JP2018117076A - Circuit board connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the loss in an electrical circuit to which a transformer, a bus-bar and a semiconductor are connected and through which a large current flows, thereby reducing heat generation in a printed wiring board.SOLUTION: A circuit board connection structure comprises a printed wiring board 10 where circuit components of a switching power supply device are disposed on the board, provided that the switching power supply device converts an input voltage into an interrupted voltage by ON/OFF of a switching element, and then transmits the interrupted voltage through a transformer to a rectification smoothing circuit having a rectifying element, a choke coil and a capacitor to convert into a rectified smoothed output voltage. In the circuit board connection structure, a lead terminal 28 connected with a secondary winding wire of the transformer, and a lead terminal 40 extending from the bus-bar are inserted in an insertion hole 32 of the printed wiring board formed between the transformer and a bus-bar and soldered there; and a lead terminal extending from the bus-bar and a lead terminal of the rectifying element are inserted in an insertion hole 34 of the printed wiring board formed between the bus-bar and the rectifying element and soldered there. In either case, an electrical circuit is formed which never runs through a print pattern on the backside of the board, and through which a large current is to flow.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a circuit board connection structure in which a circuit such as a switching power supply device including a transformer and a semiconductor such as a rectifier is arranged on a printed board.

  Conventionally, on a printed circuit board of a switching power supply device, an input voltage is converted into an intermittent voltage by turning on and off the switching element, and then transmitted to a rectifying / smoothing circuit including a secondary side rectifying element, choke coil and capacitor via a transformer. Circuit components that convert the output voltage by rectifying and smoothing are arranged.

  As a conventional connection structure between a transformer and a semiconductor that handles a large current in such a switching power supply device, for example, those shown in FIGS. 8 and 9 are known.

  In the connection structure of FIG. 8, the secondary windings 109 and 110 of the transformer and the MOSFETs 112, 113, 114, and 115 are connected by screwing the conductors 204 a and 204 b and soldering the printed circuit board 201.

  9 includes a transformer 204, a printed board 212, a bus bar 213, a diode 214, a choke coil 215, and a smoothing capacitor 216. The transformer 204 and the diode 214 are connected via the printed board 212 and the bus bar 213. Has been.

  10 and 11 show a conventional example of a connection structure of a semiconductor element to a printed board. In the connection structure of FIG. 10, the lead terminal 313 of the mounting component 312 is inserted into the through hole 317 of the printed circuit board and the auxiliary lead 314 is inserted, and the auxiliary lead 314 is provided in the through hole 317, so that the molten solder passes through the through hole. A solder fillet 315 having a sufficiently high height is formed inside 317 efficiently so that the mounting strength of the component is maintained.

  In the connection structure of FIG. 11, the connection terminal 406 a of the power element 406 and the connection terminal 414 a of the bus bar 414 are inserted into a single connection hole 402 a of the printed circuit board 402, and are electrically integrated into the conductive portion of the printed circuit board 402 by soldering. Connected.

JP 2012-188010 A Japanese Patent Laid-Open No. 2008-084925 JP 09-312466 A JP 2001-352541 A

  However, in the conventional connection structure shown in FIG. 8, the gap between the lead terminal of the semiconductor element and the lead terminal of the transformer is inserted into a separate insertion hole formed in the printed circuit board, via the printed pattern on the back surface of the circuit board. In addition, even in the conventional connection structure of FIG. 9, the lead terminals of the transformer are connected to the bus bar, and the lead terminals of the bus bar and the lead terminals of the semiconductor element are formed separately on the printed circuit board. In a switching power supply unit that is inserted into a hole and connected via a printed pattern on the back side of the board and outputs a large current to the load, the loss increases due to the large current flowing through the printed pattern, and the printed board generates heat. It becomes a problem.

  Moreover, in the connection structure of FIG. 9, since many screws are used for the connection of the transformer and the semiconductor element to the bus bar, there are many screw tightening steps and there is a problem that the assembly becomes complicated.

  10 and 11, a plurality of lead terminals are inserted into the same insertion hole of the printed circuit board and connected by soldering. However, the connection structure in FIG. 10 is a structure for reinforcement, and FIG. The structure is a connection between the semiconductor element and the bus bar, both of which are not a structure in which the transformer and the semiconductor element that are problematic in the switching power supply device are connected using the bus bar, but a large current flows through the printed pattern, and the loss increases. It does not solve the problem that the printed circuit board generates heat.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit board connection structure that can reduce heat loss of a printed circuit board by reducing loss of an electric circuit connected to a transformer, a bus bar, and a semiconductor through which a large current flows.

(Circuit board connection structure)
The present invention provides a circuit board connection structure in which a first circuit component, a bus bar member, and a second circuit component are arranged adjacent to each other on a printed circuit board.
A lead terminal of the first circuit component and a lead terminal extending from the bus bar member are inserted and soldered into a first insertion hole of the printed circuit board formed between the first circuit component and the bus bar member. ,
The lead terminal extended from the bus bar member and the lead terminal of the second circuit component were inserted into the second insertion hole of the printed circuit board formed between the bus bar member and the second circuit component and soldered. It is characterized by that.

(Connection of transformer, bus bar member, rectifying element)
On the printed circuit board, the input voltage is converted to an intermittent voltage by turning on and off the switching element, and then transmitted to a rectifying / smoothing circuit including a rectifying element, a choke coil and a capacitor via a transformer and converted to an output voltage by rectifying and smoothing. The circuit components of the switching power supply are arranged,
When the first circuit component is a transformer and the second circuit component is a rectifier,
A lead terminal connected to the secondary winding of the transformer and a lead terminal extending from the bus bar member are inserted into a first insertion hole of the printed circuit board formed between the transformer and the bus bar member and soldered. And
A lead terminal extending from the bus bar member and a lead terminal of the rectifying element are inserted and soldered into a second insertion hole of the printed board formed between the bus bar member and the rectifying element.

(Connection of choke coil, bus bar member, rectifying element)
Furthermore, when the first circuit component is a choke coil and the second circuit component is another rectifying element,
A lead terminal connected to the winding of the choke coil and a lead terminal extending from the other bus bar member are connected to another first insertion hole of the printed circuit board formed between the choke coil and the other bus bar member. Inserted and soldered,
The lead terminal extended from the other bus bar member and the lead terminal of the other rectifying element are inserted into the other second insertion hole of the printed circuit board formed between the other bus bar member and the other rectifying element. Soldered.

(Semiconductor arrangement for transformer and choke coil)
A plurality of rectifying elements are provided and connected in parallel.
The plurality of rectifying elements are arranged in one or a plurality of rows in the same direction as the arrangement direction of the transformer and the choke coil.

(Ventilation path for forced cooling)
A ventilation path through which cooling air from the cooling fan passes is formed between the row of transformers and choke coils arranged in the same direction and the row of rectifying elements.

(Modification 1 of the present invention)
In another embodiment of the present invention, in the circuit board connection structure in which the first circuit component, the bus bar member, and the second circuit component are arranged adjacent to each other on the printed board.
The lead terminal of the first circuit component and the bus bar member are connected by screwing and fixed to the printed circuit board,
The lead terminal extended from the bus bar member and the lead terminal of the second circuit component are inserted into the insertion hole of the printed board formed between the bus bar member and the second circuit component and soldered. And

(Modification 2 of the present invention)
In another embodiment of the present invention, in the circuit board connection structure in which the first circuit component and the second circuit component are arranged adjacent to each other on the printed board,
The lead terminal of the first circuit component and the lead terminal of the second circuit component are inserted and soldered into the insertion hole of the printed circuit board formed between the first circuit component and the second circuit component. It is characterized by that.

(Basic effect)
The present invention relates to a circuit board connection structure in which a first circuit component, a bus bar member, and a second circuit component are disposed adjacent to each other on a printed circuit board, and the first circuit component is interposed between the first circuit component and the bus bar member. The lead terminal of the first circuit component and the lead terminal extended from the bus bar member are inserted into the first insertion hole of the formed printed circuit board and soldered, and between the bus bar member and the second circuit component. Since the lead terminal extended from the bus bar member and the lead terminal of the second circuit component are inserted into the second insertion hole of the formed printed circuit board and soldered, the first circuit arranged on the printed circuit board When a large current flows through the electric circuit including the component, the bus bar member, and the second circuit component, the lead terminals of the two adjacent components are inserted into the same insertion hole and connected by soldering. Pre A large current flows directly to the other lead terminal without going through the pattern, and a large current does not flow to the printed circuit board pattern, so there is no problem of heat generation due to loss, and the circuit board connection structure of the present invention is provided. The operating temperature of the equipment and equipment is reduced, and reliability and durability can be improved.

(Effect when applied to transformer secondary side of switching power supply)
Also, the printed circuit board converts the input voltage into an intermittent voltage by turning on and off the switching element, and then transmits it to a rectifying and smoothing circuit including a rectifying element, a choke coil and a capacitor via a transformer, thereby rectifying and smoothing the output voltage. When the circuit component of the switching power supply device to be converted is disposed, the first circuit component is a transformer and the second circuit component is a rectifying element, the first printed circuit board formed between the transformer and the bus bar member A lead terminal connected to the secondary winding of the transformer and a lead terminal extending from the bus bar member are inserted into the insertion hole of the transformer and soldered, and the first printed circuit board formed between the bus bar member and the rectifier element is soldered. Since the lead terminal extended from the bus bar member and the lead terminal of the rectifying element were inserted into the insertion hole 2 and soldered, When the transformer secondary winding provided on the secondary side of the device is applied to a substrate connection structure that is connected to the rectifier element via the bus bar member, even if a large current is passed from the transformer to the load side via the rectifier element A large current flows through a path that becomes a transformer, a bus bar member, and a rectifying element that does not pass through the printed circuit board pattern, and the problem of heat generation due to loss when flowing through the printed circuit board pattern is solved.

(Effect when applied to choke coil side of switching power supply)
Further, when the first circuit component is a choke coil and the second circuit component is another rectifying element, another first insertion hole of the printed circuit board formed between the choke coil and another bus bar member. The printed circuit board formed between the other bus bar member and the other rectifying element is inserted and soldered to the lead terminal connected to the choke coil winding and the lead terminal extended from the other bus bar member. Since the lead terminal extended from the other bus bar member and the lead terminal of the other rectifying element are inserted into the other second insertion hole and soldered, the choke from the rectifying element is the same as in the transformer side. Even when a large current flows through the coil to the load side, a large current flows through the path that becomes the rectifier, bus bar member, and choke coil without passing through the printed circuit board pattern. Thermal problem is solved by loss when flowing.

(Effect of semiconductor placement on transformer and choke coil)
Also, a plurality of rectifying elements are provided and connected in parallel, and the plurality of rectifying elements are arranged in one or a plurality of rows in the same direction as the arrangement direction of the transformer and the choke coil. By arranging a plurality of rectifying elements in parallel, they are arranged at the same distance, and even if a plurality of rectifying elements are connected in parallel for use with a large current output, the number of the plurality of rectifying elements to the printed circuit board is small. It can be efficiently arranged in space, and the switching power supply device can be downsized.

(Effects of forced cooling air passages)
In addition, a ventilation path through which cooling air from the cooling fan passes is formed between the row of transformers and choke coils arranged in the same direction and the row of rectifier elements. Even if a large current flows through the output circuit section of the switching power supply device including the heat generation, the operating temperature of the device or equipment using the printed circuit board connection structure of the present invention is high because the cooling efficiency by forced air blowing from the cooling fan is high. It is possible to lower the reliability and durability.

(Effects of Modification 1 of the present invention)
In another embodiment of the present invention, in a circuit board connection structure in which a first circuit component, a bus bar member, and a second circuit component are arranged adjacent to each other on a printed circuit board, the first circuit component is provided. The lead terminal and the bus bar member are fixed to the printed circuit board connected by screws, and the lead terminal extending from the bus bar member is inserted into the insertion hole of the printed circuit board formed between the bus bar member and the second circuit component. Since the lead terminal of the second circuit component is inserted and soldered, a large current does not flow in the pattern of the printed circuit board, so that the problem of heat generation due to loss does not occur, and the lead terminal of the first circuit component The bus bar member is connected by screw tightening and fixed to the printed circuit board, thereby increasing the mounting strength of the first circuit component, for example, the mounting strength of the transformer of the switching power supply device. And ability.

(Effects of Modification 2 of the present invention)
In another embodiment of the present invention, in the circuit board connection structure in which the first circuit component and the second circuit component are arranged adjacent to each other on the printed circuit board, the first circuit component and the second circuit component are arranged. Since the lead terminal of the first circuit component and the lead terminal of the second circuit component are inserted into the insertion hole of the printed circuit board formed between the circuit component and the second circuit component and soldered, a large current is applied to the pattern of the printed circuit board. In addition to the effect that heat does not flow due to loss, there is no need to use a bus bar member such as a copper bar, so the circuit board connection structure is simplified, and the installation space and cost can be reduced.

An explanatory diagram showing a circuit board connection structure on which a transformer secondary side circuit of a switching power supply device is mounted The circuit diagram which showed the power converter of the switching power supply device containing the transformer secondary side circuit of FIG. Explanatory drawing which decomposed | disassembled and showed the circuit board connection structure of FIG. Explanatory drawing which took out the part of the mounting structure of the transformer of FIG. 1, a bus-bar, and a rectifier, and showed 1st Embodiment of the circuit board connection structure Explanatory drawing which showed in cross section 1st Embodiment of the circuit connection structure which connects the transformer of FIG. 4, a bus-bar, and a rectifier. Explanatory drawing which showed 2nd Embodiment of the circuit connection structure which connects a transformer, a bus-bar, and a rectifier in a cross section Explanatory drawing which showed 3rd Embodiment of the circuit connection structure which connects the transformer and rectifier which do not require a bus bar in cross section Explanatory drawing showing a conventional connection structure for connecting a transformer and a semiconductor element via a printed circuit board Explanatory drawing showing a conventional structure for connecting a transformer and a semiconductor element via a bus bar and a printed circuit board Explanatory drawing showing the conventional structure in which the lead terminals and auxiliary leads of the mounting components are inserted into the through holes of the printed circuit board and soldered An explanatory diagram showing a conventional structure in which a semiconductor element and a lead terminal of a bus bar are inserted into a connection hole of a printed circuit board and soldered

(Outline of circuit board contact structure)
FIG. 1 is an explanatory diagram showing a circuit board connection structure in which a transformer secondary circuit of a switching power supply device is mounted.

  As shown in FIG. 1, a transformer 12, a rectifying element 14, a choke coil 16, and a capacitor 18 provided in a transformer secondary side circuit of a switching power supply device are disposed on a board surface of a printed board 10.

  The transformer 12 takes out a transformer output terminal 28 on the right side. A bus bar 20 is disposed on the substrate surface between the transformer output terminal 28 and the rectifying element 14, and the transformer output terminal 28 and the rectifying element 14 are interposed via the bus bar 20. Is connected.

  A plurality of rectifying elements 14 are arranged in a bus bar 22 formed in a box shape, and a plus output terminal 24 is taken out from the bus bar 22. A plurality of capacitors 18 are arranged in two rows in the depth direction following the bus bar 22 in which the rectifying elements 14 are housed, and the minus output terminal 26 is taken out from the left substrate of the capacitor 18 row.

  The choke coil 16 takes out a choke coil terminal 30 on the right side, and the choke coil terminal 30 is also connected to the rectifying element 14 side through another bus bar 20 disposed on the substrate.

(Switching power supply circuit)
FIG. 2 is a circuit diagram showing a power conversion unit of a switching power supply apparatus including the transformer secondary side circuit of FIG. 1, and takes a single-ended forward converter as an example.

  As shown in FIG. 2, the circuit of the switching power supply device includes a rectifier including a switching element 11 connected in series to a primary winding 12 a of a transformer 12 and diodes 14 a and 14 b following a secondary winding 12 b of the transformer 12. A circuit unit and a smoothing circuit unit including a choke coil 16 and a capacitor 18 are provided.

  The switching element 11 is turned on and off by a control circuit (not shown), and after the input voltage is converted into an intermittent voltage by turning on and off the switching element 11, an intermittent voltage is generated in the secondary winding 12b via the transformer 12. The intermittent voltage generated in the secondary winding 12b of the transformer 12 is rectified by the diodes 14a and 14b, smoothed by the choke coil 16 and the capacitor 18, and converted into a DC output voltage.

  The operation of the single-ended forward type transformer secondary side circuit is as shown by the solid line in the path of the choke coil 16, the capacitor 18 and the diode 14a by the voltage generated in the secondary winding 12b of the transformer 12 when the switching element 11 is turned on. A forward current indicated by an arrow flows, electric charge is accumulated in the capacitor 18 and energy is accumulated in the choke coil 16, and when the switching element 11 is turned off, the energy accumulated in the choke coil 16 causes the capacitor 18 and the diode 14b to move from the choke coil 16. A flywheel current indicated by a dotted arrow flows through the path, and the intermittent voltage is rectified and smoothed.

  Here, the rectifying diodes 14a and 14b provided in the transformer secondary circuit in FIG. 2 correspond to the rectifying element 14 in FIG. 1, and in FIG. 1, a plurality of rectifying elements 14 are connected in parallel. Thus, the functions of the diodes 14a and 14b in FIG. 2 are realized. Further, in FIG. 1, the capacitor 18 of FIG. 2 is realized by connecting eight capacitors 18 in parallel.

(Outline of circuit parts and bus bar)
FIG. 3 is an explanatory view showing the circuit board connection structure of FIG. 1 in an exploded manner. As shown in FIG. 3, in the present embodiment, the bus bar 20 is divided into three pieces on the printed circuit board 10.

  Here, the front bus bar 20 is used to connect the transformer 12 and the rectifying element 14, the central bus bar 20 is used to connect the transformer 12 and the choke coil 16, and the rectifying element 14, and the rear bus bar 20 is the choke. Used to connect the coil 16 and the capacitor 18.

(Details of the circuit board connection structure according to the first embodiment)
4 is an explanatory view showing the first embodiment of the circuit board connection structure by taking out the mounting structure portion of the transformer, bus bar, and rectifying element of FIG. 1, and FIG. 5 is for connecting the transformer, bus bar, and rectifying element of FIG. It is explanatory drawing which showed 1st Embodiment of the circuit board connection structure in the cross section.

  As shown in FIGS. 4 and 5, an insertion hole 32 is formed in the printed circuit board 10 between the transformer 12 and the bus bar 20, and a transformer output terminal to which the secondary winding of the transformer 12 is connected to the insertion hole 32. 28 and lead terminals 36 extending from the bus bar 20 are inserted and soldered to an island-shaped printed pattern formed on the back surface of the substrate.

  An insertion hole 34 is also formed in the printed circuit board 10 between the bus bar 20 and the rectifying element 14, and a lead terminal 38 extending from the bus bar 20 and the two rectifying elements 14 taken out from the insertion hole 34 are inserted into the insertion hole 34. Two lead terminals 40 are inserted and soldered to an island-shaped print pattern formed on the back surface of the substrate.

  The rectifying element 14 of this embodiment uses two diodes housed in a package and the cathode side is commonly connected. For this reason, three lead terminals are provided from the package of the rectifying element 14. It has been taken out.

  According to such a circuit board connection structure, even if a large forward current flows from the transformer 12 through the rectifying element 14, the transformer output terminal 28 of the transformer 12 and the bus bar 20 are connected to the insertion hole 32 as shown in FIG. The lead terminal 36 is inserted and soldered, and the lead terminal 38 of the bus bar 20 and the lead terminal 40 of the rectifying element 14 are inserted into the insertion hole 34 and soldered. Without passing through the bus bar 20 and flowing through the printed pattern of the printed circuit board 10, heat is not generated due to loss, and the operating temperature of the switching power supply device that handles a large current can be reduced, improving reliability and durability. And

  When this circuit board connection structure is generally represented by the transformer 12 as a first circuit component and the rectifying element 14 as a second circuit component, the printed circuit board 10 formed between the first circuit component and the bus bar 20 is described. The lead terminal 28 of the first circuit component and the lead terminal 36 extending from the bus bar 20 are inserted into the first insertion hole 32 and soldered, and formed between the bus bar 20 and the second circuit component. It can be said that the lead terminal 38 extending from the bus bar 20 and the lead terminal 40 of the second circuit component are inserted into the second insertion hole 34 of the printed circuit board 10 and soldered.

  Further, the circuit board connection structure of the present embodiment is the same for the connection between the choke coil 16 and the rectifying element 14 although not shown. That is, an insertion hole is formed in the printed circuit board 10 between the choke coil 16 and the bus bar 20, and a choke coil terminal 30 of the choke coil 16 and a lead terminal extending from the bus bar 20 are inserted into the insertion hole. It is soldered to an island-shaped print pattern formed on the back surface.

  An insertion hole is also formed in the printed circuit board 10 between the bus bar 20 and the rectifying element 14, and a lead terminal 38 extending from the bus bar 20 and a lead terminal 40 taken out from the rectifying element 14 are inserted into the insertion hole 34. And soldered to an island-shaped print pattern formed on the back surface of the substrate.

  For this reason, even if a large flywheel current flows from the choke coil 16 to the rectifying element 14, it flows through the bus bar 20 without passing through the printed pattern on the back surface of the board, and generates heat due to loss when flowing through the printed pattern on the printed board 10. The operating temperature of the switching power supply device that handles a large current is reduced, and the reliability and durability can be improved.

(Arrangement structure of rectifier element for transformer and choco coil)
In the circuit board connection structure of the present embodiment, as shown in FIG. 4, a plurality of rectifier elements 14 are used. In this case, the plurality of rectifier elements 14 are arranged in the direction in which the transformer 12 and the choke coil 16 are arranged. For example, four pieces are arranged in two rows in the same direction.

  In this way, the plurality of rectifying elements 14 are arranged in parallel in two rows with respect to the arrangement of the transformer 12 and the choke coil 16, and are arranged at the same distance, and the plurality of rectifying elements 14 are arranged in parallel corresponding to the output of a large current. Even if connected and used, the plurality of rectifying elements 14 with respect to the printed circuit board 10 can be efficiently arranged in a small space, and the switching power supply device can be downsized.

  Further, between the row of the transformer 12 and the choke coil 16 arranged in the same direction and the row of the plurality of rectifying elements 14 shown in FIG. 4 is formed as a ventilation path through which wind is generated by forced cooling from a cooling fan (not shown). ing.

  Here, as shown in FIG. 1, the plurality of rectifying elements 14 are arranged in four rows in a row of bus bars 22 formed in a box shape, and the bus bars 20 serve as cooling plates for the rectifying elements 14. In fact, the space between the row of transformers 12 and choke coils 16 arranged in the same direction and the bus bar 22 in which a plurality of rectifying elements 14 are housed is by forced cooling from a cooling fan (not shown). It is formed as a ventilation path through which the wind passes.

  For this reason, even if a large current flows through the output circuit portion of the switching power supply device including the transformer 12, the rectifying element 14, and the choke coil 16, heat is generated due to high cooling efficiency by forced ventilation from the cooling fan. It can be reduced to improve reliability and durability.

(Second Embodiment of Circuit Board Connection Structure)
FIG. 6 is an explanatory view showing, in section, a second embodiment of a circuit board connection structure for connecting a transformer, a bus bar, and a rectifying element.

  As shown in FIG. 6, in the present embodiment, the transformer output terminal 28 of the transformer 12 and the bus bar 20 are connected by screwing into the printed circuit board 10 with screws 42 in the first embodiment of FIG. And other structures are the same.

  According to the second embodiment, since a large current does not flow in the printed pattern of the printed circuit board 10, the problem of heat generation due to loss does not occur, and the transformer output terminal 28 and the bus bar 20 of the transformer 12 are screwed together. By connecting and fixing to the printed circuit board 10, it is possible to increase the mounting strength of the transformer 12 to the printed circuit board 10.

  Note that the circuit board connection structure of the present embodiment can also be applied as a similar structure when the choke coil 16 and the rectifying element 14 are connected via the bus bar 20.

(Third embodiment of circuit board connection structure)
FIG. 7 is an explanatory view showing, in section, a third embodiment of a circuit connection structure for connecting a transformer and a rectifying element that do not require a bus bar.

  As shown in FIG. 7, in this embodiment, a bus bar is not used to connect the transformer 12 and the rectifying element 14, and an insertion hole 44 is formed in the printed circuit board 10 between the transformer 12 and the rectifying element 14. The transformer output terminal 28 of the transformer 12 and the two lead terminals 40 drawn out from the two rectifying elements 14 are inserted into the holes 44 and soldered to an island-shaped print pattern formed on the back surface of the substrate.

  For this reason, since the transformer output terminal 28 of the transformer 12 and the lead terminal 40 of the rectifying element 14 are inserted into the insertion hole 44 and connected by soldering, a large current does not flow through the printed pattern of the printed circuit board 10, thereby causing a loss. In addition to the effect of avoiding the problem of heat generation due to, there is no need to use a bus bar, so the circuit board connection structure is simplified, and the installation space and cost can be reduced.

  Note that the circuit board connection structure of the present embodiment can also be applied as a similar structure when the choke coil 12 and the rectifying element 14 are connected.

[Modification of the present invention]
Moreover, although said embodiment has taken the single-ended forward converter as an example, other than this, a flyback converter, a full bridge converter, a half bridge converter, a push-pull converter, etc. may be used.

  Moreover, although the diode is used as the rectifier element 14 in the transformer secondary side circuit of the above embodiment, a synchronous rectifier circuit may be configured. In this case, instead of the rectifier element 14, a MOS-FET Or the like.

  Moreover, although said embodiment has taken the transformer secondary side circuit of the switching power supply device as an example, it is not limited to this. For example, the present invention can be applied to a connection structure between an arbitrary first circuit component that handles a large current and an arbitrary second circuit component.

  The present invention includes appropriate modifications without impairing the object and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

10: Printed circuit board 12: Transformer 14: Rectifier 16: Choke coil 18: Capacitors 20, 22: Bus bar 24: Positive output terminal 26: Negative output terminal 28: Transformer output terminal 30: Choke coil terminals 32, 34, 44: Insertion Hole 36, 38, 40: Lead terminal 42: Screw

Claims (7)

In a circuit board connection structure in which a first circuit component, a bus bar member, and a second circuit component are arranged adjacent to each other on a printed circuit board,
A lead terminal of the first circuit component and a lead terminal extending from the bus bar member are inserted into a first insertion hole of the printed circuit board formed between the first circuit component and the bus bar member. Being soldered,
A lead terminal extended from the bus bar member and a lead terminal of the second circuit component are inserted into a second insertion hole of the printed circuit board formed between the bus bar member and the second circuit component. Circuit board connection structure characterized by being soldered.
In the circuit board connection structure according to claim 1,
The printed circuit board converts the input voltage into an intermittent voltage by turning on and off the switching element, and then transmits it to a rectifying / smoothing circuit including a rectifying element, choke coil and capacitor via a transformer to convert it to an output voltage. Circuit components of the switching power supply device to be placed,
When the first circuit component is the transformer and the second circuit component is the rectifying element,
A lead terminal to which a secondary winding of the transformer is connected to the first insertion hole of the printed circuit board formed between the transformer and the bus bar member, and a lead terminal extending from the bus bar member are provided. Inserted and soldered,
A lead terminal extending from the bus bar member and a lead terminal of the rectifying element are inserted and soldered into the second insertion hole of the printed circuit board formed between the bus bar member and the rectifying element. A circuit board connection structure characterized by that.
The circuit board connection structure according to claim 2, further comprising:
When the first circuit component is the choke coil and the second circuit component is another rectifying element,
A lead terminal to which a winding of the choke coil is connected and the other bus bar member are extended to another first insertion hole of the printed circuit board formed between the choke coil and the other bus bar member. Lead terminals are inserted and soldered,
A lead terminal extended from the other bus bar member and a lead of the other rectifying element are inserted into another second insertion hole of the printed circuit board formed between the other bus bar member and the other rectifying element. A circuit board connection structure, wherein terminals are inserted and soldered.
In the circuit board connection structure according to claim 2 or 3,
A plurality of the rectifying elements are provided and connected in parallel,
The circuit board connection structure, wherein the plurality of rectifying elements are arranged in one or a plurality of rows in the same direction as an arrangement direction of the transformer and the choke coil.
In the circuit board connection structure according to claim 4,
A circuit board connection structure characterized in that a ventilation path through which cooling air from a cooling fan passes is formed between the row of transformers and choke coils arranged in the same direction and the row of rectifying elements. .
In a circuit board connection structure in which a first circuit component, a bus bar member, and a second circuit component are arranged adjacent to each other on a printed circuit board,
The lead terminal of the first circuit component and the bus bar member are fixed to the printed circuit board connected by screws,
The lead terminal extended from the bus bar member and the lead terminal of the second circuit component are inserted into the insertion hole of the printed circuit board formed between the bus bar member and the second circuit component before soldering. A circuit board connection structure characterized by being attached.
In a circuit board connection structure in which a first circuit component and a second circuit component are arranged adjacent to each other on a circuit,
The lead terminal of the first circuit component and the lead terminal of the second circuit component are inserted into the insertion hole of the printed circuit board formed between the first circuit component and the second circuit component. Circuit board connection structure characterized by being soldered.

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