JP2013219396A - Circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a circuit board in which there is no problem even when a winding and a core temperatures become high without using a printed board having a special structure to the whole device, and which surely holds the winding to the printed board to improve its reliability.SOLUTION: A circuit board comprises a printed board 1, at least a winding 2D and a core 3 forming a magnetic path of a magnetic flux interlinked to the winding 2D. A through hole 11 with such a size that passes at least the core 3, is provided on the printed board 1, the core 3 is provided in the through hole 11, a hole for inserting a leg of the core is provided on a center part of the core 3, the core 3 comprises a sub-printed board 5 having a heat-resisting grade being higher than that of the printed board 1, and the winding 2D consists of a patten which is formed on the sub-printed board 5 and in which connection parts 2d are provided on its both edges.

Description

  The present invention relates to a circuit board used when, for example, a power supply device on which a coil, a transformer or the like is mounted is formed.

  In a circuit board such as a power supply device in which a coil or a transformer is mounted on a printed board, when the core is inserted by hollowing out the printed board, heat generation in the coil becomes a problem. As a countermeasure to such a problem, there is one in which heat is dissipated by partially increasing the thickness of the pattern so that the temperature of the printed circuit board does not rise excessively (see, for example, Patent Document 1).

JP 2010-178439 A (first page, FIG. 1)

  The conventional technology as described above can achieve an effect such as obtaining an efficient power supply device without increasing the thickness of the substrate. On the other hand, for example, a vehicle that is used in a high temperature environment such as an in-vehicle device is heat resistant. It is essential to use a high-grade board material, and a special printed board with a partially thick pattern is used not only for the coil or transformer part but also for the whole board, resulting in a high cost. It was.

  The present invention has been made to solve such a problem, and without using a printed circuit board having a special structure for the entire apparatus, a circuit board that does not have a problem even when the windings and the core become high temperature is reduced. The purpose is to get at cost.

  A circuit board according to the present invention is a circuit board provided with a printed circuit board, at least one winding, and a core that forms a magnetic path of magnetic flux linked to the winding, and the printed circuit board includes at least the above-described circuit board. A through-hole having a size capable of passing the core is provided, the core is provided in the through-hole portion, a hole through which the leg of the core is inserted is provided at the center, and the heat resistance grade is the printed board. And the winding is formed of a pattern formed on the sub printed circuit board and provided with connecting portions at both ends thereof.

  In the circuit board according to the present invention, the influence of the heat generated inside the winding on the printed circuit board is reduced by installing the core in the through hole portion formed to have a size that allows the core to pass through, and the winding. Is formed as a pattern, and a hole through which the core leg is inserted is provided in the center, and the heat-resistant grade is equipped with a secondary printed circuit board that is higher than the printed circuit board. In addition, it is possible to obtain a circuit board that can reduce the cost as a whole.

It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 1 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 2 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 3 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 4 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 5 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 6 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 7 of this invention. It is a disassembled perspective view which shows the principal part of the circuit board in Embodiment 8 of this invention.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a main part of a circuit board according to Embodiment 1 of the present invention. In the figure, a circuit board configured as a power supply device includes a printed circuit board 1, a winding 2, a core 3 composed of an I core 31 disposed on the upper side and an E core 32 disposed on the lower side. It is configured using. The winding 2 is formed, for example, by pressing a thin copper plate into a spiral shape. At both ends of the winding 2, a connecting portion 2a is inserted into a through hole 1a provided in the printed circuit board 1 and electrically connected to the printed circuit board 1 by soldering. One or more fixing protrusions 2b are provided in a winding portion that is an intermediate portion of the winding 2. The fixing protrusion 2b is formed at an appropriate position necessary for functions such as mechanical strength and noise prevention.

  The printed circuit board 1 is provided with a through hole 1b for inserting and fixing the fixing protrusion 2b in addition to the through hole 1a. The winding fixing projection 2b inserted into the through hole 1b is mechanically fixed to the printed circuit board 1 by soldering. Further, the printed circuit board 1 is provided with a through hole 11 formed to have a size that allows at least the lower E core 32 to pass therethrough. The through hole 11 is formed in a rectangular shape in which a part of the printed circuit board 1 does not exist in the projection surface of the E core 32. For this reason, the part where the winding 2 passes the leg part of the E core 32 is in a state of floating with respect to the printed circuit board 1. Note that circuit elements, other mounting parts, wiring patterns, and the like are not shown.

  In the first embodiment configured as described above, after the winding 2 is mounted on a predetermined portion of the printed circuit board 1, the E core 32 is inserted from the lower side of the through hole 11, and I is formed from above the printed circuit board 1. By combining the core 31 with the leg of the E core 32 and fixing the I core 31 and the E core 32 to the printed circuit board 1 by fixing means (not shown), the core 3 composed of the I core 31 and the E core 32 is obtained. The magnetic circuit of the magnetic flux linked to the winding 2 is formed, and a circuit board configured as a power supply device such as a reactor is obtained.

  According to the first embodiment configured as described above, the printed board 1 is provided with the through hole 11 having a size that allows the core 3 to pass therethrough, and the core 3 is installed in the through hole 11 portion. Thus, the heat transmitted from the winding 2 or the core 3 to the printed circuit board 1 can be suppressed. For this reason, it is not necessary to additionally implement a heat dissipation measure for the printed circuit board existing in the core 3 that is generated by heat stagnating in the winding portion around the core 3, and the cost of the circuit board can be reduced. Specifically, the “FR grade” indicating the flame retardancy of the copper-clad laminate is equivalent to “FR5 grade” which uses a heat-resistant glass cloth base epoxy resin as the material of the printed board 1 in the conventional one. In the first embodiment, a substrate having an FR grade lower than that can be used. For this reason, there has conventionally been a problem that the cost is greatly increased, but the first embodiment can be provided at low cost.

  In the first embodiment, the case where the I core 31 is disposed in the upper part and the E core 32 is disposed in the lower part has been described as the shape of the core 3 to be used. Needless to say, the same applies to the case where the I core 31 is disposed on the upper side or the E core is disposed on the upper and lower sides. Moreover, although the case where the number of windings 2 is one was demonstrated, even when comprised as a transformer by providing a secondary winding, the same effect is acquired. Further, although the circuit board is configured as a power supply device, it is not limited to this.

Embodiment 2. FIG.
FIG. 2 is an exploded perspective view showing the main part of the circuit board according to Embodiment 2 of the present invention. In the figure, the winding 2A having the same coil shape as that of the first embodiment is not provided with the fixing projection 2b (shown in FIG. 1) in the first embodiment at the winding portion. And the copper-clad pattern 12 corresponding to the projection shape of the winding part of the coil | winding 2A is formed in the part except the through-hole 11 of the printed circuit board 1. FIG. The winding portion of the winding 2 </ b> A is mechanically fixed by soldering to the copper-clad pattern 12 of the printed circuit board 1. Other configurations are the same as those of the first embodiment.

  In the second embodiment configured as described above, the portion extending on the printed board 1 in the winding portion of the winding 2A is directly fixed to the copper-clad pattern 12 provided on the printed board 1, Winding 2A can be held firmly. Similarly to the first embodiment, since no printed circuit board is provided in the portion where the core 3 is inserted, a heat dissipation measure for the printed circuit board 1 existing inside the core that is generated when the heat inside the core 3 stagnates. For example, there is no need to implement additional measures such as using a material equivalent to the FR5 grade as the material of the printed circuit board 1, and the effect of reducing the cost of the circuit board can be obtained.

Embodiment 3 FIG.
FIG. 3 is an exploded perspective view showing the main part of the circuit board according to Embodiment 3 of the present invention. In the figure, the winding 2A is formed, for example, by press-molding a thin copper plate into a spiral shape, and the connecting portions 2a are bent at both ends as in the second embodiment. The printed board 1 is provided with a through hole 1a and a through hole 11 similar to those in the first and second embodiments. Connection portions 2a at both ends of the winding 2A are inserted into the through holes 1a, and are electrically connected to the printed circuit board 1 by soldering. The winding 2A is mechanically fixed by being pressed from above and below by a winding holding member 4 (an upper bobbin 41 and a lower bobbin 42) made of a heat-resistant resin divided into two vertically. The upper bobbin 41 and the lower bobbin 42 are respectively provided with three holes 4a, 4b, 4c through which the legs 32a, 32b, 32c of the E core 32 are inserted. The outer diameter of the winding holding member 4 is formed larger than the through hole 11 of the printed circuit board 1, and the winding holding portion 421 protruding from the upper surface of the central portion of the lower bobbin 42 enters the through hole 11. It is configured to be able to.

  Note that the core 3 and the winding holding member 4 are fixed to the printed circuit board 1 or other fixing portions by an appropriate means (not shown). For example, the I core 31 is pressed downward by a spring-like member (not shown), and a casing is disposed under the E core 32 in this example. 32 does not move up and down. In addition, it is not always necessary when used in an environment free from vibrations, but the spiral such that the winding 2A just fits on the surface of the lower bobbin 42 that contacts the winding 2A on the upper surface of the winding holding portion 421. By providing the arc-shaped groove 421a formed of a part of a curved line, it is possible to prevent the winding 2A from vibrating due to an external force and contact between the inner winding and the outer winding. Similarly, although it is not always necessary when used in an environment free from vibration, by providing the upper bobbin 41 with the convex core locking portion 411, the movement of the I core 31 in the planar direction can be suppressed.

  Here, the heat resistance of the printed circuit board 1 is about 130 ° C. when a general FR4 grade material is used. On the other hand, the winding holding member 4 made of heat-resistant resin is made of a material such as PPS (polyphenylene sulfide) resin, and generally has a heat resistance of 200 ° C. or higher. Therefore, even if the inside of the winding 2 </ b> A becomes a temperature exceeding the heat resistance temperature of the printed circuit board 1, the heat retaining resin-made winding holding member 4 does not become a thermal problem. Other configurations are the same as those of the first embodiment.

  According to the third embodiment configured as described above, the winding part of the winding 2A is fixed so as to be sandwiched from above and below by the winding holding member 4 made of a heat-resistant resin divided into two vertically. As a heat dissipation measure for the printed circuit board 1, for example, it is not necessary to additionally implement measures such as using a material equivalent to the FR5 grade as the material of the printed circuit board 1, and an effect of reducing the cost of the obtained circuit board can be obtained. . Further, by providing the winding holding member 4 with the groove 421a into which the winding 2A is just fitted, the assembly becomes easy and the vibration resistance can be enhanced. Further, by providing the winding holding member 4 with the convex core locking portion 411 that locks the core 3, the holding force of the core 3 is improved and the reliability is also improved.

Embodiment 4 FIG.
FIG. 4 is an exploded perspective view showing the main part of the circuit board according to Embodiment 4 of the present invention. In the figure, the printed circuit board 1 is provided with a through-hole 11A having a shape of a combination of a rectangle and a circle including a projection surface of a winding portion of the winding 2B with respect to the E core 32. It has been. 11 A of through-holes are comprised so that a part of printed circuit board 1 may not exist in the projection surface of E core 32, and the projection surface of the winding part of the coil | winding 2B. The winding holding member 4A (upper bobbin 41A, lower bobbin 42A) made of heat-resistant resin has a shape combining a rectangle and a circle corresponding to the shape of the through hole 11A, and the through hole 11A is the same as in the third embodiment. Only the circular winding holding part 421 is formed so that it can be inserted into the through hole 11A. Other configurations are the same as those of the third embodiment.

  In the fourth embodiment configured as described above, as a countermeasure for heat dissipation of the printed circuit board 1 existing inside the core, which is generated when the heat inside the core 3 stagnates, for example, as in the prior art, for example, a printed circuit board. It is not necessary to take additional measures such as using a material equivalent to the FR5 grade for one material, and the cost of the obtained circuit board can be reduced. Further, when the printed board 1 is cut out over the entire projection surface of the winding 2B, the heat (for example, copper loss) generated from the winding 2B itself is large and the temperature is higher than the heat-resistant temperature of the printed board 1. However, there is an effect that it is not necessary to take additional heat dissipation measures.

  Although the case where the winding 2B has a circular shape has been described, the shape of the winding 2B is not particularly limited, and may be, for example, a shape other than a circle such as an ellipse or a rectangle. What is necessary is just to make the shape of 11 A of through-holes vacated in the printed circuit board 1 according to the shape of the coil | winding 2B.

Embodiment 5 FIG.
FIG. 5 is an exploded perspective view showing the main part of the circuit board according to Embodiment 5 of the present invention. In the figure, a circuit board configured as a power supply device is configured using a printed circuit board 1, a winding 2C insert-molded with heat-resistant resin, an upper I core 31, a lower E core 32, and the like. Yes. The unillustrated strands constituting the winding 2C are formed, for example, by pressing a thin copper plate into a spiral shape or a spiral shape. The printed circuit board 1 is provided with through holes 1a for inserting the connection portions 2a at both ends of the winding 2C. The connection portions 2a inserted into the through holes 1a are electrically connected to the printed circuit board 1 by soldering. Is done. The insert-molded winding 2 </ b> C has one or more locking projections 2 c protruding downward in the figure, and is fitted into and joined to a hole 1 c formed in the printed board 1. And mechanically fixed.

  The printed board 1 is provided with the same through hole 11 as in the first embodiment so that the E core 32 can be inserted. The through-hole 11 includes not only the leg portion of the lower E core 32 but also the printed board 1 in the lower part of the winding 2 inside the E core 32, and a part of the printed board 1 is within the projection plane of the E core 32. It is rectangular so that it does not exist. Here, the heat resistance of the printed circuit board 1 is about 130 ° C. when a general FR4 grade material is used. On the other hand, the heat-resistant resin used for the insert molding of the winding 2C is made of a material such as PPS resin, and generally has a heat resistance of 200 ° C. or higher. Therefore, even if the inside of the winding 2C reaches a temperature exceeding the heat resistance temperature of the printed circuit board 1, the winding 2C insert-molded with a heat resistant resin does not become a thermal problem.

  In the fifth embodiment configured as described above, measures against heat dissipation of the printed circuit board 1 existing inside the core, which occurs when the heat inside the core 3 stagnate, for example, the material of the printed circuit board 1 is equivalent to the FR5 grade. There is no need to implement additional countermeasures such as using a circuit board, and the cost of the circuit board can be reduced. Although the case where the winding 2C is formed of an insert molding has been described, the winding may be held by using outsert molding.

Embodiment 6 FIG.
FIG. 6 is an exploded perspective view showing the main part of the circuit board according to Embodiment 6 of the present invention. In the figure, a circuit board configured as a power supply device is configured using a printed circuit board 1, a winding 2C insert-molded with heat-resistant resin, an upper I core 31, a lower E core 32, and the like. Yes. The through-hole 11B provided in the printed circuit board 1 allows the E core 32 to be inserted, and the through-hole 11B does not exist in the projection plane of the winding portion forming the circular shape of the winding 2C. The shape is a shape that combines a rectangle and a circle. Other configurations are the same as those in the fifth embodiment, including the selective use of heat-resistant materials.

  In the sixth embodiment configured as described above, heat dissipation measures for the printed circuit board 1 existing inside the core, which occurs when the heat inside the core 3 stagnate, for example, FR5 grade equivalent to the material of the printed circuit board 1 There is no need to implement additional countermeasures such as using a circuit board, and the cost of the circuit board can be reduced. Further, by cutting out the printed circuit board 1 over the entire projection surface of the insert-molded winding 2C, heat generated by the insert-molded winding 2C itself, for example, due to copper loss, is greater than the heat resistance temperature of the printed circuit board 1. Even in such a case, it is not necessary to take additional heat dissipation measures. In addition, since the through hole 11B is a combination of a rectangle and a circle and the printed circuit board 1 does not exist below the winding 2C, the influence of heat received by the printed circuit board 1 is reduced as compared with the case of the fifth embodiment.

Embodiment 7 FIG.
FIG. 7 is an exploded perspective view showing the main part of the circuit board according to Embodiment 7 of the present invention. In the figure, a circuit board configured as a power supply device is provided with a printed board 1 which is a main board using a general FR4 grade material having a heat resistant temperature of about 130 ° C., and a winding 2D. A secondary printed circuit board 5 having a circular shape equivalent to the FR5 grade made of a material having higher heat resistance and having a through-hole through which a leg of the E core 32 is inserted in the center; an I core 31 disposed on the upper side; The lower E core 32 is used. The sub printed circuit board 5 is formed in a plurality of layers, and the winding 2D is also disposed between the layers to form a coil (not shown) connected in series.

  A connecting portion 2 d that is led out from both ends of the winding 2 </ b> D and is electrically connected to a circuit on the printed circuit board 1 protrudes from the outer peripheral portion of the sub printed circuit board 5. The connecting part 2d is electrically connected to the pattern 1d provided on the substrate 1 by soldering. The sub printed circuit board 5 is mechanically cooperated with the connection part 2d by soldering the fixing pattern 5e formed on the protruding part on the opposite side of the connection part 2d to the fixing pattern 1e of the printed circuit board 1. Fixed to. The printed board 1 is provided with the same through-hole 11 as in the first embodiment so that the lower E core 32 can be inserted. The through hole 11 has a rectangular shape so that not only the leg portion of the E core 32 but also a part of the printed circuit board 1 does not exist in the projection plane of the E core 32.

  In the seventh embodiment configured as described above, the temperature of the sub printed circuit board 5 is higher than that of the printed circuit board 1 due to heat generated by the winding 2D and the core 3 during operation, but the heat resistance is higher than that of the printed circuit board 1. By using a material equivalent to an excellent FR5 grade, there is no particular problem. In addition, although a substrate using a material having high heat resistance is expensive, since the sub printed circuit board 5 is used only for the winding 2D portion, the entire printed circuit board 1 as the main circuit board is heat resistant at high cost. It is not necessary to use a highly flexible substrate, and the cost of the circuit board can be reduced.

  In addition, although the case where the sub printed circuit board 5 was fixed to the printed circuit board 1 by direct soldering was demonstrated, it is not limited to this. For example, the sub printed circuit board 5 may be indirectly fixed to the printed circuit board 1 through another member, or an appropriate fixing means may be used for the printed circuit board 1 using or not using pins or screws. Can be fixed. Needless to say, the shape of the winding 2D may be another shape such as a spiral shape or a spiral shape, and may be changed as appropriate, for example, to a quadrangular shape.

Embodiment 8 FIG.
FIG. 8 is an exploded perspective view showing the main part of the circuit board according to Embodiment 8 of the present invention. In the figure, the printed circuit board 1 is provided with a through-hole 11C having the same shape as the fourth and sixth embodiments shown in FIGS. The through hole 11 </ b> C has a shape combining a rectangle and a circle so that the E core 32 can pass therethrough and a part of the printed circuit board 1 does not exist in the projection surface of the circular portion of the sub printed circuit board 5. . Other configurations are the same as those in the seventh embodiment including the heat resistance grade of the substrate.

  In the eighth embodiment configured as described above, a printed board using a material having high heat resistance can be used only for the coil portion. Therefore, the cost of the circuit board can be reduced. Further, since the printed circuit board 1 is cut out over the entire projection surface of the sub printed circuit board 5, heat such as copper loss generated from the sub printed circuit board 5 itself is large, and the temperature is higher than the heat resistance temperature of the printed circuit board 1. Even in such a case, it is not necessary to take additional heat dissipation measures.

  It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted. For example, although the case where the circuit board is configured as a power supply device has been described, the present invention is not limited to this. It goes without saying that the type of insulating material used, the shape and material of the core 3 and the winding 2, the fixing means, and the like can be changed as appropriate.

  1 Printed circuit board, 1a, 1b Through hole, 1c hole, 1d pattern, 1e Fixing pattern, 11, 11A, 11B, 11C Through hole, 12 Copper-clad pattern, 2, 2A, 2B, 2C, 2D winding, 2a connection Part, 2b fixing protrusion, 2c locking projection, 2d connecting part, 3 core, 31 I core, 32 E core, 32a, 32b, 32c leg, 4, 4A winding holding member, 4a, 4b, 4c hole, 41, 41A Upper bobbin, 411 Core locking part, 42, 42A Lower bobbin, 421 Winding holding part, 421a Groove, 5 Sub printed circuit board, 5e Fixing pattern.

Claims (5)

  A circuit board comprising a printed circuit board, at least one winding, and a core that forms a magnetic path of magnetic flux interlinking with the winding, the circuit board having a size capable of passing at least the core A through hole is provided, the core is provided in the through hole portion, a hole through which the core leg is inserted is provided in the center, and a heat resistant grade is higher than the printed circuit board. The circuit board is formed of a pattern formed on the sub printed circuit board and provided with connection portions at both ends thereof.   The circuit board according to claim 1, wherein the connection portion of the sub printed circuit board is electrically connected to a connection pattern provided on the printed circuit board by soldering.   The sub printed circuit board is provided with a fixing pattern, and the sub printed circuit board is mechanically fixed to the printed circuit board by soldering the fixing pattern to the fixing pattern provided on the printed circuit board. The circuit board according to claim 1, wherein the circuit board is provided.   The through hole is formed in a shape in which the projection surface of the winding portion of the winding is superimposed on the projection surface of the core, and the winding portion of the winding is installed in the through hole portion. A circuit board according to any one of claims 1 to 3.   The core that is installed in the through hole of the printed circuit board and forms a magnetic path of magnetic flux interlinking with the winding is composed of a first core portion and a second core portion that are combined with each other, and the first core 5. The circuit board according to claim 1, wherein the core part and the second core part are fixed to the printed board by a fixing means.

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