The present invention relates to a semiconductor device having a power supply circuit
There are known semiconductor devices having power supply circuits which convert a power supply voltage into a desired voltage and output the voltage. Such power supply circuits are an inverter, a rectifier, a DC/DC converter and the like. Such semiconductor devices are used, for example, for a power conditioner of a solar power generation system, a server device, and the like. For the power supply circuit in the semiconductor device, a half bridge circuit or a full bridge circuit is used. Each of these circuits has a structure in which semiconductor switching elements are in cascade connection.
In order to enhance power conversion efficiency of such a power supply circuit, it has been being investigated in recent years that high electron mobility transistors (High Electron Mobility Transistors: HEMTs) using a GaN-based semiconductor material that enables operation at a high speed (for example, exceeding 100 MHz) (hereinafter, also referred simply as “GaN-HEMTs”) are applied to the switching elements.
Notably, Patent Literature 1 discloses an LED driving device using GaN-HEMTs.
Patent Literature 1: Japanese Patent Laid-Open No. 2015-029040
In the case where the GaN-HEMTs are applied to the power supply circuit, this causes far more significant influence of a parasitic inductance in the wiring of the power supply circuit than conventional one due to higher speed operation. Therefore, there can be a concern that a malfunction of the power supply circuit arises.
Therefore, an object of the present invention is to provide a semiconductor device capable of suppressing a malfunction of a power supply circuit having GaN-HEMTs.
There is provided a semiconductor device according to the present invention including:
an insulating substrate;
a first conductive pattern part formed on the insulating substrate;
a second conductive pattern part formed on the insulating substrate;
a third conductive pattern part formed on the insulating substrate;
a fourth conductive pattern part formed on the insulating substrate;
a fifth conductive pattern part formed on the insulating substrate;
a first GaN-HEMT having a first GaN main electrode, a second GaN main electrode and a first GaN gate electrode and disposed on the first conductive pattern part;
a first MOS-FET having a first MOS main electrode, a second MOS main electrode and a first MOS gate electrode, the first MOS main electrode being electrically connected to the second GaN main electrode;
a second GaN-HEMT having a third GaN main electrode, a fourth GaN main electrode and a second GaN gate electrode and disposed on the second conductive pattern part;
a second MOS-FET having a third MOS main electrode, a fourth MOS main electrode and a second MOS gate electrode, the third MOS main electrode being electrically connected to the fourth GaN main electrode; and
a bypass capacitor having a first electrode and a second electrode,
the first GaN main electrode of the first GaN-HEMT being electrically connected to the third conductive pattern part, the second MOS main electrode of the first MOS-FET being electrically connected to the fourth conductive pattern part, the third GaN main electrode of the second GaN-HEMT being electrically connected to the fourth conductive pattern part, the fourth MOS main electrode of the second MOS-FET being electrically connected to the fifth conductive pattern part, the first electrode of the bypass capacitor being electrically connected to the third conductive pattern part, the second electrode of the bypass capacitor being electrically connected to the fifth conductive pattern part,
the first GaN-HEMT having a first side and a second side opposite to the first side, the second GaN-HEMT having a third side and a fourth side opposite to the third side,
the first GaN main electrode of the first GaN-HEMT being provided along the first side, the third GaN main electrode of the second GaN-HEMT being provided along the third side, a first imaginary line extending along the first side and a second imaginary line extending along the third side intersecting each other,
the second GaN-HEMT having a fifth side connecting the third side and the fourth side, the fifth conductive pattern part having a conductive pattern side opposite to the fifth side,
the second GaN gate electrode of the second GaN-HEMT being electrically connected to the fifth conductive pattern part via a connection member, the connection member being perpendicular to the fifth side and the conductive pattern side.
Moreover, in the semiconductor device, the first GaN-HEMT and the second GaN-HEMT may be normally-on transistors, and the first MOS-FET and the second MOS-FET may be normally-off transistors.
Moreover, in the semiconductor device, the connection member may be a metal wire or a connector.
Moreover, in the semiconductor device, the first GaN main electrode of the first GaN-HEMT may be electrically connected to a high voltage-side terminal via the third conductive pattern part, and the fourth MOS main electrode of the second MOS-FET may be electrically connected to a low voltage-side terminal via the fifth conductive pattern part.
Moreover, in the semiconductor device,
the insulating substrate may have a first substrate side from which the high voltage-side terminal and the low voltage-side terminal protrude in plan view, and a second substrate side opposite to the first substrate side, and the first GaN-HEMT may be disposed such that the first imaginary line is parallel to the first substrate side, and the second GaN-HEMT may be disposed such that the second imaginary line is oblique to the first substrate side.
Moreover, in the semiconductor device, an angle at which the first imaginary line and the second imaginary line intersect each other may be not less than 30° and not more than 60°.
Moreover, in the semiconductor device, an angle at which the first imaginary line and the second imaginary line intersect each other may be 45°.
Moreover, in the semiconductor device,
the first GaN-HEMT may have a sixth side connecting the first side and the second side, and the fourth conductive pattern part may have a conductive pattern side opposite to the sixth side, and
the first GaN gate electrode of the first GaN-HEMT may be electrically connected to the fourth conductive pattern part via a connection member, and the connection member may be perpendicular to the sixth side and the conductive pattern side.
Moreover, in the semiconductor device, the first MOS-FET may be disposed on the first GaN-HEMT, and the second MOS-FET may be disposed on the second GaN-HEMT.
Moreover, in the semiconductor device, the bypass capacitor may be resin-sealed along with the first GaN-HEMT, the second GaN-HEMT, the first MOS-FET and the second MOS-FET.
Moreover, in the semiconductor device,
a sixth conductive pattern part formed on the insulating substrate;
a seventh conductive pattern part formed on the insulating substrate;
an eighth conductive pattern part formed on the insulating substrate;
a ninth conductive pattern part formed on the insulating substrate;
a third GaN-HEMT having a fifth GaN main electrode, a sixth GaN main electrode and a third GaN gate electrode and disposed on the sixth conductive pattern part;
a third MOS-FET having a fifth MOS main electrode, a sixth MOS main electrode and a third MOS gate electrode, the fifth MOS main electrode electrically connected to the sixth GaN main electrode;
a fourth GaN-HEMT having a seventh GaN main electrode, an eighth GaN main electrode and a fourth GaN gate electrode and disposed on the seventh conductive pattern part; and
a fourth MOS-FET having a seventh MOS main electrode, an eighth MOS main electrode and a fourth MOS gate electrode, the seventh MOS main electrode electrically connected to the eighth GaN main electrode may be further included, wherein
the fifth GaN main electrode of the third GaN-HEMT is electrically connected to the eighth conductive pattern part, the sixth MOS main electrode of the third MOS-FET is electrically connected to the ninth conductive pattern part, the seventh GaN main electrode of the fourth GaN-HEMT is electrically connected to the ninth conductive pattern part, and the eighth MOS main electrode of the fourth MOS-FET is electrically connected to the fifth conductive pattern part, and
the first GaN-HEMT and the third GaN-HEMT are symmetrically disposed with the fifth conductive pattern part interposed therebetween, and the second GaN-HEMT and the fourth GaN-HEMT are symmetrically disposed with the fifth conductive pattern part interposed therebetween.
Moreover, in the semiconductor device,
another bypass capacitor having a third electrode and a fourth electrode may be further included, wherein
the third electrode is electrically connected to the eighth conductive pattern part, and the fourth electrode is electrically connected to the fifth conductive pattern part, and
the bypass capacitor and the other bypass capacitor are symmetrically disposed with the fifth conductive pattern part interposed therebetween.
In the semiconductor device according to the present invention, the first imaginary line extending along the first side of the first GaN-HEMT and the second imaginary line extending along the third side of the second GaN-HEMT intersect each other. Thereby, a bypass capacitor path can be made short, and a parasitic inductance in the bypass capacitor path can be reduced. In addition to this, in the semiconductor device according to the present invention, the metal wire electrically connecting the second GaN gate electrode of the second GaN-HEMT and the fifth conductive pattern part together is perpendicular to the fifth side of the second GaN-HEMT and the conductive pattern side of the fifth conductive pattern part. Thereby, the second GaN gate electrode is connected to the fifth conductive pattern part at the shortest distance, and the relevant metal wire can be made short. Therefore, according to the present invention, a malfunction of a power supply circuit having GaN-HEMTs can be suppressed.
Hereafter, a semiconductor device according to an embodiment of the present invention is described with reference to the drawings. Notably, constituents having the equivalent functions are given the same signs in the drawings.
First, a circuit configuration of a semiconductor device 1 according to an embodiment of the present invention is described with reference to
As shown in
Notably, the capacitances of the bypass capacitors 80 and 90 are set to be values as large as possible at which the withstand voltages of the bypass capacitors are larger than the withstand voltages of the GaN-HEMTs 10, 20, 30 and 40.
Next, a specific configuration of the semiconductor device 1 is described with reference to
The semiconductor device 1 includes an insulating substrate 2, the GaN-HEMTs 10, 20, 30 and 40 (first, second, third and fourth GaN-HEMTs), the MOS-FETs 15, 25, 35 and 45 (first, second, third and fourth MOS-FETs), the bypass capacitors 80 and 90, a resin-sealed part 95. As shown in
Moreover, the semiconductor device 1 further includes conductive pattern parts 51, 52, 53, 54, 55, 56, 57, 58 and 59 (first, second, third, fourth, fifth, sixth, seventh, eighth and ninth conductive pattern parts) and conductive pattern parts 61, 62, 63 and 64 which are formed on the insulating substrate 2. The conductive pattern parts 51 to 59 and 61 to 64 are formed, for example, by patterning the insulating substrate 2 with a copper foil. Detailed description of the individual conductive pattern parts is made later.
The insulating substrate 2 is composed of an insulating material, and, for example, composed of a material such as ceramics that is excellent in heat dissipation. As shown in
The GaN-HEMTs 10, 20, 30 and 40 are high electron mobility transistors for which a gallium nitride-based (GaN-based) semiconductor material is used. The GaN-HEMTs 10, 20, 30 and 40 are (so-called normally-on) transistors of a type where a channel exists even when a gate voltage is 0 V and a current flows therethrough.
The MOS-FETs 15, 25, 35 and 45 are field effect transistors (Field Effect Transistors: FETs) each having a MOS (Metal Oxide Semiconductor) structure. The MOS-FETs 15, 25, 35 and 45 are so-called normally-off transistors.
As shown in
The semiconductor device 1 further includes the terminals T1, T2, T3, T4, T5, T6, T7, T11, T12, T13, T14, T15 and T16 for connection to external devices (IC chips such as a driver, and a power supply). These terminals are provided so as to come and protrude from the planes of
Here, details of the individual terminals of the semiconductor device 1 are described.
The terminals T1 and T11 are terminals connected to the high voltage side of a power supply (not shown) (high voltage-side terminals). Meanwhile, the terminal T7 is a terminal connected to the low voltage side (ground) of the power supply (low voltage-side terminal). Notably, when the power supply circuit of the semiconductor devices 1 functions as a rectifier, the terminal T1 and the terminal T11 are connected to a load on the output side.
The terminals T2 and T12 are terminals for inputting gate signals to high-side switches of the half bridge circuits therethrough. The terminal T2 is electrically connected to a gate electrode 18 of the MOS-FET 15, and the terminal T12 is electrically connected to a gate electrode 38 of the MOS-FET 35. The terminals T5 and T15 are terminals for inputting gate signals to low-side switches of the half bridge circuits therethrough. The terminal T5 is electrically connected to a gate electrode 28 of the MOS-FET 25, and the terminal T15 is electrically connected to a gate electrode 48 of the MOS-FET 45. These terminals T2, T5, T12 and T15 are electrically connected to a driver (not shown) driving the power supply circuit.
The terminal T3 is a terminal for monitoring a voltage between the MOS-FET 15 and the GaN-HEMT 20. Likewise, the terminal T13 is a terminal for monitoring a voltage between the MOS-FET 35 and the GaN-HEMT 40. The terminal T4 is a terminal for outputting an output voltage of the first half bridge circuit therethrough. Likewise, the terminal T14 is a terminal for outputting an output voltage of the second half bridge circuit. Notably, when the power supply circuit of the semiconductor device 1 functions as a rectifier, an AC power supply on the input side is connected between the terminal T4 and the terminal T14.
The terminal T6 is a terminal for monitoring a voltage between the MOS-FET 25 and the terminal T7. Likewise, the terminal T16 is a terminal for monitoring a voltage between the MOS-FET 45 and the terminal T7.
Next, the GaN-HEMTs 10, 20, 30 and 40 and the MOS-FETs 15, 25, 35 and 45 are described in detail.
The GaN-HEMTs 10, 20, 30 and 40 are N-type semiconductor devices each having a lateral structure, and on the upper face of each of them, a drain electrode, a source electrode and a gate electrode are provided. For example, as shown in
Notably, the GaN-HEMTs 10, 20, 30 and 40 may have vertical structures. In this case, exemplarily stated for the GaN-HEMT 10, the drain electrode provided on the back surface of the GaN-HEMT 10 is connected to the conductive pattern part 51 via solder. The conductive pattern part 51 and the conductive pattern part 53 are joined together to be configured as an integrated conductive pattern part. Likewise also in the case of the GaN-HEMT 20, the drain electrode provided on the back surface of the GaN-HEMT 20 is connected to the conductive pattern part 52, and the conductive pattern part 52 and the conductive pattern part 55 are joined together.
The MOS-FETs 15, 25, 35 and 45 are N-type semiconductor devices each having a vertical structure. On the upper face of each of them, a source electrode and a gate electrode are provided, and on the lower face thereof, a drain electrode is provided. For example, as shown in
As shown in
The drain electrode 11 of the GaN-HEMT 10 is electrically connected to the conductive pattern part 53 via a metal wire 3. Further, the drain electrode 11 is electrically connected to the high voltage-side terminal (terminal T1) via the conductive pattern part 53. The source electrode (not shown) of the GaN-HEMT 10 is connected to the drain electrode of the MOS-FET 15 via solder. The gate electrode 13 of the GaN-HEMT 10 is electrically connected to the conductive pattern part 54 via a metal wire 5. Further, this gate electrode 13 is electrically connected to the source electrode 17 of the MOS-FET 15 via the conductive pattern part 54.
The drain electrode 21 of the GaN-HEMT 20 is electrically connected to the conductive pattern part 54 via a metal wire 3. The source electrode of the GaN-HEMT 20 is connected to the drain electrode of the MOS-FET 25 via solder. The gate electrode 23 of the GaN-HEMT 20 is electrically connected to the conductive pattern part 55 via a metal wire 6. Further, this gate electrode 23 is electrically connected to the source electrode 27 of the MOS-FET 25 via the conductive pattern part 55.
The drain electrode 31 of the GaN-HEMT 30 is electrically connected to the conductive pattern part 58 via a metal wire 3. The source electrode of the GaN-HEMT 20 is connected to the drain electrode of the MOS-FET 35 via solder. The gate electrode 33 of the GaN-HEMT 30 is electrically connected to the conductive pattern part 59 via a metal wire 7. Further, the gate electrode 33 is electrically connected to the source electrode 37 of the MOS-FET 35 via the conductive pattern part 59.
The drain electrode 41 of the GaN-HEMT 40 is electrically connected to the conductive pattern part 59 via a metal wire 3. The source electrode of the GaN-HEMT 40 is connected to the drain electrode of the MOS-FET 45 via solder. The gate electrode 43 of the GaN-HEMT 40 is electrically connected to the conductive pattern part 55 via a metal wire 8. Further, the gate electrode 43 is electrically connected to the source electrode 47 of the MOS-FET 45 via the conductive pattern part 55.
The source electrode 17 of the MOS-FET 15 is electrically connected to the conductive pattern part 54 via a metal wire 3. The gate electrode 18 of the MOS-FET 15 is electrically connected to the conductive pattern part 61 via a metal wire 3.
The source electrode 27 of the MOS-FET 25 is electrically connected to the conductive pattern part 55 via a metal wire 3. This source electrode 27 is electrically connected to the low voltage-side terminal (terminal T7) via the conductive pattern part 55. The gate electrode 28 of the MOS-FET 25 is electrically connected to the conductive pattern part 62 via a metal wire 3.
The source electrode 37 of the MOS-FET 35 is electrically connected to the conductive pattern part 59 via a metal wire 3. The gate electrode 38 of the MOS-FET 35 is electrically connected to the conductive pattern part 63 via a metal wire 3.
The source electrode 47 of the MOS-FET 45 is electrically connected to the conductive pattern part 55 via a metal wire 3. The gate electrode 48 of the MOS-FET 45 is electrically connected to the conductive pattern part 64 via a metal wire 3.
Notably, while the metal wires 3 are aluminum wires (Al wires), they may be composed of another metal material. While the metal wires 5, 6, 7 and 8 are also aluminum wires (Al wires) in the present embodiment, they may be composed of another metal material to be used. The material of the metal wires 5, 6, 7 and 8 may be adapted to the material of the gate electrodes 13, 23, 33 and 43.
Notably, for electrically connecting the semiconductor switching parts and the conductive pattern parts together, in place of the metal wires, connectors composed of conductive plate materials may be used.
Next, referring to
The conductive pattern parts 51, 52, 53, 54, 55, 61 and 62 are conductive pattern parts for constituting the first half bridge circuit. The conductive pattern parts 55, 56, 57, 58, 59, 63 and 64 are conductive pattern parts for constituting the second half bridge circuit. The conductive pattern part 55 is shared by the first half bridge circuit and the second half bridge circuit. Moreover, as shown in
The conductive pattern part 51 is a conductive pattern part for implementing the GaN-HEMT 10. Likewise, the conductive pattern part 52 is a conductive pattern part for implementing the GaN-HEMT 20. The conductive pattern part 56 is a conductive pattern part for implementing the GaN-HEMT 30. The conductive pattern part 57 is a conductive pattern part for implementing the GaN-HEMT 40.
In the present embodiment, as shown in
To the conductive pattern part 53, the drain electrode 11 of the GaN-HEMT 10 is electrically connected via the metal wire 3, and the terminal T1 and the electrode 81 of the bypass capacitor 80 are connected via solder. Likewise, to the conductive pattern part 58, the drain electrode 31 of the GaN-HEMT 30 is electrically connected via the metal wire 3, and the terminal T11 and the electrode 91 of the bypass capacitor 90 are connected via solder.
The conductive pattern part 54 electrically connects the high-side switch (the GaN-HEMT 10 and the MOS-FET 15) and the low-side switch (the GaN-HEMT 20 and the MOS-FET 25) of the first half bridge circuit together. Moreover, to the conductive pattern part 54, the terminals T3 and T4 are electrically connected via solder. Moreover, to the conductive pattern part 54, one end of the metal wire 5 whose other end is connected to the gate electrode 13 of the GaN-HEMT 10 is connected.
Likewise, the conductive pattern part 59 electrically connects the high-side switch (the GaN-HEMT 30 and the MOS-FET 35) and the low-side switch (the GaN-HEMT 40 and the MOS-FET 45) of the second half bridge circuit together. Moreover, to the conductive pattern part 59, the terminal T13 and the terminal T14 are electrically connected via solder. Moreover, to the conductive pattern part 59, one end of the metal wire 7 whose other end is connected to the gate electrode 33 of the GaN-HEMT 30 is connected.
The electrode 82 of the bypass capacitor 80 is electrically connected to the conductive pattern part 55 via solder, and the source electrode 27 of the MOS-FET 25 is electrically connected thereto via the metal wire 3. Furthermore, the electrode 92 of the bypass capacitor 90 is electrically connected to the conductive pattern part 55 via solder, and the source electrode 47 of the MOS-FET 45 is electrically connected thereto via the metal wire 3. Moreover, the terminals T6, T7 and T16 are electrically connected to the conductive pattern part 55 via solder.
As shown in
The conductive pattern part 61 is a conductive pattern part for electrically connecting the gate electrode 18 of the MOS-FET 15 and the terminal T2 together. To this conductive pattern part 61, the gate electrode 18 is electrically connected via the metal wire 3, and the terminal T2 is electrically connected via solder. Likewise, the conductive pattern part 63 is a conductive pattern part for electrically connecting the gate electrode 38 of the MOS-FET 35 and the terminal T12 together. To this conductive pattern part 63, the gate electrode 38 is electrically connected via the metal wire 3, and the terminal T12 is electrically connected via solder.
The conductive pattern part 62 is a conductive pattern part for electrically connecting the gate electrode 28 of the MOS-FET 25 and the terminal T5 together. To this conductive pattern part 62, the gate electrode 28 is electrically connected via the metal wire 3, and the terminal T5 is electrically connected via solder. Likewise, the conductive pattern part 64 is a conductive pattern part for electrically connecting the gate electrode 48 of the MOS-FET 45 and the terminal T15 together. To this conductive pattern part 64, the gate electrode 48 is electrically connected via the metal wire 3, and the terminal T15 is electrically connected via solder.
Next, arrangement relation between the GaN-HEMT 10 and the GaN-HEMT 20 is described.
As shown in
The drain electrode 11 of the GaN-HEMT 10 is provided along the side S1. Moreover, the source electrode 17 of the MOS-FET 15 is provided along the side S2. The drain electrode 21 of the GaN-HEMT 20 is provided along the side S3. Moreover, the source electrode 27 of the MOS-FET 25 is provided along the side S4.
As shown in
Notably, as an angle θ at which the imaginary line L1 and the imaginary line L2 intersect each other is larger, the length of the bypass capacitor path P1 is shorter, which suppresses the parasitic inductance more. However, this meanwhile causes the length of a path between the source electrode 17 of the MOS-FET 15 and the drain electrode 21 of the GaN-HEMT 20 to be longer, and a parasitic inductance in this path becomes larger, which leads to the cause of a malfunction of the power supply circuit. With such circumstances taken into consideration, the angle θ at which the imaginary line L1 and the imaginary line L2 intersect each other is preferably not less than 30° and not more than 135°, still preferably not less than 30° and nor more than 60°. In the present embodiment, the angle θ is substantially 45°.
As shown in
Notably, as shown in
As shown in
As shown in
In the present embodiment, similarly to the metal wire 6, the metal wire 8 electrically connecting the gate electrode 43 of the GaN-HEMT 40 and the conductive pattern part 55 together is also configured so as to have the shortest length.
Notably, the same holds true for the case of using connectors in place of the metal wires 5, 6, 7 and 8. For example, in the case of using a connector in place of the metal wire 6, the gate electrode 23 of the GaN-HEMT 20 is electrically connected to the conductive pattern part 55 via the connector. This connector is perpendicular to the side S5 of the GaN-HEMT 20 and the conductive pattern side 55S of the conductive pattern part 55. Accordingly, generally speaking, a connection member such as a metal wire and a connector is provided so as to be perpendicular to the side S5 of the GaN-HEMT 20 and the conductive pattern side 55S of the conductive pattern part 55.
As described above, in the semiconductor device 1 of the present embodiment, the GaN-HEMT 10 and the GaN-HEMT 20 are disposed on the insulating substrate 2 such that the imaginary line L1 and the imaginary line L2 intersect each other. Thereby, the bypass capacitor path P1 can be made short, and the parasitic inductance in the bypass capacitor path P1 can be reduced. Furthermore, in the semiconductor device 1, the metal wire 6 electrically connecting the gate electrode 23 of the GaN-HEMT 20 and the conductive pattern part 55 together is substantially perpendicular to the side S5 of the GaN-HEMT 20 and the conductive pattern side 55S of the conductive pattern part 55. Thereby, the gate electrode 23 of the GaN-HEMT 20 is connected to the conductive pattern part 55 at the shortest distance by the metal wire 6. Making the metal wire 6 short as above can suppress the parasitic inductance in the metal wire 6. In the present embodiment, making both the length of the bypass capacitor path P1 and the length of the metal wire 6 short can suppress a malfunction of the GaN-HEMT 20. Therefore, according to the present embodiment, a malfunction of a power supply circuit having GaN-HEMTs can be suppressed.
As above, the semiconductor device according to the present embodiment has been described. Notably, not limited to the aforementioned half bridge circuit, the semiconductor device according to the present invention can also be applied to power supply circuits with other configurations, such as a full bridge circuit and a push-pull circuit, as long as each has semiconductor switching elements in cascade connection.
Notably, similarly also as to the GaN-HEMT 10, the metal wire 5 may be provided so as to have the shortest length, this metal wire 5 electrically connecting the gate electrode 13 to the conductive pattern part 54. Namely, as shown in
Based on the aforementioned description, while those skilled in the art may conceive of additional effects and various alterations of the present invention, aspects of the present invention are not limited to the aforementioned individual embodiments. Components across different embodiments may be properly combined. Various additions, modifications and partial deletions may occur without departing from the conceptual ideas and spirit of the present invention derived from the contents and their equivalents as defined in the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/022567 | 6/19/2017 | WO | 00 |
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International Search Report dated Aug. 29, 2017 in PCT/JP2017/022567 filed Jun. 19, 2017 (with English translation of categories of cited documents). |
Number | Date | Country | |
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20180366567 A1 | Dec 2018 | US |