JP2013247168A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem of a power supply device mounting through-hole mounting components and surface mounting components mixedly, that high heat dissipation, compaction and low cost are required because a switch element, e.g., a transistor, an IGBT, an MOSFET, or the like, generates heat.SOLUTION: The power supply device includes a sub-printed wiring board having a through-hole mounted power device, and a main printed wiring board mounting a microcomputer performing drive control of a power device. A plurality of patterned electrode terminals are provided on the peripheral portion of the sub-printed wiring board. Some of the plurality of electrode terminals are connected electrically with the lead terminals of the power device, and the sub-printed wiring board is secured to the main printed wiring board by the remaining electrode terminals, in a step for reflow mounting the sub-printed wiring board and the main printed wiring board.

Description

  The present invention relates to a power supply device that requires, for example, a mixed mounting of a through-hole mounting component and a surface mounting component.

  This type of power supply device is a power supply device applied to in-vehicle chargers, inverters, step-down converters, etc. Usually, this power supply device includes transistors, IGBTs, through-hole mounted parts such as MOSFETs, resistors, capacitors, and microcomputers. A surface mount component such as a control IC is mounted on the same substrate.

JP 2008-91817 A Japanese Patent Laid-Open No. 4-139862 JP 2010-21231 A

  However, the substrate configuration of the power supply device mounted in a mixed manner as described above requires high heat dissipation, a small size, and a low-cost structure because switch elements such as transistors, IGBTs, and MOSFETs generate heat.

  For such a problem, for heat generated from the component itself, for example, as disclosed in Patent Document 1, a heat radiating material (for example, a rubber-based member formed as a rectangular parallelepiped with silicon resin or acrylic resin). The technique of disposing on the substrate so as to thermally connect the electrode part of the heat generating component (the part to which the electrode is soldered) and the metal case is shown. Specifically, the heat dissipating material is disposed on the substrate such that one side surface thereof is in contact with the electrode portion of the heat generating component and the upper surface thereof is in contact with the insulating plate. And the heat which generate | occur | produces from the electrode part of a heat-emitting component is conducted to a metal case from the contact surface with the electrode part via a contact surface with an insulating board (patent document 1).

Further, as described in Patent Document 2, in a hybrid integrated circuit device in which a semiconductor chip having a large calorific value is mounted on a printed circuit board made of glass epoxy, a square hole is provided in the semiconductor chip mounting position of the printed circuit board, A method is shown in which a metal plate is attached to the back surface of a printed wiring board so as to close the square holes, and a semiconductor chip is directly mounted on the metal plate (Patent Document 2).

Moreover, as shown in Patent Document 3, the first electronic component and the like are mounted on one surface of the lead frame, and these are sealed with a mold resin, and the other surface of the first lead frame has an electrical insulating property. A second lead frame is provided through the insulating layer, and the second electronic component is mounted on a portion of the second lead frame exposed from the mold resin, and the end of one of the two lead frames. The part is folded to the end of the other lead frame across the insulating layer, so that the ends of both the lead frames are joined to each other, so that a large component is mounted on the lead frame, and A technique for appropriately dissipating heat from a molded electronic component has been proposed.

According to Patent Document 1, although heat generation from a single component can be suppressed, a heat radiation material corresponding to the pattern area is required to pass pattern heat generation through which a large current flows, depending on the shape, to the case or the like.

  As described in Patent Document 2, there are metal core substrates, thick film printed ceramic substrates, and the like for power hybrid integrated circuit devices, but there is a limit to high integration. Further, as a substrate suitable for high integration, there is an organic wiring such as glass epoxy, but it is not suitable for power use. Therefore, when a large amount of heat is generated and high integration is required, it is difficult to realize a hybrid integrated circuit device. It takes a lot of development man-hours to make it modular, and it is not suitable for small lot products.

Conventional methods include through-hole mounting parts such as transistors and IGBTs (radial parts, axial parts, packages such as DIP, PGA, ZIP, etc.) and surface mounting parts. For reflow mounting in the soldering manufacturing process, Flow implementation is used.
Flow mounting is used for soldering through-hole mounting type boards. Molten solder always blows out and circulates so that the solder surface of the board touches the solder jet surface. It is a method of soldering.
In addition, the reflow mounting means that soldering is performed on the substrate in advance by HASL (hot air solder leveler), solder paste printing or the like by infrared heating, hot air method, vapor phase soldering method, etc. Mount the parts and pass through the reflow bath. In this way, the solder is melted and soldered.

When a through-hole mounting component and a surface layer mounting component are mixedly mounted on a substrate, it is necessary to divide the manufacturing process into two steps, flow and reflow. As a process flow, after performing reflow mounting, flow mounting is performed.
At this time, by passing the flow phase, the flow mounting is performed in a state in which a device for protecting the surface mounting portion is attached for the purpose of preventing the surface mounting component terminal once mounted from being melted by solder.
In such a mounting method, it is not possible to mount a component in order to avoid interference with the component at and around the place where the protector comes into contact with the substrate, and this restricts the component mounting position.

  Conventionally, a pattern portion where a large current flows on a substrate generally employs a method of suppressing heat generation on the substrate pattern by increasing the thickness of the substrate copper foil from the viewpoint of heat generation and securing the pattern area. The copper foil thickness of the pattern in such a case is usually about twice as large as the copper foil thickness of 60 μm with respect to 12 μm to 35 μm to reduce the resistance value on the pattern wiring.

Further, as described in Patent Document 2, a metal core substrate provided with a metal plate as an inner layer is also used as a heat countermeasure. However, each method requires a board manufacturing process compared to the normal manufacturing process, and the unit cost of the board material itself increases, so that the substrate cost compared to the normal FR4 (epoxy laminated material) board layer configuration. There is a problem that becomes expensive.
Further, when pattern wiring is performed on the same substrate, it is difficult to reduce the size of the substrate, resulting in a problem that the cost of the substrate is increased.
Furthermore, there is a problem that heat is generated due to the conductor loss of the substrate pattern due to heat generation peculiar to the power circuit and a large current flowing on the substrate pattern.

  This circuit simplifies the manufacturing process and reduces the size of the board in a circuit in which through-hole mounting parts and surface mounting parts are mounted together, and suppresses substrate pattern heat generation, a problem peculiar to power electronics. It is an object of the present invention to provide a power supply device that can reduce costs.

A power supply apparatus according to the present invention includes a sub printed wiring board (hereinafter referred to as “sub board”) on which a power device is mounted through-hole, and a main printed wiring board (hereinafter referred to as “main board”) on which a microcomputer for driving and controlling the power device is mounted. And a plurality of patterned electrode terminals are provided on the peripheral edge of the sub-substrate, and some of the plurality of electrode terminals are electrically connected to the lead terminal portion of the power device. In addition, the sub-board is fixed to the main board in the step of reflow mounting the sub-board and the main board with the remaining electrode terminals.

  In the conventional power supply device in which the through-hole mounting component and the surface mounting component are mounted in a mixed manner, it is necessary to solder the sub-board by flow mounting as a pre-process for reflow mounting. Since only the through-hole mounting components are collectively mounted on the substrate, the manufacturing process can be simplified as compared with the structure in which the manufacturing processes of the through-hole mounting and the surface mounting component are mixedly mounted, and the surface mounting component does not require a protective device. Or until now, clearance for attaching protective equipment has been required in the area of surface-mounted components and through-hole mounted components, but the main board size can be reduced by the amount of clearance. In addition, there are effects such as suppression of substrate pattern heat generation, which is a problem peculiar to power electronics, and cost reduction.

It is a perspective view which shows schematic structure of the power supply device which concerns on Embodiment 1 of this invention. It is sectional drawing which showed typically the outer layer / inner layer connection structure on the sub board | substrate in the power supply device which concerns on Embodiment 1 of this invention. It is a perspective view which shows schematic structure of the power supply device which concerns on Embodiment 2 of this invention. It is sectional drawing which showed typically the power supply device which concerns on Embodiment 3 of this invention. It is the perspective view which simplified and showed the state which connected the main board | substrate 6 in the power supply device which concerns on Embodiment 3 of this invention to the housing 10. FIG. It is explanatory drawing which shows the workpiece size and electrode formation of the sub board | substrate used for the power supply device which concerns on Embodiment 4 of this invention. It is a perspective view which shows a part of semicircular electrode terminal by which the pattern formation was performed in the power supply device which concerns on Embodiment 4 of this invention. It is sectional drawing which showed typically the power supply device which concerns on Embodiment 5 of this invention. It is sectional drawing which showed typically the modification of the power supply device which concerns on Embodiment 5 of this invention. It is sectional drawing which expanded and showed the principal part of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1
1 is a perspective view showing a schematic structure of a power supply device according to Embodiment 1 of the present invention.
In FIG. 1, the power supply device includes a sub board 3 and a main board 6, and the sub board 3 includes at least one or more power devices (for example, radial parts such as transistors and MOSFETs, axial parts) 1 and the power. Through holes 2 and 4 for mounting the device 1 are provided, and a plurality of patterned electrode terminals 5 and 7 are provided on the outer peripheral end portion of the sub-substrate 3, and some of the electrode terminals 5 are The power device 1 and the like are electrically connected to the through-hole 4 in which the through-hole is mounted, and the other (remaining) electrode terminals 7 are soldered in the process of reflow mounting the sub-board 3 and the main board 6. It functions as a fixing portion for fixing and holding the substrate 3 to the main substrate 6.

The main board 6 is mounted with a control IC 9 for driving and controlling the switch element such as the power device 1, and transmission of control signals from the main board 6 to the sub-board 3 is performed via the electrode terminals 5. Is controlled and driven.
Lead components such as the power device 1 are mounted on the sub-substrate 3 in advance through holes.
Solder is applied to the substrate by solder paste printing or the like at the location where the main substrate 6 and the sub substrate 3 are connected, that is, at the location between the sub substrate 3 and the electrode terminals (electrode terminal 5 and other (remaining) electrode terminals 7). As a result, the sub-board 3 can be soldered by reflow mounting in the same manner as other surface-mounted components such as the control IC 9.

The sub-board 3 has a mechanism as described below.
That is, the sub substrate 3 is provided with a flat portion (flat surface portion) 8 which is a suction portion, and the flat surface portion 8 is adsorbed by a suction nozzle (not shown) of the surface mount component automatic mounting machine. 3 is mounted on a desired mounting location of the main board 6.
As described above, by providing the flat surface portion 8 serving as a suction location on the sub-board 3 itself, mounting by an automatic mounting machine is possible as with other surface mounting components such as a microcomputer and a connector.

Further, the substrate pattern in the sub-substrate 3 is formed of a copper foil, and the thickness thereof is set to 60 μm or more. As described above, the resistance of the substrate pattern and the through holes 2 and 4 is reduced by setting the copper foil thickness to 60 μm or more, and the pattern heat generation due to the large current flowing is suppressed.
Originally, in order to reduce the heat generation due to the resistance value on the wiring in the board pattern through which a large current flows, the copper foil thickness is increased to ensure the heat dissipation of the board. Since the substrate pattern around the power device 1 that needs to be increased in thickness is formed on the sub-substrate, it is only necessary to use a highly heat-dissipating base material only in the portion where the pattern copper foil thickness of the substrate needs to be increased. The size of the sub-board 3 can also be reduced.

  Further, the sub-board 3 is obtained by mounting at least two or more power devices 1 on the board. For example, as shown in FIG. 2, the plurality of power devices 1 are placed on the sub-board via the through holes 4. Alternatively, the substrate patterns 4a of the outer layer / inner layer may be electrically connected to each other. Thereby, since the copper pattern is laminated in the thickness direction of the sub-substrate 3, the substrate pattern 4a can be laminated in the substrate plate thickness direction by the sub-substrate 3, so that the equivalent copper foil thickness can be secured and the resistance of the substrate pattern 4a As a result, the heat generation at the substrate pattern 4a can be reduced. Furthermore, by using only a necessary portion, that is, a substrate pattern portion around the power device 1 on the sub-substrate, as a substrate material having excellent heat dissipation such as an alumina or a ceramic substrate, the substrate heat generation can be further suppressed.

In the sub-board 3, it is necessary to perform soldering by flow mounting as a pre-process of reflow mounting. However, since the components of the sub-board 3 are concentrated only on the through-hole mounting components as described above, The manufacturing process can be simplified as compared with the structure in which the manufacturing process of the mounting component is mixedly mounted.
Specifically, a protective device is not required for the surface mount component. Or until now, a clearance for attaching the protective device has been required in the area of the surface mounting component and the through-hole mounting component, but the clearance becomes unnecessary, and the size of the substrate can be reduced accordingly.

Embodiment 2
FIG. 3 is a perspective view showing a schematic structure of the power supply device according to the second embodiment.
In FIG. 3, in addition to the first embodiment, the power supply device employs a high thermal conductivity substrate material (for example, aluminum, ceramic, metal core substrate) having a good thermal conductivity as the substrate material of the sub-substrate 3, and the main substrate. 6 and a housing 10 (metal case or heat sink) in which the sub-board 3 is stored (FIG. 5).

By doing in this way, when the heat generated in the power device 1 is released to the housing 10, the heat conductivity is improved as compared with the normal FR 4 (epoxy laminate material), so the heat conductivity of the sub-board 3 is improved. Since the heat dissipation can be improved, the heat dissipation performance of the substrate is further improved.
Furthermore, according to the second embodiment, the sub-board 3 needs only about the mounting space of the power device 1, so even if a special board material as in the second embodiment is adopted, the cost increase is minimized. it can.

Embodiment 3
FIG. 4 is a cross-sectional view schematically showing a schematic structure of the power supply device according to the third embodiment.
In addition to the second embodiment, the power supply device according to the third embodiment provides a path for transferring heat between the power device 1 and the housing 10 by providing a plurality of heat dissipation through holes 11 in the sub-board 3. Formed.
In addition, the location where the through hole 11 for heat dissipation is provided is a location where the power device 1 is in contact with the package portion or the fin for heat dissipation, and is configured to be connected to the housing 10 that houses the main board 6 and the sub board 3. The heat generated in the power device 1 may be released to the housing (or metal case) 10 through the through-hole 11 for use.
For example, as shown in FIG. 5, a heat dissipation fin 10 a is provided in the housing 10, and a heat dissipation through hole (not shown) is provided in the main substrate 6 as well as the heat dissipation through hole 11 of the sub substrate 3. The sub-board 3 is provided in the housing 10 so as to be in contact with the heat dissipation fin 10a through the heat dissipation through hole. Further, the main board 6 is structured to be fixed to the casing 10 with a plurality of screws 16 so that the heat radiating through holes of the main board 6 are firmly in contact with the heat radiating fins 10a.
With this configuration, it is possible to form a path for transferring heat between the power device 1 and the housing 10 with a cheaper and simple structure.
In FIG. 5, the heat generated by the power device 1 is released to the housing 10 through the main substrate 6, but a protrusion or step structure is formed on the housing side so that the sub substrate 3 partially contacts the housing 10. The main board 6 is shaped so as to avoid the protrusions or step structure of the housing 10, and the heat dissipation through hole portion of the main board 6 and the protrusions or step structure of the housing 10 are in direct contact with each other. Also good.

Embodiment 4
FIG. 6 is an explanatory diagram showing the work size and electrode formation of the sub-board used in the power supply device according to the fourth embodiment.
The plurality of electrode terminals 5 and 7 provided on the outer peripheral edge of the sub-substrate 3 may have a shape in which the through hole is cut in half.

In manufacturing the substrate, the unit price of the substrate is almost determined by how many substrates can be created from the desired work size 12 as shown in FIG. Accordingly, in the process of manufacturing the sub-substrate 3, a plurality of sub-substrates 3 are manufactured from a desired substrate work size. At that time, the electrode through holes 13 are arranged along the ends of the adjacent substrates, By cutting from the center of the through-hole, a semicircular through-hole, that is, an electrode can be formed. Therefore, an electrode can be easily formed with a patterned electrode terminal at the end on the sub-substrate side.
That is, as shown in FIG. 7, the semi-cylindrical sub-substrate electrode terminal 5a or 7a formed at the end of the sub-substrate 3 is formed by cutting from the center of the through hole. In the process, copper plating is performed in the same manner as other substrate patterns, so that conductivity is ensured.

Embodiment 5
FIG. 8 is a cross-sectional view schematically showing a schematic structure of the power supply device according to Embodiment 5, and FIG.
FIG. 8 is a cross-sectional view showing a modification of the power supply device according to the fifth embodiment. In FIG. 8, in addition to the first and second embodiments, the power mounted on the main board 6 of the power supply device according to the fifth embodiment. In order to avoid the lead portion and the solder fillet portion, a space (hole or through hole) 14 that allows the lead terminal portion 1a to be introduced is formed at a location where the lead terminal portion 1a of the device 1 protrudes from the back surface of the sub-substrate 3. .

  In this way, even if the lead terminal portion (on the sub substrate side) 1a of the power device 1 mounted on the sub substrate 3 protrudes on the main substrate 6, the corresponding portion contacts / interferences with the main substrate 6 due to the space 14. Therefore, it is possible to prevent the main substrate 6 or the lead solder portion (not shown) from being stressed by contact or interference.

9 and 10 show a modification of the fifth embodiment, and the hole diameter of the through-hole-like space 15 in FIGS. 9 and 10 is the through-hole 4 of the sub-board 3 into which the lead portion of the power device 1 is introduced. The diameter is smaller than the hole diameter.
In this way, by configuring the space 15 to have a diameter narrower than the through hole 4 of the sub-board 3, the bonding strength of the solder joint between the main board 6 and the sub-board 3 can be further strengthened, and the solder connection at the corresponding part Reliability can be improved.

When the power device 1 is mounted on the sub-board 3, a solder fillet is formed on the lead terminal portion 1a on the tip end side of the lead terminal portion 1a of the power device 1 and the through-hole land 4b (not shown). Furthermore, in the through-hole 4 in which the lead terminal portion 1a is inserted in the main board 6 when the sub-board 3 and other surface-mounted parts are mounted on the main board 6 in the previous process, the through-hole on the side of the sub-board 3 is inserted. The land 4b comes into contact with the solder fillet.
Further, when reflow mounting is performed in this state, the solder fillet is melted by crushing the solder fillet by the weight of the power device 1 and the sub-board 3. The melted solder spreads at the interface between the sub-substrate side through-hole land 4b and the main substrate-side through-hole 15a due to the osmotic pressure action. Accordingly, the main board 6 and the sub board 3 can be soldered also through the through-hole lands 4b and 15a, so that the solder joint surface is increased and the solder joint strength can be further enhanced.

  It should be noted that within the scope of the present invention, the embodiments can be combined, or the embodiments can be appropriately modified and omitted.

DESCRIPTION OF SYMBOLS 1 Power device 1a Lead terminal part of power device 2 Through hole for mounting power device 3 Sub board (sub printed wiring board)
4 Through-hole for mounting power device 4a Substrate pattern 4b Sub-substrate side through-hole land 5 Electrode electrically connected to through-hole 6 Main substrate (main printed circuit board)
7 Sub-terminal holding and fixing electrode terminals 8 Flat surface (suction location)
9 Control IC
10 Case (metal case or heat sink)
11 Heat Dissipation Through Hole 12 Sub Board Work Size 13 Electrode Through Hole 14 Main Board Space 15 Through Hole Space 15a Main Board Side Through Hole

Power apparatus according to the invention, the pre-power device through-hole mounting the sub-printed circuit board, and a main printed circuit board mounted with a microcomputer for driving and controlling the power device, the outer peripheral end portion of the sub-printed circuit board Is provided with a plurality of patterned electrode terminals, and a part of the plurality of electrode terminals is electrically connected to the lead terminal portion of the power device, and the remaining electrode terminals are connected to the sub terminals. The printed wiring board and the main printed wiring board are soldered in a reflow mounting step, and the sub printed wiring board is fixed to the main printed wiring board by the soldered electrode terminals .

Claims (9)

A sub-print wiring board on which a power device is mounted through-hole, and a main printed wiring board on which a microcomputer for driving and controlling the power device is mounted,
Provided with a plurality of patterned electrode terminals on the peripheral edge of the sub-printed wiring board,
Some of the plurality of electrode terminals are electrically connected to the lead terminal portion of the power device, and the sub printed wiring board is connected to the sub printed wiring board and the main by the remaining electrode terminals. A power supply device, wherein the power supply device is fixed to the main printed wiring board in a reflow mounting process with the printed wiring board.   The power supply device according to claim 1, wherein the sub-printed wiring board is provided with a flat surface portion that can be sucked by a component mounting machine.   The power supply device according to claim 1 or 2, wherein the pattern in the sub-printed wiring board is formed of a patterned copper foil and has a thickness of 60 µm or more.   The said power device is comprised by the at least 2 or more device by which the through-hole mounting was carried out, and these power devices were electrically connected by the inner / outer layer conductor pattern of the said sub printed wiring board, The power supply device according to claim 3.   The power supply device according to any one of claims 1 to 4, wherein the sub-printed wiring board is made of a highly thermally conductive base material.   6. The sub printed wiring board according to claim 1, wherein a heat radiating through hole is provided at a position where the sub printed wiring board is in contact with a package portion of the power device or a heat radiating fin of the power device. The power supply device according to item.   7. The electrode terminal according to claim 1, wherein the electrode terminal comprises a semicircular through hole formed by cutting a circular through hole during the manufacturing process of the sub-printed wiring board. The power supply device described in 1.   8. The main printed wiring board is provided with a hole-like or through-hole-like space that allows introduction of the lead terminal portion of the power device. The power supply described.   9. The power supply device according to claim 8, wherein a hole diameter of the through-hole-like space is smaller than a hole diameter of the through-hole of the sub printed wiring board into which the lead terminal portion of the power device is introduced.

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