JP2022057272A - Board coil and transformer - Google Patents

Abstract

To provide a technique for improving the performance of a tactile sensor sheet in which a plurality of tactile sensor chips are arranged on a flexible sheet.SOLUTION: A board coil (10) is formed by electrically connecting and laminating winding patterns (1a to 9a) provided on a plurality of layers (1 to 9) constituting a multilayer board at connection portions (1d to 8d, 2e to 9e) in the winding patterns (1a to 9a), and the connection portions (1d to 8d, 2e to 9e) in the winding patterns (1a to 9a) have an elongated shape extending in the circumferential direction of the winding pattern when viewed from the normal direction of the board coil (10), and are arranged on the outer peripheral portion of the winding patterns (1a to 9a).SELECTED DRAWING: Figure 9

Description

The present invention relates to a substrate coil and a transformer formed by superimposing winding patterns on a substrate.

In recent years, it has been desired to reduce the size and cost of power electronics devices. Therefore, there is an urgent need to develop high-density mounting technology, small magnetic parts, low profile technology, and high-efficiency opening technology for parts mounted on power electronics equipment. As for the small magnetic component low profile technology, the shift from bulk type components formed by winding coils to substrate type components formed by superimposing winding patterns on a substrate is being promoted.

For this board type component, the connection of each layer of PWB (Printed Wired Board) becomes a problem. That is, it is necessary to change the location of the connection point for each layer when viewed from the normal direction of the substrate, which leads to an increase in the number of layers and the size, and further increases the parasitic L and the capacitance C between the layers, so that the outside Inconveniences such as the need for additional resonance L have occurred.

In addition, depending on the connection location of each layer of PWB, the skin effect of the current passing through the pattern of each layer causes non-uniformity of the current density in the connection portion, resulting in current concentration and temperature rise in a specific portion of the connection portion. was there.

Japanese Unexamined Patent Publication No. 2001-077353 Japanese Unexamined Patent Publication No. 2006-190934 Japanese Unexamined Patent Publication No. 2002-324962

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to reduce the size and height of a substrate coil formed by stacking substrates provided with winding patterns. At the same time, it is to provide a technique capable of reducing current concentration on a specific connection portion in each layer and improving reliability.

The present invention for solving the above problems is formed by electrically connecting and laminating winding patterns provided on a plurality of layers constituting a multilayer substrate at a connection portion in the winding pattern. It is a board coil
The connection portion in the winding pattern has an elongated shape extending in the circumferential direction of the winding pattern when viewed from the normal direction of the substrate coil, and is arranged on the outer peripheral portion of the winding pattern. It is a substrate coil as a feature.

According to this, each winding pattern provided on each substrate of the substrate coil can be connected at the connection portion arranged on the outer peripheral portion of the winding pattern. Therefore, it is possible to arrange the connection portion so as not to obstruct the energization in each winding pattern, and it is possible to improve the winding efficiency of the substrate coil. As a result, it is possible to reduce the size and height of the substrate coil. Here, the connecting portion is a part of the winding pattern of each substrate, and refers to a place where a connecting means (described later) for connecting to the upper or lower winding pattern is arranged.

Here, the high-frequency current easily passes through the inner peripheral side of each winding pattern due to its skin effect. Therefore, if the connection portion has a large area in the radial direction of the winding pattern, the current preferentially flows on the inner peripheral side of the connection portion, and an excessive current is generated in a specific portion of the connection portion. Reliability may decrease due to flow and overheating. On the other hand, in the present invention, the connecting portion has an elongated shape extending in the circumferential direction of the winding pattern and is arranged on the outer peripheral portion of the winding pattern. Therefore, it is possible to prevent non-uniformity of the current density from occurring inside the connection portion, and it is possible to improve the reliability of the substrate coil. In the above, all of the connecting portions have an elongated shape extending in the circumferential direction of the winding pattern and are arranged on the outer peripheral portion of the winding pattern, which enhances the effect. However, the present invention may also be used when some of the connecting portions do not have an elongated shape extending in the circumferential direction of the winding pattern, or when some of the connecting portions are not arranged on the outer peripheral portion of the winding pattern. include.

Further, in the present invention, among the winding patterns provided in the plurality of layers, the connecting portion of the two winding patterns that are overlapped and connected to each other is described as described above when viewed from the normal direction of the substrate coil. The connection portions may be arranged at positions overlapping each other on the outer peripheral portion of the winding pattern, and the connection portions may be connected by a connection means extending in the normal direction of the substrate coil.

According to this, it is possible to connect each winding pattern only by connecting each connecting portion by a connecting means extending in the normal direction of the substrate coil, and it is possible to form the substrate coil more easily. It becomes.

Further, in the present invention, the pair of connecting portions of the two winding patterns connected to each other and the pair of connecting portions of the two winding patterns connected next are continuous on the outer periphery of the winding pattern. It may be arranged so as to be lined up. According to this, in each winding pattern, a connecting portion for connecting to the previous winding pattern and a connecting portion for connecting to the next winding pattern are continuously provided on the outer periphery of the winding pattern. It is possible to arrange them so that they are lined up. Therefore, the distance between both ends of the winding in each winding pattern can be reduced, and the gap between both ends can be narrowed. As a result, it is possible to improve the winding efficiency in each winding pattern as much as possible. In this case as well, the effect is enhanced when all the pairs of connecting portions are continuously arranged on the outer circumference of the winding pattern. However, it is also included in the present invention that some pairs of connections do not line up continuously on the outer circumference of the winding pattern.

Further, in the present invention, the connecting portion may be provided at a portion protruding further toward the outer peripheral side from the outer peripheral side of the winding pattern, and the connecting means may be a penetrating through hole penetrating a plurality of layers. This makes it possible to connect the winding patterns without affecting the region for current passage in each winding pattern. Therefore, the winding efficiency can be improved more reliably, and the size and height of the substrate coil can be reduced. Moreover, since the connection portion is connected by a through hole as a connection means, each substrate can be connected by forming a through hole penetrating the multilayer substrate after stacking the substrates of each layer. It is possible to improve the productivity of the substrate coil. In this case as well, the effect is enhanced by providing all the connecting portions in the portions protruding further toward the outer peripheral side from the outer peripheral side of the winding pattern. However, it is also included in the present invention that a pair of some connecting portions is not provided in a portion protruding further toward the outer peripheral side from the outer peripheral side of the winding pattern.

Further, in the present invention, the connecting means is arranged in a row or two in the circumferential direction of the winding pattern on the connecting portion of the two winding patterns connected to each other, and is a method of the winding pattern. It may be a via hole formed between the connecting portions in the linear direction. According to this, it is possible to make the via holes more densely arranged at the connection portion and arrange them efficiently. As a result, the area of the connecting portion can be suppressed, and the winding efficiency of the winding pattern can be improved more reliably.

Further, in the present invention, the connecting means is a conductive portion (conductive plating or the like) applied to the side surface of the connecting portion of the insulating layer formed between the two winding patterns connected to each other. It may be. According to this, the area of the connection portion as seen from the normal direction of the winding pattern can be reduced as much as possible, the winding efficiency is improved, and the size of the substrate coil is reduced and the height is reduced. It is possible. Further, it is possible to reduce the manufacturing cost, reduce the parasitic L and the parasitic C in the substrate coil, prevent the malfunction of the device in which the substrate coil is incorporated, and reduce the noise. In addition to plating, the conductive portion may be configured by attaching a conductive film formed by sputtering or the like or a metal foil.

Further, in the present invention, the magnetic core is provided so as to cover a part of the winding pattern when viewed from the normal direction of the substrate coil, and the connection portion is provided from the normal direction of the substrate coil. As you can see, it may be arranged in a portion not covered by the magnetic core. Here, the magnetic core streamlines the flow of the magnetic field generated by the winding of the coil and increases the magnetic field. On the other hand, the magnetic field generated by passing between the connecting portions has a different direction from the magnetic field generated by the winding of the coil, and may cause the magnetic field generated by the winding of the coil to be disturbed. On the other hand, in the present invention, since the connecting portion is arranged in the portion where the magnetic core is not provided in a plan view, the magnetic field passing between the connecting portions disturbs the flow of the magnetic field by the magnetic core. Can be suppressed. As a result, it is possible to more reliably improve and increase the efficiency of the flow of the magnetic field generated by the winding of the substrate coil.

Further, in the present invention, two magnetic circuits are arranged so as to cover a part of the winding pattern in a point-symmetrical manner with respect to the center of the winding pattern when viewed from the normal direction of the substrate coil. A magnetic core made of the same may be provided, and the connection portion may be arranged symmetrically with respect to a portion covered by the two magnetic circuits when viewed from the normal direction of the substrate coil. According to this, even if the current flowing between the connecting portions disturbs the flow of the magnetic field due to the magnetic core described above, the flow of the magnetic field due to the magnetic core is caused symmetrically with respect to the winding pattern. It is possible to suppress the biased influence on. As a result, it is possible to stabilize the distribution of the magnetic field generated by the substrate coil.

Further, the present invention is a transformer that is arranged so as to overlap a plurality of coils, has a magnetic core, inputs a current to one coil, and outputs an induced current flowing through another coil.
The magnetic core has a portion arranged so as to penetrate the center of the plurality of coils.
At least a part of the plurality of coils may be a transformer (including a transformer and an isolation transformer), which is characterized by being the substrate coil described above. In this case, the transformer can be made smaller and shorter, and the device to which the transformer is mounted can be made smaller.

In that case, the magnetic core may have a path core structure in which the core is arranged between the coils in the plurality of coils. Further, the magnetic core may be a rod core composed of a rod-shaped core penetrating the center of the plurality of coils.

Each of the above configurations and processes can be combined with each other to construct the present invention as long as there is no technical contradiction.

According to the present invention, in a substrate coil formed by stacking substrates provided with winding patterns, it is possible to reduce the size and height of the coil and reduce the current concentration on the connection portion of each specific layer. However, it is possible to improve the reliability. By making a board coil, it becomes possible to directly incorporate a coil, an inductance, a transformer, etc. into an electronic circuit board. As a result, it is possible to reduce the size of electronic devices, reduce the number of component mounting points, and reduce production costs.

It is a top view of the substrate coil which concerns on Example 1 of this invention. It is sectional drawing in the case of constructing a transformer using two coils including a substrate coil in the Example of this invention. It is a schematic diagram which shows the connection state of the winding pattern from the 1st substrate to the 9th substrate. It is a top view for demonstrating the state of connection when the winding pattern of each substrate from a 1st substrate to 9th substrate is connected by a conventional method. It is a schematic diagram which shows the flow of the current when the high frequency current is applied to the substrate coil. It is a schematic diagram for demonstrating the connection part in the winding pattern of each substrate in Example 1 of this invention, and the state of connection by a via hole. It is a schematic diagram for demonstrating the connection part in the winding pattern of each substrate, and the state of the current flow in Example 1 of this invention. It is a perspective view when the magnetic core is combined with the substrate coil in Example 1 of this invention. It is a top view when the winding pattern in each substrate in Example 1 of this invention, and the winding of a substrate coil are combined with a magnetic core. It is a perspective view which shows the winding and the connection part in Example 2 of this invention. It is a top view when the winding pattern in each substrate in Example 2 of this invention, and the winding of a substrate coil are combined with a magnetic core. It is a figure for demonstrating the 1st aspect of the manufacturing method of the substrate coil in Example 2 of this invention. It is a figure for demonstrating the 2nd aspect of the manufacturing method of the substrate coil in Example 2 of this invention. It is a figure for demonstrating the 3rd aspect of the manufacturing method of the substrate coil in Example 2 of this invention. It is a top view of the substrate coil which concerns on Example 3 of this invention. It is sectional drawing of the transformer which concerns on Example 4 of this invention.

[Application example]
The outline of the application example of the present invention will be described below with reference to some drawings. The substrate coil 10 to which the present invention is applied is exemplified in FIG. The substrate coil 10 is formed by, for example, stacking nine layers of substrates 1 to 9 on which a winding pattern is provided, and winding patterns (1a to 9a) of two substrates that are continuously overlapped with each other. For example, a coil is formed by being electrically connected by a via hole (VIA). As shown in FIG. 1, for example, on the first substrate 1, the first winding pattern 1a, which is an arcuate conductor pattern corresponding to the first layer of the substrate coil, is formed.
Is provided.

Here, as in the prior art shown in FIG. 4, in the winding patterns 101a to 109a of the substrates 101 to 109, the connection points 101d to 108d are on the winding patterns 101a to 109a from the inner peripheral side to the outer peripheral side. When formed so as to be widely distributed in the coil, the area of the winding pattern used as the coil is reduced, so that the winding efficiency is lowered.

Further, when a high frequency current is applied to the substrate coil 110, each winding pattern 101a
Since the current density on the inner peripheral side of ~ 109a becomes higher, the current density of the VIA on the inner peripheral side among the plurality of VIAs becomes higher at the conventional connection points 101d to 108d, and heat generation increases in some VIAs. However, inconveniences such as a decrease in reliability may occur.

On the other hand, in this application example, as shown in FIG. 6, the connection points in the winding pattern of each substrate are arranged on the outer peripheral side of each winding pattern, and the VIA is arranged in a row or in the circumferential direction at the connection points. It was decided to configure them in parallel in two rows. This increases the area that can be used as a coil in each winding pattern, and it is possible to improve the winding efficiency. The connection points in the present application example and the following examples correspond to the connection portions of the present invention.

Further, as shown in FIG. 7, even if the high-frequency current flows unevenly toward the inner peripheral side of the winding pattern due to the skin effect, it once flows on the outer peripheral side at the connection points 2d and 3e, and the next third substrate 3 In the third winding pattern 3a, it is possible to trace the trajectory of returning from the outer peripheral side to the inner peripheral side. As a result, it is possible to suppress the concentration of the current density in a specific VIA, and it is possible to improve the reliability.

<Example 1>
Hereinafter, embodiments for carrying out the present invention will be described in detail by way of example with reference to each drawing (including the drawing once described in the above application example). However, the specific configuration described in this embodiment is not intended to limit the scope of the present invention to the configuration unless otherwise specified.

FIG. 1 shows a plan view of the substrate coil 10 according to the embodiment of the present invention. The substrate coil 10 according to the present embodiment is, for example, a winding pattern (1a) of two substrates in which 9 layers of substrates 1 to 9 having a winding pattern are provided are stacked and continuously overlapped. ~ 9a) By electrically connecting the two to each other, a substrate coil corresponding to a total number of turns of 8 turns is formed. FIG. 1 shows a state in which the first substrate 1 arranged at the uppermost portion can be visually recognized.

The first substrate 1 is provided with a first winding pattern 1a, which is an arcuate conductor pattern corresponding to the first layer of the substrate coil. Then, the input end 1b connected to the first winding pattern 1a, the ninth winding pattern 9a in the ninth board 9 (not shown) and the output end connected to the second board 2 through the eighth board 8. It has 1c. It also has openings 1f, 1g, and 1h for inserting a magnetic core (described later). This winding pattern and the opening for inserting the magnetic core are commonly provided in the second substrate 2 to the ninth substrate 9 (2a to 9a, 2f to 9f, 2g to 9g, 2h to). 9h).

FIG. 2 is a cross-sectional view when a transformer 50, which is a transformer, is configured by using a substrate coil 10 and a second substrate coil 40 having a different total number of turns. The transformer 50 is configured by magnetically coupling a 9-layer (8-turn) substrate coil 10 shown in FIG. 1 and a second substrate coil 40 having a different number of layers and turns by a magnetic core 60. To. Then, a current is input to the substrate coil 10 as one substrate coil, and an induced current flowing through the second substrate coil 40, which is another substrate coil, is output and transformed. By configuring the transformer 50 by using the plurality of substrate coils 10 and 40 in this way, it is possible to realize the miniaturization and the height reduction of the transformer 50. Similarly, the inductor element can be configured by combining the substrate coil 10 and the magnetic core 60.

The winding pattern provided on each substrate of the substrate coil may be a single winding (single turn) or a large number of windings (multi-turn) as in the first winding pattern 1a of FIG. By winding the winding pattern once, the number of substrates increases in order to increase the total number of windings, but there is an advantage that the pattern can be thickened and a large current can be energized. When a large number of windings (multi-turn) is adopted, connection points are provided at the outer peripheral side end portion and the inner peripheral side end portion of each winding pattern. Further, the number of turns of the substrate coil 10 and the number of turns of the second substrate coil 40 may be the same or different. Further, instead of the substrate coil 10 or the second substrate coil 40, a normal winding coil may be used.

FIG. 3 shows a schematic diagram of the connection state of the first winding pattern 1a to the ninth winding pattern 9a from the first substrate 1 to the ninth substrate 9. As shown in the figure, in each board, since the connection point connecting to the upper board and the connection point connecting to the lower board are separated, one winding pattern forms one turn. This is not possible, and by stacking nine boards from the first board 1 to the ninth board 9, an eight-turn coil is configured.

FIG. 4 is a plan view for explaining a state of connection when the winding patterns 1a to 9a of each substrate from the first substrate 1 to the ninth substrate 9 are connected by a conventional method. Here, the winding patterns of the respective substrates are connected to each other by a plurality of holes for interlayer conduction (via (VIA) holes, hereinafter simply referred to as VIA). Actually, in the plan view of the substrate coil 110, only the VIA at the connection point 101d connecting the first winding pattern 101a and the second winding pattern 102a can be visually recognized, and the second winding pattern 102a and the third winding pattern 102a can be visually recognized. The VIA at the connection point 102d connecting the pattern 103a to the connection point 108d connecting the eighth winding pattern 108a and the ninth winding pattern 109a is originally invisible, but in the figure, the positional relationship with each other is shown. Therefore, it is described in the same manner as the VIA at the connection point 101d.

As can be seen from FIG. 4, as described above, in the winding patterns 101a to 109a of the boards 101 to 109, the connection points for connecting to the upper board and the connections to connect to the lower board are connected. Winding efficiency was reduced due to the distance between the locations. Further, since the connection points 101d to 108d are formed so as to be widely distributed from the inner peripheral side to the outer peripheral side on each winding pattern 101a to 109a or in the circumferential direction, the winding efficiency is also achieved by this. Was even lower.

Further, it is known that when a high-frequency current is applied to the substrate coil 110, the current density on the inner peripheral side of each winding pattern 101a to 109a increases due to the skin effect of the high-frequency current as shown in FIG. .. (The arrow indicating the current indicates one of the positive and negative directions of the alternating current.) Then, at each connection point 101d to 108d, the current density of the VIA on the inner peripheral side of the plurality of VIAs becomes high. As a result, heat generation may increase in some VIAs, resulting in inconveniences such as a decrease in reliability. In addition, there are also inconveniences such as an increase in variation in the magnetic field in each connection point due to the current passing through each connection point 101d to 108d.

On the other hand, in this embodiment, as shown in FIG. 6, the connection points in the winding pattern of each substrate are arranged on the outer peripheral side of each winding pattern, and the VIA is arranged in one or two rows in the circumferential direction. We decided to configure them in parallel. This corresponds to forming the connecting portion into an elongated shape extending in the circumferential direction of the winding pattern. Further, here, VIA corresponds to a connecting means extending in the normal direction of the substrate coil. Further, in the winding pattern of each substrate, the connection points with the winding pattern of the lower substrate and the connection points with the upper substrate are arranged so as to be lined up on the outer periphery of the winding pattern. More specifically, in FIG. 6, in the second winding pattern 2a on the second substrate 2, the connection portion 2d for connecting to the connection portion 3e of the third winding pattern 3a on the third substrate 3 and the first substrate. The first winding pattern (not shown) in 1 and the connection portion 2e for connecting are continuously arranged on the outer periphery of the second winding pattern 2a with a gap 2i between both ends of the winding pattern 2a. Arranged like this. Here, the connection point 3e and the connection point 2d correspond to a pair of connection portions of the two winding patterns.

According to this, as shown in FIG. 7, for example, the high-frequency current flowing through the second winding pattern 2a of the second substrate 2 was biased toward the inner peripheral side of the winding pattern due to the skin effect (indicating the current). The arrow indicates one of the positive and negative directions of the alternating current.) However, the current flows once on the outer peripheral side at the connection points 2d and 3e, and then flows from the outer peripheral side to the inner side in the third winding pattern 3a of the next three substrates 3. Since the trajectory of returning to the circumferential side is followed, it is possible to suppress the concentration of the current density on a specific VIA at the connection points 2d and 3e.

FIG. 8 shows an example of a perspective view when the magnetic core 60 is combined with the substrate coil 10 in this embodiment. In this figure, for the sake of simplicity, only the windings 10a formed by the winding patterns 1a to 9a of the substrates 1 to 9 are shown. As described above, the magnetic core 60 has a point-symmetrical shape with respect to the center of the winding 10a in a plan view, and has a shape extending in a fan shape from the center of the winding 10a toward the outer peripheral side. However, it is arranged so as to cover the winding wire 10a.

FIG. 9 shows a plan view of each winding pattern 1a to 9a in each of the boards 1 to 9 in this embodiment, and a plan view when the magnetic core 60 is combined with the board coil 10. FIG. 9A is a pattern diagram of each winding pattern 1a to 9a in the first substrate 1 to the ninth substrate 9. FIG. 9B is a plan view when the magnetic core 60 is combined with the substrate coil 10. In FIG. 9B, only the cross sections of the center core 60a, the first side core 60b, and the second side core 60c are shown for the magnetic core 60 so that the arrangement of each connection portion can be easily understood.

In this embodiment, the winding 10a in the substrate coil 10 is formed by superimposing the winding pattern 9a from the winding pattern 1a in the first substrate 1 to the ninth substrate 9 shown in FIG. 9A. Each of the winding patterns 1a to 9a is a pattern in which a gap is provided in a substantially circular shape, and the winding patterns 1a to 9a are in a form of gradually rotating counterclockwise in order.

The connection point 1d on the counterclockwise side across the gap between both ends in the winding pattern 1a and the connection point 2e on the clockwise side across the gap between both ends in the winding pattern 2a are connected by VIA. Similarly, in the winding pattern 2a, the connection point 2d on the counterclockwise side across the gap between both ends, the connection point 3e on the clockwise side across the gap between both ends in the winding pattern 3a, ... In the winding pattern 8a. The connection point 8d on the counterclockwise side with a gap at both ends and the connection point 9e on the clockwise side with a gap at both ends in the winding pattern 9a are connected by VIA.

Then, as shown in FIG. 9B, the connection point 1d (2e), the connection point 2d (3e), and the connection point 2d (3e).
The connection points 3d (4e) and the connection points 4d (5e) are arranged in the gap between the first side core 60b of the magnetic core 60 and the center core 60a. Similarly, the connection points 5d (6e), the connection points 6d (7e), the connection points 7d (8e), and the connection points 8d (9e) are within the gap between the second side core 60c of the magnetic core 60 and the center core 60a. Is located in. In this way, the connection points in the winding patterns 1a to 9a of the substrates 1 to 9 are arranged symmetrically between the center core 60a of the magnetic core 60, the first side core 60b, and the second side core 60c, respectively. The disturbance of the magnetic field due to VIA at the connection point can be made uniform in the magnetic circuits on both side core sides, and the function as an inductor element or a transformer can be stabilized. Similarly, although not shown, the connection points of the winding patterns 1a to 9a of each substrate may be arranged in a place not covered by the magnetic core 60. This makes it possible to prevent the magnetic disturbance caused by the current flowing through the through holes at each connection point from affecting the magnetic field passing through the magnetic core 60. As a result, it is possible to stabilize the function as an inductor or a transformer.

<Example 2>
Next, Example 2 of the present invention will be described. In the first embodiment, among the winding patterns 1a to 9a of the first substrate 1 to the ninth substrate 9, the winding patterns that are continuously overlapped are arranged on the outer peripheral portion of each winding pattern 1a to 9a. An example of connecting using VIA at the connection points has been described, but in this embodiment, windings that are continuously overlapped by through-holes at the connection points protruding from the winding patterns 1a to 9a to the outer peripheral side have been described. An example of connecting line patterns to each other will be described.

FIG. 10 shows a perspective view of the winding wire 20a of the substrate coil in this embodiment. Also in this embodiment, the point that the winding 20a is formed by connecting the connection points of the winding patterns 11a to 19a on each substrate is the same as in the first embodiment. However, as shown in the first embodiment, when the connection points of the winding patterns 1a to 9a are connected by VIA, the winding patterns that are continuously overlapped by VIA each time the substrates 1 to 9 are overlapped. It was necessary to connect them together, which sometimes complicated the manufacturing process.

On the other hand, in this embodiment, the connection points of the winding patterns 11a to 19a are arranged so as to project toward the outer peripheral side of the winding patterns 11a to 19a. Then, the connection points in the winding patterns that are continuously overlapped are arranged at overlapping positions in a plan view. Then, it was decided to connect each connection point with a through hole penetrating the entire substrate coil. According to this, after stacking the first substrate to the ninth substrate, by forming a through hole at each connection point, it is possible to connect the winding patterns that continuously overlap each other. , It is possible to simplify the manufacturing process.

FIG. 11 shows a plan view of the winding patterns 11a to 19a on each substrate in this embodiment and a plan view when the magnetic core 60 is combined with the winding 20a of the substrate coil. FIG. 11A is a pattern diagram of each winding pattern 11a to 19a in the first substrate to the ninth substrate. FIG. 11B is a plan view when the magnetic core 60 is combined with the winding wire 20a of the substrate coil. In FIG. 11B, only the cross sections of the center core 60a, the first side core 60b, and the second side core 60c are shown for the magnetic core 60 so that the arrangement of each connection portion can be easily understood.

In this embodiment, as shown in FIG. 11A, the windings 20a in the substrate coil are formed by overlapping the winding patterns 11a to 19a in the first substrate to the ninth substrate. Each of the winding patterns 11a to 19a constituting the winding 20a is a pattern in which a gap is provided in a substantially circular shape, and the winding patterns 11a to 19a gradually rotate counterclockwise in order. It is in the form.

The connection points 11e, 11d to 19d, and 19e in the winding patterns 11a to 19a in this embodiment are arranged so as to further project from the outer periphery of the arc of the winding patterns 11a to 19a toward the outer peripheral side. Then, the connection points 11d on the counterclockwise side across the gaps at both ends of the winding pattern 11a and the connection points 12e on the clockwise side across the gaps at both ends of the winding pattern 12a are arranged so as to overlap each other in a plan view. It is connected by a through hole.

Similarly, in the winding pattern 12a, the connection point 12d on the counterclockwise side across the gap between both ends, the connection point 13e on the clockwise side across the gap between both ends in the winding pattern 13a, ... In the winding pattern 18a. The connection points 18d on the left counterclockwise side across the gaps at both ends and the connection points 19e on the clockwise side across the gaps at both ends in the winding pattern 19a are arranged so as to overlap and are connected by a through hole. There is.

Then, as shown in FIG. 11B, the connection points 11d (12e), the connection points 12d (13e), the connection points 13d (14e), and the connection points 14d (15e) are the first side core 60b of the magnetic core 60. , Arranged in the gap between the center cores 60a. Similarly, the connection points 15d (16e), the connection points 16d (17e), the connection points 17d (18e), and the connection points 18d (19e) are within the gap between the second side core 60c of the magnetic core 60 and the center core 60a. Is located in.

Also here, by arranging the connection points of the winding patterns 11a to 19a of each substrate symmetrically between the center core 60a of the magnetic core 60 and the side cores 60b and 60c, through holes at each connection point can be provided. The magnetic disturbance due to the flowing current can be made uniform in the magnetic circuits on both side cores 60b and 60c, and the function as an inductor or a transformer can be stabilized. Similarly, although not shown, the connection points of the winding patterns 11a to 19a of each substrate may be arranged in a place not covered by the magnetic core 60. This makes it possible to prevent the magnetic disturbance caused by the current flowing through the through holes at each connection point from affecting the magnetic field passing through the magnetic core 60. As a result, it is possible to stabilize the function as an inductor or a transformer.

Next, an aspect of the procedure for manufacturing the substrate coil of this embodiment will be described first with reference to FIG. As shown in FIG. 12A, in this embodiment, the fourth substrate 14 and the fifth substrate 15 are formed of a common double-sided substrate, and winding patterns 14a and 15a are formed on both surfaces thereof. Then, as shown in FIGS. 12 (b) to 12 (e), on the winding pattern 14a side, the third substrate 13 on which the winding pattern 13a is formed to the first substrate 11 on which the winding pattern 11a is formed are formed. Can be stacked. On the other hand, on the winding pattern 15a side, the sixth substrate 16 on which the winding pattern 16a is formed to the ninth substrate 19 on which the winding pattern 19a is formed are overlapped. Then, as shown in 12 (f), a through hole is finally formed, and each connection point is connected.

Next, another aspect of the procedure for manufacturing the substrate coil will be described with reference to FIG. In this example, as shown in FIG. 13A, the fourth substrate 14 and the fifth substrate 15 are formed of a common double-sided substrate, and winding patterns 14a and 15a are formed on both sides thereof. At this point, an embedded through hole is formed in the double-sided substrate, and the winding patterns 14a and 15a are connected to each other.

Next, as shown in FIGS. 13 (b) to 13 (e), the third substrate 13 to the first substrate 11 are superposed on the winding pattern 14a side, and the sixth substrate 16 is placed on the winding pattern 15a side. -The ninth substrate 19 is overlapped. Then, as shown in 13 (f), a through-hole is finally formed, and the remaining connection points are connected. In this example, the connection points 14d (15e) between the winding patterns 14a and 15a are connected by embedded through holes, and therefore, as shown in FIG. 11, the outer periphery from the winding patterns 14a and 15a is not necessarily the same. There is no need to project to the side. The connection portion 14d (15e) may be provided inside the arc portion of the winding patterns 14a and 15a.

Further, in that case, the form of the embedded through hole at the connection point does not need to be a form in which four through holes are arranged in the circumferential direction unlike other connection points, for example, one relatively. It may be formed by a through hole having a large cross section.

Further, with reference to FIG. 14, a third aspect of the procedure for manufacturing the substrate coil will be described. Figure 1
Reference numeral 4 is a substrate coil 20 produced in this embodiment. FIG. 14A is a schematic view showing a connection state of the substrate coil 20. FIG. 14B is a cross-sectional view of the substrate coil 20. In this embodiment, an embedded through hole and a through hole are used in combination.

As shown in FIG. 14A, the first winding pattern 11a and the second winding pattern 12a, the third winding pattern 13a and the fourth winding pattern 14a, the fifth winding pattern 15a and the sixth winding pattern The 16a and the 7th winding pattern 17a and the 8th winding pattern 18a are formed on the upper and lower surfaces of the core substrate, which is a double-sided substrate, and are connected by embedded through holes to form a pair. A pair of these four winding patterns are further connected by through-holes and laminated to form a substrate coil 20.

As shown in FIG. 14B, the embedded thru holes in the four core boards include connection points 11d and connection points 12e, connection points 13d and connection points 14e, connection points 15d and connection points 16e, and connection points 17d. The connection point 18e is connected. These four embedded thru holes are provided inside the arcuate portions of the winding patterns 11a to 18a in the top view. Further, they may be provided at the same position in the top view.

Further, the connection point 12d and the connection point 13e, the connection point 14d and the connection point 15e, the connection point 16d and the connection point 17e, and the connection point 18d and the connection point 19e are connected by the through hole. These four through holes connect each connecting portion at a portion protruding further toward the outer peripheral side from the outer periphery of the arcuate portion in each winding pattern 11a to 18a.

In FIG. 14A, the connection points are shown by black dots, the embedded through holes and through-holes that connect the connection points are shown by solid lines, and the through-through holes that do not connect the connection points are shown by dotted lines. In FIG. 14B, the embedded thruhole is shown in black. Further, the through-holes are hatched with diagonal lines, and the range in which the winding patterns are connected is shown in black. The number of winding patterns is not limited to nine, and the number of core substrates is not limited to four.

<Example 3>
Next, Example 3 of the present invention will be described. In this embodiment, the connection points of the winding patterns are arranged so as to project from the arc of the winding pattern on each substrate to the outer peripheral side, and the connection points of the winding patterns that are continuously overlapped are viewed in a plan view. An example of being connected by being arranged so as to overlap with each other and being plated on the side surface of the layer sandwiched between the connection points will be described.

FIG. 15 shows a plan view of the substrate coil 30 in this embodiment. Also in this embodiment, the point that the winding is formed by connecting the connection points of the winding patterns 21a to 29a in the first substrate 21 to the ninth substrate 29 is the same as in the first and second embodiments. However, as shown in Examples 1 and 2, when the connection points of the winding patterns are connected by VIA or through holes, the structure of the connection points may become complicated.

On the other hand, in the present embodiment, at the connection points of the winding patterns 21a to 29a, the side surface of the insulating layer (board) between the connection points of the continuously overlapping winding patterns is plated. , I decided to connect each connection point. According to this, the area of the connection portion as seen from the normal direction of the winding patterns 21a to 29a can be made as small as possible, the winding efficiency is improved, the substrate coil 30 is downsized, and the height is low. It is possible to realize the conversion.

Further, it is possible to reduce the manufacturing cost, reduce the parasitic L and the parasitic C in the substrate coil 30, prevent the malfunction of the device in which the substrate coil 30 is incorporated, and reduce the noise. Further, as in Examples 1 and 2, when a high-frequency current is passed, it is possible to suppress a decrease in reliability due to overheating of the measurement portion of the connection portion. In this case, the connection portion of each winding pattern may be projected to the outer peripheral side as in the connection portion 21d of the first winding pattern 21a shown in FIG. Alternatively, the connection portion may not be projected to the outer peripheral side, and the side surface of the arc of the winding pattern may be plated as it is. The plating applied to the side surface of the substrate in this embodiment corresponds to the conductive portion.

<Example 4>
Next, Example 4 of the present invention will be described. In the above embodiment, the transformer provided with the substrate coil in which only a part of the winding pattern is covered by the magnetic core has been described. However, in this embodiment, the substrate coil in which the winding pattern is not covered by the magnetic core has been described. A transformer equipped with the above and a transformer to which a path core structure is applied between two types of coils will be described.

FIG. 16 is a cross-sectional view of the transformer in this embodiment. FIG. 16A is a cross-sectional view of a transformer 51 including a substrate coil 10 in which the winding pattern is not covered by a magnetic core and a second substrate coil 40. The magnetic core 61 is a bar core located near the center of the winding pattern so as to be surrounded by the winding pattern of each substrate. In the configuration of FIG. 16A, the connection portion (not shown) on the winding pattern is not covered by the magnetic core 61. Therefore, it avoids the disadvantage that the magnetic field generated from the current flowing on the winding pattern is disturbed and the amount of the magnetic field passing between the side cores (not shown) becomes non-uniform, and increases the degree of freedom in arranging the connection points. It is possible.

FIG. 16B is a cross-sectional view of a transformer 52 in which a path core structure is applied between a substrate coil 10 having a magnetic core 62 and a second substrate coil 40. In order to improve the operating efficiency of the transformer, the resonance L is externally attached, and if the transformer and the resonance L are arranged side by side, the mounting area increases, and if they are stacked vertically, a shield is required, which has the disadvantage of increasing the height. .. Therefore, in any of the above cases, it is difficult to reduce the size and height of the transformer. In the configuration of FIG. 16B, the magnetic core 62a is also inserted between the substrate coil 10 and the second substrate coil 40, and the path core structure is applied to reduce the size and height of the transformer 52. , It is possible to induce resonance of the substrate coil 10 and the second substrate coil 40.

Further, the number of turns of the substrate coil 10 and the number of turns of the second substrate coil 40 may be the same or different, and instead of the second substrate coil 40, a normal winding coil is used. The point that it may be used is the same as that of the transformer 50 of the first embodiment.

In addition, in order to make it possible to compare the constituent elements of the present invention with the configurations of the examples, the constituent elements of the present invention are described below with reference numerals in the drawings.
<Invention 1>
The winding patterns (1a to 9a) provided on the plurality of layers (1 to 9) constituting the multilayer board are electrically connected at the connection portions (1d to 8d, 2e to 9e) in the winding patterns (1a to 9a). It is a substrate coil (10) formed by being connected to and laminated with each other.
The connection portions (1d to 8d, 2e to 9e) in the winding pattern (1a to 9a) have an elongated shape extending in the circumferential direction of the winding pattern when viewed from the normal direction of the substrate coil (10). The substrate coil (10) is characterized by having the above and being arranged on the outer peripheral portion of the winding pattern (1a to 9a).

1-9, 11-19, 21-29 ... 1st substrate-9th substrate 1a-9a, 11a-19a, 21a-29a ... 1st winding pattern-9th winding pattern 1b, 11b ... Input ends 1c, 11c ... Output ends 1d to 8d, 11d to 18d ... Connection points 2e to 9e, 12e to 19e ... Connection points 10, 20, 30 ... Board coil 60 ... Magnetic core

Claims (11)

A substrate coil formed by electrically connecting and laminating winding patterns provided on a plurality of layers constituting a multilayer substrate at a connection portion in the winding pattern.
The connection portion in the winding pattern has an elongated shape extending in the circumferential direction of the winding pattern when viewed from the normal direction of the substrate coil, and is arranged on the outer peripheral portion of the winding pattern. The feature is the board coil. Of the winding patterns provided in the plurality of layers, the connecting portion of the two winding patterns that are overlapped and connected to each other is the outer peripheral portion of the winding pattern when viewed from the normal direction of the substrate coil. The substrate coil according to claim 1, wherein the connection portions are arranged at positions overlapping each other and are connected to each other by a connecting means extending in the normal direction of the substrate coil. The pair of connecting portions of the two winding patterns connected to each other and the pair of connecting portions of the two winding patterns connected next are arranged so as to be continuously arranged on the outer periphery of the winding pattern. 2. The substrate coil according to claim 2. The connecting portion is provided at a portion protruding further toward the outer peripheral side from the outer peripheral side of the winding pattern.
The substrate coil according to claim 2 or 3, wherein the connecting means is a through-hole that penetrates a plurality of layers. The connecting means are arranged in a row or two in a row in the circumferential direction of the winding pattern on the connecting portion of the two winding patterns connected to each other, and the connecting portion of the connecting portion is arranged in the normal direction of the winding pattern. The substrate coil according to claim 2 or 3, wherein the via holes are formed between them. 2. The substrate coil described. It comprises a magnetic core arranged so as to cover a part of the winding pattern when viewed from the normal direction of the substrate coil.
The substrate coil according to any one of claims 1 to 6, wherein the connection portion is arranged in a portion not covered with the magnetic core when viewed from the normal direction of the substrate coil. .. A magnetic core composed of two magnetic circuits arranged so as to cover a part of the winding pattern in a point-symmetrical manner with respect to the center of the winding pattern when viewed from the normal direction of the substrate coil is provided.
One of claims 1 to 6, wherein the connecting portion is arranged symmetrically with respect to a portion covered by the two magnetic circuits when viewed from the normal direction of the substrate coil. The substrate coil described in the section. It is a transformer that is arranged so that multiple coils are stacked, has a magnetic core, inputs current to one coil, and outputs induced current flowing to the other coil.
The magnetic core has a portion arranged so as to penetrate the center of the plurality of coils.
The transformer according to any one of claims 1 to 8, wherein at least a part of the plurality of coils is the substrate coil. The transformer according to claim 9, wherein the magnetic core has a path core structure in which a core is arranged between the coils in the plurality of coils. The transformer according to claim 9, wherein the magnetic core is a rod core including a rod-shaped core penetrating the center of the plurality of coils.

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