JP4415372B2 - Method for manufacturing power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize size reduction of a circuit board, to control the temperature rise of an power conversion section and to allow a large current to flow in the power conversion section. <P>SOLUTION: The circuit pattern 43 of a lead frame 41 is used as the conductive path of the power conversion section 31, thereby enabling to allow a bigger current to flow in the power conversion section 31. In addition, since a radiation section 48 which radiates heat outside is integrally formed on the circuit pattern 43 of the lead frame 41, the temperature rise of the power conversion section 31 can be suppressed by using the radiation section 48. In addition, the conductive path of the power conversion 31 and the radiation section 48 can be manufactured simultaneously by the common lead frame 41. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

The present invention relates to a method of manufacturing a power supply device including a power conversion unit through which a large current flows and a control unit through which a small current flows, such as a DC / DC converter, a switching power supply device, an inverter, and an uninterruptible power supply (UPS).

  In general, this type of power supply device includes a power conversion unit that extracts a desired output voltage from an arbitrary input voltage and a control unit that controls the power conversion unit. Since a larger current flows through the line and the heat generating component connected to the line than a control unit operating with a small current, a mounting structure suitable for energizing a large current is particularly required in the power conversion unit. However, a conventional printed circuit board in which a wiring pattern made of copper foil is etched on an insulating substrate, and an electric circuit is wired using this wiring pattern as a conductive path, the thickness of the copper foil is generally 35 microns. Even those that support current are limited to about 75 to 105 microns. The reason is that it is caused by a problem in forming the circuit board, and it is difficult to make the thickness of the copper foil larger than that in the processing method by etching. For this reason, in recent years, multi-layer boards that support large currents and those with increased copper foil thickness have been developed. However, when the circuit board wiring pattern is used as the conductive path of the power converter. The heat dissipation capability from the wiring pattern is determined by the width and thickness of the wiring pattern itself, and almost no heat dissipation effect can be expected. In addition, the width and thickness of the wiring pattern itself are regulated, and the thermal conductivity is poor. In particular, in the wiring pattern on which the heat generating component is mounted, the vicinity region thereof becomes a local high temperature portion. Therefore, it was necessary to consider the design so that these heat spots do not exceed the rated temperature of the circuit board.

  In addition, along with the downsizing and large capacity (large current) of electronic equipment, there is also a demand for downsizing of circuit boards. However, if the conductive path of the power conversion unit is formed by the circuit board wiring pattern, It is necessary to solve the problem of large current and heat spots of heat-generating parts at the same time.

  Therefore, in order to effectively dissipate heat from the heat-generating component connected to the wiring pattern of the power conversion unit, for example, in Patent Document 1, a power transistor that is a heat-generating component and heat generated by the power transistor are radiated. There is disclosed a structure in which a heat radiating plate is assembled in close contact with a screw, and a power transistor lead and a screw are soldered to a circuit board.

Further, in another patent document 2, in consideration of flowing a large current on the wiring pattern of the circuit board, while forming an etching pattern with a copper foil as a circuit conductor for small current on the insulating substrate, There has been disclosed a printed circuit board for power circuit wiring in which a conductive metal bar made of copper or a copper alloy is fixed by soldering as a circuit conductor for passing a large current.
Japanese Unexamined Patent Publication No. 7-135384 JP-A-5-167207

  In the above prior art, preparing a unique heat sink for each heat generating component as in Patent Document 1 has a certain effect in suppressing the heat spot of the wiring pattern described above. In order to increase the productivity while being planned, the individual heat sinks significantly hinder. In addition, since the amount of current that can be passed as the power conversion unit is limited by the wiring pattern of the circuit board regardless of the shape of the heat sink, it is not possible to provide a power supply device that can handle a large current.

  In Cited Document 2, a metal bus bar is directly soldered and connected to the surface of the circuit board in order to flow a large current on the wiring pattern of the circuit board. It is necessary to install them individually, which also hinders downsizing of the apparatus and improvement of manufacturability. Furthermore, since the metal bus bar is connected to the wiring pattern by soldering, a heat radiator as in the cited document 1 is also necessary to effectively suppress the heat generating component and the surrounding heat spot. It is more difficult to reduce the size of the device and improve the manufacturability because the bus bar and the radiator are mixed.

Therefore, in view of the above problems, the present invention can suppress a temperature rise in the power conversion unit without causing manufacturing difficulties while reducing the size of the circuit board, and allows a large current to flow through the power conversion unit. It is an object of the present invention to provide a method for manufacturing a power supply device.

A second object of the present invention is to provide a method of manufacturing a power supply device that can effectively suppress heat-generating components and the surrounding heat spots.

According to another aspect of the present invention, there is provided a method of manufacturing a power supply device, comprising: a power conversion unit including a power conversion unit through which a large current flows; and a control unit through which a small current flows. a step of assembling a circuitry substrate disposed above tethered scree around part circuit pattern serving as conductive paths of the power conversion unit, and the circuit pattern of the lead frame, ensure electrical connections between the circuit board so as to form a heat radiating portion for radiating heat to the board connecting portion and the outside to be connected to, or disconnected and forming a lead frame, all pre-Symbol peripheral portion from the circuit pattern, or the heat radiating portion If the heat dissipation capacity is insufficient only, leaving a part or the whole of the peripheral portion, a step of the perimeter leaving the heat radiation portion for radiating heat to the outside, Ru der performs.

  In this case, the circuit pattern of the lead frame is used as the conductive path of the power conversion unit. However, the circuit pattern of the lead frame is not limited by the wiring pattern formed on the circuit board and is several times thicker than the wiring pattern. Therefore, a larger current can be passed through the power conversion unit without increasing the size of the circuit board. In addition, after connecting the circuit pattern board connection part to the circuit board, if necessary, the peripheral part of the lead frame is separated to easily form multiple independent circuit patterns as conductive paths for the power converter. it can. In addition, the lead frame circuit pattern is integrally formed with a heat radiating part that radiates heat to the outside. The conductive path and the heat radiating part of the conversion part can be simultaneously manufactured by a common lead frame, and the manufacturability can be improved.

  In addition, the peripheral part is originally separated from the circuit pattern as an unnecessary part of the lead frame, but if the heat dissipation capacity as the power conversion part is insufficient only by the heat dissipation part formed in the circuit pattern, leave this peripheral part without separation. If the heat dissipating part is used, the necessary heat dissipating capacity can be ensured without having to install a heat dissipating member with a separate member.

In the method of manufacturing the power supply device of the present invention, in the step of forming the lead frame, a component connecting portion for connecting a heat generating component of the power conversion portion may be formed in the circuit pattern of the lead frame.

  In this case, since the heat generating component of the power conversion unit can be connected to the component connecting part formed in the circuit pattern of the lead frame, the heat from the heat generating component is directly transmitted from the component connecting part of the same lead frame to the heat radiating unit, and heat is generated. It is possible to effectively suppress heat spots in the component and its surroundings.

Moreover, the manufacturing method of the power supply device of this invention may form the clearance gap between the said lead frame and the said circuit board, and may connect the said control part and the said power conversion part .

  In this way, heat exchange with air is promoted not only on one side of the heat radiating part not facing the circuit board but also on the other side of the heat radiating part facing the circuit board. Heat dissipation can be improved. Further, the influence of heat from the lead frame to the circuit board can be avoided, and a stable operation as a power supply device can be realized.

The manufacturing method of the power supply apparatus of the present invention may further perform step Ru provided with high heat dissipation film layer on the surface of the heat radiating portion.

  The film layer having high heat dissipation herein may be white or black alumite if the material of the lead frame is aluminum, for example, or may use a paint for radiation heat dissipation. If it does in this way, while being able to dissipate heat more effectively from a thermal radiation part via a film layer, a film layer plays the role of oxidation prevention of a lead frame, and it can improve the reliability as a device.

In the method for manufacturing a power supply device according to the first aspect of the present invention, it is possible to suppress a temperature rise in the power conversion unit without manufacturing difficulty while reducing the size of the circuit board. A large current can flow.

  In addition, when the radiation capacity is insufficient with only the heat radiating part, the part or the whole of the peripheral part is left, and by using the remaining peripheral part as a heat radiating part, a necessary heat radiating capacity as a power conversion part Can be secured.

In the power supply device manufacturing method according to the second aspect of the present invention, heat from the heat generating component is directly transmitted from the component connecting portion of the same lead frame to the heat radiating portion, and heat spots in the heat generating component and its surroundings can be effectively suppressed.

In the method for manufacturing a power supply device according to claim 3 of the present invention, heat exchange with air is promoted from the other side of the heat dissipating part facing the circuit board, and heat dissipation from the heat dissipating part can be enhanced. The heat influence from the heat radiation part to the circuit board can be avoided.

In the power supply device manufacturing method according to the fourth aspect of the present invention, heat can be more effectively dissipated from the heat radiating portion through the film layer, and lead film oxidation can be prevented by the film layer.

  Hereinafter, a preferred embodiment of a power supply device as a high-current electronic device according to the present invention will be described in detail with reference to FIGS.

  First, the configuration of the completed power supply device will be described with reference to FIGS. Reference numeral 11 denotes a circuit board, which is provided with a small current pattern 3 for passing a small current on one side surface of an insulating substrate 1 made of a plate material such as epoxy resin or glass fiber. As is well known, the small current pattern 3 is formed into a desired shape by etching a metal foil such as a copper foil. In this embodiment, the circuit board 11 is composed of only a single insulating substrate 1 and a wiring pattern (small current pattern 3) formed on the surface thereof. However, in order to increase the wiring density, insulation with a wiring pattern is used. A circuit board 11 in which substrates are laminated in multiple layers may be used. Further, a power pattern for flowing a large current may be provided on the other surface of the insulating substrate 1 as a part of the wiring pattern.

  On one side of the circuit board 11 on which the small current pattern 3 is disposed, an electronic component 22 constituting the control unit 21 through which a small current of the control system flows together with the small current pattern 3 is mounted. The control unit 22 of the power supply device is provided to control each unit of the power conversion unit 32 described later, specifically, a monitoring unit (an output voltage detection circuit, a load current detection circuit, etc.) that monitors each unit of the power conversion unit 32 ), And a control signal generation unit (such as a PWM control circuit and a drive circuit) that provides an appropriate control signal to a control element (such as a switching element) of the power conversion unit 32 in response to a monitoring result from the monitoring unit . Therefore, the electronic component 22 of the control unit 21 includes circuit elements that handle relatively small signals such as a control IC, a shunt regulator, and a photocoupler.

  On the other hand, on the other side of the circuit board 11 where the wiring pattern is not provided, a power conversion unit 31 through which a large current of the power system flows is provided together with a circuit pattern 43 of the lead frame 41 described later. The power conversion unit 31 is mainly for extracting a desired output voltage from an arbitrary input voltage supplied to the power supply device. As the electronic component 32 mounted as a circuit element of the power conversion unit 31, for example, a transformer, There are inevitably many heat-generating components through which a large current flows, such as switching elements, rectifier elements, commutation elements, choke coils, and smoothing capacitors.

  A plurality of through-holes 6 serving as lead frame connection holes for inserting and soldering a substrate connection portion 47 of a lead frame 41 described later are provided at locations where the small current pattern 3 of the circuit board 11 is disposed.

  On the other hand, 41 is a lead frame, which is formed by laser processing, pressing or etching a metal plate 42 having a thickness of about 0.1 mm to 1.0 mm, and its shape is a required current capacity and mechanical. Designed with strength. The highly conductive metal plate 42 used as the base material of the lead frame 41 is a uniform rolled plate having a thickness of, for example, 0.25 mm so that a fine circuit pattern 43 (to be described later) can be wired at a high density with the lead frame 41 alone. Consists of. In consideration of thermal conductivity, the metal plate 42 is preferably made of a metal whose main component is at least one selected from, for example, copper, iron, aluminum, and nickel. A plurality of separation grooves 44 (see FIG. 5) are formed in the metal plate 42 by a well-known etching process or press process applied to both surfaces thereof. Each separation groove 44 has an opening formed through the lower surface from the upper surface of the metal plate 42, and the separation groove 44 allows a plurality of circuit patterns 43 and external connection terminal pieces 45 to be connected to the metal plate 42. Separated in 42 plane directions.

  The circuit pattern 43 of the lead frame 41 is formed with a component connection portion 46 at a position where the terminal electrode 33 of the electronic component 32 is placed and soldered, and is raised toward one side of the circuit board 11. One or more substrate connecting portions 47 are formed to protrude. The board connecting portion 47 is provided so as to be able to be inserted into the through hole 6 so as to face the through hole 6 provided in the circuit board 11, and is connected to the small current pattern 3 of the circuit board 11 by soldering. In addition, a heat radiating portion 48 having high heat radiating properties is integrally formed at a portion of the circuit pattern 43 excluding the component connecting portion 46 and the board connecting portion 47. The heat radiating portion 48 can also be realized by forming the metal plate 42, which is a base material of the lead frame 41, with a material having excellent heat radiating properties such as aluminum, for example, but preferably white or black as shown in FIG. A surface layer or a coating is formed on the surface of the heat radiating portion 48 with a high heat dissipation film layer 50 made of alumite film or a paint having excellent radiation heat dissipation. Note that such a film layer 50 is provided only on the surface of the heat radiating portion 48 and is not provided in other parts of the lead frame 41. In this case, it is possible to avoid a manufacturing defect that makes it impossible to perform soldering connection by the film layer 50 at the terminal piece 45, the component connection part 46, and the board connection part 47. Further, the film layer 50 may be provided only on one side of the heat radiating part 48 not facing the circuit board 11 or may be provided on both surfaces of the heat radiating part 48 as shown in FIG.

  51 is an insulating resin for holding each circuit pattern 43 finally isolated in an island shape and the terminal piece 45 connected to the circuit pattern in the plane direction, and the insulating resin 51 is embedded in the separation groove 44 without a gap. The insulating resin 51 and the lead frame 41 constitute, for example, a rectangular lead frame substrate 52 that is substantially the same shape as the circuit substrate 11. Each terminal piece 45 is provided so as to protrude outward from the peripheral edges on one side of the lead frame substrate 52 and the circuit board 11. Instead of the terminal piece 45, a separate terminal pin or the like may be attached to the circuit pattern 43, but it is preferable to form the circuit pattern 43 and the terminal piece 45 integrally from the viewpoint of improving workability. In addition, when attaching the completed power supply device to a mounted portion such as a printed circuit board (not shown), the tip of the terminal piece 45 is inserted into a through hole provided in the printed circuit board. The terminal piece 45 and the through hole of the printed board can be connected by soldering. Further, 53 is a gap formed between the other side surface of the circuit board 11 and one side surface of the lead frame substrate 52, and the circuit board 11 and the lead frame 52 are arranged in a non-contact state by the gap 53. .

Next, a manufacturing method of a power supply device according to the present invention will be described in accordance with the steps on the basis of FIGS. 4-7. First, in FIG. 4, the assembly process of the circuit board 11 is performed. In this method, copper foils are formed on one side and the other side of the insulating substrate 1, and a hole is drilled with a drill or the like at a location where the through hole 5 is to be formed. To do. Thereafter, a necessary resist is printed and unnecessary copper foil is removed by etching, and then the resist is peeled off to form a small current pattern 3 having a desired shape on one side surface of the insulating substrate 1.

  Subsequent to the assembly process of the circuit board 11, a mounting process of the electronic component 22 is performed. As shown in FIG. 4, the solder paste is printed in advance on the position where the small current pattern 3 is to be bonded, and after the electronic component 22 is mounted and bonded on the small current pattern 3, it is passed through a high temperature bath. Assembling as the control unit 21 is completed when all the electronic components 22 are fixed to the small current pattern 3.

  On the other hand, apart from the assembly of the control unit 21, a lead frame manufacturing process for obtaining a lead frame 41 having a desired shape from the metal plate 42 is performed independently. As shown in FIG. 5, the lead frame 41 is formed of a metal plate 42 made of a material having good thermal conductivity and electrical conductivity such as copper foil or phosphor bronze, and a large current of the power conversion unit 31 is generated. It has a pattern shape corresponding to the flowing portion and the lead extraction portion to the outside. In this embodiment, the lead-out portion to the outside is arranged side by side as a terminal piece 45 on one side of the lead frame 41, and one end of these terminal pieces 45 is a frame-like portion 54 formed around the lead frame 41. The other end of the terminal piece 45 is connected to a circuit pattern 43 having a shape corresponding to the power pattern 2. Further, the single circuit pattern 43 that does not include the terminal piece 45 is also all connected to the frame-like portion 49 around the lead frame 41. Thus, the circuit pattern 43 and the terminal piece 45 are all supported by the frame-like portion 54 in the initial state of the lead frame 41 before being superimposed on the circuit board 11.

  Thereafter, in order to enhance the heat radiation performance of the circuit pattern 43, particularly the heat radiation portion 48, the surface treatment or coating process of the lead frame 41 is performed as necessary. For example, when the metal plate 42 is aluminum, it is located in the heat radiation part 48 of the circuit pattern 43, and a black or white alumite film is formed on the surface thereof. Even if the crotch and the metal plate 42 are made of a material other than aluminum, for example, a coating material excellent in radiation heat radiation may be applied to the surface of the heat radiation portion 48.

  When the lead frame manufacturing process is completed, the process proceeds to the manufacturing process of the lead frame substrate 52. Here, the board connecting portion 47 formed in advance at the appropriate position of the circuit pattern 43 is bent in the vertical direction. Next, the insulating resin 51 is embedded in the separation groove 44 that is located at a place where the electronic component 32 is mounted and is opened between the circuit patterns 43 without any gaps. This insulating resin 51 is used to prevent the independent island-like circuit patterns 43 from being detached and the circuit patterns 43 from wobbling in the subsequent cutting process of the outer periphery of the lead frame 41.

  In this embodiment, the lead frame substrate is such that one side and the other side of the insulating resin 51 are flush with one side and the other side of the lead frame 41 so that the surface of each circuit pattern 43 is exposed to the outside. 52 is formed. Thus, by not covering the surface of the circuit pattern 43 with the insulating resin 51, it is possible to efficiently dissipate heat from the heat radiation part 48 into the air.

  In the step of embedding the insulating resin 51, the one side surface and the other side surface of the lead frame 41 are in contact with each other between the upper die and the lower die of a resin injection machine (not shown), and the region where the electronic component 32 is finally mounted ( An uncured insulating resin 51 is injected into the separation groove 44 located in the component mounting portion. In particular, the separation grooves 44 in the component mounting portion are not scattered in an island shape because only one side of all the circuit patterns 43 is connected to the frame-like portion 54 on the periphery of the lead frame 41. Since it is formed by two continuous holes, when the insulating resin 51 is injected into an appropriate position of the separation groove 44, the insulation resin 51 can be embedded in the entire separation groove 44 without a gap. The insulating resin 51 is then cured by heat or the like, and holds each circuit pattern 43 so as not to leave. At this stage, the lead frame substrate 52 in a state where the frame-like portions 54 are connected is completed.

  When the manufacturing process of the lead frame substrate 52 is completed, the mounting process of the electronic component 32 that becomes the circuit element of the power conversion unit 31 is performed. In the mounting process of the electronic component 32, the solder paste is printed in advance on the position to be bonded to the circuit pattern 43, that is, on the component connecting portion 46, and the electronic component 32 is mounted and bonded on the lead frame substrate 52. This is done by soldering through a temperature bath. FIG. 6 shows a state at a stage where the mounting process of the electronic component 32 is completed, and the assembly as the power conversion unit 31 is completed here.

  Thus, the separately manufactured control unit 21 and power conversion unit 31 are integrally connected in the next joining step. As shown in FIG. 7, the board connecting portion 47 protruding from one side of the lead frame board 52 is inserted into the through hole 6 from the other side of the circuit board 11, and between the circuit board 11 and the lead frame board 52. This is done by fixing the tip of the substrate connecting portion 47 and the through hole 6 with solder 57 (see FIG. 2) in a state where the gap 53 is formed. Then, when the frame-like portion 54 of the lead frame 41 is cut along the periphery of the lead frame substrate 52 with the terminal pieces 45 left, a power supply substrate as shown in FIGS. 1 and 2 is completed. Note that it is not essential to separate the frame-shaped portion 54. If the heat radiation capacity of the circuit pattern 43 alone is not sufficient, leave the frame-shaped portion 54 partially or entirely, and the same It is good also as a heat dissipation part.

  In the above-described series of manufacturing steps, after the circuit board 11 and the lead frame board 52 are coupled, the electronic components 22 and 32 may be mounted, bonded, and soldered. The circuit board 11 and the lead frame board 52 Before connecting the electronic components 22, 32, only mounting and bonding the electronic components 22, 32, and simultaneously connecting the circuit board 11 and the lead frame substrate 52, these electronic components 22, 32 may be connected by soldering. . That is, the operations of mounting / bonding and soldering the electronic components 22 and 32 may be performed at any stage in consideration of manufacturability and the like.

  In the completed power supply device, when an input voltage is supplied between specific terminal pieces 45, the control unit 21 and the power conversion unit 31 operate, and an output voltage is taken out from another terminal piece 45. At this time, the output voltage and output current from the power conversion unit 31 are constantly monitored by the control unit 21, and the control unit 21 outputs a control signal for stabilizing the output voltage based on the monitoring result. Send to 31. Such monitoring signals for the output voltage and output current and the control signal for the power converter 31 are transmitted through the board connecting part 47 of the lead frame board 52 connected to the through hole 6 of the circuit board 11.

  In addition, as a large current flows through the circuit pattern 43 that is a conductive path of the power conversion unit 31, among the electronic components 32 constituting the power conversion unit 31, heat is generated from heat-generating components such as switching elements and rectification elements. Will occur. However, the heat of this heat-generating component is quickly transmitted to the circuit pattern 43 of the lead frame 41 made of the metal plate 42 having good thermal conductivity, and promptly enters the air from the surface of the heat radiating part 48 formed at a proper position of the circuit pattern 43. Therefore, the heat spot can be reduced by suppressing the heat concentration in the heat generating component and its surroundings, and the entire lead frame substrate 52 acts as a radiator. In particular, in the present embodiment, since the film layer 50 having a high heat dissipation property is provided on the surface of the heat radiating part 48, heat dissipation from the heat radiating part 48 through the film layer 50 is further promoted, and the locality in the power conversion part 31 is increased. Temperature rise can be effectively reduced.

  Further, since a gap 53 is provided between the lead frame 41 and the circuit board 11, the heat reaching the heat radiating portion 48 of the circuit pattern 43 is caused by the other side of the lead frame 41 not facing the circuit board 11. In addition, it is dissipated into the air from one side surface of the lead frame 41 facing the circuit board 11. Therefore, coupled with the provision of the film layer 50 on the surface of the heat radiating portion 48, heat exchange between the heat radiating portion 48 and the outside can be efficiently performed on both surfaces of the heat radiating portion 48. In addition, since heat from the lead frame 41 is not directly transferred to the circuit board 11, adverse effects on the electronic components 22 mounted on the circuit board 11 can be reduced.

As described above, in the present embodiment, in the method of manufacturing a power supply device including the power conversion unit 31 through which a large current flows and the control unit 21 through which a small current flows, the small current pattern 3 serving as a conductive path of the control unit 21 is obtained. a step of assembling the circuitry substrate 11 disposed on the insulating substrate 1, the circuit pattern 43 as a conductive path of the power conversion unit 31 Tsunagare the frame portion 54 is a peripheral part, and to the circuit pattern 43, The step of forming the lead frame 41 so as to form a board connecting portion 47 connected to achieve electrical connection with the circuit board 11 and a heat radiating portion 48 that radiates heat to the outside, and all of the frame-like portion 54 Is removed from the circuit pattern 43, or when the heat dissipation capacity is not sufficient with only the heat radiating portion 48, a part or the whole of the frame-shaped portion 54 is left, and the remaining peripheral frame-shaped portion 54 is heated to the outside. And a step of forming a radiating heat dissipation portion .

  In this case, the circuit pattern 43 of the lead frame 41 is used as the conductive path of the power conversion unit 31. However, the circuit pattern 43 of the lead frame 41 is not restricted by the wiring pattern formed on the circuit board 11, and the wiring pattern Therefore, a larger current can be passed through the power conversion unit 31 without increasing the size of the circuit board 11. In addition, after connecting the board connecting portion 47 of the circuit pattern 43 to the circuit board 11, if necessary, the frame-like portion 54 that is the peripheral portion of the lead frame 41 is cut off, so that a plurality of circuit patterns 43 independent in an island shape are obtained. Can be easily formed as a conductive path of the power converter 31. In addition, the circuit pattern 43 of the lead frame 41 is integrally formed with a heat radiating part 48 that radiates heat to the outside, so that the temperature increase of the power conversion part 31 can be suppressed by using the heat radiating part 48. In addition, the conductive path of the power conversion unit 31 and the heat radiating unit 48 can be manufactured at the same time by the common lead frame 41, and the productivity can be improved.

  In the present embodiment, the component connection portion 46 for connecting the electronic component 32 that is the heat generating component of the power conversion portion 31 is formed in the circuit pattern 43 of the lead frame 41.

  In this case, since the heat generating electronic component 32 of the power conversion unit 31 can be connected to the component connecting portion 46 formed on the circuit pattern 43 of the lead frame 41, the component connection of the lead frame 41 with the same heat from the electronic component 32 is possible. It is directly transmitted from the part 46 to the heat radiating part 48, and the heat spots in the electronic component 32 and its periphery can be effectively suppressed.

  Further, in this embodiment, all the frame-like parts 54 are separated from the circuit pattern 43, and the power converter 31 is made compact, but if necessary, without separating the frame-like part 54 from the circuit pattern 43, The remaining frame portion 54 may be a heat radiating portion that radiates heat to the outside.

  The frame-like portion 54 is originally separated from the circuit pattern 43 as an unnecessary part of the lead frame 41. However, if the heat-dissipating capacity as the power conversion portion 31 is insufficient only by the heat-dissipating portion 48 formed in the circuit pattern 43, this frame-like portion If the heat radiation part 48 is left without being separated, the necessary heat radiation capacity can be ensured without the need to install a radiator or the like with a separate member.

  In this embodiment, a gap 53 is formed between the lead frame 41 (lead frame substrate 52) and the circuit board 11.

  In this way, heat exchange is promoted with the air that is the gap 53 not only on one side surface of the heat radiating part 48 not facing the circuit board 11 but also on the other side surface of the heat radiating part 48 facing the circuit board 11. In addition, the heat dissipation from the heat radiating portion 48 of the lead frame 41 can be enhanced. Further, the influence of heat from the lead frame 41 to the circuit board 11 can be avoided, and a stable operation as a power supply device can be realized.

  In this embodiment, a film layer having a high heat dissipation property is provided on the surface of the heat dissipation portion 48. The film layer with high heat dissipation herein may be white or black alumite if the material (metal plate 42) of the lead frame 41 is aluminum, for example, or may use a radiation heat radiation paint. In this way, heat can be more effectively dissipated from the heat radiating portion 48 via the film layer 50, and the film layer 50 can play a role in preventing the oxidation of the lead frame 41, thereby improving the reliability of the device.

  In addition, a present Example is not limited to said each Example, A various deformation | transformation implementation is possible. For example, in order to increase the mounting density of the circuit board 11, a wiring pattern serving as a conductive path of the control unit 21 or the power conversion unit 31 is formed on the other side surface of the circuit board 11, and the electronic components 22 and 32 are mounted thereon. May be. Also, all the electronic components 32 of the power conversion unit 31 are disposed on one side of the lead frame 41 facing the circuit board 11, and the entire other side of the lead frame 41 is the heat radiating unit 48. A high film layer 50 may be provided. In this way, the entire other side surface of the lead frame 41 becomes the heat radiating surface of the power conversion unit 31, and the heat radiating effect can be further enhanced.

It is a rear view of the power supply device in a completed state showing a preferred embodiment of the present invention. It is a side view of the power supply device in a completed state. It is a principal part sectional drawing of a thermal radiation part same as the above. It is a top view which shows the completion state of a circuit board single-piece | unit same as the above. FIG. 6 is a rear view showing the state of the lead frame alone. It is a top view which shows the state of the stage which the mounting of each electronic component of a power conversion part was complete | finished same as the above. It is a side view of the state which joins a lead frame board | substrate and a circuit board same as the above.

1 Insulating substrate 3 Small current pattern
11 Circuit board
21 Control unit
31 Power converter
32 Electronic parts (heating parts)
41 Lead frame
43 Circuit pattern
46 Parts connection
47 Board connection
48 Heat sink
50 membrane layers
53 Clearance
54 Frame (periphery)

Claims (4)

In a method of manufacturing a power supply device including a power conversion unit through which a large current flows and a control unit through which a small current flows,
A step of assembling a circuitry substrate by disposing a small current pattern serving as a conductive path of the control unit on an insulating substrate,
Joint scree circuit pattern to be conductive path of the power conversion part to the peripheral part, and this circuit pattern, the heat radiating unit for radiating heat to the board connecting portion and the outside to be connected to ensure electrical connections between the circuit board Forming a lead frame so as to form
Or disconnect all pre SL peripheral portion from the circuit pattern, or if the only radiating section insufficient heat dissipation capacity, leaving a part or the whole of the periphery, the heat perimeter leaving this to the outside manufacturing method of a power supply device and carrying out the steps of the heat radiating unit that radiates a. 2. The method of manufacturing a power supply device according to claim 1 , wherein in the step of forming the lead frame, a component connecting portion for connecting a heat generating component of the power conversion portion is formed in a circuit pattern of the lead frame. Forming a gap between the circuit board and the lead frame, the production of the power supply device according to claim 1 or 2, characterized in that for connecting the control unit and the power converting unit Way . Method of manufacturing a power supply device according to any one of claims 1 to 3, wherein the performing further step of Ru maintain high film layer having heat dissipation on the surface of the heat radiating portion.

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