阅读说明：本技术 电力变换器 (Power converter ) 是由 出口昌孝 上田晃宏 安井孝児 大野裕孝 于 2020-03-31 设计创作，主要内容包括：本发明公开电力变换器。电力变换器包括：多个功率模块,收容有电力变换用的半导体元件；一对保持板,在第1方向上夹住多个功率模块的层叠体；一对连结梁,在与所述第1方向交叉的第2方向上的所述层叠体的各个侧端,连结所述一对保持板；以及基板,与各个所述功率模块的控制端子连接。在所述一对保持板的至少一方设置有对所述基板进行定位的定位部。(The invention discloses a power converter. The power converter includes: a plurality of power modules housing semiconductor elements for power conversion; a pair of holding plates sandwiching the stacked body of the plurality of power modules in the 1 st direction; a pair of coupling beams that couple the pair of holding plates to each side end of the stacked body in a 2 nd direction intersecting the 1 st direction; and a substrate connected to the control terminals of the power modules. At least one of the pair of holding plates is provided with a positioning portion for positioning the substrate.)

1. A power converter, comprising:

a plurality of power modules housing semiconductor elements for power conversion;

a pair of holding plates for holding a stacked body of a plurality of power modules in the 1 st direction;

a pair of coupling beams that couple the pair of holding plates to each side end of the stacked body in a 2 nd direction intersecting the 1 st direction; and

a substrate connected to the control terminals of the power modules,

the control terminal extends along a 3 rd direction crossing both the 1 st direction and the 2 nd direction,

the substrate is adjacent to the stacked body in the 3 rd direction, wherein,

at least one of the pair of holding plates is provided with a positioning portion for positioning the substrate.

2. The power converter of claim 1, further comprising a capacitor, wherein,

the plurality of power modules have power terminals on a surface opposite to a surface on which the control terminals are provided,

the capacitor is connected to the power terminals of the plurality of power modules.

3. Power converter according to claim 1 or 2,

at least one of the pair of holding plates is in contact with an inner surface of a case in which the laminate is housed.

4. The power converter according to any one of claims 1 to 3, further comprising an elastic member, wherein,

each of the pair of coupling beams is divided into a 1 st divided beam and a 2 nd divided beam in the 1 st direction,

the 1 st split beam and the 2 nd split beam are connected by the elastic member.

5. The power converter according to any one of claims 1 to 3, further comprising a spring, wherein,

the compressed spring is interposed between one of the pair of holding plates and the stacked body.

6. Power converter according to claim 1,

the 2 nd direction is orthogonal to the 1 st direction,

the 3 rd direction is orthogonal to both the 1 st direction and the 2 nd direction.

7. Power converter according to claim 1,

further comprising a plurality of coolers stacked with a plurality of the power modules along the 1 st direction, wherein,

the stack includes a plurality of the power modules and the plurality of coolers.

Technical Field

The technology disclosed in the present specification relates to a power converter including a stacked body of a plurality of power modules each housing a semiconductor element for power conversion.

Background

Jp 2017 a 085822 and jp 2011 a 103728 disclose power converters having a stacked body including a plurality of power modules and a plurality of coolers. The power converters disclosed in japanese patent application laid-open nos. 2017 and 085822 and 2011 and 103728 are mounted in electric vehicles. The power converter is a device that converts electric power of a power source into driving power of a motor for running. Each of the plurality of power modules accommodates a semiconductor element for power conversion. The semiconductor element for power conversion generates a large amount of heat. The plurality of power modules and the plurality of coolers 1 are alternately stacked 1 by 1, and each power module is cooled from both sides. In order to bring the power module and the cooler into close contact, the stacked body is pressed in the stacking direction by a spring. One end of the stacked body in the stacking direction is pressed against the inner surface of the case, and the spring applies pressure to the stacked body from the other end side.

In the power converter of japanese patent laid-open publication No. 2017-085822, control terminals extend from the respective power modules, and the control terminals of the plurality of power modules are connected to a substrate. The driving signal is transmitted from the substrate to the semiconductor element of the power module via the control terminal. The substrate is fixed to a case of the power converter.

Disclosure of Invention

In the power converter of japanese patent laid-open publication No. 2017-085822, the laminated body and the substrate are individually fixed to the case. When the power converter vibrates, the stacked body (power module) and the substrate are displaced relative to each other, and a strong force may be applied to a connection portion of the control terminal to the substrate. In addition, when the relative positional error between the substrate and the laminate is large, a strong force may be applied to the connection portion of the control terminal to the substrate. When a strong force is applied to the connection portion of the control terminal and the substrate, there is a possibility that a contact failure occurs. In the power converter of japanese patent application laid-open No. 2017-085822, a long control terminal is used with a space (gap) secured between a substrate and a laminated body (power module). If the control terminal is long, the control terminal can be deformed with respect to relative displacement between the substrate and the stacked body (power module), and the force generated at the connection portion with the substrate can be relaxed. However, the space between the substrate and the stacked body (power module) is an ineffective space. The present specification provides a technique capable of reducing a space between a substrate and a laminated body (power module) while securing vibration-resistant characteristics of a connection portion between a control terminal and the substrate.

The 1 st aspect of the present invention is a power converter. The power converter includes:

a plurality of power modules housing semiconductor elements for power conversion; a pair of holding plates for holding a stacked body of a plurality of power modules in the 1 st direction; a pair of coupling beams that couple the pair of holding plates to each side end of the stacked body in a 2 nd direction intersecting the 1 st direction; and a substrate connected to the control terminals of the power modules. At least one of the pair of holding plates is provided with a positioning portion for positioning the substrate. The control terminal extends in a 3 rd direction intersecting both the 1 st direction and the 2 nd direction. The substrate is adjacent to the stacked body in the 3 rd direction.

According to the above aspect 1, the substrate is fixed to the pair of holding plates sandwiching the stacked body. Since the relative positions of the laminate and the substrate are determined by the pair of holding plates, the substrate and the laminate (power module) vibrate integrally. During vibration, the relative displacement between the stacked body (power module) and the substrate is reduced. In addition, the relative position of the substrate with respect to the stacked body (power module) is also accurately determined. Therefore, even if the space between the power module and the substrate of the stacked body is narrowed (i.e., even if a short control terminal is employed), a strong force is prevented from being applied to the connection site of the control terminal and the substrate.

In the above-described aspect 1, the power converter may include a capacitor. The plurality of power modules may have a power terminal on a surface opposite to a surface on which the control terminal is provided, and the capacitor may be connected to the power terminals of the plurality of power modules.

In the above aspect 1, at least one of the pair of holding plates may be in contact with an inner surface of a case in which the stacked body is housed.

In the 1 st aspect, the power converter may include an elastic member. Each of the pair of coupling beams may be divided into a 1 st divided beam and a 2 nd divided beam in the 1 st direction, and the 1 st divided beam and the 2 nd divided beam may be coupled by the elastic member.

In the 1 st aspect, the power converter may include a spring.

The compressed spring may be interposed between one of the pair of holding plates and the stacked body.

In the 1 st aspect, the 2 nd direction may be orthogonal to the 1 st direction.

The 3 rd direction may be orthogonal to both the 1 st direction and the 2 nd direction.

In the 1 st aspect, the power converter may include a plurality of coolers stacked with the plurality of power modules along the 1 st direction. The stack may include a plurality of the power modules and a plurality of the coolers.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

fig. 1 is a perspective view of a power module employed in a power converter of the embodiment.

Fig. 2 is a perspective view (view from obliquely below) of a power module employed in the power converter of the embodiment.

Fig. 3 is a perspective view of the power converter.

Figure 4 is an exploded view of the stack and frame.

Fig. 5 is an exploded view of the laminate, the assembly of frames, the substrate, and the capacitor.

Fig. 6 is a side view of the power converter.

Fig. 7 is a plan view (with a case) of the power converter.

Fig. 8 is a perspective view of an assembly of a modified example of the frame and the laminated body (a view in which the restraint ring is removed).

Fig. 9 is a perspective view of an assembly of a modified example of the frame and the laminated body (a view of attaching the restraint ring).

Fig. 10 is a perspective view (view seen obliquely from below) of a modification of the power module.

Fig. 11 is a side view of a power converter employing a modification of the power module.

Detailed Description

Referring to the drawings, a power converter 2 of the embodiment is explained. The power converter 2 of the embodiment is mounted on an electric vehicle. The power converter 2 is a device that converts electric power of a power supply into driving power of a motor for running. The power converter 2 includes a plurality of power modules 10 in which semiconductor devices for power conversion are housed.

First, the power module 10 is explained. Fig. 1 shows a perspective view of a power module 10. For the sake of convenience of explanation, the + Z direction of the coordinate system in the figure is defined as up. Fig. 2 shows a perspective view of the power module 10 viewed obliquely from below. It is intended to be left with the orientation of the coordinate systems in fig. 1 and 2 being different.

The power module 10 houses 2 semiconductor elements 11a and 11b for power conversion. The Semiconductor elements 11a and 11b are switching elements, and are IGBTs (Insulated Gate Bipolar transistors) or MOSFETs (Metal Oxide Semiconductor Field Effect transistors). The semiconductor elements 11a and 11b may be switching elements other than IGBTs and MOSFETs. The semiconductor elements 11a and 11b may be a composite device in which a switching element and a diode are connected in antiparallel.

The 2 semiconductor elements 11a and 11b are embedded in a resin package 12. The package 12 is flat, and the heat sink 13 is exposed on both sides of the width. The heat sink 13 is in contact with a cooler 21 described later, and efficiently transfers heat of the semiconductor elements 11a and 11b to the cooler 21.

The 2 semiconductor elements 11a and 11b are connected in series inside the package 12. 3 power terminals 14a-14c extend from the lower surface of package 12. Each of the positive and negative electrodes of the series connection of the 2 semiconductor elements 11a, 11b is conducted to each of the power terminals 14a, 14 b. The midpoints of the series connection conduct to the power terminal 14 c.

A plurality of control terminals 15 extend from the upper surface of the package 12. The plurality of control terminals 15 are electrically connected to the gate electrodes of the semiconductor elements 11a and 11b and the temperature sensor.

When 3 power modules 10 are connected in parallel, an inverter that converts direct-current power into three-phase alternating-current power can be realized.

Fig. 3 shows a perspective view of the power converter 2. Fig. 3 shows only the main components of the power converter 2, and the housing of the power converter 2 and other components housed in the housing are not shown.

The power converter 2 includes a plurality of power modules 10, a plurality of coolers 21, a substrate 40, and a capacitor 50. In fig. 3, the substrate 40 is depicted in phantom lines.

The power converter 2 includes 7 power modules 10. In fig. 3, only the power module 10 on the left end is denoted by a symbol 10, and the remaining power modules are denoted by the symbols. As described above, when 3 power modules 10 are connected in parallel, an inverter can be configured. 7 power modules 10 are used for 2 sets of inverters and 1 voltage converter. 1 power module 10 is used for a voltage converter.

The plurality of power modules 10 and the plurality of coolers 21 are alternately stacked 1 by 1. In fig. 3, only a pair of coolers 21 sandwiching the power module 10 at the left end is denoted by a reference numeral, and the remaining coolers are not denoted by a reference numeral. The plurality of power modules 10 and the plurality of coolers 21 constitute a stacked body 20. The stacked body 20 does not necessarily have to be configured by a plurality of power modules 10 and a plurality of coolers 21, and may be configured by only a plurality of power modules 10, for example. The X direction of the coordinate system in the drawing corresponds to the stacking direction of the plurality of power modules 10 and the plurality of coolers 21. Hereinafter, for convenience of description, the stacking direction (X direction) of the plurality of power modules 10 and the plurality of coolers 21 may be simply referred to as a stacking direction.

The pair of coolers 21 sandwiching the power module 10 are connected by 2 connecting pipes 22a, 22 b. The interior of the cooler 21 serves as a flow path through which the refrigerant passes, and the 2 connecting pipes 22a and 22b communicate with the adjacent coolers 21. All the pairs of coolers 21 are connected by 2 connecting pipes 22a, 22 b. The 2 connecting pipes 22a and 22b are arranged to hold the power module 10 in the Y direction of the coordinate system in the drawing. In fig. 3, reference numerals 22a and 22b are given to only 1 group of the connection pipes, and the reference numerals are omitted in the remaining connection pipes.

The cooler 21 at one end of the stacked body 20 in the stacking direction is provided with a supply pipe 23a and a discharge pipe 23 b. The supply pipe 23a and the discharge pipe 23b are connected to a refrigerant cycle device not shown. The refrigerant supplied from the supply pipe 23a is distributed to all the coolers 21 via the connecting pipe 22 a. While the refrigerant flows through the flow path inside the cooler 21, the refrigerant absorbs heat of the power module 10. As described above, the heat sink 13 is exposed on the surface of the package 12 of the power module 10, and the heat of the semiconductor elements 11a and 11b is absorbed by the refrigerant via the heat sink 13. The refrigerant having absorbed heat returns to the refrigerant cycle device through the connecting pipe 22b and the discharge pipe 23 b.

The stacked body 20 is constrained by the frame 30. The frame 30 surrounds the stack 20. The frame 30 is composed of a pair of holding plates 31, 32 and a pair of coupling beams 33. Fig. 4 shows an exploded view of the stack 20 and the frame 30. Referring to fig. 4 together with fig. 3, the frame 30 is explained. In fig. 4, the cooler 21 on one end side in the stacking direction is referred to as a cooler 21a, and the cooler 21 on the other end side is referred to as a cooler 21 b.

The pair of holding plates 31 and 32 are disposed so as to sandwich the stacked body 20 in the stacking direction (X direction). The holding plate 31 is in contact with the cooler 21a on one end side of the stacked body 20, and the holding plate 32 faces the cooler 21b on the other end side via a plate spring 34. The holding plate 31 is provided with a pair of through holes 31a, and the supply pipe 23a is inserted through one of the through holes 31a and the discharge pipe 23b is inserted through the other through hole 31 a.

The pair of holding plates 31 and 32 are connected to each side end of the stacked body 20 in the Y direction by a pair of connection beams 33. The pair of coupling beams 33 are disposed so as to sandwich the stacked body 20 in the Y direction. The stacked body 20 is surrounded by a pair of holding plates 31, 32 and a pair of tie beams 33.

Each coupling beam 33 is divided into a 1 st divided beam 33a coupled to the holding plate 31 and a 2 nd divided beam 33b coupled to the holding plate 32. The front end of the 1 st split beam 33a and the front end of the 2 nd split beam 33b are joined by welding. In fig. 3, reference numeral 33c denotes a joint portion. In fig. 4, the frame 30 before joining the 1 st split beam 33a and the 2 nd split beam 33b is depicted.

As described above, the plate spring 34 is interposed between the cooler 21b and the holding plate 32 at one end of the stacked body 20. The 1 st split beam 33a and the 2 nd split beam 33b are joined in a state where the laminated body 20 is pressed by the plate spring 34 in the laminating direction. That is, the frame 30 holds the stacked body 20 in a pressurized state. In other words, the frame 30 restrains the leaf spring 34 and the stacked body 20 in a state where the leaf spring 34 is compressed. By the pressing of the plate spring 34, the cooler 21 and the power module 10 are strongly contacted, and heat is favorably transferred from the power module 10 to the cooler 21.

The assembly of the stack 20 and the frame 30 is referred to as an assembly 39. The substrate 40 is fixed to the package 39, and the capacitor 50 is fixed to the package. Fig. 5 shows an exploded view of the assembly 39, the substrate 40, and the capacitor 50. The structure of the power converter 2 will be described with reference to fig. 3 and 5.

The circuit for controlling the semiconductor elements 11a and 11b housed in the power module 10 is mounted on the substrate 40. Various chips such as a memory and an arithmetic element are mounted on the substrate 40, but these chips are not shown. The control circuit mounted on the substrate 40 generates drive signals for the semiconductor elements 11a and 11b in accordance with a command sent from a host controller, not shown. The substrate 40 is provided with a plurality of through holes 43, and the control terminals 15 of the power modules 10 are connected to the respective through holes 43. The through hole 43 is connected to a printed wiring (not shown) on the substrate 40. The semiconductor elements 11a and 11b and the control circuit are electrically connected via the control terminal 15 and the through hole 43.

The drive signal generated by the control circuit is sent to the semiconductor elements 11a and 11b via the through hole 43 and the control terminal 15. As described above, some of the control terminals 15 are connected to the sensors provided in the power module 10, and the signals of the sensors are also sent to the control circuit mounted on the substrate 40 via the control terminals 15 and the through holes 43. The control circuit controls the power flowing through the semiconductor elements 11a and 11b based on the sensor data so that the semiconductor elements 11a and 11b do not overheat.

As shown in fig. 3 and 5, the control terminal 15 extends to the upper side of the power module 10, and the substrate 40 is disposed adjacent to the upper side of the package 39.

The base plate 40 is fixed to the holding plates 31, 32 of the frame 30. A protrusion 35 for determining the relative position of the substrate 40 with respect to the holding plate 31 is provided on the upper surface of the holding plate 31, and a protrusion 36 for determining the position of the substrate 40 is also provided on the upper surface of the holding plate 32. The base plate 40 is provided with fitting holes 41(42) corresponding to the projections 35(36) of the holding plates 31 (32). The protrusions 35(36) of the holding plates 31(32) are fitted into the fitting holes 41(42) of the substrate 40, the relative position of the substrate 40 with respect to the holding plates 31, 32 (i.e., the components 39) is determined, and the substrate 40 is fixed to the holding plates 31, 32 (i.e., the components 39).

The advantage of the substrate 40 being positioned to be fixed to the holding plates 31, 32 is explained. The base plate 40 is fixed to the holding plates 31, 32 (i.e., the assembly 39), so when the power converter 2 vibrates, the base plate 40 and the power module 10 vibrate together. When the substrate 40 and the stacked body 20 (power module 10) are fixed to the case, respectively, a difference is generated in the vibration of the substrate 40 and the vibration of the stacked body 20 (power module 10). When the substrate 40 and the stacked body 20 (power module 10) vibrate, high stress may occur in a portion where the control terminal 15 and the through hole 43 contact each other. Alternatively, when the substrate 40 and the module 39 are fixed to the housing, respectively, a positional error may occur between the control terminal 15 and the through hole 43, and a high stress may occur in the control terminal 15 due to the positional error.

When a high stress is generated in the control terminal 15, a contact failure may occur between the control terminal 15 and the through hole 43. In order to alleviate the high stress, it is necessary to use a long control terminal to allow the deformation of the control terminal 15. However, when a long control terminal is used, an unnecessary space is formed between the stacked body 20 (power module 10) and the substrate 40.

On the other hand, in the power converter 2 of the embodiment, the position of the substrate 40 with respect to the assembly 39 is accurately determined. On this basis, the substrate 40 is fixed to the component 39, so the substrate 40 and the component 39 (power module 10) vibrate together. Therefore, high stress does not occur at the portion where the control terminal 15 and the through hole 43 are in contact. Since high stress does not occur, the control terminal 15 can be made short, and the unnecessary space between the power module 10 and the substrate 40 can be reduced.

Fig. 6 shows a side view of the power converter 2. As shown in fig. 6, the space (gap G) between the power module 10 and the substrate 40 is small. The upper surfaces of the holding plates 31 and 32 may be located slightly higher than the upper surface of the power module 10.

A capacitor 50 is disposed below the package 39. The power module 10 includes power terminals 14a and 14b on a surface (lower surface) opposite to a surface (upper surface) on which the control terminal 15 is provided in a Z direction of a coordinate system in the drawing, and the capacitor 50 is connected to the power terminals 14a and 14 b.

As shown in fig. 5, the 1 st terminal 51a and the 2 nd terminal 51b are exposed on the upper surface of the capacitor 50. The 1 st terminal 51a of the capacitor 50 is connected to the positive power terminal 14a of the plurality of power modules 10, and the 2 nd terminal 51b is connected to the negative power terminal 14b of the power module 10. The power terminals 14a and 14b extend downward and are bent in the X direction on the way. The bent tip ends of the power terminals 14a and 14b are connected to the terminals 51a and 51b of the capacitor 50. The capacitor 50 is provided to suppress switching noise of the semiconductor elements 11a and 11b housed in the power module 10.

Fig. 7 shows a top view of the power converter 2. In fig. 7, a housing 60 housing the assembly 39 is also depicted. In fig. 7, the substrate 40, the capacitor 50, and components other than those accommodated in the case 60 are not shown. The holding plate 31 is in contact with the inner surface 60a of the housing 60. Since the stack 20 is constrained by the frame 30, it is not necessary to provide an unnecessary space between the frame 30 and the inner surface 60 a. The holding plate 32 may be in contact with the inner surface of the housing 60.

Next, a modified example of the frame will be described. Fig. 8 and 9 show perspective views of the frame 130 and the assembly 139 of the stacked body 20 according to a modification. Fig. 8 is a view in which a confinement ring 138 (described later) is removed, and fig. 9 is a view in which the confinement ring 138 is attached.

The frame 130 includes a pair of holding plates 31 and 32 arranged to sandwich the stacked body 20 in the stacking direction, and a pair of coupling beams 133 coupling the holding plates 31 and 32. The pair of coupling beams 133 are located on both sides of the stack 20 in the Y direction of the coordinate system in the drawing. The coupling beam 133 is divided into a 1 st divided beam 133a and a 2 nd divided beam 133b in the stacking direction (X direction). The 1 st split beam 133a is coupled to the holding plate 31, and the 2 nd split beam 133b is coupled to the holding plate 32.

A hook 137a is provided at the tip of the 1 st divided beam 133a on the 2 nd divided beam 133b side. A hook 137b is provided at the front end of the 2 nd split beam 133b on the 1 st split beam 133a side. The restraint ring 138 is installed in a manner to surround the hooks 137a, 137 b. The 1 st split beam 133a and the 2 nd split beam 133b are joined by a confinement ring 138. The 1 st split beam 133a, the 2 nd split beam 133b, and the confinement rings 138 constitute the coupling beam 133.

The confinement rings 138 are made of an elastomer. The restraint ring 138 connects the 1 st split beam 133a and the 2 nd split beam 133b in a state where the holding plates 31, 32 press the stacked body 20. By using the confinement ring 138 made of an elastic body, the plate spring 34 provided in the power converter 2 of the embodiment can be eliminated. Since the plate spring 34 is not required, the length of the unit 139 in the X direction (stacking direction) can be shortened.

A modified example of the method of mounting capacitor 50 will be described. Fig. 10 is a perspective view of a power module 110 according to a modification example as viewed from below. In the power module 110, the power terminals 114a-114c are exposed at the lower surface of the package 112. Power terminals 114a-114c are at the same level relative to the lower surface of package 112.

Fig. 11 shows a side view of a power converter 2a using the power module 110. Since the power terminals 114a to 114c are exposed at the same level on the lower surface of the package 112, the capacitor 50 is mounted on the lower surface of the package 12. When the capacitor 50 is mounted on the lower surface of the package 112, the power terminals 114a and 114b are electrically connected to the terminals 51a and 51b (see fig. 5) of the capacitor 50. The power converter 2a can bring the capacitor 50 close to the package 112 of the power module 110. Since the distance between the substrate 40 and the package 112 is also short, the length of the power converter 2a in the Z direction can be shortened.

Attention points related to the techniques described in the examples are described. In the power converter 2 of the embodiment, the holding plates 31 and 32 are provided with projections 35 and 36 for determining the position of the substrate 40, and the substrate 40 is provided with fitting holes 41 and 42 into which the projections 35 and 36 are fitted. Instead of this, the substrate 40 may be provided with a protrusion, and the holding plates 31 and 32 may be provided with a groove for determining the position of the protrusion of the substrate 40. The protrusion or the groove for determining the position of the substrate is preferably provided on both of the pair of holding plates 31 and 32, but may be provided on at least one of the holding plates 31 and 32. The fitting holes 41 and 42 may be screw grooves, or may be positioned by inserting screws into the screw grooves. The projections 35 and 36 may be hooks, or may be positioned by hooking the hooks to the fitting holes 41 and 42.

A protrusion or a groove that determines the position of the substrate is an example of the positioning portion. The positioning portion for determining the position of the substrate 40 may be a hook or a screw, instead of the projection or the groove.

The capacitor 50 may be arranged beside the laminate 20 in the Y direction of the coordinate system in the drawing.

In the coordinate system in the figure, the X direction (stacking direction) is an example of the 1 st direction, the Y direction is an example of the 2 nd direction, and the Z direction is an example of the 3 rd direction. The Y direction may be orthogonal to the X direction, and the Z direction may be orthogonal to both the X direction and the Y direction.

Specific examples of the present invention have been described above in detail, but these are merely examples and do not limit the claims. The techniques described in the claims include various modifications and changes of the specific examples illustrated above. Technical elements described in the specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations recited in the claims at the time of filing. Further, the techniques exemplified in the present specification or the drawings can achieve a plurality of objects at the same time, and achieving one of the objects has technical usefulness.