JPH069112U - Trance - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention reduces the number of parts by forming a coil directly on a printed circuit board and makes it thin, and is also suitable for high voltage type and insulation type. The purpose of the present invention is to provide a transformer that can be done. [Structure] Two coils 12, 13 made of a conductive pattern spirally formed on the surface of a printed circuit board, and the printed circuit board so that they face each other in the area of the coils. Mounted cores 14,1
5, the transformer 10 is configured so that the core includes the holding portions 14d and 15a that should be in contact with the upper surface and the lower surface of the printed circuit board, respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a transformer arranged on a printed circuit board.

[0002]

[Prior art]

 Conventionally, when a transformer is arranged on a printed circuit board, the transformer is configured as shown in FIG. 4, for example. That is, in FIG. 4, the transformer 1 is formed in a hollow cylindrical shape having a hollow portion 2a, and is wound between the flange portions 2b and 2c with respect to the coil bobbin 2 having the flange portions 2b and 2c at both ends. By winding the winding in the groove 2d, the primary coil 3 and the secondary coil 4 are formed, and the winding lead terminals of the coils 3 and 4 are moved downward from the lower flange portion 2c of the coil bobbin 2. The coil bobbin 2 is constructed by bending the pin 5 provided so as to extend and inserting and fixing the core 6 in the hollow portion 2a of the coil bobbin 2.

When the transformer 1 configured as described above is mounted on the printed board 7, the pins 5 are inserted into the mounting holes 7 a provided on the printed board 7 and the transformer 1 is soldered or the like. 1 is fixed on the printed circuit board 7 and is electrically connected to a conductive pattern or the like formed on the printed circuit board 7.

[0004]

[Problems to be solved by the device]

 However, in the thus configured transformer 1, the winding is wound around the groove of the coil bobbin 2 to form the primary coil 3 and the secondary coil 4, and the windings of the coils 3 and 4 are further formed. It is necessary to bind the lead terminal to the pin 5.

Therefore, the number of parts is large, the assembling work becomes complicated, and the coil bobbin is mounted on the printed circuit board at the time of mounting on the printed circuit board, so that the mounting dimension becomes relatively high. There was a problem of being lost.

Further, since the primary coil 3 and the secondary coil 4 are wound in the same groove portion, there is a problem that they are not suitable when a high voltage type or an insulation type transformer is configured. It was

In view of the above points, the present invention reduces the number of parts and makes it thin by forming the coil directly on the printed circuit board, and is also suitable for high voltage type and insulation type. The purpose is to provide a transformer, which is adapted to be used.

[0008]

[Means for Solving the Problems]

 According to the present invention, the above object is to provide two coils, each of which has a conductive pattern spirally formed on the surface of the printed circuit board, and to be opposed to each other in the area of the coil from both surfaces of the printed circuit board. , A core attached to the printed circuit board, the core being provided with holding portions to be brought into contact with the upper surface and the lower surface of the printed circuit board, respectively.

[0009]

[Action]

 According to the above configuration, each coil can be configured by forming the conductive pattern on the printed circuit board, so that the coil bobbin is not necessary, so that the number of parts can be reduced and the coil bobbin winding groove can be formed. Since the winding work of the winding wire is eliminated, the component cost and the assembly cost can be significantly reduced.

Further, since each coil is formed in a plane on the printed board, the height of the projection on the printed board is significantly reduced, and the entire coil can be made thin.

Further, by increasing the creepage distance between the coils, a high voltage type or an insulation type coil can be easily constructed.

[0012]

Embodiments The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 shows an embodiment of a transformer according to the present invention.

The transformer 10 has two coils, namely, a primary coil 12 and a secondary coil 13, each of which has a conductive pattern spirally formed on the surface of the printed circuit board 11, in the illustrated case, on the upper surface and the lower surface. In the area of the coils 12 and 13, the cores 14 and 15 are attached to the printed board 11 so as to face each other from above and below the printed board 11.

As shown in FIG. 2, the primary coil 12 has an end portion 12 a on one side (spiral outer side) with respect to two connection lead patterns 17 and 18 extending leftward in the drawing. It is directly and integrally connected to one of the lead patterns 17, and the other end (inner side of the spiral) 12b crosses the spirally formed primary coil 12, and the other end Is connected to the lead pattern 18.

Regarding this intersection, in the case of FIG. 1, the end portion 12b is connected to the lead pattern 18 via the conductive pattern 19 formed on the inner side of the printed circuit board 11 having the multilayer structure, and FIG. In this case, it can be connected to the lead pattern 18 via a jumper 21 that crosses over the insulating layer 20 placed on the primary coil 12.

Similarly to the primary coil 12, the secondary coil 13 is also connected to the lead patterns 22 and 23 formed on the lower surface of the printed board 11, and the lead patterns 22 and 23 are connected through through holes. , Is guided to the upper surface of the printed circuit board 11.

Further, of the cores 14 and 15, the core 14 is, as shown in FIG. 1, a disk-shaped main body 14 a, a central core portion 14 b extending downward from the central portion of the main body 14 a, The main body 14a is composed of an annular core portion 14c extending downward from a peripheral portion of the main body 14a.

In the core 14 thus configured, the central core portion 14b is inserted into the insertion hole 11a and the annular core portion 14c is inserted into the area of the printed circuit board 11 including the coils 12 and 13 from above. The core portion 14b and the annular core portion 14c, which are inserted into the hole 11b and protruded from the lower surface of the printed circuit board 11, can be fixed to the upper surface of the core 15 with an adhesive or the like. As a result, the cores 14 and 15 are attached so as to sandwich the printed circuit board 11 therebetween.

Here, the upper core 14 is provided with a stepped portion 14d that should be in contact with the upper surface of the printed board 11 inside the annular core portion 14c inserted into the insertion hole 11b of the printed board 11. Further, the lower core 15 is provided with a protrusion 15a, which protrudes upward and is abutted on the lower surface of the printed circuit board 11, on the upper surface thereof inside the region facing the annular core portion 14c of the core 14. ing.

As a result, in the cores 14 and 15, the step portion 14d and the protrusion 15a respectively sandwich the print substrate 11 from above and below, and the cores 14 and 15 are stably fixed to the printed circuit board 11 without rattling. Will be retained.

The transformer 10 according to the present invention is constructed as described above, and the transformer 10 is assembled by mounting the cores 14 and 15 on the printed circuit board 11 on which the coils 12 and 13 are formed. Will be completed.

Therefore, the number of parts is small, and the assembling can be performed easily.

Since the coils 12 and 13 are formed on the surface of the printed circuit board 11 in a plane, the heights of the coils 12 and 13 protruding above the printed circuit board 11 with the cores 14 and 15 attached thereto are high. However, it can be remarkably reduced, and the reduction in thickness can be promoted.

In the above-described embodiment, the primary coil 12 and the secondary coil 13 are formed on the upper surface and the lower surface of the printed circuit board 11, respectively, but the invention is not limited to this. Obviously, both of the secondary coils may be formed on the upper surface of the printed circuit board so as to be in a spiral shape close to each other.

[0025]

[Effect of device]

 As described above, according to the present invention, by forming the coil directly on the printed circuit board, the number of parts is reduced and the structure is thin, and it is also suitable for high voltage type and insulation type. A very good transformer could be provided, which could be used.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a transformer according to the present invention.

FIG. 2 is a schematic plan view of the transformer of FIG. 1 with a core removed.

FIG. 3 is a schematic perspective view of the transformer of FIG.

FIG. 4 is a schematic diagram showing an example of a conventional transformer.

[Explanation of symbols]

 10 Transformer 11 Printed Circuit Board 11a, 11b Insertion Hole 12 Primary Coil 13 Secondary Coil 14 Upper Core 14d Step 15 Lower Core 15a Protrusions 17, 18, 22, 23 Lead Pattern 19 Conductive Pattern 20 Insulating Layer 21 Jumper

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board having two coils formed of a conductive pattern spirally formed on the surface of the printed circuit board.
And a core attached to the printed circuit board,
A transformer, characterized in that the core is provided with holding portions to be brought into contact with the upper surface and the lower surface of the printed circuit board, respectively.