JPH05135968A - Coil element for transformer, transformer using the same and wiring method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a compact coil element for a transformer with a small leakage flux. [Structure] A four-layer multilayer printed circuit board 12 is used, and coil patterns 14a and 14c forming a coil on the primary side are formed on the first and third layers on the surface of the multilayer printed circuit board 12, and two layers are formed on the second and fourth layers. Coil patterns 14b, 14 forming the coil on the next side
d are formed respectively. Each coil pattern constitutes a ring-shaped 1 turn part of which is opened,
Both ends of the ring-opening portion are extended outward to form a connection terminal portion 15, and a through hole is formed in the terminal portion 15. And 2 provided in the coil pattern on the same side
Each of the connection terminals (four in total) is displaced by one pitch, and the connection terminals at the center thereof are brought into conduction with the inner surface of the through hole 16b by soldering or the like. Further, terminal pins can be inserted and arranged in the other two through holes 16a and 16c.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coil element for a transformer,
The present invention also relates to a transformer using the coil element and a method of connecting the transformer, and more particularly to improvement of a coil element manufactured by forming a coil pattern on a printed circuit board and an applied product thereof.

[0002]

2. Description of the Related Art As a coil element used in a transformer, there is one which is constructed by using a printed board, for example. That is, a coil pattern for one turn is formed on one side or both sides of the printed circuit board, a predetermined number of the printed circuit boards with the coil pattern are laminated and arranged, and predetermined end portions of each coil pattern are appropriately connected by terminal pins. By connecting, a coil element having a series of coils is manufactured. And the end of each coil pattern is
The pair of end portions to be connected are made to coincide with each other in the vertical direction, and the positions of the end portions are sequentially shifted in the lateral direction in order to insulate the other end portions.

[0003]

However, the above-mentioned conventional coil element has the following various problems. That is, first, all of the ends of the coil pattern formed on each printed circuit board were connected via the terminal pins, but the distance between adjacent terminal pins should be at least 5 mm due to the manufacturing technology, the strength of the element, and other reasons. The above must be opened, which is a hindrance to the miniaturization of the element. In particular, as the number of turns increases, the number of required terminal pins also increases, and the above problem becomes remarkable.

Further, since the shape of the coil pattern formed on each printed circuit board constituting the coil element has to shift the position of its end as described above, a large number of printed circuit boards having different pattern shapes are manufactured, They must be assembled and arranged in order, which not only complicates the work but also increases the cost.

Furthermore, since the coil pattern forming the primary side and the coil pattern forming the secondary side are formed on different printed circuit boards, loss due to the leakage magnetic flux occurs.

The present invention has been made in view of the above background, and an object of the present invention is to achieve a small size, an easy assembling work, and a common pattern among elements (printed circuit boards). Accordingly, it is an object of the present invention to provide a coil element for a transformer which can reduce the cost and has a small leakage magnetic flux, a transformer using the coil element, and a connection method suitable for the transformer.

[0007]

In order to achieve the above object, in a transformer coil element according to the present invention, each layer of a multilayer printed circuit board is provided with coil patterns constituting a primary side and a secondary side alternately. The one ends of the coil patterns on the same side are connected to each other through through holes.

A predetermined number of the coil elements are stacked on the transformer base, and terminal pins standing upright on the transformer base are provided at the other ends of the coil patterns provided on the coil elements. A transformer is formed by inserting and arranging the terminals in the holes and connecting the respective terminal pins to the through holes provided at the other end to establish mutual conduction between the coil patterns on the same side between the coil elements. I decided to do it.

Further, by connecting predetermined terminal pins among the primary side and secondary side terminal pins provided in the transformer having the above-mentioned configuration, the coil elements are connected to the input side and the output side respectively. The provided coil patterns may be connected in series or in parallel.

[0010]

Since the coil patterns on the primary side and the secondary side are alternately arranged on each layer of the multilayer printed circuit board, the generation of leakage magnetic flux between the coil patterns is reduced. Also, since the coil patterns are connected to each other through through holes provided on the multilayer printed circuit board, the number of terminal pins used when actually mounting on the circuit is reduced, and the layout of through holes is reduced. The pitch is set short. Further, since the desired coil can be manufactured using the same coil element, it can be easily assembled. Furthermore, the winding ratio is changed by connecting predetermined terminal pins to each other and connecting the coil patterns provided in the coil elements to the input side and the output side in series or in parallel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of the coil element according to the first invention. As shown in the figure, in the coil element 10 according to the present invention, first, predetermined coil patterns 14a to 14d are provided on each layer of the multilayer printed board (four-layer board in this example) 12. That is, for convenience, the surface of the multilayer printed circuit board 12 will be referred to as the first layer, and the second layer, the third layer, and the fourth layer will be sequentially described below.
A coil pattern 14a forming a primary side coil in a layer,
14c, and coil patterns 14b and 14d forming a coil on the secondary side are formed on the second layer and the fourth layer on the back surface side, respectively.

Then, each coil pattern 14a-14d
Both form a ring-shaped one turn in which a part of the ring is opened, and both ends of the ring-opened portion extend outward to form a connection terminal portion 15 (see FIG. 2). In this example, the coil patterns 14a and 14c formed on the first and third layers are used.
And the coil pattern 14 formed on the second and fourth layers
Both b and 14d have the same pattern rotated by 180 degrees. Then, each of the connection terminal portions 15 is formed with a through hole that vertically penetrates the multilayer printed circuit board 12.

The coil patterns 14a, 1 on the primary side are also provided.
4c and the connection terminal portion 15 provided on the secondary side coil patterns 14b and 14d,
They are arranged 180 degrees in the opposite direction. Further, the connection terminal portions 15 of two pieces (four pieces in total) provided on the coil patterns 14a, 14c (14b, 14d) on the same side are displaced by one pitch, and are vertically displaced at the center. They match each other, with one on each side.
The connection terminals 15 at the center are brought into conduction by plating (soldering) or the like on the inner surface of the through hole 16b. Terminal pins, which will be described later, can be inserted and arranged in the two through holes 16a and 16c located on the other sides, so that they can be electrically connected to an external circuit or another coil element.

As a result, both the primary side and the secondary side are 2
A coil element having a coil for each turn is configured, and in the case of a transformer having a turns ratio of 2 turns on each of the primary side and the secondary side, it can be configured by using one of the coil elements 10 according to the present invention. Further, a transformer having a desired winding ratio can be configured by combining a predetermined number of the coil elements 10 having the above configuration, if necessary.

In this example, the coil patterns 14a, 14 exposed on the front and back surfaces of the multilayer printed board 12 are used.
By coating the surface of d with an insulating paint, it is possible to prevent solder or the like from adhering to the coil patterns 14a and 14d. Further, a window hole 18 is formed in the central portion of the multilayer printed circuit board 10 along the inner peripheral edge of each coil pattern 14. In the coil element 10 having such a configuration, since the coil pattern is connected through the through hole 16b in the middle, it is not necessary to insert the terminal pin into the through hole 16b in the middle, and the three through holes 16a to The arrangement pitch of 16c can be shortened.

FIG. 3 is an exploded perspective view showing an embodiment of the transformer 20 according to the second invention which is formed by using the coil element 10 described above. As shown in the figure, in this example,
An example in which four coil elements 10 having the above configuration are used is described. That is, first, four terminal pins 24a to 24d and 26a to 26d are planted respectively on a pair of opposing sides of the transformer base 22 made of ferrite having a substantially rectangular plane. Reference numeral 27 indicates a side surface of the transformer base 22 that projects from the lower end of the side surface and can be surface-mounted.

On the transformer base 22, the above-mentioned 4
The individual coil elements 10 are stacked and arranged. At this time, the front and back surfaces of the respective coil elements 10 are alternately arranged in reverse. As a result, at the end portion on the primary side, the first and second terminal pins 24a and 24b have through holes 16a, which are formed in the coil elements 10 located at the top and the third, respectively.
16c is inserted and arranged, and the third and fourth terminal pins 24c and 24d are inserted and arranged in through holes 16c and 16a formed in the second and fourth coil elements 10, respectively. The terminal pins 24a to 24d and the through holes 16a and 16c are brought into conduction by soldering or the like.

Similarly, at the secondary side end, the terminal pins 26a to 26d are inserted and arranged in the through holes 16a and 16c formed in the secondary side coil pattern and soldered. It is made conductive. Thereby, the coil patterns on the primary side and the secondary side formed on the first and third coil elements 10 respectively have the first and second terminal pins 24a, 24b, 26a,
26b are connected in parallel, and the coil patterns formed on the second and fourth coil elements 10 are also connected in parallel.

Further, in this embodiment, an insulating sheet 28 having a hole 28a is interposed between the adjacent upper and lower coil elements 10 so as to insulate the opposing coil patterns. Further, in a state where each coil element 10 is mounted on the transformer base 22, a pair of ferrite magnetic cores 30 and 30 are mounted from above and below. When the ferrite cores 30 and 30 are mounted, the protrusions 30a and 3 provided on the facing surfaces of the ferrite cores 30 and 30 are arranged.
0a is inserted and arranged in the window hole 18 provided in each coil element 10 and the hole 28a provided in the insulating sheet 28.

In this way, the transformer 20 according to the present invention is
Can be manufactured by using the coil elements 10 having the same shape and configuration in the present example. Moreover, the assembling work is performed by sequentially turning the same coil element 10 upside down and by turning the through holes 16a. It suffices to insert up to 16c into the terminal pins 24 and 26 provided on the transformer base 22, which is extremely simple. Then, the transformer 2 having such a configuration
When using 0, the base end portion 2 of each terminal pin 24, 26
By properly connecting 7 to each other, the transformer 20 having a desired winding ratio is formed and mounted on an actual circuit.

Next, using the transformer 20 having the above structure,
A connection method according to the third invention will be described. First, as shown in FIG. 4A, the first terminal pin 24a on the primary side is provided.
And the third terminal pin 24c are connected to each other, the second terminal pin 24b and the fourth terminal pin 24d are connected to each other, and the first terminal pin 24a side and the fourth terminal pin 24 are connected.
Connect the d side to the input side terminal. Similarly, the first terminal pin 26a and the third terminal pin 26c on the secondary side are connected, and the second terminal pin 26b and the fourth terminal pin 2 are connected.
6d are respectively connected, and the first terminal pin 26a side and the fourth terminal pin 26d side are connected to the output side terminal. By taking such connection, a transformer having a winding ratio of 2: 2 is formed.

Further, as shown in FIG. 2B, the second terminal pin 24b and the third terminal pin 24c on the primary side are connected, and the first terminal pin 24a and the fourth terminal pin 24d are connected. Are connected to the input side terminals respectively. As a result, the coil patterns on the primary side are connected in series. On the other hand, the secondary side is connected in the same manner as shown in FIG.
By taking such connection, a transformer having a winding ratio of 4: 2 is formed.

Further, as shown in FIG. 6C, a transformer having a winding ratio of 2: 4 is formed by connecting the wiring opposite to that shown in FIG. Furthermore, as shown in FIG. 6D, the second terminal pins 24b on the primary side and the secondary side,
26b and the third terminal pins 24c and 26c are connected to each other, and the first terminal pins 24a and 26a and the fourth terminal pins 24d and 26d are connected to the input side and output side terminals, respectively. As a result, the coil patterns are connected in series on both the secondary sides. By taking such connection, a transformer having a winding ratio of 4: 4 is formed. As described above, in this example, it is possible to obtain transformers having different turns ratios by using the same transformer 20 and only changing the wiring method.

In addition, in the above-mentioned embodiment, a coil element formed by using a multilayer printed circuit board having a four-layer structure will be described, and a transformer formed by using the coil element formed of the four-layer printed circuit board and the transformer will be described. Although the method for connecting the transformer has been described, the present invention is not limited to this, and it is of course possible to use a multilayer printed circuit board having four or more layers, and as the number of layers increases, the above effect becomes more remarkable.

[0025]

As described above in detail, in the present invention, the coil patterns formed in the multilayer printed circuit board are connected to each other by using the through holes formed at the predetermined positions of the circuit board. The arrangement pitch of the through holes formed at the ends of each coil pattern can be shortened, and the coil element can be miniaturized. Moreover, since the coil patterns on the primary side and the secondary side are alternately arranged in one coil element, the leakage magnetic flux is reduced and the loss can be suppressed.

Further, in the present invention, the transformer can be constructed by using a predetermined number (including one) of the same coil elements, and as a result, the assembling work is easy and the pattern between the elements can be improved. Cost reduction can be achieved by achieving commonality. Moreover, by appropriately changing the wiring method, different desired turns ratios can be obtained while using the same transformer.

[Brief description of drawings]

FIG. 1 is a perspective view showing a preferred embodiment of a coil element according to the present invention.

FIG. 2 is an exploded perspective view showing a coil pattern that constitutes the coil element shown in FIG.

FIG. 3 is an exploded perspective view showing an embodiment of a transformer according to the present invention manufactured by using the coil element shown in FIG.

FIG. 4 is a diagram showing an example of a wiring method in the transformer shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 coil element 12 multilayer printed circuit board 14a-14d coil pattern 16b through hole (those provided at one end) 16a, 16c through hole (those provided at the other end) 20 transformer 22 transformer base 24a-24d, 26a-26d 1 to 4 terminal pins

Claims (3)

[Claims] 1. A multilayer printed circuit board is provided with coil patterns constituting a primary side and a secondary side alternately on each layer, and one end portions of the coil patterns on the same side are connected through through holes. Coil element for transformer characterized by. 2. A coil pin according to claim 1, wherein a predetermined number of the coil elements are laminated on a transformer base, and terminal pins which are erected on the transformer base are arranged at the other end of the coil pattern provided on each coil element. The coil patterns on the same side between the coil elements are electrically connected to each other by inserting and arranging the terminal pins in the through holes provided in the other part and connecting the terminal pins to the through holes provided in the other end. A transformer that is characterized by 3. A transformer according to claim 2, wherein among the terminal pins on the primary side and the secondary side provided on the transformer, predetermined terminal pins are connected to each other to connect the input side and the output side to each other. A method for connecting a transformer characterized in that the coil patterns provided in each coil element can be connected in series or in parallel.