JP2008060109A - Thermal dissipation substrate, manufacturing method thereof, power supply unit, and plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply unit for preventing the minimization of the power loss of a plasma television from being affected even if the inductance value of a coil used for the power supply unit, such as a PDP (plasma display panel), varies. <P>SOLUTION: A sheet-like heat transfer resin section 10 to which a lead frame 12 is embedded is fixed on a metal plate 11, and further one portion of the lead frame 12 is embedded to the heat transfer resin section 10 to form a coil 20 being bent by nearly 90 degrees. A ferrite core 17 is inserted into a hole 16 formed nearly at the center of the coil 20, and the inductance value (L component) is adjusted, thus restraining the power loss of the plasma television. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat dissipation substrate used in a plasma display device (including a plasma television), an in-vehicle power supply unit, a manufacturing method thereof, a power supply unit, and a plasma display device.

  2. Description of the Related Art Conventionally, a heat dissipation substrate is often used for a plasma display device, an in-vehicle power supply unit, and the like because heat dissipation is a problem. Hereinafter, although the heat radiating substrate used for PDP (plasma display panel) etc. is demonstrated to an example, it cannot be overemphasized that it can apply to a consumer device, a vehicle-mounted power supply unit, etc.

  Heat dissipation in the power unit of the plasma television will be described with reference to FIG. FIG. 9 is a perspective view showing an example of a power supply unit of a conventional plasma television, and corresponds to, for example, Patent Document 1. FIG. In FIG. 9, electronic components such as a capacitor 2 are mounted on a circuit board 1. A planar coil element and a power semiconductor (not shown because both are hidden behind the heat sink 3) are mounted below the heat sink 3.

  For example, in a power supply unit (for example, a power recovery circuit) for a plasma television, while causing LC oscillation (details will be described using FIGS. 10A and 10B described later) at a voltage close to 110 V, the maximum A large current near 100 A flows. For this reason, the power supply unit for plasma televisions must dissipate heat, and the substrate is required to dissipate heat. Therefore, as shown in FIG. 9, the planar coil elements and semiconductors (both not shown in FIG. 9) that generate heat radiate heat using a huge heat sink 3.

  And in plasma TVs, it is necessary to further reduce power consumption as well as heat dissipation. Next, with reference to FIGS. 10A and 10B, description will be made on the power consumption in the power recovery circuit that is a part of the power supply unit of the plasma television (or plasma display device).

  FIGS. 10A and 10B are a block diagram and a circuit diagram of a power source used in a plasma television. FIG. 10A is an example of a block diagram of a power supply used for a plasma television. In FIG. 10A, the central plasma panel 4 corresponds to a display unit (for example, a plasma panel on which an image is displayed), but functions as a kind of capacitor (or load capacity, C component) in terms of circuit. A scan-side power recovery circuit 5 is formed on the left side of the central plasma panel 4, and a sustain-side power recovery circuit 6 is formed on the right side. The LC oscillation is performed between the scan-side power recovery circuit 5 and the sustain-side power recovery circuit 6 and the central plasma panel 4, thereby reducing power consumption.

  FIG. 10B is an example of a circuit diagram of a power source used in the plasma television, and corresponds to a circuit diagram illustrating how the plasma panel 4 is oscillated LC. In FIG. 10B, a scan-side power recovery circuit 5 is installed on the left side of the plasma panel 4, and a sustain-side power recovery circuit 6 is installed on the right side of the plasma panel 4.

  In FIG. 10B, the power recovery circuit 5 on the scan side is formed from an inductance forming coil 7a, a capacitor C1, switches S1 to S4 made of power semiconductor elements, diodes D1 to D2, and the like. Yes. Similarly, the sustain side power recovery circuit 6 includes an inductance forming coil 7b, a capacitor C2, switches S5 to S8 made of power semiconductor elements, diodes D3 to D4, and the like. Then, as shown in FIG. 10B, the plasma panel 4 has a load capacitance (C component), and the coil 7a of the power recovery circuit 5 on the scan side and the coil 7b of the power recovery circuit 6 on the sustain side have inductance (L Component). And by causing LC oscillation between the C component and the L component, the power consumption of the plasma display is reduced. The necessary power is supplied from (Vsus).

  Conventionally, a commercially available wound coil has been used as an inductance component of such a power recovery circuit (for example, the coils 7a and 7b in FIGS. 10A and 10B). However, the inductance value (L component) of a commercially available wound coil has a variation of about ± 20%.

On the other hand, the capacitance value (for example, the C component of the plasma panel 4) of the plasma panel constituting the plasma display (portion shown as the plasma panel 4 in FIGS. 10A and 10B) also has a certain variation. . As a result, when a coil component (L component) having a variation of about ± 20% and a plasma panel (C component) having a certain variation are combined, the variations are superimposed on each other, and the plasma TV May affect the optimization of LC oscillation in
JP 2004-273937 A

  As described above, the conventional configuration saves power by using a power recovery circuit that supplies and recovers power by LC oscillation using the load capacity (C component) of the plasma panel 4 and the L component of the coils 7a and 7b. When trying to do so, there is a problem that variations in the L component and the C component may affect the reduction in power consumption by optimizing the LC oscillation.

  In the present invention, in order to solve the above-described problems, the inductance of the coil is made variable, and the LC oscillation is optimized while absorbing the characteristic variation of the plasma panel (for example, the variation of the C component). It is intended to realize power consumption.

  As a result, even for a plasma panel having a certain amount of variation, LC oscillation can be optimized individually, and low power consumption of the plasma television can be realized.

  In order to solve the above-described problems, the present invention provides a metal plate, a sheet-like heat transfer resin portion made of an inorganic filler and a resin fixed on the metal plate, and embedded in the heat transfer resin portion. A heat dissipating substrate comprising a lead frame having a coil pattern at a portion thereof, wherein at least a part of the coil pattern is embedded in the heat transfer resin portion and bent by approximately 90 degrees from the lead frame; It is a thing.

  With such a structure of the heat dissipation substrate, a coil pattern that is at least partially bent from a plane made of another lead frame or a metal plate in a state of being embedded in the heat transfer resin portion, an inductance portion ( L component). By making the inductance portion (L component) variable, the value can be increased or decreased depending on the position of the ferrite core, for example, even after the plasma television is manufactured (or even during the manufacturing). .

  As a result, in the heat dissipation substrate of the present invention, its manufacturing method, and the power supply unit and plasma display device using the same, the LC oscillation is optimized and adjusted according to the capacity value (so-called C component) of each plasma panel. Therefore, power consumption can be reduced.

  Further, by forming the lead frame (and the coil portion formed from the lead frame) with a mold, the inductance value of the coil portion can be highly accurate and the cost can be reduced. Further, by embedding a lead frame (and a part of a coil portion formed from the lead frame) in the heat transfer resin portion, an effect of improving the dimensional stability and heat dissipation can be obtained.

  According to the heat dissipation substrate of the present invention, the manufacturing method thereof, the power supply unit using the same, and the plasma display device using the same, when the load capacity (C component) of the plasma panel varies, the inductance value of the coil portion By adjusting (L component), it is possible to minimize power loss due to characteristic variations and the like, and to realize low power consumption of various devices including a plasma television.

(Embodiment)
As an embodiment, a heat dissipation substrate will be described with reference to FIG. 1A and 1B are a perspective view and a cross-sectional view of a heat dissipation board in the embodiment. 1A and 1B, 10 is a heat transfer resin portion, 11 is a metal plate, 12 is a lead frame, 13 is a power device, 14 is a capacitor, 15 is a bent portion, 16 is a hole, and 17 is a ferrite core. , 18a, 18b are arrows.

  FIG. 1A is a perspective view of a heat dissipation board, and corresponds to, for example, a power supply unit of a plasma television. In FIG. 1A, a sheet-like heat transfer resin portion 10 in which a lead frame 12 is embedded in a wiring pattern is fixed on a metal plate 11. The lead frame 12 embedded in the sheet-like heat transfer resin portion 10 is actively used as a wiring pattern, and the power device 13 and the capacitor 14 are mounted on the surface of the lead frame 12. Here, the power device 13 is a semiconductor or the like that switches high voltage or large current, and corresponds to, for example, switches S11 to S18 shown in FIG. Similarly, the capacitor 14 in FIG. 1A corresponds to capacitors C11 and C12 in FIG. 4B described later.

  In FIG. 1A, a part of the heat transfer resin portion 10 is bent (or raised) from the metal plate 11 at an angle of approximately 90 degrees to form a bent portion 15. In the bent portion 15, at least a part of the coil made of the lead frame 12 is embedded in a state of being bent by approximately 90 degrees (the coil will be described later with reference to FIG. 2 and the like). Then, a hole 16 is formed in a substantially central portion of the bent portion 15. Then, the ferrite core 17 is inserted into the hole 16 as indicated by an arrow 18a. An arrow 18b in FIG. 1A is used in the description of FIG. 2 described later, and is for explaining the coil pattern embedded in the heat transfer resin portion 10 in FIG.

  FIG. 1B corresponds to a cross-sectional view of an arbitrary portion in FIG. As shown in FIG. 1B, a sheet-like heat transfer resin portion 10 is fixed on a metal plate 11 with a lead frame 12 embedded therein. In FIG. 1B, the power device 13 and the capacitor 14 are not shown.

  As shown in FIG. 1B, the lead frame 12 is embedded in the sheet-like heat transfer resin portion 10 and the surface thereof is flattened (at least the step between the lead frame 12 and the heat transfer resin portion 10 is 30 microns or less. As described above, it is preferable that the thickness is 20 microns or less, and more desirably 10 microns or less, so that the formation of a solder resist (not shown) formed thereon and the mountability of the power device 13 and the like are improved. .

  Then, as shown in FIGS. 1A and 1B, the power device 13 and the capacitor 14 are directly mounted on the lead frame 12 to cope with a large current. By using the lead frame 12 (for example, a thickness of 500 microns) as described above, it is possible to cope with a large current of, for example, 100 A, compared to a copper foil (typically a thickness of 18 to 36 microns) used for a general printed wiring board. . The heat generated in the power device 13 and the like can also be radiated to the heat transfer resin portion 10 and the metal plate 11 through the lead frame 12 having excellent heat dissipation.

  In the present embodiment, since the coil is integrated as a part of the lead frame 12, the connection between the coil and the lead frame 12 becomes unnecessary, so that problems related to the connection hardly occur. On the other hand, when the conventional winding coil is used, it is necessary to solder both ends of the winding coil to the lead frame 12, so problems caused by connection such as soldering (manhours, cost, reliability, current capacity) Had occurred.

  Next, a state in which at least a part of the coil embedded in the heat transfer resin portion is bent will be described with reference to FIG. 2A to 2C are a perspective view and a cross-sectional view illustrating a coil pattern embedded in a heat transfer resin portion, and FIG. 2A is viewed from the arrow 18b side in FIG. It corresponds to the state. 2B and 2C correspond to cross-sectional views taken along arrow 18c in FIG. Reference numeral 19 in FIG. 2A denotes a dotted line, which is an auxiliary line for explanation. Reference numeral 20 denotes a coil, and a part of the lead frame 12 has a spiral coil pattern. Further, the inductance of the coil 20 can be easily adjusted by bending a part or more of the coil 20 by approximately 90 degrees.

  In FIG. 2A, the lead frame 12 is fixed on the metal plate 11 while being embedded in the heat transfer resin portion 10. A part of the lead frame 12 is omitted by a dotted line 19.

  As shown in FIG. 2A, a part of the coil 20 made of the lead frame 12 is bent approximately 90 degrees, for example, in the state of being embedded in the heat transfer resin part 10 near the center. Then, a hole 16 is formed in a part of the heat transfer resin portion 10 in which the coil 20 is embedded, for example, at a substantially central portion of the coil 20. Then, the ferrite core 17 is inserted into the hole 16 as indicated by an arrow 18a while being rotated as indicated by an arrow 18b, for example. At this time, a thread may be formed on the surface of the ferrite core 17 or the surface of the hole 16. Thus, in a state where the coil 20 is embedded in the heat transfer resin portion 10, at least a part thereof (in FIG. 2A to FIG. 2C, the coil 20 is bent in the vicinity of the half thereof, but not in the middle of the coil 20. The entire coil 20 may be bent by approximately 90 degrees), and the power supply unit can be bent from the outside (for example, through the back cover case of the plasma television) by using a driver or the like. The position of 17 can be easily adjusted. Further, by bending the coil 20 by approximately 90 degrees, the workability using the ferrite core 17 and the ease of adjustment are enhanced. Moreover, the influence of the metal plate 11 is also suppressed.

  2B and 2C correspond to cross-sectional views taken along arrow 18c in FIG. As shown in FIG. 2B, the sheet-like heat transfer resin portion 10 in which the lead frame 12 is embedded is fixed on the metal plate 11. Then, in a state where the coil 20 is embedded in the heat transfer resin part 10, a part is raised (or bent by approximately 90 degrees) to form a bent part 15.

  As shown in FIG. 2B, the ferrite core 17 is rotated as shown by the arrow 18b, thereby turning the ferrite core 17 into the hole 16 (the hole 16 is not shown in FIG. 2B). The dotted line 19 in FIG. 2 (B) indicates the position of the hole 16). And the inductance value of the coil 20 is changed by adjusting the position of the ferrite core 17 and the coil 20 as shown to FIG. 2 (B)-(C).

  The ferrite core 17 may have a rod shape, but may have a collar as shown in FIGS. 2 (A) to 2 (C). By attaching a hook, it is easy to create a closed magnetic circuit and the amount of inductance adjustment can be increased.

  It is not necessary to expose the coil 20 from the heat transfer resin portion 10. The coil 20 may be completely embedded in the heat transfer resin portion 10. By completely embedding the coil 20 in the heat transfer resin portion 10, the reliability of the coil 20 can be improved. Alternatively, a part (or one surface) of the coil 20 can be embedded so as to be substantially flush with the heat transfer resin portion 10. When the coil 20 is embedded so as to be substantially flush with the heat transfer resin portion 10 like the lead frame 12, a solder resist (in FIG. 1 to FIG. 2 etc., a solder resist is formed on the coil 20 and the lead frame 12. Is not shown). By embedding the coil 20 in the heat transfer resin portion 10 or the solder resist, contact between the ferrite core 17 and the coil 20 is prevented. Further, by forming the solder resist, it is possible to prevent the solder from flowing (or spreading too much) on the lead frame 12 during soldering.

  Next, a state in which the central portion of the spiral (or mosquito coil) coil 20 is electrically connected to another lead frame 12 will be described with reference to FIGS. 3A to 3C, the coil 20 is not bent by approximately 90 degrees for easy explanation.

  FIGS. 3A and 3B are perspective views showing a state in which one end of the coil is pulled out by a jumper, and FIG. 3C is a cross-sectional view showing a case where a lead frame is used. In FIG. 3A, reference numeral 21 denotes a jumper, which is a conductor formed of a copper wire or the like. By mounting a jumper 21 as indicated by an arrow 18a between a part of the coil 20 embedded in the sheet-like heat transfer resin portion 10 and the lead frame 12 on the metal plate 11, as shown in FIG. Connecting. A dotted line 19 in FIG. 3A indicates the mounting position of the jumper 21. In FIG. 3B, the central portion of the coil 20 and the lead frame 12 are electrically connected by a jumper 21. As the jumper 21, a commercially available jumper chip (a so-called 0Ω chip resistor), an insulating coated lead frame, or the like can be used. For the connection between the jumper 21 and the lead frame 12 or the coil 20, it is also effective to use welding (laser welding, spot welding or the like) in addition to soldering. By welding, problems caused by solder can be prevented and high reliability can be obtained.

  FIG. 3C shows a lead frame 12 (or the lead frame 12 constituting the coil 20), and electrically connects the central portion of the spiral (or mosquito coil) coil 20 to another lead frame 12. This corresponds to a cross-sectional view for explaining how to do this. For example, a part of the coil 20 or the lead frame 12 can be peeled off from the heat transfer resin portion 10 and bent to form a jumper 21 as shown in FIG. Thus, by using a part of the coil 20 and the lead frame 12 as the jumper 21, the number of connection points can be reduced as compared with the case where the commercially available jumper 21 is used. Then, soldering or welding is performed at a position indicated by an arrow 18b. In FIG. 3C, insulation (or insulation coating) on the surface of the jumper 21 composed of the lead frame 12 is not shown.

  Next, the case where the heat dissipation substrate with variable inductance described in FIG. 1 and the like is applied to a power supply module of a plasma television will be described with reference to FIGS. 4 (A) and 4 (B).

  FIGS. 4A and 4B are a block diagram and a circuit diagram illustrating a state where the present invention is applied to a power supply module of a plasma television. 4A is an example of a block diagram of a power supply module of a plasma television, and FIG. 4B is an example of a circuit diagram. 4A and 4B, 22 is a power recovery circuit on the scan side, 23 is a plasma panel, and 24 is a power recovery circuit on the sustain side.

  In FIG. 4A, the plasma panel 23 shows an actual plasma panel. In FIG. 4B, 23 shows the load capacity (C component) of the plasma panel 23 in the circuit diagram.

  In FIG. 4A, the plasma panel 23 functions as a kind of load capacity. Then, LC oscillation using the load capacity (C component) of the plasma panel 23 is performed from the scan-side power recovery circuit 22 and the sustain-side power recovery circuit 24 installed on the left and right of the plasma panel 23. The video signal is sent to the scan-side power recovery circuit 22, the sustain-side power recovery circuit 24, the panel drive circuit (address), and the like via the signal processing circuit.

  Next, a more detailed description will be given with reference to FIG. In FIG. 4B, the power recovery circuit 22 on the scan side is formed by a capacitor C11, switches S11 to S14 formed of a semiconductor, diodes D11 to D12, a coil 20a, and the like. Similarly, the power recovery circuit 24 on the sustain side is formed of a capacitor C12, switches S15 to S18 made of a semiconductor, diodes D13 to D14, a coil 20b, and the like. The coils 20a and 20b have been described with reference to FIGS. 1 and 2 and the like, and their inductance values are made variable by the ferrite core 17.

  Note that the difference between FIG. 4B and FIG. 10B is whether the coil is variable or fixed. In the present embodiment, by making the inductance of the coil 20 variable, the conventional circuit design (with the conventional circuit constants) can be used as it is. Furthermore, by utilizing the features of the present embodiment (high heat dissipation, coil 20 can be reduced, etc.), circuit optimization (or cost reduction by reducing the number of parts) is possible.

  Next, the reduction in power consumption during light emission of the plasma display will be described. In the case of a plasma display, when a display is performed by applying a voltage to a light emitting portion corresponding to each pixel of the plasma panel 23, charging and discharging are often performed using a load capacity indicated by the plasma panel 23. The charged / discharged power is absorbed from the load capacity indicated by the plasma panel 23 through the coil 20a of the power recovery circuit 22 on the scan side and the coil 20b of the power recovery circuit 24 on the sustain side, and re-released. Thus, the power loss is reduced by reusing the power supplied from (Vsus) by LC oscillation using the plasma panel 23 as the C component.

  As described above, the plasma panel 23 in FIG. 4B is used as the load capacity (C component), and the power is recovered by using the energy transfer by the LC oscillation by the coils 20a and 20b, thereby reducing the power consumption of the plasma television. Is realized.

  Generally, the load capacity of the plasma panel 23 varies greatly (so-called design difference) depending on its size (40 inches, 50 inches, etc.), resolution, pixel dimensions, product design specifications, and the like. Further, even in the plasma panel 23 having the same specification (or the same design), the load capacity varies due to variations among products (so-called individual differences).

  Conventional power supply units use commercially available coil components. Therefore, the inductance value has a variation of a maximum of ± 20% on the specifications. Therefore, there is a limit to minimizing power loss. However, in the case of the power supply unit using the heat dissipation board of the present invention, the inductance value can be individually adjusted according to the load capacity of the plasma panel 23 as shown in FIGS. The capacity variation can be absorbed. Furthermore, it is possible to cope with plasma panels 23 having different specifications (or inches) with one type of power supply unit.

  Next, reduction of power consumption of the plasma panel 23 will be described with reference to FIG.

  5A to 5C are timing charts for applying (light emission) to the plasma panel. In FIG. 5, 25 is a sine voltage, and 26 is a pulse voltage. 5A to 5C, the X axis is time, and the Y axis is voltage. FIGS. 5A and 5C illustrate mismatching (occurrence of time shifts indicated by T1 and T2) between the inductance of the coil 20 of the power supply unit and the load capacity of the plasma panel 23. FIG. It is. In the light emitting part of the plasma panel 23, for example, a sine voltage 25 is applied by the power recovery circuit as described with reference to FIG. Then, by superimposing the pulse voltage 26 here, the plasma panel 23 exceeds the threshold voltage and emits light. In FIG. 5A, the peak of the sine voltage 25 and the timing of the pulse voltage 26 are shifted by T1. As a result, a voltage loss corresponding to Vdif1 occurs as shown in FIG. Further, in FIG. 5C, since the peak of the sine voltage 25 and the timing of the pulse voltage 26 are shifted by T2, a voltage loss corresponding to Vdif2 occurs. On the other hand, FIG. 5B shows a case where the peak of the sine voltage 25 coincides with the timing of the pulse voltage 26. Since the peak of the sine voltage 25 coincides with the timing of the pulse voltage 26, voltage loss is caused. Is unlikely to occur. 5A to 5C, a part of the sine voltage 25 is indicated by a dotted line. Here, the sine voltage 25 is a sine voltage for convenience, and is not limited to a sine wave or the like.

  Here, in order for the plasma display to emit light, the sum of the sine voltage 25 and the pulse voltage 26 needs to exceed a certain voltage or a kind of threshold voltage (for example, 110 V). Here, the signal of (Vsus) (or the sine voltage 25 shown in FIGS. 5A to 5C) has an extremely short period of 5 microseconds although the voltage is about 100 to 200 V, for example. Therefore, the LC oscillation is easily influenced by variations in the load capacity of the plasma panel 23 and variations in the inductance of the coil 20. Such variation affects the timing of the sine voltage 25 and the pulse voltage 26. In addition, variations in the characteristics of various electronic components used in such an electronic circuit tend to affect the timing.

  In the case of the present invention, as shown in FIGS. 5A and 5C, the inductance is adjusted by adjusting the position of the ferrite core 17 to be inserted into the coil 20, as shown in FIG. It can respond by changing. As a result, unnecessary voltage loss and power loss in the plasma television can be reduced.

  Here, the inductance value of the coil 20 is also affected by the dimensions (number of inches) of the plasma panel 23, but is about 0.1 to 10.0 μH (preferably 0.2 μH or more) at about 40 to 50 inches, for example. The circuit constant is desirably 5.0 μH or less, and more desirably 0.5 μH or more and 2.0 μH or less. Therefore, in the present invention, the inductance is varied within this range. Here, a plurality of coils 20 may be formed and arranged side by side (or combined with each other). If the inductance per coil 20 is less than 0.1 μH (microhenry) or exceeds 10 μH, LC oscillation in a plasma television may be affected. The inductance value can be changed according to the specifications of the plasma panel 23. Next, the effect of reducing power consumption by reducing the voltage loss will be described with reference to FIG.

  FIG. 6 is a diagram for explaining the effect of reducing the power consumption of the plasma television. In FIG. 6, 27 is when the power recovery circuit is not used, and 28 is when the power recovery circuit is used (conventional example). Reference numeral 29 denotes a time when the power recovery circuit is used (the present invention), in which the inductance of the coil 20 is made variable as shown in FIGS. In FIG. 6, the X axis represents the number of sustain pulses, and the Y axis represents the power consumption in the plasma panel 23 and the like. FIG. 6 shows that the power consumption increases in each graph as the number of sustain pulses increases. In FIG. 6, power consumption is lower when the power recovery circuit is used (conventional example) 28 than when the power recovery circuit is not used 27. Further, when the power recovery circuit is used (the present invention) 29, the power consumption is further smaller than when the power recovery circuit is used (conventional example) 28. In the case of using the power recovery circuit (invention) 29, this can be achieved by adjusting the inductance variation of the coil 20 in one plasma TV as described with reference to FIGS. This is because a significant loss was reduced.

  As described above, the power supply unit proposed in the present invention can further reduce the power consumption by adjusting the inductance of the coil 20 of the power supply unit formed using the heat dissipation substrate. In addition, since this suppression effect can be obtained even when the number of sustain pulses is increased, it is possible to cope with an increase in the size and definition of a plasma television. And the power consumption of a plasma display apparatus can be reduced by using the thermal radiation board | substrate of this invention, for example as a power supply unit for plasma display apparatuses.

  Further, to turn on the plasma display, a peak current of about 110 A flows through the wiring through which the sustain pulse voltage Vsus flows, and a peak current of about 50 A flows through each power recovery wiring. Therefore, high power dissipation is also required for the power unit for plasma televisions.

  Next, with reference to FIGS. 7A and 7B, the heat radiation effect in the component mounting portion of the heat dissipation board proposed in the present invention will be described. FIGS. 7A and 7B are cross-sectional views showing the heat dissipation of the heat dissipation substrate. FIG. 7A is before heat generation (before current application), and FIG. 7B is after heat generation (after current application). ). In FIG. 7, 30 is a solder and 31 is a heat sink. Note that the heat sink 31 is not shown in FIG. As shown in FIG. 7A, the heat transfer resin portion 10 is formed on the metal plate 11 with the coil 20 and the lead frame 12 embedded therein. Then, using the solder 30, the power device 13 that requires heat dissipation is mounted on the surface of the lead frame 12. FIG. 7B shows a state where heat generated in the power device 13 is diffused to the heat transfer resin portion 10 and the metal plate 11 through the lead frame 12. In FIG. 7B, an arrow 18a indicates a direction in which heat is diffused.

  In the case of the present invention, heat generation can be suppressed by embedding the coil 20 having the same cross-sectional area in the heat transfer resin portion 10. As a result, the coil 20 (embedded in the heat transfer resin portion 10) of the present embodiment has a conductor (or lead frame 12) constituting the coil 20 in comparison with a conventional coil (for example, a wound coil). The cross-sectional area can be reduced. This is because the temperature of the coil 20 of the present invention hardly rises due to the heat dissipation effect. As a result, the cross-sectional area of the coil 20 conductor can be reduced, and the area and size of the coil 20 itself can be further reduced with the same number of turns. Since the area occupied by the coil 20 can be reduced, the power supply module can be reduced in size and cost.

  In FIG. 7B, as shown in FIG. 8 to be described later, the coil 20 is formed by press molding, so that the conductor cross section can be made into a substantially square shape. Therefore, compared with the conventional copper wire (the cross section is round), the resistance value is Can also be suppressed. Thus, since the wiring length (or line length) itself forming the coil 20 can be shortened, the coil 20 of the present invention increases the Q value (generally, it is desirable that the Q value of the coil is high) as a coil characteristic. It is done.

  Next, an example of a method for manufacturing the heat dissipation substrate will be described with reference to FIG. 8A to 8D are cross-sectional views illustrating an example of a method for manufacturing a heat dissipation substrate.

  8A to 8D, reference numeral 32 denotes a plate material. First, as shown in FIG. 8A, a plate material 32 made of a copper plate or the like is prepared. Next, the plate material 32 is processed into a predetermined shape using a press device or a mold (not shown). Thus, as shown in FIG. 8B, the lead frame 12 processed into a predetermined shape is created. For example, a part of the plate 32 is punched into a coil shape (for example, a mosquito coil-like spiral pattern).

  Next, as shown in FIG. 8C, the heat transfer resin portion 10 and the lead frame 12 are set on the metal plate 11. Then, as shown by the arrow 18, the metal plate 11 and the lead frame 12 are embedded in the heat transfer resin portion 10. In FIG. 8C, the pressing device and the mold are not shown. By pressing in such a heated state, the viscosity of the heat transfer resin portion 10 can be lowered and the wraparound property to the gap of the lead frame 12 can be improved. Here, for example, as shown in FIG. 8C, the heat transfer resin portion 10 is formed into an oval shape (or a bowl shape or the like), thereby reducing air remaining in the gap between the metal plate 11 and the heat transfer resin portion 10. . Here, the air residue is also called a void, and is a space generated at the interface between the metal plate 11 or the lead frame 12 and the heat transfer resin portion 10 and may affect the heat dissipation.

  FIG. 8D shows a cross-sectional view after the heat transfer resin portion 10 is thermally cured with the lead frame 12 and the metal plate 11 embedded therein. The holes 16 in the heat transfer resin portion 10 shown in FIGS. 1 and 2 can be formed at the time of pressing shown in FIG. As a method for forming the holes 16, a mold may be used, but before the heat transfer resin portion 10 is thermally cured, it may be processed with a punch, a drill, a reamer, or the like.

  This will be described in more detail. The thickness of the lead frame 12 is desirably about 0.1 mm to 2.0 mm (desirably 1.0 mm or less). When the thickness of the lead frame 12 is less than 0.1 mm, it is easy to bend or bend, and its handling is difficult. If the thickness of the lead frame 12 exceeds 2.0 mm, punching with a press becomes difficult, and the pattern accuracy of the lead frame 12 itself decreases. Therefore, in terms of processing accuracy, the lead frame 12 is preferably 0.2 to 1.0 mm (more preferably 0.3 to 0.5 mm).

Further, the heat transfer resin portion 10 is preferably composed of 70 wt% or more and 95 wt% or less of an inorganic filler and 5 wt% or more and 30 wt% or less of a thermosetting resin. Here, the inorganic filler has a substantially spherical shape, and its diameter is suitably from 0.1 to 100 microns (if it is less than 0.1 microns, it becomes difficult to disperse in the resin, and if it exceeds 100 microns, the heat transfer is The thickness of the resin part 10 is increased, which affects the thermal diffusivity). Therefore, the filling amount of the inorganic filler in the heat transfer resin part 10 is filled at a high concentration of 70 to 95% by weight in order to increase the thermal conductivity. In particular, in the present embodiment, the inorganic filler is a mixture of two types of Al ₂ O ₃ having an average particle size of 3 microns and an average particle size of 12 microns. By using the Al ₂ O ₃ of the large and small two types of particle size, it is possible to fill the Al ₂ O ₃ of small particle size in the gap Al ₂ O ₃ of large particle size, Al ₂ O ₃ 90 wt% near Can be filled to a high concentration. As a result, the heat conductivity of the heat transfer resin portion 10 is about 5 W / (m · K). The inorganic filler may include at least one selected from the group consisting of MgO, BN, SiO ₂ , SiC, Si ₃ N ₄ , and AlN instead of Al ₂ O ₃ .

When an inorganic filler is used, heat dissipation can be improved, but when using MgO in particular, the linear thermal expansion coefficient can be increased. Further, when SiO ₂ is used, the dielectric constant can be reduced, and when BN is used, the linear thermal expansion coefficient can be reduced. Thus, the heat transfer resin portion 10 having a thermal conductivity of 1 W / (m · K) or more and 20 W / (m · K) or less can be formed. When the thermal conductivity is less than 1 W / (m · K), the heat dissipation performance of the heat dissipation board is affected. Moreover, when it is going to make thermal conductivity higher than 20 W / (m * K), it is necessary to increase the amount of fillers and may affect the workability at the time of a press.

  The thermosetting resin contains at least one kind of resin among epoxy resin, phenol resin and cyanate resin. These resins are excellent in heat resistance and electrical insulation. If the thickness of the heat transfer resin portion 10 is reduced, heat generated in the power device 13 attached to the lead frame 12 can be easily transferred to the metal plate 11, but conversely, the withstand voltage becomes a problem. Therefore, the optimum thickness may be set to 50 microns or more and 1000 microns or less in consideration of the withstand voltage and the thermal resistance.

  Next, the material of the lead frame 12 will be described. The lead frame 12 is preferably made of copper as a main material. This is because copper has both excellent thermal conductivity and electrical conductivity. In order to improve the workability and thermal conductivity as the lead frame 12, the copper material used as the lead frame 12 is selected from a group of at least Sn, Zr, Ni, Si, Zn, P, Fe, etc. other than copper. It is desirable to use an alloy made of at least one kind of material. For example, an alloy (hereinafter referred to as Cu + Sn) in which Cu is a main component and Sn is added thereto can be used. In the case of a Cu + Sn alloy, for example, by adding Sn to 0.1 wt% or more and less than 0.15 wt%, the softening temperature can be increased to 127 ° C. For comparison, the lead frame 12 was made using Sn-free copper (Cu> 99.96% by weight). The electrical conductivity is low, but distortion may occur particularly in the formed portion of the completed heat dissipation board. there were. As a result of detailed examination, the softening point of the material was as low as about 110 ° C., and it was expected that the material could be deformed during subsequent component mounting (soldering). On the other hand, when a copper-based material with Cu + Sn> 99.96% by weight was used, it was not particularly affected by the heat generated by various mounted components and a plurality of LEDs. There was no effect on solderability and die bondability. Therefore, when the softening point of this material was measured, it was found to be 127 ° C. Thus, it is desirable to add some elements mainly composed of copper. As an element added to copper, in the case of Zr, the range of 0.015 wt% or more and 0.15 wt% or less is desirable. When the addition amount is less than 0.015% by weight, the effect of increasing the softening temperature may be small. On the other hand, if the amount added is more than 0.15% by weight, the electrical characteristics may be affected. Also, the softening temperature can be increased by adding Ni, Si, Zn, P or the like. In this case, Ni is 0.1 wt% or more and less than 5 wt%, Si is 0.01 wt% or more and 2 wt% or less, Zn is 0.1 wt% or more and less than 5 wt%, and P is 0.005 wt% or more. Less than 0.1% by weight is desirable. And these elements can make the softening point of a copper raw material high by adding single or multiple in this range. In addition, when there are few addition amounts than the ratio described here, the softening point raise effect may be low. Moreover, when there are more than the ratio described here, there exists a possibility of affecting the electrical conductivity. Similarly, in the case of Fe, 0.1 wt% or more and 5 wt% or less is desirable, and in the case of Cr, 0.05 wt% or more and 1 wt% or less are desirable. These elements are the same as those described above.

The tensile strength of the copper alloy used for the lead frame 12 is desirably 600 N / mm ² or less. In the case of a material having a tensile strength exceeding 600 N / mm ² , the workability of the lead frame 12 may be affected. Further, such a material having high tensile strength tends to increase its electric resistance. On the other hand, if the tensile strength is 600 N / mm ² or less (and if the lead frame 12 requires fine and complicated processing, it is preferably 127 N / mm ² or less), the spring back (pressure even if bent to the required angle) If it is removed, it will be repelled by the reaction force), and the formation accuracy can be improved. As described above, as the lead frame material, the conductivity can be lowered by mainly using Cu, and the workability can be improved by further softening, and the heat dissipation effect by the lead frame 12 can also be enhanced. The tensile strength of the copper alloy used for the lead frame 12 is desirably 10 N / mm ² or more. This is because the copper alloy used for the lead frame 12 needs to have a strength higher than the tensile strength (about 30 to 70 N / mm ² ) of general lead-free solder. When the tensile strength of the copper alloy used for the lead frame 12 is less than 10 N / mm ² , when the power device 13 or the like is soldered and mounted on the lead frame 12, it is possible to cause cohesive failure at the lead frame 12 portion instead of the solder portion. There is sex.

  It is also useful to previously form a solder layer or tin layer on the surface of the lead frame 12 exposed from the heat transfer resin portion 10 (the mounting surface of the power device 13 or the like) so as to improve solderability. It is. It is desirable that no solder layer be formed on the surface of the lead frame 12 that contacts the heat transfer resin portion 10 (or the embedded surface). When a solder layer or a tin layer is formed on the surface in contact with the heat transfer resin portion 10 in this way, this layer becomes soft during soldering, which affects the adhesion (or bond strength) between the lead frame 12 and the heat transfer resin portion 10. May give. In FIG. 1 and FIG. 2, the solder layer and the tin layer are not shown.

The metal metal plate 11 is made of aluminum, copper, or an alloy containing them as a main component with good thermal conductivity. In particular, in the present embodiment, the thickness of the metal plate 11 is set to 1 mm, but the thickness can be designed according to product specifications (note that when the thickness of the metal plate 11 is 0.1 mm or less, in terms of heat dissipation and strength) In addition, if the thickness of the metal plate 11 exceeds 50 mm, it is disadvantageous in terms of weight). The metal plate 11 is not only a plate-like one, but also a fin portion (or uneven portion) for increasing the surface area on the surface opposite to the surface on which the heat transfer resin portion 10 is laminated in order to further improve heat dissipation. ) May be formed. The total expansion coefficient is 8 × 10 ⁻⁶ / ° C. to 20 × 10 ⁻⁶ / ° C. By bringing the expansion coefficient close to the linear expansion coefficient of the metal plate 11 or the power device 13, the heat dissipation board of the present invention, and a power source using the same The warpage and distortion of the entire unit can be reduced. In addition, when these components are surface-mounted, matching the thermal expansion coefficients with each other is also important in terms of reliability. Further, the metal plate 11 can be screwed to another heat radiating plate (not shown).

  In FIGS. 1 to 4, the metal plate 11 can be omitted. Further, a radiator or fin for heat dissipation may be attached to the metal plate 11.

  As described above, the metal plate 11, the sheet-like heat transfer resin portion 10 made of an inorganic filler and a resin fixed on the metal plate 11, and a part embedded in the heat transfer resin portion 10 A heat dissipation board comprising a lead frame 12 having a coil 20 on the heat sink, wherein at least a part of the coil 20 is embedded in the heat transfer resin portion 10 and bent by about 90 degrees from the lead frame 12. By providing the substrate, it is possible to easily change the inductance of the coil 20 from the outside of the heat dissipation substrate, thereby providing a heat dissipation substrate capable of dealing with high heat dissipation and a large current.

  Further, the metal plate 11, a sheet-like heat transfer resin portion 10 made of an inorganic filler and a resin fixed on the metal plate 11, and a coil 20 partially embedded in the heat transfer resin portion 10 are included. A heat dissipation board comprising a lead frame 12, wherein at least a part of the coil 20 is embedded in the heat transfer resin portion 10 and is a structure portion (bending portion 15) bent from the lead frame 12 by approximately 90 degrees. ) And the hole 16 at the substantially center of the coil 20, the inductance of the coil 20 can be easily changed from the outside of the heat radiating board. Provided is a heat dissipation board capable of handling current.

  A metal plate 11, a heat transfer resin portion 10 made of an inorganic filler and a thermosetting resin fixed on the metal plate 11, and a lead having a coil 20 embedded in the heat transfer resin portion 10. A heat radiating board comprising a frame 12, wherein at least a part of a coil pattern formed by the coil 20 is embedded in the heat transfer resin portion 10 and is bent by about 90 degrees from the lead frame 12. By providing a heat dissipating board having (bending portion 15), a substantially central hole 16 of the coil 20, and a ferrite core 17 inserted into the hole 16, the inductance of the coil 20 is reduced. By providing a heat dissipation board that can be easily changed from the outside, it is possible to provide a heat dissipation board that can handle high heat dissipation and a large current.

  At least a part thereof, a step of setting the lead frame 12 having the coil 20 bent from the lead frame 12 at approximately 90 degrees, the metal plate 11, and the heat transfer resin portion 10 therebetween, the lead frame 12 and the heat transfer resin A step of heating and pressing the portion 10 and the metal plate 11 using a mold to embed the lead frame 12 in the heat transfer resin portion 10; a step of curing the heat transfer resin portion 10; By providing a method of manufacturing a heat dissipation board having the above, it is possible to easily change the inductance of the coil 20 from the outside of the heat dissipation board, thereby providing a heat dissipation board capable of dealing with high heat dissipation and a large current.

  Metal plate 11, sheet-like heat transfer resin portion 10 made of inorganic filler and thermosetting resin fixed on metal plate 11, and coil 20 partially embedded in heat transfer resin portion 10 A power supply unit having a heat dissipation substrate, wherein the power supply unit includes at least a part of the coil 20 embedded in the heat transfer resin portion 10. A power supply unit having a structure part (bent part 15) bent about 90 degrees from the center, a hole 16 formed in the approximate center of the coil 20, or a mechanism part for adjusting inductance by a ferrite core 17 inserted into the hole 16. By doing so, it is possible to provide a power supply unit that can adjust the inductance value according to the application for PDP and in-vehicle use. Power saving, it is possible to reduce the power loss.

  A metal plate 11, a heat transfer resin portion 10 made of an inorganic filler and a resin fixed on the metal plate 11, and a lead frame 12 embedded in the heat transfer resin portion 10 and having a coil 20 in part. A plasma display device using a power supply unit having a heat dissipation substrate, wherein the power supply unit includes at least a part of the coil 20 embedded in the heat transfer resin portion 10 from the lead frame 12. Each plasma display device has a structure portion (bending portion 15) bent by approximately 90 degrees or a mechanism portion that adjusts the inductance by the ferrite core 17 to reduce the power loss of the plasma display panel. Of the LC resonance circuit in the power recovery circuit formed by the coil 20 and the plasma panel 23 in FIG. Since optimize seed timing, it is possible to provide a plasma display device with a reduced power loss.

  As described above, the heat dissipation board, the manufacturing method thereof, and the light emitting module and the display device using the heat dissipation board according to the present invention not only enable reduction of power consumption of the PDP, but also various power supply units for vehicles. It can be applied, and downsizing and high performance of equipment are possible.

(A), (B) is the perspective view and sectional drawing of the thermal radiation board in an embodiment, respectively (A) is a perspective view explaining the coil pattern embedded in the heat transfer resin part, (B) and (C) are sectional views, respectively. (A), (B) is a perspective view showing how a part of a coil is pulled out to the outside by a jumper, and (C) is a sectional view. (A), (B) is a block diagram and a circuit diagram for explaining the application to a power supply module of a plasma television (A) to (C) are timing charts for applying (light emission) to the plasma panel. The figure explaining the reduction effect of the power consumption of the plasma television (A), (B) is sectional drawing which shows the mode of the heat dissipation of a thermal radiation board | substrate. (A)-(D) are sectional drawings explaining an example of the manufacturing method of a thermal radiation board | substrate. A perspective view showing an example of a conventional power recovery circuit (A) and (B) are a block diagram and circuit diagram of a power supply used in a plasma television.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat transfer resin part 11 Metal plate 12 Lead frame 13 Power device 14 Capacitor 15 Bending part 16 Hole 17 Ferrite core 18 Arrow 19 Dotted line 20 Coil 21 Jumper 22 Scan side power recovery circuit 23 Plasma panel 24 Sustain side power recovery circuit 25 Sine voltage 26 Pulse voltage 27 When power recovery circuit is not used 28 When power recovery circuit is used (conventional example)
29 When using a power recovery circuit (present invention)
30 Solder 31 Heat sink 32 Plate material

Claims (10)

A metal plate,
A sheet-like heat transfer resin portion made of an inorganic filler and a resin fixed on the metal plate;
A heat dissipating board comprising a lead frame embedded in the heat transfer resin part and partially having a coil pattern,
A heat dissipation board bent at approximately 90 degrees from the lead frame in a state where at least a part of the coil pattern is embedded in the heat transfer resin portion. The heat dissipation board according to claim 1, wherein a hole is provided at substantially the center of the coil pattern embedded in the heat transfer resin portion. The heat dissipation substrate according to claim 1, wherein a ferrite core is inserted into a hole at a substantially central portion of the coil pattern embedded in the heat transfer resin portion. 2. The heat dissipation substrate according to claim 1, wherein the heat transfer resin portion has a thermal conductivity of 1 W / (m · K) or more and 20 W / (m · K) or less. The heat dissipation substrate according to claim 1, wherein the inorganic filler includes at least one selected from the group consisting of Al ₂ O ₃ , MgO, BN, SiO ₂ , SiC, Si ₃ N ₄ , and AlN. The heat dissipation substrate according to claim 1, wherein the resin is a thermosetting resin and includes at least one selected from the group consisting of an epoxy resin, a phenol resin, and an isocyanate resin. Sn is 0.1% by weight to 0.15% by weight, Zr is 0.015% by weight to 0.15% by weight, Ni is 0.1% by weight to 5% by weight, and Si is 0.01% by weight. 2% by weight or less, Zn from 0.1% by weight to 5% by weight, P from 0.005% by weight to 0.1% by weight, Fe from 0.1% by weight to 5% by weight The heat dissipation board according to claim 1, wherein a lead frame mainly composed of copper including at least one selected from the above is used. at least,
A step of setting a lead frame having a coil pattern bent at approximately 90 degrees in part, a metal plate, and a heat transfer resin portion therebetween,
The lead frame, the heat transfer resin portion, and the metal plate are heated / pressurized with a mold, and the lead frame is embedded in the heat transfer resin portion and integrated, and
Curing the heat transfer resin part;
A method for manufacturing a heat dissipation board. A metal plate,
A sheet-like heat transfer resin portion made of an inorganic filler and a thermosetting resin fixed on the metal plate;
A power supply unit having a heat dissipation board composed of a lead frame embedded in the heat transfer resin part and partially having a coil pattern,
The heat dissipation substrate is at least
A structure part bent at approximately 90 degrees from the lead frame in a state where at least a part of the coil pattern is embedded in the heat transfer resin part,
Or a hole formed near the approximate center of the coil pattern,
Or in the mechanism part that adjusts the inductance by the ferrite core inserted in the hole,
A power supply unit having at least one. A metal plate,
A heat transfer resin portion made of an inorganic filler and a resin, fixed on the metal plate;
A plasma display device having a power recovery circuit using a heat dissipation substrate composed of a lead frame embedded in the heat transfer resin portion and partially having a coil pattern,
The heat dissipation substrate is
A structure part in which at least a part of the coil pattern is embedded in the heat transfer resin part and bent by about 90 degrees from the lead frame;
Or a hole formed near the approximate center of the coil pattern,
Or in the adjustment mechanism part of the inductance by the ferrite core,
Having at least one,
Plasma display device with adjusted inductance value.

Images