JP5104933B2 - Transformer parts - Google Patents

Description

  The present invention relates to a transformer component, and more particularly to a transformer component formed by laminating printed boards on which spiral conductors are formed.

  As a coil component using a planar spiral conductor, there is a type in which a spiral conductor is formed on a magnetic substrate by a thin film method, such as a common mode filter. Since this type of coil component is very small and can be surface-mounted, it is used in many electronic devices.

  However, in this type of coil component, since the spiral conductor is formed by a thin film method, it is difficult to ensure a sufficient conductor thickness. For this reason, it is difficult to significantly reduce the direct current resistance, and it is not necessarily suitable for applications where a relatively large current flows. A typical example of such an application is a transformer.

  As a method for reducing the direct current resistance of a spiral conductor, a method is known in which a printed circuit board on which a spiral conductor is formed is cut into pieces and a plurality of pieces are sandwiched between magnetic materials (see Patent Document 1). In the transformer component described in Patent Document 1, spiral conductors are formed on both sides of a printed circuit board, which are used as primary windings or secondary windings. Then, a transformer component is configured by laminating a printed circuit board constituting the primary winding and a printed circuit board constituting the secondary winding.

JP-A-6-231978

  However, in the transformer component described in Patent Document 1, since the spiral conductor is formed on both surfaces of the printed circuit board, among the spiral conductor constituting the primary winding and the spiral conductor constituting the secondary winding, Only a part of the spiral conductors are arranged close to each other, and the distance between the other spiral conductors is increased. For this reason, there is a problem that the magnetic coupling between the primary winding and the secondary winding becomes insufficient, and transmission loss increases.

  Accordingly, an object of the present invention is to improve magnetic coupling between a primary winding and a secondary winding in a transformer component in which a plurality of printed circuit boards on which spiral conductors are formed are stacked.

  The transformer component according to the present invention includes first and second magnetic bodies, first to fourth printed circuit boards provided between the first magnetic body and the second magnetic body, and the first The first to fourth spiral conductors formed on one surface of each of the first to fourth printed circuit boards and the one surface of each of the first to fourth printed circuit boards, respectively. Formed on the other surface of each of the first to fourth printed circuit boards and the first to fourth printed circuit boards, respectively. First to fourth inner lead conductors connected to inner circumference ends of the first to fourth spiral conductors, through the first through fourth conductors, and the first outer lead conductors and the first outer conductors, respectively. Inner drawer A first external terminal connected to one of the bodies, a second external terminal connected to one of the second outer lead conductor and the second inner lead conductor, and the third outer lead conductor And a third external terminal connected to one of the third inner lead conductors, and a fourth external terminal connected to one of the fourth outer lead conductor and the fourth inner lead conductor The first spiral conductor and the second spiral conductor are disposed to face each other, and the third spiral conductor and the fourth spiral conductor are disposed to face each other. The other of the conductor and the first inner lead conductor is the other of the third outer lead conductor and the third inner lead conductor, and the fourth outer lead conductor and the fourth inner lead conductor. The other One of the second outer lead conductor and the second inner lead conductor is connected to the other of the third outer lead conductor and the third inner lead conductor and the fourth outer lead conductor. The other outer lead conductor and the fourth inner lead conductor are connected to one of the other.

  According to the present invention, since the spiral conductor constituting the primary winding and the spiral conductor constituting the secondary winding are arranged to face each other, the magnetic coupling between the primary winding and the secondary winding is achieved. Will improve. Thereby, it is possible to provide a transformer component with a small transmission loss.

  In the present invention, the first spiral conductor and the second spiral conductor have the same pattern shape, and the third spiral conductor and the fourth spiral conductor have the same pattern shape. It is preferable. According to this, it is possible to configure a 1: 1 transformer having high symmetry.

  In the present invention, further comprising fifth and sixth external terminals, the other of the first outer lead conductor and the first inner lead conductor is connected to the fifth external terminal, The other of the second outer lead conductor and the second inner lead conductor is connected to the sixth external terminal, and the third outer lead conductor and the third inner lead conductor are connected to each other. The other of the other and the other of the fourth outer lead conductor and the fourth inner lead conductor is connected to the fifth external terminal, and the third outer lead conductor and the third outer lead conductor are connected to the fifth external terminal. It is preferable that the other of the other outer lead conductors and the other of the fourth outer lead conductor and the fourth inner lead conductor is connected to the sixth external terminal. According to this, since the fifth and sixth external terminals can be used as the center tap, a pulse transformer with a center tap can be configured.

  In this case, the laminated body including the first and second magnetic bodies and the first to fourth printed circuit boards has a first and second side surfaces parallel to each other and the first and second side surfaces. The first and second external terminals are disposed on the first side surface of the stacked body, and the third and fourth external terminals are The fifth external terminal is disposed at a position farther from the second external terminal when viewed from the first external terminal, and is disposed on the second side surface of the laminate. It is preferable that the external terminal 6 is disposed at a position farther from the fourth external terminal when viewed from the third external terminal. According to this, it is possible to secure a sufficient distance between the terminal belonging to the primary side and the terminal belonging to the secondary side.

  Furthermore, in this case, it is preferable that the fifth external terminal is disposed on the third side surface of the multilayer body, and the sixth external terminal is disposed on the fourth side surface of the multilayer body. . According to this, it is possible to easily ensure insulation between the terminal belonging to the primary side and the terminal belonging to the secondary side.

  As described above, according to the present invention, since the magnetic coupling between the primary winding and the secondary winding is improved, it is possible to provide a transformer component with a small transmission loss.

1 is a schematic perspective view showing an appearance of a transformer component 100 according to a preferred embodiment of the present invention. It is a figure which shows the structure of printed circuit boards 10-40. It is typical sectional drawing which looked at the printed circuit boards 10-40 from the lamination surface side. 3 is an equivalent circuit diagram of the transformer component 100. FIG. It is an equivalent circuit diagram of a transformer component according to a modification. It is a figure which shows the structure of the printed circuit boards 10-40 by a modification. 3 is a schematic cross-sectional view showing a configuration example of magnetic bodies 110 and 120. FIG. 6 is a diagram for explaining a method of manufacturing the transformer component 100. FIG. 6 is a diagram for explaining a method of manufacturing the transformer component 100. FIG. It is a figure for demonstrating the layout of the external terminal by a modification.

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

  FIG. 1 is a schematic perspective view showing an appearance of a transformer component 100 according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the transformer component 100 according to the present embodiment includes a substantially rectangular parallelepiped laminate 100s in which magnetic bodies 110 and 120 and printed boards 10 to 40 are laminated, and a first provided in the laminate 100s. To sixth external terminals 101 to 106. The printed boards 10 to 40 are stacked in this order, and are provided so as to be sandwiched between the magnetic bodies 110 and 120.

  The laminated body 100s including the magnetic bodies 110 and 120 and the printed boards 10 to 40 includes an upper surface 100a and a lower surface 100b that are parallel to each other, and first to fourth side surfaces 100c to 100f that are substantially perpendicular to the upper surface 100a and the lower surface 100b. And. One of the upper surface 100a and the lower surface 100b is a surface that becomes a mounting surface in actual use. The external terminals 101 to 103 are disposed on the side surface 100c, and also project from the upper surface 100a and the lower surface 100b. Similarly, the external terminals 104 to 106 are disposed on the side surface 100d, and also project from the upper surface 100a and the lower surface 100b.

  The transformer component 100 according to the present embodiment is a so-called pulse transformer, in which external terminals 101 and 102 are primary side signal terminals, external terminals 106 are primary side center taps, external terminals 104 and 105 are secondary side signal terminals, and external terminals. 103 is used as the secondary center tap.

  FIGS. 2A to 2D are diagrams showing the configurations of the printed boards 10 to 40, respectively, and all are views from the upper surface 100a side of the laminated body 100s, that is, as viewed from the arrow A shown in FIG. In the figure, the solid line indicates the component located on the front side as viewed from the arrow A, and the broken line indicates the component located on the back side as viewed from the arrow A.

  As shown in FIGS. 2A to 2D, each of the printed boards 10 to 40 is formed on one surface and a spiral conductor formed on one surface, and is connected to the outer peripheral end of the corresponding spiral conductor. And an inner peripheral lead conductor formed on the other surface and connected to the inner peripheral end of the corresponding spiral conductor via a through-hole conductor penetrating the printed circuit board. That is, the spiral conductor is formed only on one surface, and the spiral conductor is not formed on the other surface.

  More specifically, as shown in FIG. 2A, the printed circuit board 10 includes one surface 10a and the other surface 10b, and a spiral conductor 11 is provided on the one surface 10a. The spiral conductor 11 is wound counterclockwise (counterclockwise) from the inner peripheral end 11a to the outer peripheral end 11b when viewed from the arrow A. The outer peripheral end 11 b of the spiral conductor 11 is connected to the connection conductor 105 a through the outer peripheral lead conductor 12 formed on one surface 10 a of the printed circuit board 10. The connection conductor 105 a is an internal conductor connected to the external terminal 105. Further, the inner peripheral end 11a of the spiral conductor 11 is led out to the other surface 10b through a through-hole conductor 11c penetrating the printed circuit board 10, and through an inner peripheral lead conductor 13 provided on the other surface 10b. It is connected to the connection conductor 103a. The connection conductor 103 a is an internal conductor connected to the external terminal 103.

  As shown in FIG. 2B, the printed circuit board 20 includes one surface 20a and the other surface 20b, and a spiral conductor 21 is provided on the one surface 20a. The spiral conductor 21 is wound counterclockwise (counterclockwise) from the inner peripheral end 21a to the outer peripheral end 21b when viewed from the arrow A. The outer peripheral end 21b of the spiral conductor 21 is connected to the connection conductor 101a through the outer peripheral lead conductor 22 formed on one surface 20a of the printed circuit board 20. The connection conductor 101a is an internal conductor connected to the external terminal 101. Further, the inner peripheral end 21a of the spiral conductor 21 is drawn out to the other surface 20b through a through-hole conductor 21c penetrating the printed circuit board 20, and through an inner peripheral lead conductor 23 provided on the other surface 20b, It is connected to the connection conductor 106a. The connection conductor 106 a is an internal conductor connected to the external terminal 106.

  As shown in FIG. 2C, the printed circuit board 30 includes one surface 30a and the other surface 30b, and a spiral conductor 31 is provided on the one surface 30a. The spiral conductor 31 is wound clockwise (clockwise) from the inner peripheral end 31a to the outer peripheral end 31b when viewed from the arrow A. The outer peripheral end 31 b of the spiral conductor 31 is connected to the connection conductor 104 a via the outer peripheral lead conductor 32 formed on one surface 30 a of the printed circuit board 30. The connection conductor 104 a is an internal conductor connected to the external terminal 104. Further, the inner peripheral end 31a of the spiral conductor 31 is drawn out to the other surface 30b through a through-hole conductor 31c penetrating the printed circuit board 30, and through an inner peripheral lead conductor 33 provided on the other surface 30b, It is connected to the connection conductor 103b. The connection conductor 103 b is an internal conductor connected to the external terminal 103.

  As shown in FIG. 2D, the printed circuit board 40 includes one surface 40a and the other surface 40b, and a spiral conductor 41 is provided on the one surface 40a. The spiral conductor 41 is wound clockwise (clockwise) from the inner peripheral end 41a toward the outer peripheral end 41b when viewed from the arrow A. The outer peripheral end 41 b of the spiral conductor 41 is connected to the connection conductor 102 a via an outer peripheral lead conductor 42 formed on one surface 40 a of the printed circuit board 40. The connection conductor 102 a is an internal conductor connected to the external terminal 102. Further, the inner peripheral end 41a of the spiral conductor 41 is drawn out to the other surface 40b through a through-hole conductor 41c penetrating the printed circuit board 40, and through an inner peripheral lead conductor 43 provided on the other surface 40b. It is connected to the connection conductor 106b. The connection conductor 106 b is an internal conductor connected to the external terminal 106.

  Although not particularly limited, in this embodiment, the number of turns of each of the spiral conductors 11 to 41 is 4 and they have the same shape. Further, the printed boards 10 to 40 are provided with openings 10c to 40c inside the spiral conductors 11 to 41, respectively. As will be described later, the openings 10c to 40c are filled with a magnetic material, thereby forming a closed magnetic circuit.

  FIG. 3 is a schematic cross-sectional view of the printed boards 10 to 40 as viewed from the laminated surface side. In addition, illustration of the opening parts 10c-40c is abbreviate | omitted in FIG.

  As shown in FIG. 3, in the transformer component 100 according to the present embodiment, the spiral conductor 11 and the spiral conductor 21 are arranged to face each other, and the spiral conductor 31 and the spiral conductor 41 are arranged to face each other. Insulating resin 50 is interposed between adjacent printed circuit boards 10 to 40, thereby preventing contact between conductors provided on adjacent printed circuit boards 10 to 40.

  FIG. 4 is an equivalent circuit diagram of the transformer component 100 according to the present embodiment.

  As shown in FIG. 4, the transformer component 100 according to the present embodiment constitutes a pulse transformer in which the external terminals 101 and 102 are primary signal terminals and the external terminals 104 and 105 are secondary signal terminals. The external terminal 106 is a primary side center tap, and the external terminal 103 is a secondary side center tap.

  Here, the spiral conductor 21 serving as the primary coil and the spiral conductor 11 serving as the secondary coil are arranged to face each other as shown in FIG. Similarly, the spiral conductor 41 serving as the primary coil and the spiral conductor 31 serving as the secondary coil are also arranged to face each other as shown in FIG. For this reason, since it becomes possible to adjoin a primary side coil and a secondary side coil irrespective of the thickness of the printed circuit boards 10-40, it becomes possible to raise both magnetic coupling.

  In the present embodiment, if the external terminals 101 and 105 are on the positive electrode side and the external terminals 102 and 104 are on the negative electrode side, in the primary route from the external terminal 101 to the external terminal 102 via the external terminal 106, The spiral conductors 21 and 41 are routed clockwise (clockwise), and similarly, in the secondary side route from the external terminal 105 to the external terminal 104 via the external terminal 103, the spiral conductors 11 and 31 are moved to the right. It will go around (clockwise). Since the spiral conductors 11 and 21 close to the positive electrode side are arranged opposite to each other and the spiral conductors 31 and 41 close to the negative electrode side are arranged to face each other, the symmetry of the primary signal and the symmetry of the secondary signal The characteristics can be made almost the same. Such a configuration is difficult to achieve in a coil component of a type in which spiral conductors are formed on both sides of a printed circuit board, such as the coil component described in Patent Document 1.

  Moreover, in the present embodiment, the inner peripheral end of each spiral conductor is drawn out to the external terminal 103 or 106 via the inner peripheral lead conductors 13, 23, 33, 43, and this is used as a center tap. It becomes possible. On the other hand, in the case of a coil component in which spiral conductors are formed on both sides of a printed circuit board, such as the coil component described in Patent Document 1, the center tap is pulled out to an external terminal unless a large number of printed circuit boards are used. It is difficult.

  In FIG. 4, the spiral conductor 21 serving as the primary coil and the spiral conductor 11 serving as the secondary coil are coupled in the same direction, and the spiral conductor 41 serving as the primary coil and the spiral serving as the secondary coil. Although the conductors 31 are coupled in the same direction, the present invention is not limited to this, and they may be coupled in opposite directions as shown in FIG. In this case, in the primary route reaching the external terminal 102 from the external terminal 101 via the external terminal 106, the spiral conductors 21 and 41 are routed clockwise (clockwise), while the external terminal 105 is connected to the external terminal 103. In the secondary route that reaches the external terminal 104 via, the spiral conductors 11 and 31 are routed counterclockwise (counterclockwise).

  In order to obtain such a configuration, as shown in FIG. 6, the winding direction of the spiral conductors 11 and 31 formed on the printed circuit boards 10 and 30 may be reversed from the example shown in FIG. More specifically, as shown in FIG. 6A, the spiral conductor 11 is wound clockwise (clockwise) from the inner peripheral end 11a to the outer peripheral end 11b when viewed from the arrow A, and FIG. As shown in (c), the spiral conductor 31 may be wound counterclockwise (counterclockwise) from the inner peripheral end 31a toward the outer peripheral end 31b when viewed from the arrow A. The patterns on the printed circuit boards 20 and 40 shown in FIGS. 6B and 6D are the same as the patterns on the printed circuit boards 20 and 40 shown in FIGS.

  7A and 7B are schematic cross-sectional views showing a configuration example of the magnetic bodies 110 and 120. FIG.

  FIG. 7A shows an example in which the magnetic body 110 on the lower surface 100b side is a flat plate, and the magnetic body 120 on the upper surface 100a side is a so-called E type. The E type means a flat plate portion 121 constituting the upper surface 100a, an outer peripheral projection 122 for connecting to the magnetic body 110 via the outside of the printed boards 10 to 40, and an opening provided in the printed boards 10 to 40. It is a shape provided with the internal peripheral protrusion part 123 for connecting with the magnetic body 110 via 10c-40c.

  FIG. 7B shows an example in which the magnetic body 110 on the lower surface 100b side is a so-called U-type, and the magnetic body 120 on the upper surface 100a side is a so-called convex type. The U-shape is a shape including a flat plate portion 111 constituting the lower surface 100b and an outer peripheral projection portion 112 for connecting to the magnetic body 120 via the outside of the printed boards 10 to 40. Further, the convex type includes a flat plate part 121 constituting the upper surface 100a and an inner peripheral projection part 123 for connecting to the magnetic body 110 through the openings 10c to 40c provided in the printed boards 10 to 40. Shape.

  One or both of the magnetic bodies 110 and 120 are preferably made of a metal magnetic powder-containing resin. This is because if a magnetic metal powder-containing resin is used as the material of the magnetic bodies 110 and 120, magnetic saturation can be prevented without providing a structural magnetic gap such as an air gap. That is, in this embodiment, the magnetic body 110 and the magnetic body 120 are connected through the outer peripheral protrusion 122 or 112 and the inner peripheral protrusion 123, thereby forming a complete closed magnetic circuit. That is, there is no air gap in the closed magnetic path. When a sintered ferrite core is used, a gap must be provided so that magnetic saturation does not occur even when a current exceeding a certain level is applied. However, when a resin containing metal magnetic powder is used, a minute gap between the metal magnetic powder and the resin is required. Many gaps exist, and this increases the saturation magnetic flux density, so that magnetic saturation can be prevented without forming an air gap between the magnetic body 110 and the magnetic body 120. Therefore, it is not necessary to machine the magnetic core with high accuracy to form the air gap.

  The metal magnetic powder-containing resin is a magnetic material in which metal magnetic powder is mixed into the resin. As the metal magnetic powder, it is preferable to use a permalloy material. Specifically, a Pb—Ni—Co alloy having an average particle diameter of 20 to 50 μm is used as the first metal magnetic powder, and carbonyl iron having an average particle diameter of 3 to 10 μm is used as the second metal magnetic powder. It is preferable to use a metal magnetic powder containing these at a predetermined ratio, for example, a weight ratio of 70:30 to 80:20, preferably 75:25. The content of the metal magnetic powder is preferably 90 to 96% by weight. If the amount of metal magnetic powder is reduced relative to the resin, the saturation magnetic flux density decreases. Conversely, if the amount of metal magnetic powder is increased, the saturation magnetic flux density increases. Can be adjusted.

  Further, as the metal magnetic powder, the first metal magnetic powder having an average particle diameter of 5 μm and the second metal magnetic powder having an average particle diameter of 50 μm are mixed at a predetermined ratio, for example, 75:25. It is particularly preferable that As described above, when two types of metal magnetic powders having different particle sizes are used, a high-density magnetic core can be formed under low pressure or non-pressure forming, and high magnetic permeability and low loss can be obtained. A magnetic core can be realized.

  The resin contained in the metal magnetic powder-containing resin functions as an insulating binder. As the resin material, liquid epoxy resin or powder epoxy resin is preferably used. The resin content is preferably 4 to 10% by weight.

  The thicknesses of the magnetic bodies 110 and 120 are preferably the same, and the total thickness is preferably 0.3 to 1.2 mm. This is because if the total thickness of the magnetic bodies 110 and 120 is less than 0.3 mm, not only the mechanical strength of the component but also the inductance of the coil is reduced. Is saturated and does not become so large.

  In the present embodiment, it is preferable that an insulating film is formed on the surfaces of the magnetic bodies 110 and 120. The insulating film can be formed by chemical conversion treatment, and it is preferable to use iron phosphate, zinc phosphate or zirconia for chemical conversion treatment. As described above, when a metal magnetic powder-containing resin is used as a material for constituting a closed magnetic circuit, the metal magnetic powder is a conductor, so that insulation between external terminals becomes a problem. However, if an insulating coating is provided on the surfaces of the magnetic bodies 110 and 120, the surface of the metal magnetic powder-containing resin is coated with insulation, so that sufficient insulation between the external terminals can be ensured.

  8 and 9 are views for explaining the method of manufacturing the transformer component 100 according to the present embodiment, both of which are (a) a plan view and (b) a sectional view.

  First, as shown in FIGS. 8A and 8B, a large printed circuit board 10x as a base of the printed circuit board 10 is prepared, and an opening 10c, a through hole 10d for a through hole conductor, and a slit 10e are formed simultaneously. . Next, a large number (four in this case) of spiral conductors 11, lead conductors 12, 13 and through-hole conductors 11c are formed on the printed board 10x. The same processing is performed on the large printed circuit boards 20x to 40x that are the bases of the printed circuit boards 20 to 40, whereby four large printed circuit boards 10x to 40x that are the bases of the printed circuit boards 10 to 40 are completed.

  Next, these printed circuit boards 10x to 40x are stacked via an insulating resin, and sandwiched between magnetic bodies 110 and 120 from above and below as shown in FIGS. 9 (a) and 9 (b). As a result, the magnetic bodies 110 and 120 also enter the opening 10c and the slit 10e, and become the inner peripheral protrusion 123 and the outer peripheral protrusion 122, respectively. Then, the printed circuit boards 10x to 40x are cut at the positions of the cutting lines Cx and Cy and separated into individual pieces. Thereafter, the external terminals 101 to 106 are formed on the side surfaces of the individual chips, thereby completing the transformer component 100 according to the present embodiment.

  As described above, in the transformer component 100 according to the present embodiment, since the spiral conductor serving as the primary winding and the spiral conductor serving as the secondary winding are disposed to face each other, the primary winding and the secondary winding are arranged. It becomes possible to increase the magnetic coupling with the wire. Thereby, it is possible to provide a transformer component with a small transmission loss. In addition, in this embodiment, the spiral conductors 11 and 21 close to the positive electrode side are arranged opposite to each other, and the spiral conductors 31 and 41 close to the negative electrode side are arranged to face each other. It becomes possible to make the symmetry of the signal substantially the same.

  Furthermore, in this embodiment, since the inner peripheral ends of the spiral conductors formed on different printed circuit boards are connected via the external terminals 103 and 106, these external terminals 103 and 106 are used as center taps. It becomes possible to be. Moreover, since the primary winding and the secondary winding are formed on two printed circuit boards that are not adjacent to each other, the primary winding is compared with the case where the primary winding and the secondary winding are formed on both sides of the printed circuit board. The parasitic capacitance generated between the lines and between the lines of the secondary winding is reduced. Thereby, it is possible to improve the high frequency characteristics.

  In addition, in the present embodiment, as shown in FIG. 1, the distance L2 between the primary-side external terminal 102 and the secondary-side external terminal 103 is larger than the distance L1 between the primary-side external terminals 101 and 102. Since the external terminals 101 to 103 are provided on the same side surface 100c, it is possible to improve the insulation on the primary side and the secondary side. The same applies to the external terminals 104 to 106 provided on the side surface 100d.

  FIG. 10 is a view for explaining the layout of the external terminals according to the modification, and all are views seen from the upper surface 100a side.

  FIG. 10A is a diagram showing an example in which the external terminals 103 and 106 are arranged on the side surfaces 100e and 100f, respectively. According to this example, the external terminals 101 and 102 belonging to the primary side and the external terminal 103 belonging to the secondary side are arranged on different side surfaces, and the external terminals 104 and 105 belonging to the secondary side and the external belonging to the primary side Since the terminal 106 is disposed on a different side surface, the insulation on the primary side and the secondary side is further enhanced.

  10B, in addition to the layout shown in FIG. 10A, the external terminals 101 and 102 belonging to the primary side are offset to the side surface 100f side, and the external terminals 104 and 105 belonging to the secondary side are set to the side surface 100e side. It is a figure which shows the example made to offset to. According to this example, the distance between the external terminals 101 and 102 belonging to the primary side and the external terminal 103 belonging to the secondary side is further increased, and the external terminals 104 and 105 belonging to the secondary side and the external terminals belonging to the primary side Since the distance from the terminal 106 is further increased, the insulation on the primary side and the secondary side is further enhanced.

  10C, in addition to the layout shown in FIG. 10B, the external terminal 106 that is the primary center tap is offset to the side surface 100c side, and the external terminal 103 that is the secondary side center tap is set to the side surface 100d side. It is a figure which shows the example made to offset to. According to this example, the distance between the external terminals 101 and 102 belonging to the primary side and the external terminal 103 belonging to the secondary side is further increased, and the external terminals 104 and 105 belonging to the secondary side and the external terminals belonging to the primary side Since the distance from the terminal 106 is further increased, the insulation on the primary side and the secondary side is further enhanced.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above-described embodiment, the spiral conductors 11 to 41 have the same shape, but it is not essential that the spiral conductors have the same shape in the present invention. For example, the number of turns of the spiral conductor constituting the primary side winding may be different from the number of turns of the spiral conductor constituting the secondary side winding. According to this, it is possible to provide a pulse transformer in which the primary side signal amplitude and the secondary side signal amplitude are different.

  In the above embodiment, the inner peripheral ends of the spiral conductors are connected to each other as a center tap. On the contrary, the outer peripheral ends of the spiral conductors are connected to each other and the center tap is connected to the center tap. You may use as. Further, the inner peripheral end of one spiral conductor and the outer peripheral end of the other spiral conductor may be connected and used as a center tap. Furthermore, it is not essential to pull out the center tap to the external terminal, and the connection may be performed inside the laminate. However, if the center tap is pulled out to the external terminal, it is possible to connect an external wiring to the center tap. Therefore, it is preferable to pull out the center tap to the external terminal.

  Furthermore, although the four printed circuit boards 10-40 are used in the said embodiment, the number of the printed circuit boards used in this invention is not limited to four sheets.

10-40 Printed circuit boards 10a, 20a, 30a, 40a One surface 10b, 20b, 30b, 40b of the printed circuit board The other surface 10c-40c of the printed circuit board Opening 10d Through hole 10e Slit 10x-40x Printed circuit board (before cutting)
11, 21, 31, 41 Spiral conductors 11a, 21a, 31a, 41a Spiral conductor inner peripheral ends 11b, 21b, 31b, 41b Spiral conductor outer peripheral ends 11c, 21c, 31c, 41c Through-hole conductor 50 Insulating resin 100 Transformer parts 100a Upper surface 100b of laminated body Lower surface 100c to 100f of laminated body Side surface 100s Laminated bodies 101 to 106 External terminals 110 and 120 Magnetic body 111 Flat plate portion 112 Outer peripheral projection portion 121 Flat plate portion 122 Outer peripheral projection portion 123 Inner peripheral projection portion

Claims (5)

First and second magnetic bodies;
First to fourth printed circuit boards provided between the first magnetic body and the second magnetic body;
First to fourth spiral conductors respectively formed on one surface of the first to fourth printed circuit boards;
First to fourth outer lead conductors respectively formed on the one surface of the first to fourth printed circuit boards and connected to outer peripheral ends of the first to fourth spiral conductors, respectively.
Inner peripheries of the first to fourth spiral conductors are formed on the other surfaces of the first to fourth printed boards, respectively, through through-hole conductors penetrating the first to fourth printed boards, respectively. First to fourth inner circumferential lead conductors connected to the ends;
A first external terminal connected to one of the first outer lead conductor and the first inner lead conductor;
A second external terminal connected to one of the second outer lead conductor and the second inner lead conductor;
A third external terminal connected to one of the third outer lead conductor and the third inner lead conductor;
A fourth external terminal connected to one of the fourth outer lead conductor and the fourth inner lead conductor,
The first spiral conductor and the second spiral conductor are arranged to face each other,
The third spiral conductor and the fourth spiral conductor are arranged to face each other,
The other of the first outer lead conductor and the first inner lead conductor is the other of the third outer lead conductor and the third inner lead conductor, the fourth outer lead conductor and the fourth outer lead conductor. Is connected to one of the other outer circumferential conductors,
The other of the second outer lead conductor and the second inner lead conductor is the other of the third outer lead conductor and the third inner lead conductor, the fourth outer lead conductor and the fourth outer lead conductor. A transformer component, characterized in that it is connected to either one of the other inner lead conductors.   The first spiral conductor and the second spiral conductor have the same pattern shape, and the third spiral conductor and the fourth spiral conductor have the same pattern shape. The transformer component according to claim 1. Further comprising fifth and sixth external terminals;
The other of the first outer lead conductor and the first inner lead conductor is connected to the fifth external terminal;
The other of the second outer lead-out conductor and the second inner lead-out conductor is connected to the sixth external terminal;
The other one of the third outer lead conductor and the third inner lead conductor and the other one of the fourth outer lead conductor and the fourth inner lead conductor is the fifth external terminal. Connected to
The other of the third outer lead conductor and the third inner lead conductor and the other of the fourth outer lead conductor and the fourth inner lead conductor is the sixth external terminal. The transformer component according to claim 1, wherein the transformer component is connected to the transformer. The laminated body composed of the first and second magnetic bodies and the first to fourth printed circuit boards includes first and second side surfaces parallel to each other and first and second side surfaces perpendicular to the first and second side surfaces. 3 and 4 side surfaces,
The first and second external terminals are disposed on the first side surface of the laminate,
The third and fourth external terminals are disposed on the second side surface of the laminate,
The fifth external terminal is disposed at a position farther from the second external terminal when viewed from the first external terminal,
4. The transformer component according to claim 3, wherein the sixth external terminal is disposed farther than the fourth external terminal when viewed from the third external terminal. 5.   The fifth external terminal is disposed on the third side surface of the multilayer body, and the sixth external terminal is disposed on the fourth side surface of the multilayer body. 4. The transformer component according to 4.

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