JP2009212265A - Transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer which has nonconventional compact structure, in which a member projects little from a printed wiring board, comprises a small number of components and is therefore inexpensive and easy to manufacture. <P>SOLUTION: The transformer provided in the printed wiring board 1 is constituted by providing the printed wiring board 1 which is formed by incorporating a flat plate frame-shaped core 3 with: a primary conductor pattern 61a in a state where a primary-side winding portion 3a of the core is wound with the printed wiring board 1 interposed; and a secondary conductor pattern 61b in a state where a secondary-side wiring portion 3b of the core 3 is wound with the printed wiring board 1 interposed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transformer provided on a printed wiring board, and more particularly to downsizing and cost reduction thereof.

  Conventionally, a transformer such as a power transformer provided on a printed wiring board such as a control board of various electric devices is a separate component from the printed wiring board, and is screwed and soldered to the front surface (or back surface) of the printed wiring board. Attached by etc.

  For example, a power supply (low voltage power supply) for a control board of an inverter power supply device such as an electric vehicle (EV) or a plug-in hybrid vehicle (PHEV) is applied to a printed wiring board 100 that forms the control board as shown in FIG. A conversion transformer 200 is provided, and a high voltage power source of 200V to 300V of the primary winding is stepped down to 12V or 6V by this transformer.

  In the transformer 200, for example, a primary or secondary winding is wound around a core 201 made of a frame-like (b-shaped) magnetic body (silicon steel plate or the like), and the core 201 is wound around the periphery of the core 201. It is formed by covering a magnetic outer case 202. Further, left and right end portions of the outer case 202 bent in an L shape are attached to the printed wiring board 100 by screwing or soldering. Note that reference numeral 203 in FIG. 5 denotes a winding portion of the transformer 200.

  In this case, the transformer 200 is bulky because the core 201 is erected on the printed wiring board 100, and the winding portion 203 places the primary and secondary windings on the core 201 many times. Since it is formed by winding, it is thick and large. In addition, in the production thereof, a complicated and time-consuming work of winding the primary and secondary windings around the core 201 many times is necessary. Therefore, it is expensive.

  Therefore, as shown in FIG. 6, the printed circuit boards (printed wiring boards) 301 and 302 on the primary side, each having a rectangular hole 300 formed at the center thereof, are surrounded by the printed circuit board 303 on the secondary side. A spiral conductive pattern 304 to be a winding is formed, and the primary side and secondary side printed circuit boards 301 to 303 are overlapped via an insulating tape 305, and the polymer is vertically divided by the core 201. It is proposed to form a power transformer corresponding to the transformer 200 by inserting the middle legs 306a and 307a of the split cores 306 and 307 into the holes 300 by sandwiching the split cores 306 and 307 in the horizontal direction, and sandwiching them from both the upper and lower sides. (For example, refer to Patent Document 1).

The power transformer of FIG. 6 described in Patent Document 1 includes a primary conductor and a secondary winding formed of a planar conductor pattern 304 formed in a spiral shape on the printed circuit boards 301 to 303. Therefore, the winding shown in FIG. The winding portion corresponding to the portion 203 is thin, and the trouble of winding the winding is unnecessary. Further, since the primary side and secondary side printed circuit boards 301 to 303 are formed by being sandwiched between the split cores 306 and 307, they are not as bulky as the transformer 200 of FIG. Therefore, it is smaller and cheaper than the transformer 200 of FIG.
Japanese Patent Laid-Open No. 7-115024 (abstract, paragraphs [0010]-[0014], FIG. 1 etc.)

  In the power transformer of FIG. 6, when the polymer of the printed boards 301 to 303 is regarded as one printed wiring board, the divided cores 306 and 307 are laterally oriented but protrude from the upper and lower surfaces of the printed wiring board. There is a problem that it cannot be formed small so that the member does not protrude from the wiring board.

  The split cores 306 and 307 have a complicated structure having middle legs 306a and 307a, and the split legs 306 and 307 insert the middle legs 306a and 307a into the hole 300 and sandwich the polymer. Therefore, it is necessary to align the divided cores 306 and 307 and the printed boards 301 to 303 with high accuracy, and the insulating tape 305 is also necessary. Therefore, the number of parts is large, extremely precise parts processing is required, and further complicated assembly work is required, resulting in a problem that the cost is high and the manufacturing is troublesome.

  The present invention is a transformer provided on a printed wiring board such as the power transformer, and has an unprecedented small structure in which almost no members protrude from the printed wiring board, and has a small number of parts and is inexpensive and easy to manufacture. The purpose is to provide a transformer.

  In order to achieve the above-described object, the transformer of the present invention includes a printed wiring board formed by incorporating a flat frame-like core with a primary winding portion of the core sandwiched between the printed wiring boards. A primary conductor pattern in a wound state and a secondary conductor pattern in a state in which a secondary winding portion of the core is wound with the printed wiring board interposed therebetween are provided ( Claim 1).

  In the transformer of the present invention, a core is built in the printed wiring board, and the primary and secondary windings wound around the core are formed by the primary and secondary conductor patterns of the printed wiring board.

  In this case, the transformer has an unprecedented small structure in which almost no members protrude from the printed wiring board. In addition, the core is a simple flat frame, and assembly work or the like is unnecessary, and high-accuracy alignment of the members is also unnecessary, so that manufacturing is easy. Furthermore, since it is not necessary to superimpose a plurality of substrates and an insulating tape or the like is not necessary, the number of components can be reduced and it can be formed at low cost.

  Therefore, it is possible to provide a transformer that has an unprecedented small structure in which almost no members protrude from the printed wiring board, has a small number of components, and is easy to manufacture.

  Next, in order to describe the present invention in more detail, an embodiment will be described in detail with reference to FIGS.

(One embodiment)
First, the case where it applies to the transformer provided in the printed wiring board (double-sided board | substrate) in which a wiring pattern is formed in both surfaces is demonstrated with reference to FIGS.

  FIG. 1 is a perspective view of the transformer section 2 of the printed wiring board 1. 2 is an enlarged perspective view of the transformer unit 2 with a part of the printed wiring board 1 removed, and FIG. 3 is a cross-sectional view of the transformer unit 2 taken along line AA in FIG.

  The printed wiring board 1 is a control board of an inverter power supply device such as an electric vehicle (EV) or a plug-in hybrid car (PHEV), for example, a glass epoxy double-sided board, but unlike a known double-sided board, The transformer portion 2 is formed with a magnetic body (silicon steel plate or the like) structure and a flat frame-shaped (b-shaped) core 3 built therein. Specifically, in the manufacturing process of the printed wiring board 1, the printed wiring board 1 is formed by pressing the core 3 into the printed wiring board 1 before curing.

  Also, the printed wiring board 1 is formed by arranging a large number of electrode patterns 41a along the one side on the substrate surface side, for example, in the vicinity of the left and right sides of the primary winding part 3a formed by one side of the core 3. Each electrode pattern 42a is also formed at a position on the back side of the substrate opposite to each electrode pattern 41a on the back side of the substrate. The opposing electrode patterns 41a and 42a on the front surface side and the back surface side of the substrate are electrically connected by, for example, through holes (including via holes) 5a.

  Further, the printed wiring board 1 is, for example, in the vicinity of the right and left sides of the secondary side winding part 3b on the other side facing the primary side winding part 3a of the core 3 in the same manner as the right and left side of the primary side winding part 3a. A large number of electrode patterns 41b are arranged along the other side on the substrate surface side, and each electrode pattern 42b is also formed at a position on the back side of the substrate facing each electrode pattern 41b. The opposing electrode patterns 41b and 42b on the substrate front side and the substrate back side are electrically connected by, for example, a through hole (including a via hole) 5b.

  Furthermore, on the substrate surface side of the primary side winding part 3a, each electrode pattern 41a in the vicinity of the left and right sides of the primary side winding part 3a has a plurality of 1 formed so as to cross the primary side winding part 3a. The next conductor pattern 61a connects the left and right ones that are shifted by one. Further, on the back side of the substrate of the primary side winding part 3a, each electrode pattern 42a in the vicinity of the left and right sides of the primary side winding part 3a has a plurality of 1s formed so as to cross the primary side winding part 3a. The next conductor pattern 62a connects the left and right ones at the same position. By doing in this way, each primary conductor pattern 61a, 61b is formed in the printed wiring board 1 in the state which wound the primary side winding part 3a on both sides of the printed wiring board 1. FIG.

  Similarly, on the substrate surface side of the secondary winding part 3b, each electrode pattern 41b in the vicinity of the left and right sides of the secondary winding part 3b has a plurality of pieces formed so as to cross the secondary winding part 3b. The left and right ones that are shifted by one are connected by the secondary conductor pattern 61b. Further, on the back side of the substrate of the secondary winding part 3b, each electrode pattern 42b in the vicinity of the left and right sides of the secondary winding part 3b has a plurality of 2 formed so as to cross the secondary winding part 3b. The next conductor pattern 62b connects the left and right ones at the same position. By doing in this way, each secondary conductor pattern 61b, 62b is formed in the printed wiring board 1 in the state which wound the secondary side winding part 3b on both sides of the printed wiring board 1. FIG.

  In FIG. 1, 71 and 72 are primary connection land portions connected to the primary windings of the conductor patterns 61a and 62a, and 81 and 82 are 2 connected to the secondary windings of the conductor patterns 61b and 62b. This is a connection land portion on the next side. The electrode patterns 41a to 42b, the conductor patterns 61a to 62b, and the connection land portions 71 to 82 are, for example, copper patterns, and are formed together with other electrodes and wiring patterns by the pattern forming process of the printed wiring board 1. .

  Then, the transformer 3 of the control board of the inverter power supply device is connected to the transformer section 2 of the printed wiring board 1 by the core 3 built in the printed wiring board 1 and the conductor patterns 61a to 62b formed on the board surface of the printed wiring board 1. Is formed.

  In this case, since the printed wiring board 1 and the core 3 are integrated and the winding structure is formed by the conductor patterns 61a to 62b of the printed wiring board 1, the transformer of the control board of the inverter power supply device is connected to the printed wiring board. It can be formed into an unprecedented ultra-small structure in which almost no members protrude from 1.

  The core 3 has a simple flat frame shape, is inexpensive, and does not require assembly work. Further, it is not necessary to position the member with high accuracy. Therefore, a transformer can be easily formed. Furthermore, since it is not necessary to superimpose a plurality of substrates and an insulating tape or the like is not required, the number of components is small and the cost is low.

  Therefore, it is possible to provide a transformer that has an unprecedented ultra-compact structure in which almost no members protrude from the printed wiring board 1, has a small number of components, and is easy to manufacture.

  In addition, since the winding structure is formed by the conductor patterns 61a to 62b of the printed wiring board 1, there is an advantage that the magnetoelectric conversion characteristics can be easily and easily set to desired characteristics.

(Other embodiments)
Next, a case where the present invention is applied to a transformer provided on a printed wiring board (single-sided board) having a wiring pattern formed on one side will be described with reference to FIG.

  4 is a cross-sectional view of the transformer portion 21 of the printed wiring board 11 having a single-sided board structure corresponding to FIG. In the figure, the same reference numerals as those in FIGS.

  In the case of the printed wiring board 11, the point that the core 3 is incorporated is the same as that of the printed wiring board 1. The respective conductor patterns 62a and 62b of the primary side winding part 3a and the secondary side winding part 3b of the form are formed by jumper wires 9. The jumper wire 9 is automatically planted by automatic wiring.

  And also in this embodiment, since the printed wiring board 11 and the core 3 are integrated and the winding structure is formed by the conductive patterns 61a and 61b of the printed wiring board 11, the control board of the inverter power supply device The transformer can be formed in an unprecedented ultra-compact structure in which almost no members protrude from the printed wiring board 11, and has the same effect as in the case of the above-described embodiment except that the jumper wire 9 is used.

  The present invention is not limited to the two embodiments described above, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the core 3 is made of a silicon steel plate. Instead, it may be formed of ferrite or a synthetic resin mixed with iron powder or carbon.

  Further, the printed wiring boards 1 and 11 may be any kind, and may be so-called flexible boards.

  Furthermore, the conductor patterns 61a to 62b and the like may be various conductor patterns other than a copper pattern such as an aluminum pattern.

  The present invention can be applied to various transformers provided on printed wiring boards such as various electric devices.

It is a one part perspective view of the printed wiring board of one Embodiment of this invention. FIG. 2 is an enlarged perspective view of a state where a part of the printed wiring board in FIG. 1 is removed. FIG. 2 is a partial cross-sectional view of FIG. 1. It is a partial sectional view of a printed wiring board of other embodiments of the present invention. It is a perspective view of an example of the past. It is a disassembled perspective view of the other conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Printed wiring board 3 Core 3a Primary side winding part 3b Secondary side winding part 61a, 62a Primary conductor pattern 61b, 62b Secondary conductor pattern

Claims (1)

  A primary conductor pattern in which a primary winding portion of the core is wound around the printed wiring board on a printed wiring board formed by incorporating a flat frame-like core, and 2 of the core A transformer formed by providing a secondary conductor pattern in a state in which a secondary winding portion is wound with the printed wiring board interposed therebetween.

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