
Outer peripheral connecting holes 51, 52 and inner peripheral connecting hole 53 are provided, the primary side terminal 41 is embedded in the outer peripheral connecting hole 51, and the secondary side terminal 42 is provided.
Are planted in the outer peripheral connection hole 52 and the inner peripheral terminal 43 is planted in the inner peripheral connection hole 53, whereby the terminals 41 to 43 are arranged. Therefore, it is not necessary to secure an extra space distance on the conductor forming surface 54, and the coil area can be maximized. As a result, the magnetic coupling proportional to the coil area is maximized, and the magnetic coupling between the coils is improved.

FIG. 6 is a circuit diagram when the printed coil type transformer is mounted on a switching power supply. DC power supply V
in is applied to the primary winding and is turned on / off by the switching element Q. Then, since a switching signal is induced in the secondary winding, it is sent to the output circuit having the diodes D1 and D2, the choke coil L and the capacitor C, and the rectified and smoothed DC voltage is supplied to the load L. Here, the primary winding has a primary coil N11 and a primary coil N12 connected in series, and the secondary winding has a secondary coil N21 and a coil N22 connected in parallel. Also, the terminal P1
1 is connected to the DC power source Vin, and the terminal P13 is connected to the switching element Q. Further, the terminals P21 and P23
Connects the output circuits to both ends of the secondary coil N21 and the secondary coil N22.

FIG. 7 is a perspective view for explaining the connection state of the conductor patterns of the flat plate coil used in the circuit of FIG. In addition, here, a flat coil having a conductor pattern formed only on one surface is shown. In the figure, the secondary side coils N21 and N22 for the secondary winding are designated as the primary side coil N1 for the primary winding.
1 and N12, the coil N12 side faces the printed circuit board 20. Further, the connection coil 60 is provided between the secondary coils N21 and N22. The primary side coils N11 and N12 have a two-turn spiral conductor pattern 55 from the primary side outer peripheral connection hole 51 toward the inner peripheral connection hole 53.
It has a and d. Regarding the conductor pattern 55a, the primary side outer peripheral connection hole 51 and the terminal P31 corresponding to the terminal P11 are provided.
Connected to the inner peripheral connection hole 53 corresponding to the conductor pattern 5
5d is connected to the primary side outer peripheral connecting hole 51 corresponding to the terminal P12 and the inner peripheral connecting hole 53 corresponding to the terminal P32.

The secondary coils N21 and N22 have two-turn spiral conductor patterns 55b and c extending from the secondary outer peripheral connection hole 52 toward the inner peripheral connection hole 53. The conductor pattern 55b is connected to the secondary side outer peripheral connecting hole 52 corresponding to the terminal P23 and the inner peripheral connecting hole 53 corresponding to the terminal P33. Further, the conductor pattern 55c is connected to the secondary side outer peripheral connecting hole 52 corresponding to the terminal P23 and the inner peripheral connecting hole 53 corresponding to the terminal P33. The connection pattern 61 of the connection coil 60 makes the necessary connection. In the printed circuit board 20, the terminals P11 and P13 are arranged on the primary circuit side, and
1, P23 are arranged on the secondary circuit side.

FIG. 8 shows a connection pattern 61 of the connection coil 60.
FIG. For the primary side, the wiring pattern 61
The terminal P12 and the terminal P31 are connected by a, and the connection pattern 6
The terminal P13 and the terminal P32 are connected by 1b. Also,
On the secondary side, the connection pattern 61c connects the terminals P21 and P33. By doing so, as shown in FIG. 6, the coils are connected in series on the primary side and the coils are connected in parallel on the secondary side. Here, regarding the inner peripheral connection hole 53, the terminals P11 to P11 on the primary side are provided.
For the parts near P13, the primary coils N11, N12
Terminals P31 and P32 connected to the secondary side coil N2 are provided for parts near the secondary side terminals P21 to P23.
A terminal P33 that is connected to the terminals 1 and N22 is provided. Since the distance d between the terminals P31 and P32 and the terminal P33 corresponds to the insulation distance between the primary and secondary sides, when the terminals are separately arranged in the inner peripheral connection hole 53 in this way, the primary side and the secondary side are arranged. It is preferable because the insulation distance is increased.

FIG. 9 is an explanatory diagram of the NI distribution in the thickness direction of the coil laminate 50. (A) shows the case where the primary side coil P and the secondary side coil S are laminated, and (B) shows the secondary side coil S. The case where it is sandwiched between the primary side coils P is shown. Generally, the leakage magnetic flux of a transformer is the current I in the coil and the number of coil turns N.
Proportional to the product NI. Therefore, there is a leakage flux distribution in the coil, and the leakage flux becomes large at a large NI, so that the AC resistance of the coil also increases. When stacking the primary coil P and the secondary coil S, the outermost layer of the coil is NI.
Is zero and the leakage flux is also zero. Therefore, placing the connecting coil 60 in the outermost layer has an effect of reducing the AC resistance in the connecting coil. Further, when the secondary coil S is sandwiched by the primary coils P, NI becomes zero in the central layer and the outermost layer. Therefore, by providing the connecting coil 60 in the central layer or the outermost layer, it is possible to reduce the AC resistance in the connecting coil 60. Further, when the connection coil 60 is provided in the outermost layer, a shield effect can be obtained electrostatically, which is preferable.

FIG. 10 is an explanatory view of another connection pattern 61 of the connection coil 60, (A) is a plan view of the connection coil 60,
(B) is a connection diagram of the coil. On the primary side, the terminals P11 and P12 are connected by a wiring pattern 62a,
The connection pattern 62b connects the terminals P13 and P32, and the connection pattern 62c connects the terminals P31 and P32. For the secondary side, the wiring pattern 6
The terminal P21 and the terminal P33 are connected at 2d. With this configuration, the coils are connected in parallel on the primary side and the coils are connected in parallel on the secondary side. In this way, various connection states can be selected even with the same coil laminated body simply by selecting the connection pattern of the connection coil 60.

11A and 11B are explanatory views of the wiring state of the connection coil 60 in the coil laminated body 50. FIG. 11A is a perspective view showing the laminated state, and FIG. 11B is a top view of the connection coil 60. The connection coil 60 is placed on the uppermost layer, and the first layer is on the lower layer,
The conductor forming surface 54 of the kth layer, ..., The Nth layer are laminated. On the conductor forming surface 54 of the k-th layer, the inner peripheral connecting hole 53
1 is provided with a starting end Ck, and one of the outer peripheral connection holes 51 is provided with a terminating end Dk, and a spiral conductor pattern 55 is connected between the starting end Ck and the terminating end Dk. Correspondingly, in the connecting coil 60, the starting end Bk is provided at one of the inner peripheral connecting holes 53 corresponding to the starting end Ck, and the ending end Ek is provided at one of the outer peripheral connecting holes 51 corresponding to the ending end Dk. Has been. Since the start end Bk uses the inner peripheral connection hole 53, the connection with the outside becomes inconvenient. Therefore, one of the outer peripheral connection holes 51 is assigned to the external connection terminal Ak, and the external connection terminal Ak and the starting end Bk are connected by a radial connection pattern 61.

If the conductor forming surface 54 is an N layer, the connecting coil 60 is provided with N starting ends Bk at the center.
A maximum of 2N terminals including terminals Ak and terminations Ck are provided in the peripheral portion. Here, since each conductor forming surface 54 is independent,
The peripheral terminal Dk can be provided at an arbitrary position, and the peripheral terminal Ek is provided at a position corresponding to this.

Connections such as series, parallel and branching between the coils are made by interconnection of terminals Ai, Bj, Ek (i, j, k = 1, ..., N). Therefore, since the connection coil 60 is provided with the terminals Ak, the starting ends Bk, and the peripheral terminals Ek corresponding to the starting ends Ck and the endings Dk of the respective conductor forming faces 54, the N conductor forming faces 54 are located at arbitrary positions from the starting ends. There is an effect that the terminals can be connected to each other and the degree of freedom in coil connection is increased. Further, by appropriately selecting the connection pattern of the connection coil 60, it is possible to realize a plurality of connection relationships between the conductor patterns even on the same conductor formation surface 54, which also has the effect of increasing mass productivity.

FIG. 12 is a diagram for explaining the wire connection state of the apparatus of FIG. In the figure, the printed coil is the 11th surface,
Five layers are laminated in the order of the 21st surface, the connecting coil 60, the 22nd surface, and the 12th surface. Primary coil n1 of transformer
Includes an eleventh surface having the terminal P11 as an outer terminal and the first surface.
The two-sided structure has the twelfth surface having the conductor pattern 55d connected in series with the one-surface conductor pattern 55a. Then, the inside of the conductor pattern 55a on the eleventh surface and the inside terminal of the connection pattern 61a of the connection coil 60 are the inner peripheral terminal 4
3a, connection pattern 61a of the connection coil 60
Of the outer surface and the outer terminal of the conductor pattern 55d of the twelfth surface are connected by the primary side terminal 41a, and the inner terminal of the conductor pattern 55d of the twelfth surface and the inner terminal of the connection pattern 61d of the connection coil 60 are inner peripheral terminals. 43b, and the outer terminal of the connection pattern 61d of the connection coil 60 is the terminal P1.
Used as 3.

The secondary coil n2 has a conductor pattern 55.
The outer terminal of b is used as the terminal P23, and the outer surface of the conductor pattern 55c has a two-sided surface, and the outer surface of the conductor pattern 55c is used as the terminal P23. The terminal 43c connects to the inner terminal of the connection pattern 61c of the connection coil 60. Then, the connection pattern 6 of the connection coil 60
Since the outer terminal of 1c is used as the terminal P21, the conductor pattern 55b and the conductor pattern 55c are connected in parallel.

FIG. 13 is a block diagram of a conventional device for comparison with the embodiment of FIG. Here, without using the connection coil 60, four layers of print coils are laminated in order of the 11th surface, the 12th surface, the 21st surface, and the 22nd surface. The primary coil n1 of the transformer has a two-sided structure including an eleventh surface having the terminal P11 as an outer terminal and a twelfth surface having the terminal P13 as an outer terminal. The inner terminals of the conductor patterns 55a and 55d are connected to the inner peripheral terminal 43d. Has been done. In addition, the secondary coil n2
Includes a 21st surface having the terminal P21 as an outer terminal, and a terminal P2.
The outer surface of the conductor patterns 55b and 55c is connected to the inner terminal 43e. Therefore, here, the conductor patterns 55a,
55d is connected in series as a primary winding n1, and the conductor patterns 55b and 55c are connected in series as a secondary winding n2.

Next, the effect of this embodiment will be described with reference to FIGS. 12 and 13. First, the improvement of magnetic coupling will be described. Magnetic coupling improves as the number of directly facing surfaces of the primary coil and the secondary coil increases. In the conventional configuration shown in FIG. 13, the twelfth surface and the twenty-first surface are the main components of magnetic coupling. On the other hand, in the embodiment shown in FIG. 12, the eleventh surface and the twenty-first surface and the twelfth surface and the twenty-second surface are the main components of magnetic coupling. Since the magnetic coupling has the property of being proportional to the square of the coil area, the magnetic coupling is improved four times.

Next, the reduction of loss will be described. The AC resistance increases when the current flows in the same direction in the parallel conductors, and suppresses the increase in the AC resistance when the current flows in the opposite direction (proximity effect). In the conventional configuration shown in FIG. 13, current flows in the same direction on the 11th and 12th surfaces and the 21st and 22nd surfaces, so the AC resistance increases. On the other hand, in the embodiment shown in FIG. 12, the eleventh surface and the twenty-first surface and the twelfth surface and the twenty-second surface have opposite current directions, so that the AC resistance can be suppressed. As a result, the coil loss is reduced and the loss can be reduced.

Next, the stray capacitance will be described. FIG.
In the conventional configuration shown in (1), the space between the eleventh surface and the twelfth surface, the space between the twelfth surface and the twenty-first surface, and the space between the twenty-first surface and the twenty-second surface become a capacitor, which causes stray capacitance. Normally, the energy stored in the capacitor is proportional to the square of the voltage, and the energy increases as the potential difference between adjacent layers increases. With a normal power supply, the potential difference between the 11th and 12th surfaces is about 10 times the potential difference between the 21st and 22nd surfaces. Therefore, the energy stored in the stray capacitances on the 11th and 12th surfaces is dominant.
On the other hand, in the embodiment shown in FIG. 12, the eleventh surface and the first surface
Since the two layers are separated, the energy stored during this period is 1 /
It is reduced to about 10. As a result, the stray capacitance is reduced and the high frequency characteristics of the transformer are improved.

Finally, the point of matching the winding directions will be described. Generally, the voltage increasing direction coincides with the coil winding direction. Therefore, when the winding directions of adjacent coils are the same in the opposite direction, the voltage difference between the coil layers becomes larger, and the energy stored in the stray capacitance between layers increases, so that the high-frequency characteristics of the transformer deteriorate. To do. Figure 1
In the conventional configuration shown in FIG. 3, the eleventh surface, the twelfth surface, and the second surface
The winding directions of the conductor patterns are opposite between the 1st surface and the 22nd surface. That is, the 11th and 21st surfaces are right-handed (CW), and the 12th and 22nd surfaces are left-handed (CCW). Here, "left-handed" means that, when the conductor pattern is observed from the direction of arrow G, the shape of the vortex from the outer terminal Pij toward the center is counterclockwise. Right-handed means that, when the conductor pattern is observed from the direction of arrow G, the shape of the vortex from the outer terminal Pij toward the center is clockwise.

On the other hand, in the embodiment shown in FIG. 12, all conductor patterns except the connection coil 60 are unified in the right-handed winding direction. With this structure, the energy stored in the stray capacitance between the layers is reduced, the stray capacitance is substantially reduced, and the high frequency characteristics of the transformer are improved.

FIG. 14 is a constitutional perspective view showing the second embodiment of the present invention. The difference from the embodiment of FIG. 12 is that since the connection coil 60 is not used, a large number of conductor patterns 55 are formed on the conductor formation surface 54 even if the number of laminated print coils is small.
Is the point that is provided. In the figure, the print coil is laminated in four layers in the order of the 11th surface, the 21st surface, the 22nd surface and the 21st surface. The primary coil n1 of the transformer is
An eleventh surface having the terminal P11 as an outer terminal and a twelfth surface having the terminal P13 as an outer terminal. The conductor pattern 55a on the eleventh surface and the conductor pattern 55d on the twelfth surface are connected in series by the inner peripheral terminal 43f. In the secondary coil n2, the outer terminal of the conductor pattern 55b is the terminal P2.
The two-side structure of the 21st surface used as 1 and the 22nd surface where the outer terminal of the conductor pattern 55c is used as the terminal P23 is used. The conductor pattern 55b and the conductor pattern 55c are connected in series by the inner peripheral terminal 43g. To be done.
Regarding the winding direction, the 11th and 21st surfaces are right-handed (CW), and the 12th and 22nd surfaces are left-handed (CC).
W).

When the print coil having such a configuration is used in the circuit of FIG. 6, the terminal P13 and the terminal P23 are connected to the primary ACGND and the secondary ACGND, respectively. Here, ACGND means the ground on the AC equivalent circuit, and is connected to the ground or a conductive object having a certain size that acts as a substitute for the ground. Since the potential induced in the conductor pattern increases in proportion to the number of turns, the AC potential increases from the outer peripheral portion toward the inner peripheral portion between the eleventh surface and the twenty-first surface, and the twelfth surface and the inner surface. With respect to the 22nd surface, the AC potential increases from the outer peripheral portion toward the inner peripheral portion. Therefore, between the 11th and 21st surfaces and the 12th surface
The potential gradient in the radial direction becomes equal between the surface and the 22nd surface,
Stray capacitance can be reduced. Since this capacitance is a part of the stray capacitance generated on the magnetic coupling surface of the primary and secondary windings described above, there is an effect that the high frequency insulation characteristic of the transformer is improved.

FIGS. 15A and 15B are perspective views showing the configuration of an embodiment having two secondary outputs. FIG. 15A shows the case where the respective secondary windings are provided in parallel, and FIG. 15B shows the case where the secondary windings are nested. ing. In the figure, each conductor pattern forming surface N2 of the secondary winding
kx is represented by the outer terminal 2kx of the conductor pattern. Here, x is the output number of the secondary winding, here a or b, k represents the connection relationship of the terminals, k = 1 when the terminals are on the AC ground side, and the potential generation side In this case, k = 2.

In the case of FIG. 15A, the conductor forming surfaces N22a and N21a of the first output of the secondary winding are laminated adjacent to each other and connected by the inner peripheral terminal 43g. In addition, the second output conductor forming surfaces N22b and N21 of the secondary winding
b are laminated adjacently and are connected by the inner peripheral terminal 43h. Then, the conductor forming surface N11 of the primary winding
And N12, the conductor forming surfaces N22a to N21b of the secondary winding.
Sandwiched between. By doing so, due to the relationship of the magnetic coupling surfaces of the primary and secondary windings described above, the leakage inductance is reduced as compared with the conventional example, the increase in resistance due to the proximity effect is suppressed, and the stray capacitance is also small. effective.

In the case of FIG. 15B, the conductor forming surfaces N22b and N22a having the potential generating side terminals of the secondary winding are laminated adjacent to each other, and the conductor forming surface having the AC ground side terminal of the secondary winding. N21a and N21b are laminated adjacent to each other.
Then, the conductor forming surfaces N11 and N12 of the primary winding sandwich the conductor forming surfaces N22b to N21b of the secondary winding. Therefore, the upper three layers and the lower three layers are divided into left-handed and right-handed layers, respectively, so that the stray capacitance can be further reduced as compared with FIG.

FIG. 16 shows an application example in the case of providing a plurality of primary coils. (A) connects four surfaces in series and widens the conductor pattern width of each surface, and (B) shows a set of two surfaces. It shows the case of connecting in parallel. In FIG. 16A, the conductor forming surfaces are N11, N22a, N13, N22b, N21.
It has an eight-layer structure of b, N12, N21a, and N14, and the upper four layers and the lower four layers are each divided into left-handed / right-handed layers. As the primary winding, N11,
N13, N12 and N14 are laminated in this order,
The inner peripheral terminal 43f1 connects the conductor forming surfaces N11 and N12, and the inner peripheral terminal 43f2 connects the conductor forming surfaces N12 and N1.
3 is connected, and the conductor forming surface N13 is formed by the inner peripheral terminal 43f2.
And N14 are connected, and conductor forming surfaces N11 and N1 are connected.
The AC voltage generated in the primary winding is highest in the conductor forming surface N14 and lowest in the conductor forming surface N11.

Conductor forming surface N22a of the first output of the secondary winding
And N21a are stacked separately from the second and seventh layers from the top and are connected by the inner peripheral terminal 43g. Also,
Second output conductor forming surfaces N22b and N21b of the secondary winding
Are adjacently stacked and are connected by the inner peripheral terminal 43h. Here, the current capacity is increased by halving the number of turns per conductor formation surface and doubling the width of the conductor pattern as compared with the case of FIG. 15B. The intermediate primary winding is connected to the conductor forming surfaces N12 and N
13, the conductor forming surface N which is the second output circuit of the secondary winding.
22b and N21b are sandwiched. Then, the intermediate primary winding is connected to the conductor forming surface N2 which is the first output circuit of the secondary winding.
It is sandwiched between 2a and N21a, and the outermost layer is covered with conductor forming surfaces N11 and N14 of the primary winding connected to the outside.

In the case of FIG. 16 (B), the first input circuits of the conductor forming surfaces N11a and N12a, which are the primary windings, are laminated separately on the first and eighth layers from the top and the inner peripheral terminals are formed. Four
It is connected by 3f4. In addition, the conductor forming surface N11b
The second input circuits of N12b and N12b are laminated adjacent to the fourth and fifth layers from the top and are connected by the inner peripheral terminal 43f5. And, the first input circuit and the second input circuit are
The terminals P11 and P13 are connected in parallel. still,
First output conductor forming surfaces N22a and N21a of the secondary winding
Is laminated apart from the second and seventh layers from the top,
It is connected by the inner peripheral terminal 43g. The second output conductor forming surfaces N22b and N21b of the secondary winding are adjacently stacked and connected by the inner peripheral terminal 43h. With such a configuration, the conductor pattern for the primary winding can increase the current capacity while having the same number of turns and the same width as the conductor pattern in the case of FIG.

FIG. 17 is a circuit diagram showing an embodiment of the present invention in a choke coil. As in the case of FIG. 6, a DC power source Vin is applied to the primary winding and is turned on / off by the switching element Q. Then, since a switching signal is induced in the secondary winding, it is sent to the output circuit having the diodes D1 and D2, the main winding of the choke coil L and the capacitor C1, and the rectified and smoothed DC voltage is supplied to the main load L1. To do. A rectifying / smoothing circuit including a diode D3 and a capacitor C2 is connected to the auxiliary winding side of the choke coil L to supply DC power to the auxiliary load L2.

Here, in the choke coil L, a primary coil N31 and a primary coil N32 are connected in series on the auxiliary winding side, and a secondary coil N41 and a coil N42 are connected in parallel on the main winding side. ing. The terminal P31 is connected to one end of the capacitor C2, and the terminal P33 is connected to the capacitor C2 via the diode D3. Furthermore,
The terminal P41 and the terminal P43 connect the diode D1 and the capacitor C1.

FIG. 18 is a view for explaining the connection state of the choke coil used in FIG. Basically, FIG. 18 is substantially the same as the laminated state of the printed coil of FIG. 12, but the reference numerals of the conductor forming surface and the terminals are aligned with FIG. 17 in order to maintain the consistency with FIG. Print coil
Five layers are laminated in the order of the 31st surface, the 41st surface, the connecting coil 60, the 42nd surface and the 32nd surface. Choke coil L
The auxiliary winding has a two-sided structure including a 31st surface having the terminal P31 as an outer terminal and a 32nd surface having a conductor pattern 55d connected in series with the conductor pattern 55a on the 31st surface. The inner side of the conductor pattern 55a on the 31st surface and the inner terminal of the connection pattern 61a of the connection coil 60 are connected by the inner peripheral terminal 43a, and the outer terminal of the connection pattern 61a of the connection coil 60 and the conductor pattern 55 on the 32nd surface.
The outer terminal of d is connected by the primary side terminal 41a,
The inner terminal of the conductor pattern 55d on the surface and the inner terminal of the connection pattern 61d of the connection coil 60 are connected by the inner peripheral terminal 43b, and the outer terminal of the connection pattern 61d of the connection coil 60 is used as the terminal P33.

On the main winding side of the choke coil L, the 41st surface where the outer terminal of the conductor pattern 55b is used as the terminal P43 and the outer terminal of the conductor pattern 55c are the terminal P.
The conductor pattern 55b and the conductor pattern 55c are configured as a two-sided structure of the 42nd surface used as 43, and the connection pattern 61c of the connection coil 60 is formed by the inner peripheral terminal 43c.
Connected to the inner terminal of. Since the outer terminal of the connection pattern 61c of the connection coil 60 is used as the terminal P41, the conductor pattern 55b and the conductor pattern 55c are connected in parallel.

[0050]

As described above, according to the present invention,
Since the conductor patterns 55 on each conductor formation surface 54 are laminated with the insulating layer sandwiched therebetween, the distance required for insulation can be short, and the printed coil laminate can be miniaturized. In addition, by using the connection relationship between the connection pattern 61 of the connection coil 60 and the outer peripheral terminals 51, 52 and the inner peripheral terminal 53 connected to the conductor pattern 55 of each conductor forming surface 54, each conductor forming surface 54 is connected to the primary side. The discretion to use as a coil or the secondary coil is allowed, and even if the number of laminated coils increases, it is sufficient to connect the external signal line to the outer peripheral terminal, which facilitates the wiring work. is there. Further, since the secondary coil 20 is sandwiched by the primary coil 10 and the conductor forming surface 54 is connected to the inner peripheral terminal 53 to form the primary winding and the secondary winding of the transformer, the primary and secondary windings are formed. Due to the relationship of the magnetic coupling surfaces of the lines, there is an effect that the leakage inductance is reduced as compared with the conventional example, the increase in resistance due to the proximity effect is suppressed, and the stray capacitance is also small.

[Brief description of drawings]

FIG. 1 is a configuration perspective view of a device using a conventional bobbin.

FIG. 2 is a configuration diagram of a conventional device.

FIG. 3 is a configuration perspective view of an assembled state showing an embodiment of the present invention.

FIG. 4 is a configuration diagram of a printed coil laminate.

FIG. 5 is a cross-sectional view of a printed coil type transformer mounted on a printed circuit board.

FIG. 6 is a circuit diagram when a print coil type transformer is mounted on a switching power supply.

7 is a perspective view illustrating a connection state of conductor patterns of a flat plate coil used in the circuit of FIG.

8 is an explanatory diagram of a connection pattern 61 of the connection coil 60. FIG.

9 is an explanatory diagram of NI distribution in the thickness direction of the coil laminate 50. FIG.

FIG. 10 is an explanatory diagram of another connection pattern 61 of the connection coil 60.

FIG. 11 is a connection coil 60 in the coil laminate 50.
3 is an explanatory diagram of a wiring state of FIG.

FIG. 12 is a diagram illustrating a wire connection state of the apparatus of FIG.

13 is a block diagram of a conventional device for comparison with the embodiment of FIG.

FIG. 14 is a configuration perspective view showing a second embodiment of the present invention.

FIG. 15 is a configuration perspective view showing an embodiment when there are two secondary outputs.

FIG. 16 is an explanatory diagram when a plurality of primary coils are provided.

FIG. 17 is a circuit diagram showing an embodiment of the present invention in a choke coil.

FIG. 18 is a diagram illustrating a wire connection state of the choke coil used in FIG.

[Explanation of symbols]

 10 primary side coil 20 secondary side coil 30 core 41 primary side terminal 42 secondary side terminal 43 inner peripheral terminal 50 coil laminated body 51 primary side outer peripheral connection hole 52 secondary side outer peripheral connection hole 53 inner peripheral connection hole 24 conductor forming surface 55 conductor pattern 58 flat coil 60 connection coil 61 connection pattern

Claims (8)

[Claims] 1. A print in which a plurality of conductor forming surfaces (54) on which a conductor pattern (55) having a number of turns of at least 2 is formed around a core insertion hole (56) are laminated with an insulating layer interposed therebetween. In the coil, each conductor forming surface is provided with a plurality of outer peripheral connecting holes (51, 52) provided on the outer peripheral side of the conductor pattern and a plurality of inner peripheral connecting holes (53) provided on the inner peripheral side. The outer peripheral connecting hole and the inner peripheral connecting hole are connected to the conductor pattern of the conductor forming surface of itself according to the function of each conductor forming surface, and are laminated on the laminated conductor forming surface, and are connected to the outer peripheral connecting hole and the inner peripheral connecting hole. The connection coil (60) having a connection pattern (61) for connecting the peripheral connection holes, and the outer peripheral connection hole and the inner peripheral connection hole provided on the laminated conductor forming surface and the connection coil are electrically connected to each other. And means for connecting (41-43), A printed coil characterized in that 2. The conductor forming surface functions as a primary coil (10) corresponding to the primary winding (n1) of the transformer and a secondary coil (2) corresponding to the secondary winding (n2) of the transformer.
0) The printed coil according to claim 1, having 0). 3. The order of stacking of the conductor forming surfaces corresponds to the secondary winding (n2) of the transformer by dividing the primary coil (10) corresponding to the primary winding (n1) of the transformer into two. 3. The print coil according to claim 2, wherein the secondary coil (20) for holding is sandwiched from both upper and lower sides. 4. The stacking order of the conductor forming surface and the connecting coil is such that the secondary coil (20) corresponding to the secondary winding (n2) of the transformer is divided into two, and the connecting coil is connected to this secondary coil. It inserts in the division surface of a side coil, It is characterized by the above-mentioned.
Print coil. 5. The stacking order of the conductor forming surface and the connection coil is such that a primary coil (20) corresponding to a primary winding (n2) of a transformer is divided into two, and the connection coil is divided into two parts. The laminate is laminated on the outer layer.
Print coil. 6. The print coil according to claim 1, wherein the conductor patterns on the conductor forming surface are wound in the same direction on the laminated conductor forming surfaces. 7. The function of the conductor forming surface has a primary coil (10) corresponding to the main winding of the choke coil and a secondary coil (20) corresponding to the auxiliary winding of the choke coil. The printed coil of claim 1, wherein the printed coil is a coil. 8. A print in which a plurality of conductor forming surfaces (54) on which a conductor pattern (55) having a number of turns of 2 or more is formed around a core insertion hole (56) are laminated with an insulating layer interposed therebetween. In the coil, each conductor forming surface is provided with a plurality of outer peripheral connecting holes (51, 52) provided on the outer peripheral side of the conductor pattern and a plurality of inner peripheral connecting holes (53) provided on the inner peripheral side. The outer peripheral connection hole and the inner peripheral connection hole are connected to the conductor pattern of the conductor formation surface of itself according to the function of each conductor formation surface, and the outer peripheral connection hole and the inner circumference connection hole provided on the laminated conductor formation surface are connected. Means (41-41) for electrically connecting the holes to each other
43), and a printed coil comprising: