JP5594242B2 - Switching element drive circuit - Google Patents

Description

  The present invention includes a plurality of switching elements and a pair provided on a circuit board and transmitting an input signal to the input side terminal to the output side terminal while insulating between the input side terminal and the output side terminal. The present invention relates to a drive circuit for a switching element applied to an electronic device including a magnetic insulating element and a drive circuit that is provided on the circuit board and that opens and closes the plurality of switching elements via the magnetic insulating element.

  As this type of circuit, for example, as seen in the following Patent Document 1, a series connection body of a pair of switching elements and a circuit board on which a driving circuit for opening and closing these switching elements is mounted are provided. What is applied to a power converter configured as described above is known. According to this apparatus, it is possible to step down and output the voltage of a high-voltage DC power supply having a terminal voltage of several hundred volts.

JP 2005-286270 A

  By the way, the circuit board has a high-voltage wiring pattern for the purpose of transmitting power and the like, and a low-voltage wiring pattern for the purpose of transmitting a control signal output from the drive circuit to open and close the switching element. Is formed. Here, when a high-voltage wiring pattern and a low-voltage wiring pattern are projected on a virtual plane parallel to the circuit board, these wiring patterns are formed so that the high-voltage wiring pattern and the low-voltage wiring pattern intersect on this virtual plane. Sometimes. In this case, due to the occurrence of a surge (switching surge) due to switching of the switching state, high-frequency noise (for example, common mode noise) is superimposed on the signal transmitted through the low-voltage wiring pattern, and the switching element may malfunction. .

  In order to solve such a problem, when the wiring pattern is formed on the circuit board while avoiding the intersection of the high voltage wiring pattern and the low voltage wiring pattern, there is a concern that the wiring pattern becomes long.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to perform switching capable of avoiding the intersection of the high-voltage wiring pattern and the low-voltage wiring pattern while avoiding the wiring pattern from becoming long as much as possible. The object is to provide a drive circuit for the element.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to the first aspect of the present invention, an input signal to the input side terminal is provided to the output side terminal while being insulated between the plurality of switching elements and the input side terminal and the output side terminal provided on the circuit board. The magnetic insulating element is applied to an electronic device including a pair of magnetic insulating elements that transmit and a drive circuit that is provided on the circuit board and that opens and closes the plurality of switching elements via the magnetic insulating elements. In the front view of the plate surface of the circuit board, the input side terminal and the output side terminal are different from each other of the magnetic insulation elements in the front view of the plate surface of the circuit board. A pair of opposing sides of a boundary line that is provided on each of the sides and defines a substantially rectangular region of a part of the circuit board as a prescribed region in a front view of the plate surface of the circuit board. of A region that extends in a direction parallel to the boundary line and that bisects the defined region is defined as a central region, and each of a pair of regions that are provided so as to sandwich the central region among the defined regions is a first region. The region is defined as a region and a second region, and one of the pair of magnetic insulating elements is a first magnetic insulating element, the other is a second magnetic insulating element, and the central region includes the first magnetic insulating element. An insulating element and the second magnetic insulating element are provided, and a connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the first magnetic insulating element is provided in the first region, In the second region, a connection part of the switching control terminal of the switching element corresponding to the output side terminal of the second magnetic insulation element is provided, and the first magnetic insulation element has its own output side Connect the terminal to the first area And the second magnetic insulation element is provided so that its output side terminal faces in the direction of the second region, and is connected to the output side terminal of the magnetic insulation element and the connection. Are connected by a high voltage wiring pattern, and the input side terminal of the magnetic insulation element and the drive circuit are connected by a low voltage wiring pattern, and the high voltage wiring pattern and the low voltage wiring pattern are parallel to the circuit board. When the high-voltage wiring pattern and the low-voltage wiring pattern are projected on a virtual plane, the high-voltage wiring pattern and the low-voltage wiring pattern are provided so as not to intersect each other on the virtual plane.

  In the said invention, the 1st, 2nd magnetic insulation element used as a pair is provided in the center area | region. Specifically, the first magnetic insulation element is provided so that the output-side terminal of the first magnetic insulation element faces the first region, and the output-side terminal of the second magnetic insulation element is the second. A second magnetic insulation element is provided so as to face in the direction of the region. In the first region, a connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the first magnetic insulation element is provided, and in the second region, the output side of the second magnetic insulation element A connection portion of the switching control terminal of the switching element corresponding to the terminal is provided. Then, these wiring patterns are provided on the circuit board so that the high-voltage wiring pattern and the low-voltage wiring pattern do not intersect on the projection plane.

  According to such an invention, the high-voltage wiring pattern can be prevented from becoming long as much as possible, and in the central region, the high-voltage wiring pattern is provided in a direction orthogonal to the direction parallel to the boundary line (reference direction). It is possible to suppress the arrangement of the low-voltage wiring pattern by the high-voltage wiring pattern as much as possible in the region. Therefore, for example, in the circuit board, a region between the connection portion corresponding to the output side terminal of the first magnetic insulation element and the connection portion corresponding to the output side terminal of the second magnetic insulation element is defined as a low-voltage wiring pattern. Can be used as an arrangement region of the high-voltage wiring pattern, and the intersection of the high-voltage wiring pattern and the low-voltage wiring pattern can be avoided.

  The high-voltage wiring pattern is desirably provided so that the high-voltage wiring patterns do not intersect with each other on the virtual plane when the high-voltage wiring pattern is projected onto the virtual plane.

According to a second aspect of the invention, in the invention according to the first aspect, each of the previous SL first magnetic insulation element and the second magnetic insulating element, in a front view of the plate surface of the circuit board, the central region it is characterized in that said are provided to the axis intersection difference through the middle of the pair of borders and drawn in a direction parallel and the central region.

  In the above invention, for the purpose of effectively using the mounting area of the circuit board, the magnetic insulating elements that are paired in the above manner are provided in the central area. When the magnetic insulation elements are arranged in this way, the switching control terminal provided in the first region and the second region are usually provided in the first region in a direction orthogonal to the reference direction in front view of the plate surface of the circuit board. There is a tendency that the distance from the connection portion of the provided opening / closing control terminal is shortened. In this case, the arrangement of the low-voltage wiring pattern is likely to be limited by the high-voltage wiring pattern in the central region. For this reason, in the said invention, the merit provided with the invention specific matter of the invention which concerns on Claim 1 is large.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, when viewed from the front of the plate surface of the circuit board, it intersects with the first magnetic insulation element and the output of the first magnetic insulation element. An axis perpendicular to the side on which the side terminal is provided is defined as a first reference axis, and intersects with the second magnetic insulation element in the front view of the plate surface of the circuit board and the second magnetic insulation element An axis perpendicular to the side on which the output side terminal is provided is defined as a second reference axis, and each of the first magnetic insulation element and the second magnetic insulation element includes the first reference axis and the second reference axis. The reference axes are provided so as to be parallel to each other.

  In the said invention, the 1st magnetic insulation element and the 2nd magnetic insulation element are provided in the said aspect. That is, in a front view of the plate surface of the circuit board, the direction perpendicular to this side from the center of the first magnetic insulation element toward the side where the output side terminal of the magnetic insulation element is provided, and the second magnetic insulation element These first and second magnetic insulation elements are provided so that an angle formed by a direction perpendicular to the side from the center toward the side where the output terminal of the magnetic insulation element is provided is 180 degrees. According to such an invention described above, it is possible to suitably suppress an increase in the length of the high-voltage wiring pattern.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the switching element is of a voltage control type, and the magnetic insulating element includes an opening / closing control of the switching element. The output side terminal corresponding to the terminal and the output terminal is provided, and in the first region, in addition to the connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the first magnetic insulation element In addition, a connection portion of the output terminal of the switching element is further provided, and the connection portion is arranged in the first magnetic insulating element in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the first region. The output side terminal corresponding to the connection portion is provided, and the second region includes, in addition to the connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the second magnetic insulation element. The A connection portion for the output terminal of the switching element is further provided, and the connection portion is arranged in the second magnetic insulating element in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the second region. The output side terminal corresponding to is provided.

  In the voltage control type switching element, the switching operation of the switching element is performed by adjusting the voltage between the switching control terminal and the output terminal. For this reason, in the said invention, in addition to the connection part of the switching control terminal, the connection part of the output terminal is provided in each of the 1st area | region and the 2nd area | region. In the above invention, the first magnetic insulating element is provided with output-side terminals corresponding to the connection portions in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the first region. The second magnetic insulating element is provided with output-side terminals corresponding to the connection portions in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the second region. According to the above invention, even when the number of terminals of each switching element is increased, it is possible to avoid the intersection of the high-voltage wiring pattern and the low-voltage wiring pattern while suppressing the increase in the length of the high-voltage wiring pattern as much as possible. Can do.

  Invention of Claim 5 is an electric power converter provided with the switching module which has the serial connection body of the said switching element used as the pair in the invention of any one of Claims 1-4. The circuit board is provided above the switching module so as to be substantially parallel to a placement surface of the module, and the defined area is the front side of the plate surface of the circuit board in the front view with respect to the circuit board. The region is substantially the same as the projection region of the switching module.

1 is a system configuration diagram according to a first embodiment. FIG. The perspective view which shows a part of DCDC converter concerning the embodiment. The enlarged view which shows a part of circuit board etc. concerning the embodiment. The front view which shows the arrangement | positioning aspect of the wiring pattern and pulse transformer concerning the embodiment. The front view which shows the arrangement | positioning aspects, such as a pulse transformer, when a high voltage wiring pattern and a low voltage wiring pattern cross | intersect. The front view which shows the wiring pattern concerning 2nd Embodiment, and the arrangement | positioning aspect of a pulse transformer. The figure which shows the arrangement | positioning aspects, such as a connection terminal of the circuit board concerning other embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a drive circuit according to the present invention is applied to a DCDC converter mounted on a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a system according to the present embodiment.

  The illustrated high voltage battery 10 is a power supply source of a rotating machine (motor generator) (not shown) as an in-vehicle power generation device, and is a storage battery that outputs a predetermined high voltage (several hundreds of volts). The high voltage battery 10 can be connected to a DCDC converter CV. Incidentally, as the high voltage battery 10, for example, a lithium ion storage battery or a nickel metal hydride storage battery can be employed.

  The DCDC converter CV includes a switching module (hereinafter referred to as a module 12) having a series connection body of a pair of switching elements Q1 and Q3 and a parallel connection body (full bridge circuit) of a series connection body Q2 and Q4 of a pair of switching elements. 14 is an isolated converter that steps down the voltage of the high-voltage battery 10 and outputs it. In this embodiment, N-channel MOS transistors are assumed as the switching elements Q1 to Q4.

  The input terminals (drains) of the switching elements Q1 and Q2 on the high potential side are connected to the positive electrode side of the high voltage battery 10 via the positive terminal P, and the output terminals (sources) of the switching elements Q3 and Q4 on the low potential side are It is connected to the negative electrode side of the high voltage battery 10 via the negative electrode terminal N. A free wheel diode (not shown) is connected between the input / output terminals of the switching elements Q1 to Q4.

  Both ends of the primary side coil 14a of the transformer 14 are connected to the connection points of the pair of switching elements Q1 and Q3 and the connection points of the pair of switching elements Q2 and Q4 via the terminals OUT1 and OUT2, respectively. ing.

  Both ends of the secondary coil 14b of the transformer 14 are connected to the anode sides of the diodes RD1 and RD2, and the cathode sides of the diodes RD1 and RD2 are short-circuited. The diodes RD1 and RD2 are connected to a smoothing circuit 16 (LC filter) including a reactor 16a and a capacitor 16b.

  The primary side of the high-voltage battery 10 and the DCDC converter CV constitutes an in-vehicle high-voltage system and is insulated from a ground line GL connected to a case (not shown) of the DCDC converter CV. On the other hand, the secondary side of the DCDC converter CV constitutes an in-vehicle low-voltage system that operates with the ground line GL as a reference.

  For this reason, in this embodiment, the midpoint tap mt of the secondary side coil 14b of the transformer 14 is connected to the ground line GL. According to such a configuration, the diodes RD1 and RD2 are configured such that the high potential side switching element Q1 and the low potential side switching element Q4 are turned on, or the high potential side switching element Q2 and the low potential side switching element Q3. Depending on whether is turned on, the voltage of “½” of the voltage across the secondary coil 14b is alternately output. The midpoint tap mt is a terminal connected to the center of the secondary side coil 14b of the transformer 14 (a midpoint that is a point equidistant from both terminals).

  The output voltage of the DCDC converter CV is applied to the low voltage battery 18. The low-voltage battery 18 is a storage battery (for example, a lead storage battery) that constitutes a part of the in-vehicle low-voltage system and outputs a predetermined low voltage (for example, 12 V).

  The control circuit 20 is a control unit that uses the low voltage battery 18 as a power supply source and controls the battery. The control circuit 20 operates the switching elements Q1 to Q4 of the DCDC converter CV via the first and second drive circuits DC1 and DC2 in order to control the state of charge (SOC) of the low-voltage battery 18 as desired. Specifically, the control circuit 20 turns on / off the switching elements Q1, Q3 via the first drive circuit DC1, and turns on / off the switching elements Q2, Q4 via the second drive circuit DC2. Hereinafter, a circuit configuration for operating the switching element via the drive circuit will be described. Incidentally, the circuit configuration for operating the switching elements Q1 and Q3 via the first drive circuit DC1 and the circuit configuration for operating the switching elements Q2 and Q4 via the second drive circuit DC2 are the same. Next, a circuit configuration via the first drive circuit DC1 will be described.

  The first and second drive circuits DC1 and DC2 are connected to the first and second pulse transformers PT1 and PT2, respectively. The first and second pulse transformers PT1 and PT2 include one primary coil 22a and two secondary coils 22b and 22c, and transform pulses input from the drive circuit to the primary coil 22a. Thus, the magnetic insulation element is output to the secondary coils 22b and 22c. Incidentally, the first pulse transformer PT1 and the second pulse transformer PT2 have the same configuration.

  One end of the secondary side coil 22b of the first pulse transformer PT1 is connected to the source of the switching element Q1 via the output side terminal St1 and the output side connection terminal (source connection terminal S1), and the secondary side coil 22b. The other end of the switching element Q1 is connected to the switching control terminal (gate) of the switching element Q1 through the output terminal Gt1, the switching connection terminal (gate connection terminal G1), and the series connection body of the resistors 24 and 26. The gate and the source of the switching element Q1 are connected by a resistor 28. Furthermore, a diode 30 is connected in parallel to the resistor 24 so as to allow current to flow from the gate to the secondary coil 22b.

  Incidentally, the source connection terminal and the gate connection terminal specifically include, for example, an attachment portion (through hole) formed on the circuit board and a wiring pattern connected to the outer edge of the through hole. In addition, the configuration including the resistors 24 and 26 and the diode 30 suppresses an excessive increase in the charge supply rate to the gate when the gate of the switching element Q1 is charged, and is applied to the gate when the gate is discharged. This is to quickly release the accumulated electric charge.

  On the other hand, one end of the secondary side coil 22c of the first pulse transformer PT1 is connected to the source of the switching element Q3 via the output side terminal St3 and the source connection terminal S3, and the other end of the secondary side coil 22c is The output side terminal Gt3, the gate connection terminal G3, and the series connection body of the resistors 32 and 34 are connected to the gate of the switching element Q3. As with the switching element Q1, the gate and source of the switching element Q3 are connected by a resistor 36, and the resistor 32 allows current to flow from the gate to the secondary coil 22c. A diode 38 having a function is connected in parallel.

  The secondary coils 22b and 22c of the first pulse transformer PT1 are connected so that the polarities of the voltages generated in the secondary coils are opposite to each other.

  In such a configuration, when a pulse signal having a predetermined duty ratio (for example, 50%) is input from the first drive circuit DC1 to the first pulse transformer PT1 (the primary coil 22a), the secondary coil 22b. In addition, voltages that are logically inverted from each other are applied to each of the secondary coils 22c, whereby the applied voltages to the respective gates of the switching elements Q1 and Q3 change in a complementary manner.

  Here, in the present embodiment, the same pulse signal as that of the first pulse transformer PT1 is input from the first drive circuit DC1 to the second pulse transformer PT2 from the second drive circuit DC2. Processing for adjusting the output voltage of the DCDC converter CV is performed by adjusting the phase of the output pulse from the first drive circuit and the output pulse from the second drive circuit. In this process, the switching element on the high potential side of one series connection body and the switching element on the low potential side of the other series connection body are simultaneously turned on in the series connection body of the two pairs of switching elements. This is based on the fact that the output voltage of the DCDC converter CV is determined by the period of time.

  Next, the internal configuration of the power conversion device according to the present embodiment will be described with reference to FIGS.

  First, FIG. 2 shows an enlarged perspective view of a part of the DCDC converter CV according to the present embodiment.

  As illustrated, the module 12 included in the DCDC converter CV is actually disposed on the case 40 of the DCDC converter CV and has a substantially rectangular parallelepiped shape. A circuit board 42 (printed board) is provided above the module 12 so as to be substantially parallel to the arrangement surface (the upper surface inside the case 40).

  The circuit board 42 is a planar rectangular (rectangular) member formed by arranging a wiring pattern made of a conductive material such as copper on an insulating base made of resin or the like. On the circuit board 42, although not shown, first and second drive circuits DC1 and DC2, first and second pulse transformers PT1 and PT2, a control circuit 20 and the like are mounted. In the present embodiment, a multilayer substrate having a plurality of layers (for example, three layers) is assumed as the circuit substrate 42. Moreover, although the said case 40 has comprised the box shape actually, only the one part bottom face part is shown in FIG.

  Here, the circuit board 42 is connected to the switching elements Q1 to Q4 in the module 12, and the first and second drive circuits DC1 and DC2 and the first and second pulse transformers PT1 and PT2. Various connection terminals are provided. Hereinafter, this will be described with reference to FIG.

  FIG. 3A shows the vicinity of a specified region (a region surrounded by an alternate long and short dash line in the drawing) that is a part of a substantially rectangular region of the circuit board 42 in a front view of the plate surface (front surface) of the circuit board 42. FIG. 3B is a side view of the module 12.

  In the present embodiment, the defined area is defined as an area that is substantially the same as the projection area of the module 12 on the circuit board 42 in a front view of the plate surface of the circuit board 42. In the present embodiment, since the module 12 has a substantially rectangular parallelepiped shape as described above, the defined area has a planar rectangular shape (rectangular shape) when the plate surface of the circuit board 42 is viewed from the front.

  In the defined region thus determined, a gate connection terminal Gn connected to the gate of the switching element Qn (n = 1 to 4) and a source connection terminal Sn connected to the source are provided. Incidentally, the gate connection terminal Gn and the source connection terminal Sn of the circuit board 42 have a plane parallel to the module 12 in the direction from the module 12 side to the circuit board 42 side, as shown in FIG. Each of the module terminals extending in the orthogonal direction is connected. These module terminals are terminals connected to the gate and source of each switching element Qn.

  In the drawing, terminals connected to the positive terminal P and the negative terminal N and terminals OUT1 and OUT2 for connecting the module 12 and the transformer 14 are shown together. Further, a through hole 44 for attaching a screw for fixing the case 40 and the circuit board 42 is also shown.

  Then, the arrangement | positioning aspect of the element in the circuit board 42 and a wiring pattern is demonstrated using FIG. FIG. 4 is a view showing the vicinity of the prescribed region in a front view of the plate surface of the circuit board 42, as in FIG. 3A.

  First, the arrangement | positioning aspect of an element etc. is demonstrated. In addition, in this embodiment, it is a rectangular area | region extended in the direction (henceforth a reference direction) parallel to a pair of boundary lines L1 and L2 which oppose among a boundary line (a dashed-dotted line in a figure) which forms a prescription | regulation area | region. An area that bisects the defined area is defined as a central area Ac. Then, each of the pair of rectangular areas adjacent to the central area Ac among the defined areas is defined as a first area A1 and a second area A2.

  The first pulse transformer PT1 (second pulse transformer PT2) has a substantially rectangular parallelepiped shape and is mounted in the central region Ac. Specifically, the first pulse transformer PT1 (second pulse transformer PT2) has a substantially rectangular shape in a front view of the plate surface of the circuit board 42, and one side of the pulse transformer has a side in the transformer. A pair of input side terminals It1 (It2) connected to both ends of the primary side coil are provided. Of the first pulse transformer PT1 (second pulse transformer PT2), four output-side terminals St1, Gt1, St3, Gt3 (on the side facing the side where the input-side terminal It1 (It2) is provided) St4, Gt4, St2, Gt2) are provided. Then, the input side terminal and the output side terminal are soldered to the circuit board 42, whereby the pulse transformer is mounted.

  When each of the first pulse transformer PT1 and the second pulse transformer PT2 draws an axis (center axis Lc: indicated by a one-dot chain line in the drawing) extending through the center of the central region Ac and in the reference direction, The pulse transformers PT1 and PT2 and the central axis Lc are mounted so as to intersect each other when the plate surface of the substrate 42 is viewed from the front.

  Here, in a front view of the plate surface of the circuit board 42, in a direction intersecting the first pulse transformer PT1 and orthogonal to the side where the output side terminal of the transformer PT1 is provided (a direction orthogonal to the reference direction). The extending axis is defined as the first reference axis Lα1, and the axis that intersects with the second pulse transformer PT2 and is orthogonal to the side on which the output side terminal of the transformer PT2 is provided is defined as the second reference axis Lα2.

  The first pulse transformer PT1 is provided so that its output-side terminals St1, Gt1, St3, and Gt3 are directed toward the first region A1. In the first region A1, a source connection terminal S1, a gate connection terminal G1, a source connection terminal S3, and a gate connection terminal G3 are provided in order from the upper side in the drawing along the reference direction. Then, in the first pulse transformer PT1, the output side terminal St1 corresponding to the source connection terminal S1, the output side terminal Gt1 corresponding to the gate connection terminal G1, and the source connection terminal S3 in order from the upper side in the drawing along the reference direction. And an output side terminal Gt3 corresponding to the gate connection terminal G3.

  On the other hand, the second pulse transformer PT2 is provided so that its output side terminals St4, Gt4, St2, and Gt2 are directed in the direction of the second region A2. In the second region A2, a gate connection terminal G2, a source connection terminal S2, a gate connection terminal G4, and a source connection terminal S4 are provided in order from the upper side in the drawing along the reference direction. In the second pulse transformer PT2, the output side terminal Gt2 corresponding to the gate connection terminal G2, the output side terminal St2 corresponding to the source connection terminal S2, and the gate connection terminal G4 in order from the upper side in the drawing along the reference direction. Are provided on the output side terminal Gt4 corresponding to, and the output side terminal St4 corresponding to the source connection terminal S4.

  The first and second pulse transformers PT1 and PT2 are provided so that the first reference axis Lα1 and the second reference axis Lα2 are parallel to each other. In other words, when viewed from the front of the plate surface of the circuit board 42, it is orthogonal to this side from the center of the first pulse transformer PT1 (indicated by ● in the figure) toward the side where the output terminal of the transformer is provided. These pulse transformers PT1, PT2 are provided so that the angle between the direction and the direction perpendicular to this side from the center of the second pulse transformer PT2 toward the side where the output side terminal of this transformer is provided is 180 degrees. It has been.

  Each of the first drive circuit DC1 and the second drive circuit DC2 is mounted so as to be arranged on both sides of the central axis Lc and in a direction orthogonal to the reference direction in a front view of the plate surface of the circuit board 42. Yes. Specifically, the drive circuits DC1 and DC2 are provided above the second pulse transformer PT2 in the drawing.

  Next, the arrangement pattern of the wiring pattern on the circuit board 42 will be described.

  As shown in the figure, each of the output terminals St1, Gt1, St3, Gt3 of the first pulse transformer PT1 and each of the connection terminals S1, G1, S3, G3 in the first region A1 are separated from each other. Are connected by a high-voltage wiring pattern. Specifically, when these high-voltage wiring patterns are projected on a virtual plane parallel to the circuit board 42 in a direction perpendicular to the circuit board 42 (hereinafter referred to as vertical projection), the high-voltage wiring patterns are formed on the virtual plane. It is formed on the circuit board 42 so that the patterns do not cross each other.

  On the other hand, each of the output terminals Gt2, St2, Gt4, St4 of the second pulse transformer PT2 and each of the connection terminals G2, S2, G4, S4 in the second region A2 are different from each other. Connected by. Specifically, the high-voltage wiring patterns are formed on the circuit board 42 so that the high-voltage wiring patterns do not intersect each other on the virtual plane when the high-voltage wiring patterns are vertically projected on the virtual plane.

  The low-voltage wiring pattern that connects the second drive circuit DC2 and the input-side terminal It2 of the second pulse transformer PT2 is the virtual plane when the low-voltage wiring pattern and the high-voltage wiring pattern are vertically projected on the virtual plane. Are formed on the surface of the circuit board 42 so that the low-voltage wiring pattern and the high-voltage wiring pattern do not cross each other.

  On the other hand, when the low voltage wiring pattern connecting the first drive circuit DC1 and the input side terminal It1 of the first pulse transformer PT1 is vertically projected with respect to the virtual plane, It is formed on the back surface of the circuit board 42 at a position corresponding to the mounting position of the primary side coil of the second pulse transformer PT2 so that the low-voltage wiring pattern and the high-voltage wiring pattern do not intersect on the virtual plane.

  In the present embodiment, the low-voltage wiring pattern is formed on the back surface of the circuit board 42 and at a position corresponding to the mounting position of the primary coil because the high-frequency noise caused by the switching surge causes the low-voltage wiring pattern to be formed. This is for avoiding superimposition on the transmitted signal. Here, the high-voltage wiring pattern refers to a wiring pattern in which the amount of potential fluctuation that the wiring pattern can take is much larger than the amount of potential fluctuation that the low-voltage wiring pattern can take.

  According to such a circuit configuration, it is possible to avoid as much as possible the formation of the high-voltage wiring pattern in the direction orthogonal to the reference direction in the central region Ac. For this reason, in a front view of the plate surface of the circuit board 42, the region where the high voltage wiring pattern for connecting the connection terminals of the first pulse transformer PT1 and the first region A1 is provided, and the second pulse transformer PT2 and the second pulse transformer PT2. The low-voltage wiring pattern can be appropriately formed by utilizing the space between the region A2 and the region where the high-voltage wiring pattern for connecting the connection terminals is provided. Thereby, the crossing of a high voltage wiring pattern and a low voltage wiring pattern can be avoided.

  Incidentally, inconvenience when the above-described circuit configuration is not adopted will be described with reference to FIG.

  FIG. 5A shows a case where the orientation of the output side terminals of both the first pulse transformer PT1 and the second pulse transformer PT2 is the second region A2 side in FIG.

  In the arrangement of the connection terminals in the first pulse transformer PT1 and the first region A1 shown in the figure, the high-voltage wiring pattern that connects the output-side terminals St1, Gt1 of the first pulse transformer PT1 and the connection terminals S1, G1. If the length is to be shortened as much as possible, the high voltage wiring pattern is formed so that the high voltage wiring pattern crosses in the direction perpendicular to the reference direction (left and right direction in the figure) in the central region Ac.

  For this reason, the low-voltage wiring pattern connecting the input-side terminal It1 of the first pulse transformer PT1 and the first drive circuit DC1 and the high-voltage wiring pattern intersect in the virtual plane.

  On the other hand, in FIG. 5B, the connection terminal corresponding to each pulse transformer is divided into the first area A1 and the second area A2, and a pulse transformer having an output side terminal corresponding to this arrangement is provided. The case where it is adopted is shown.

  In the arrangement of the pulse transformer and connection terminals shown in the figure, the output terminals St1, Gt1 and St3, Gt3 of the second pulse transformer PT2, and the connection terminals S1 provided in the first region A1 and the second region A2, respectively. , G1 and S3, G3 are formed so as to cross in the direction perpendicular to the reference direction in the central region Ac. Therefore, the low voltage wiring pattern that connects the input side terminal It1 of the first pulse transformer PT1 and the first drive circuit DC1, and the input side terminal It2 of the second pulse transformer PT2 and the second drive circuit DC2 are connected. The low-voltage wiring pattern and the high-voltage wiring pattern intersect at the virtual plane.

  In such an arrangement, for example, noise is mixed in a signal transmitted through a high-voltage wiring pattern connected to the gate of the switching element, and the switching element may malfunction. In this case, both the high-voltage side and low-voltage side switching elements are simultaneously turned on, and the positive electrode and the negative electrode of the high-voltage battery may be short-circuited.

  In order to solve such a problem, for example, the dead time for avoiding the switching elements on the high voltage side and the low voltage side from being turned on at the same time is extended, or leakage from the high voltage wiring pattern to the low voltage wiring pattern is performed. It may be possible to add parts for reducing high-frequency noise (common mode noise). However, these countermeasures may increase switching loss, make it difficult to increase the switching frequency, and increase the cost.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) In a front view of the plate surface of the circuit board 42, the first pulse transformer PT1 is provided so that its output terminal is directed toward the first region A1, and the second pulse transformer PT2 is provided. Is provided so that the output-side terminal of itself is directed in the direction of the second region A2. In addition, a connection terminal corresponding to the first pulse transformer PT1 is provided in the first region A1, and a connection terminal corresponding to the second pulse transformer PT2 is provided in the second region A2. The output side terminals of the first and second pulse transformers PT1 and PT2 and the high-voltage wiring pattern connecting the corresponding connection terminals, and the input side terminals of the first and second pulse transformers PT1 and PT2 These wiring patterns are formed on the circuit board 42 so that the low-voltage wiring patterns connecting the first and second drive circuits DC1 and DC2 do not intersect at the virtual plane.

  According to such an arrangement of the connection terminal and the pulse transformer, it is possible to reduce the degree of inductive coupling between the high-voltage wiring pattern and the low-voltage wiring pattern while suppressing an increase in the wiring pattern as much as possible, resulting from a switching surge. The reliability of the DCDC converter CV can be improved, for example, the occurrence of malfunction of the switching element can be avoided.

  Further, it is possible to avoid an increase in dead time for avoiding a malfunction of the switching element, and it is possible to avoid an increase in switching loss and improve a switching frequency.

  (2) Each of the first pulse transformer PT1 and the second pulse transformer PT2 is provided such that the first reference axis Lα1 and the second reference axis Lα2 are parallel to each other. Thereby, the expansion | extension of the high voltage | pressure wiring pattern which connects between the gate and source | sauce of a switching element via the secondary side coil of a pulse transformer can be suppressed suitably.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, switching elements Q1 to Q4 applied to the DCDC converter CV are not modularized but switching elements as discrete components are used.

  FIG. 6 shows a front view of the circuit board 42 according to the present embodiment. In FIG. 6, the same members as those shown in FIG. 4 are denoted by the same reference numerals for the sake of convenience.

  On the back surface of the circuit board 42 shown in the figure, switching elements Q1 to Q4 are mounted. Here, the gate and source of each of the switching elements Q1 to Q4 are connected to the gate connection terminal Gn and the source connection terminal Sn provided on the circuit board 42 by soldering.

  The drains and positive terminals P of the switching elements Q1 and Q2, the source of the switching element Q1, the drain and terminal OUT1 of the switching element Q3, the source of the switching element Q2, the drain and terminal OUT2 of the switching element Q4, and the switching elements Q3 and Q4 The sources and the negative terminal N are connected by a bus bar 50 (insert bus bar). The bus bar 50 is a member obtained by coating a conductive material (a long metal plate) with a non-conductive material. The bus bar 50 is provided on the back surface side of the circuit board 42, and more specifically, is provided at a predetermined distance from the back surface of the circuit board 42.

  Incidentally, in the present embodiment, when the bus bar 50 and the low-voltage wiring pattern are vertically projected on the virtual plane, the intersection of the bus bar 50 and the low-voltage wiring pattern is allowed on the virtual plane. This is based on the fact that the influence of noise is very small because the distance between the board surface of the circuit board 42 and the bus bar is sufficiently long.

  As described above, in the present embodiment, in the above circuit configuration using the bus bar 50, by adopting a technique for avoiding the intersection of the low voltage wiring pattern and the high voltage wiring pattern and the bus bar 50, inconvenience due to the switching surge is avoided. It can be suitably avoided.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the circuit configuration includes the two pulse transformers PT1 and PT2 for opening and closing each of the switching elements Q1 and Q3 and the switching elements Q2 and Q4. However, the present invention is not limited to this. For example, it is good also as a circuit structure provided with four pulse transformers for opening / closing each of switching element Q1-Q4 separately. In this case, each pulse transformer has a pair (two) of output side terminals for outputting signals to the gate and source of one switching element corresponding to the transformer. In this case, the pair of (two) pulse transformers that operate the switching elements Q1 and Q3 correspond to the first magnetic insulation element, and the two pulse transformers that operate the switching elements Q2 and Q4 correspond to the second magnetic insulation. It corresponds to an element.

  In the first embodiment, a circuit configuration is employed in which the first drive circuit DC1 is mounted on the opposite side of the position where the second drive circuit DC2 is provided (below the specified area) across the specified area. May be. Even in this case, the first drive circuit DC1 and the input-side terminal It1 of the first pulse transformer PT1 can be connected by the low-voltage wiring pattern using the central region Ac without crossing the high-voltage wiring pattern. it can.

  The switching element is not limited to an N-channel MOS transistor, and may be an insulated gate bipolar transistor (IGBT), for example. The switching element is not limited to the voltage control type, and may be a current control type (bipolar power transistor), for example. In this case, a connection terminal corresponding to the switching control terminal (base) of each switching element is provided on the circuit board 42.

  The magnetic insulation element is not limited to a pulse transformer, for example, a change in current flowing through a signal line from one electric circuit system is detected by a magnetoresistive element in a non-contact manner, and an electric signal is sent to the other electric circuit system. It may be a magnetic coupler that transmits.

  The arrangement mode of the pair of pulse transformers PT1 and PT2 in the central region Ac is not limited to that exemplified in the first embodiment. For example, when an axis line is drawn in the center region Ac in a direction perpendicular to the reference direction, each of the first pulse transformer PT1 and the second pulse transformer PT2 is connected to the pulse transformer PT1 in a front view of the plate surface of the circuit board 42. , PT2 and the axis may be provided so as to intersect.

  Further, for example, on the condition that the output side terminal of the first pulse transformer PT1 is directed to the first area A1 and the output side terminal of the second pulse transformer PT2 is directed to the second area A2, the circuit board is used. 42, when viewed from the front of the plate surface, the direction perpendicular to the side from the center of the first pulse transformer PT1 toward the side where the output terminal of the transformer is provided, and the center of the second pulse transformer PT2 The first and second pulse transformers PT1 and PT2 are provided so that an angle formed with a direction orthogonal to the side toward the side where the output terminal is provided is greater than 90 degrees and less than 180 degrees. Also good.

  In each of the above embodiments, a configuration in which the wiring pattern is formed in an intermediate layer of the circuit board (a layer other than the front surface and the back surface among a plurality of layers of the multilayer substrate) may be employed.

  -The power converter to which the present invention is applied is not limited to a power converter provided with a full bridge circuit, for example, a power converter provided with a half bridge circuit including only a series connection body of a pair of (two) switching elements. May be.

  The arrangement mode of the connection terminals Gn and Sn in the first area A1 and the second area A2 is not limited to that exemplified in the first embodiment. For example, as shown in FIG. 7A, when the arrangement positions a1 to a4 of the connection terminals in the first area A1 and the arrangement positions b1 to b4 of the connection terminals in the second area A2 are defined, FIG. Connection terminals may be arranged as in the arrangement patterns B to H shown in FIG. In this case, the arrangement pattern of the output side terminals of the pulse transformer corresponding to each arrangement pattern is as shown in FIG.

  DESCRIPTION OF SYMBOLS 12 ... Switching module, 42 ... Circuit board, Qn ... Switching element, CV ... DCDC converter, PT1, PT2 ... Pulse transformer.

Claims (5)

A plurality of switching elements and a magnetic insulating element which is provided on a circuit board and forms a pair for transmitting an input signal to the input side terminal to the output side terminal while insulating between the input side terminal and the output side terminal And a drive circuit that is provided on the circuit board and that opens and closes the plurality of switching elements via the magnetic insulating element,
The magnetic insulating element has a substantially rectangular shape in front view of the plate surface of the circuit board,
Each of the input side terminal and the output side terminal is provided on each of different sides of the magnetic insulating element in a front view of the plate surface of the circuit board,
In a front view of the board surface of the circuit board, a substantially rectangular area of a part of the circuit board is defined as a prescribed area,
A region extending in a direction parallel to a pair of opposing boundary lines among the boundary lines forming the defined region, and defining a region that bisects the defined region as a central region,
Each of the pair of regions provided so as to sandwich the central region among the defined regions is defined as a first region and a second region,
One of the paired magnetic insulation elements is a first magnetic insulation element, the other is a second magnetic insulation element,
The central region is provided with the first magnetic insulation element and the second magnetic insulation element,
In the first region, a connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the first magnetic insulation element is provided,
In the second region, a connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the second magnetic insulation element is provided,
The first magnetic insulation element is provided so that its output side terminal faces in the direction of the first region, and the second magnetic insulation element has its output side terminal in the first area. Provided to face in the direction of the area of 2,
The output side terminal of the magnetic insulation element and the connection portion are connected by a high voltage wiring pattern, and the input side terminal of the magnetic insulation element and the drive circuit are connected by a low voltage wiring pattern,
When the high-voltage wiring pattern and the low-voltage wiring pattern project the high-voltage wiring pattern and the low-voltage wiring pattern on a virtual plane parallel to the circuit board, the high-voltage wiring pattern and the low-voltage wiring pattern on the virtual plane The switching element drive circuit is provided so as not to cross each other. Before SL Each of the first magnetic insulation element and the second magnetic insulating element, wherein in a front view of the plate surface of the circuit board, the pair of and the drawn the boundary in a direction parallel to the central region driving circuit of a switching element according to claim 1, wherein a is provided so as to axis line exchange difference through the middle of the central region. In a front view of the plate surface of the circuit board, an axis that intersects the first magnetic insulation element and is orthogonal to a side on which the output side terminal of the first magnetic insulation element is provided is defined as a first reference axis. And
In a front view of the plate surface of the circuit board, an axis that intersects with the second magnetic insulation element and is orthogonal to a side on which the output side terminal of the second magnetic insulation element is provided is defined as a second reference axis. And
2. The first magnetic insulation element and the second magnetic insulation element are provided so that the first reference axis and the second reference axis are parallel to each other. Or the drive circuit of the switching element of 2. The switching element is of a voltage control type,
The magnetic insulating element is provided with the output side terminal corresponding to the switching control terminal and the output terminal of the switching element,
In the first region, in addition to the connection portion of the switching control terminal of the switching element corresponding to the output side terminal of the first magnetic insulation element, a connection portion of the output terminal of the switching element is further provided. And
In the first magnetic insulating element, the output side terminals corresponding to the connection portions are provided in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the first region,
In the second region, in addition to the connection part of the switching control terminal of the switching element corresponding to the output side terminal of the second magnetic insulation element, a connection part of the output terminal of the switching element is further provided. And
The second magnetic insulating element is provided with the output-side terminals corresponding to the connection portions in the order in which the connection portions are arranged in a direction parallel to the pair of boundary lines in the second region. 4. The switching element drive circuit according to claim 1, wherein The electronic device is a power conversion device including a switching module having a series connection body of the switching elements to be paired,
The circuit board is provided above the switching module so as to be substantially parallel to the arrangement surface of the module,
The said prescription | regulation area | region is an area | region substantially the same as the projection area | region of the said switching module with respect to this circuit board in the front view of the board surface of the said circuit board. The switching element drive circuit.

Images