JP2003324184A - Semiconductor power module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor power module which attains size reduction and high-precision wire bonding. <P>SOLUTION: The semiconductor power module 2 is provided with a case 6 having an open upper end and arranged inside with a power semiconductor chip, and a cover 8 for covering the opening of the case 6. Electrode terminals 34a, 34b and 34c which are electrically connected to the power semiconductor chip are drawn out to the outside and bent along the upper surface of the cover 8. The cover 8 is mounted on the case 6 so as to slide along the opening end of the case 6. By such an arrangement, since wire bonding can be carried out in a state that the electrode terminals 34a, 34b and 34c are bent, a wire bonding tool can be shortened. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor power module used in an inverter device or the like.

[0002]

2. Description of the Related Art As a conventional semiconductor power module,
There is a structure in which a power semiconductor chip is arranged in a case and the upper surface is covered with a lid.

The conventional semiconductor power module 100 shown in FIGS. 11A and 11B is formed in a rectangular shape, and various components such as a power semiconductor chip are stacked on a rectangular heat dissipation plate 102. A frame-shaped resin case 104 is provided so as to surround the heat dissipation plate 102. In the figure, reference numeral 106 is a hole provided at each vertex of the heat dissipation plate 104, and is a mounting bolt hole for fastening the heat dissipation plate 104 to an external cooling member with a bolt.

The case 104 has an open upper end,
The opening of the case 104 is closed by the lid 110. The lid 110 is attached to the case 104 by being pushed in from above. An electrode terminal 1 electrically connected from one side of the case 104 forming the peripheral edge of the opening to a semiconductor chip housed in the case 104 via a bonding wire.
12 is pulled out and bent inside the case. A through hole 114 is provided in the electrode terminal 112. A nut insertion hole (not shown) is formed in the case 104 so as to be aligned with the through hole 114 and coaxial with the through hole 114, so that a nut (not shown) can be inserted into the hole. It has become. The inner diameter of the through hole 114 is
The inner diameter of the nut is set to be approximately equal to or slightly larger than the inner diameter of the nut. A bus bar (external wiring) is arranged on the electrode terminal 112, and a screw (not shown) is screwed onto the nut to connect the bus bar to the electrode terminal. It can be fixed to 112.

In another conventional semiconductor power module 200 shown in FIGS. 12 (a) and 12 (b), an electrode terminal 21 is used.
2 is different from the semiconductor module 100 in that it is bent to the outside of the case 204 and faces the case 204 portion forming the peripheral edge of the opening, unlike the semiconductor module 100 in that the lid 210 is attached to the case 204 by being pushed from above. The same as 100.

[0006]

In the structure in which the electrode terminals 112 and 212 are bent as described above, the cases 104 and 204 for accommodating the nuts for joining the electrode terminals are required, and the module becomes large.

Therefore, in the semiconductor module 300 shown in FIGS. 13 (a) and 13 (b), a nut is arranged on the lid 310 side and the lid 310 is placed in the upper position in a state where the electrode terminal 312 is not bent (solid line position 312a in the figure). Insert the electrode terminal 312 into the case 304 by pushing it in from the case 304.
04 By bending the inside (dotted line position 312b in the figure), the through hole 314 of the electrode terminal 312 is aligned with the nut of the lid 310.

With this structure, the module can be made smaller than in the case of FIGS. However, since it is necessary to perform wire bonding while the electrode terminals 312 are standing, it is necessary to lengthen the bonding tool as compared with the case where wire bonding is performed with the electrode terminals bent, and as a result, the accuracy of bonding is reduced. To do.

Therefore, an object of the present invention is to provide a semiconductor power module which can be miniaturized and can perform wire bonding with high accuracy.

[0010]

In order to achieve the above object, a semiconductor power module according to a first aspect of the invention has a case in which an upper end is opened and a power semiconductor chip is arranged inside, and an opening of the case is closed. In the semiconductor power module having a lid and externally extracting the electrode terminal electrically connected to the power semiconductor chip, the electrode terminal is pulled out from the case and bent along the upper surface of the lid, and the lid is It is characterized in that it is configured to be attached to the case by sliding along the opening end of the case.

According to a second aspect of the present invention, there is provided a semiconductor power module according to the first aspect, wherein the lid has a nut that is screwed into a screw that penetrates the electrode terminal and fastens an external wire to the electrode terminal. It is characterized in that a nut supporting portion for supporting is provided.

A semiconductor power module according to a third aspect of the present invention has a case having an upper end opened and a power semiconductor chip disposed therein, and a lid closing the opening of the case, and electrically connected to the power semiconductor chip. In a semiconductor power module in which a plurality of connected electrode terminals are drawn out to the outside, the plurality of electrode terminals are drawn out from one side of an upper wall surrounding the opening of the case and bent along the upper surface of the lid, and the lid is a case It is configured to be attached to the case by sliding toward the electrode terminal side along the opening end of the.

A semiconductor power module according to a fourth aspect is the semiconductor power module according to the third aspect, wherein a nut that is screwed into a screw that penetrates the electrode terminal and fastens the external wiring to the electrode terminal is supported in the lid. It is characterized in that a nut supporting portion is provided.

A semiconductor power module according to a fifth aspect is the semiconductor power module according to the fourth aspect, wherein the lid is located between the plurality of electrode terminals and the housing component in the case with respect to the sliding direction of the nut support portion. It is characterized in that it is mounted on the case by sliding it toward the electrode terminal side in the state of being arranged on the opening end of the case.

A semiconductor power module according to a sixth aspect of the present invention is the semiconductor power module according to the fourth aspect, wherein the lid and the case have a plurality of electrode terminals with respect to the sliding direction of the nut support part with the housing component in the case interposed therebetween. Designed to prevent interference between the nut support and the housing parts when the lid is slid toward the electrode terminals when the lid is placed on the open end of the box so that it is located on the opposite side of the box. Is characterized by.

A semiconductor power module according to a seventh aspect is the semiconductor power module according to the sixth aspect, wherein the upper wall surrounding the opening of the case has a first portion having a first height and a first portion. And a second portion that is higher than the height by a predetermined height, and the lid slides on the second portion when the nut support moves in the sliding direction from the upstream side to the downstream side of the storage component in the case. After that, it is slid on the first portion and then mounted on the case.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In the specification of the present application, terms indicating directions (for example, “up”, “down”, “right”,
“Left” and other terms including these terms are used as appropriate, but they only indicate directions in the drawings used for description, and the present invention should not be limitedly interpreted by these terms. .

Embodiment 1. A semiconductor power module according to Embodiment 1 of the present invention will be described with reference to FIGS. The semiconductor power module 2 controls the electric power supplied from the external power source through the two power source terminals, the P terminal and the N terminal, by an internal circuit in accordance with one of the U, V and W phases. , The controlled electric power is output to the outside through one output terminal. Three such semiconductor power modules 2 are used and applied to an inverter device.

Specifically, the semiconductor power module 2 is
It is formed in a rectangular shape, and various components shown below are stacked on a rectangular heat dissipation plate 4, and a frame-shaped resin case 6 is provided so as to surround the heat dissipation plate 4. The opening provided on the upper side of the case 6 is closed by a lid 8. As will be described later in detail, the lid 8 is slidably attached to the case 6. Each apex of the heat sink 4 is provided with mounting bolt holes 9 for fastening the heat sink 4 to an external cooling member with bolts.

An insulating substrate 10 is joined to the surface of the heat dissipation plate 4 via a brazing material 11 such as solder. Insulating substrate 1
A predetermined circuit pattern 12 made of copper is formed on the upper surface of 0. On the circuit pattern 12, a plurality of semiconductor chips 16 (for example, an IGBT and a diode) provided according to the use and purpose of the semiconductor power module 2 are mounted by being joined with a brazing material (not shown). The semiconductor chips 16 are connected to each other via a thin metal wire 18 such as aluminum.

A control connector 20 is arranged on the side surface of the case 6. The control connector 20 is a connector for exchanging control signals between an external circuit and an internal circuit. Specifically, the connector pin 22 of the control connector 20 has a predetermined circuit pattern (not shown) formed on the control board 24 arranged in the upper space of the case 6.
Is electrically connected via a thin metal wire (not shown). Via solder (not shown) on the control board 24,
A control chip 25 for controlling the semiconductor chip 16 is mounted. Note that, in FIG. 2, various components arranged on the control board 24 are not shown. Control board 2
The circuit pattern on 4 is the relay terminal 26 extending in the vertical direction.
Is connected to one end of. The other end of the relay terminal 26 is connected to a conductor pad 28 provided near the insulating substrate 10. To the conductor pad 28, through the thin metal wire 18,
The circuit pattern 12 on the insulating substrate 10 is electrically connected.

Between the control board 24 and the insulating board 10,
A conductive shield plate 30 for shielding noise is arranged. The shield plate 30 is grounded, for example, via a relay terminal (not shown).

The internal space of the case 6 below the shield plate 30 is filled with silicon gel 32 to ensure insulation.

The three electrode plates 34a, 34b, 34c are inserted into the resin case 6 and integrally molded. The electrode plates 34a, 34b, 34c are pulled out to the outside of the case 6 from one side (the side extending in the longitudinal direction in the example of the figure) that is insulated from each other and surrounds the opening of the case 6, and as shown in FIG. Bent inward along the surface of
The P terminal, the N terminal, and the AC terminal of the DC terminal, which is the external connection terminal (main circuit connection terminal) for power, are formed.
The other end of the electrode plate 34a forming the P terminal, the other end of the electrode plate 34b forming the N terminal, and the other end of the electrode plate 34c forming the AC terminal are connected to the circuit pattern 12 via a thin metal wire.
And the semiconductor chip 16, and as a result, when the semiconductor power module 2 is operating, the direct current flowing from the P terminal 34a to the N terminal 34b is changed to the control connector 20.
Is converted into an alternating current by the action of the semiconductor chip 16 based on the control signal input from the alternating current, and this alternating current is output from the alternating current terminal 34c. At this time, the semiconductor chip 16
A large amount of heat generated in the heat dissipation plate 4 passes through the insulating substrate 10.
And is further radiated to an external cooling member such as a radiation fin attached to the radiation plate 4 by a bolt through the bolt hole 9.

FIG. 4 is a sectional view similar to FIG. 3 with the lid 8 attached to the case 6. The lid 8 is located along the opening end of the case 6 from the right side to the left side in FIG. 2, that is, from the side opposite to the side where the electrode terminals 34 (34a, 34b, 34c) are located. As shown in FIG. 4, the upper portion of the case 6 is covered by sliding it toward the side of the case 6. As shown in FIG. 4, the lower surface of the bent electrode terminal 34 and the upper surface of the lid 8 face each other when the sliding is completed. A through hole 36 is provided in each electrode terminal 34, and a nut insertion hole is formed on the lower surface side of the lid 8 so as to be aligned with the through hole 36 and coaxial with the through hole 36. The nut 38 is inserted. The inner diameter of the through hole 36 is set to be substantially equal to or slightly larger than the inner diameter of the nut 38, and the nut 38 is screwed with the bus bar (not shown) arranged on the electrode terminal 34.
The bus bar is connected to the electrode terminal 3 by screwing (not shown).
It can be fixed to 4.

In the illustrated example, the lid 8 is provided with an electrode terminal 34.
Although the step is provided so that the region including the portion facing to is higher than other regions, the shape of the lid 8 does not limit the present invention, and for example, the lid portion excluding the nut support portion 40 is flat. It may be formed into a shape.

The lid 8 slides on a guide extending along the shorter side of the four sides surrounding the opening of the case 6. The guide may have any cross-sectional shape. For example, as shown in FIG. 5A, a convex portion having a rectangular cross-section is provided on the case 6 side, and a concave portion that engages with this is provided on the lid 8 side. May be provided, or conversely, as shown in FIG. 5B, a convex portion having a rectangular cross section is provided on the lid 8 side, and
You may make it provide the recessed part which engages with this at the case 6 side. Alternatively, as shown in FIG. 7C, a stepped portion that engages with each other may be provided on the case 6 side and the lid 8 side.

When the nut support portion 40 provided on the lower surface side of the lid 8 interferes with the component on the control board 24, first, the nut support portion 40 is positioned between the electrode terminal 34 and the component in the sliding direction. After the lid 8 is placed on the case 6 as described above, the lid 8 may be attached to the case 6 by sliding the lid 8 toward the electrode terminal 34 side. Thereby, it is possible to avoid increasing the thickness of the module in order to secure the passage of the nut support portion 40.

FIG. 6 is a schematic side view showing an example of the bonding apparatus (the structure is partially omitted in the figure). The bonding device 50 uses a wedge tool 52 as a bonding tool. The ultrasonic tool 5 is attached to the wedge tool 52 via a horn 54.
6 is connected to the semiconductor chip 16 or the circuit pattern 12 by pressing the wire 58 made of aluminum at the tip of the tool 52, and by driving the ultrasonic transducer 56,
The wire 58 is thermocompression bonded to the semiconductor chip 16 or the like.

As shown in FIG. 7, an object to be bonded (semiconductor chip 1
6 or the circuit pattern 12) Compared with the work height d1 (for example, 50 mm) from the surface to the upper end of the electrode terminal 34, the bonding clearance required between the surface and the component of the bonding device 50 (for example, the horn 54). d
If 2 (for example, 40 mm) is short, the bonding device 5
0 and the electrode terminal 34 may interfere with each other. Therefore, since it is necessary to lengthen the bonding tool 52 in order to avoid interference, the accuracy of the bonding position is reduced accordingly.

On the other hand, in the present embodiment, the electrode terminal 3
No. 4 is capable of performing wire bonding in a bent state (in the conventional example of FIG. 13, it is necessary to close the lid with the electrode terminals standing, and therefore, wire bonding needs to be performed with the electrode terminals standing. ), The bonding tool 52 can be shortened. As a result, it is possible to improve the accuracy of the position of wire bonding, and it is possible to reduce the size and cost of the bonding device 50.

In the conventional semiconductor power modules shown in FIGS. 11 and 12, wire bonding can be performed with the electrode terminals bent, but in the present embodiment, a module smaller than these modules is used. It has an advantage that can be provided.

Embodiment 2. The semiconductor power module according to the present embodiment has a nut support portion provided on the lower surface side of the lid when sliding from the side opposite to the side on which the electrode terminal is located toward the side on which the electrode terminal is located. Has a structure for preventing the components from interfering with the components housed in the case. Hereinafter, the same reference numerals are used for the same components as those in the first embodiment. For convenience of explanation, the sliding direction is the X direction, and the arrangement direction of the electrode terminals orthogonal to the sliding direction is the Y direction.

Referring to FIGS. 8 to 10, the lid 8 ′ of the semiconductor power module 60 according to the present embodiment has a first horizontal portion 62 having the nut 38 arranged on the lower surface side, and the horizontal portion 62.
A second horizontal portion 64 whose lower surface (excluding the nut support portion 40) is higher than a predetermined height by a predetermined height, and the first and second horizontal portions 6
And a step portion (vertical portion) 66 connecting the two and 64.

On the other hand, the case 6 ′ guides the first horizontal portion 62 of the lid 8 ′ along the X direction so that the nut support portion 40 is guided to the lower side of the electrode terminal 34.
The first horizontal guides 68 (shown by the hatched portions in FIG. 9) extending in the X direction are opposed to both ends in the Y direction of the horizontal portion 62. The first horizontal guide 68 is used for the electrode terminal 3
The second horizontal guide 72 extends to the vicinity of the side facing the four arrangement side and the upper surface thereof is higher than the first horizontal guide 68 by the predetermined height.

According to this structure, the nut support portion 40 is arranged on the open end of the box 6'so as to be located on the side opposite to the electrode terminal 34 with the part (for example, the part 74) housed in the case interposed therebetween. In this state, even if the lid 8 ′ is slid toward the electrode terminal 34 side, as shown in FIG.
While the first horizontal portion 62 of the above slides on the second horizontal guide 72, the nut support portion 40 does not interfere with the component (for example, the component 74) housed in the case 6 ′, and the nut support portion 40 It moves to the downstream side of the storage component 74 in the sliding direction (X direction). When the lid 8'is further slid in the X direction and the rear end (vertical portion 66) of the first horizontal portion 62 passes through the second horizontal guide 72, the lid 8'is sunk below the predetermined height, This time, the first horizontal portion 62 is above the first horizontal guide 68, and the second horizontal portion 64 is above the second horizontal guide 72.
Slide up (see Figure 9). Further, the lid 8'is slid in the X direction to completely cover the case 6'with the lid 8 ', as shown in FIG.

As best shown in FIG. 9, both ends of the vertical portion 66 of the lid 8'in the Y direction slide along the side wall 76 of the case 6'after the lid 8'is sunk. As a result, as shown in FIG. 10, when the case 6'is closed by the lid 8 ', the closing property of the case 6'is maintained.

The specific embodiments of the present invention have been described above, but the present invention is not limited to these and various modifications can be made. For example, in the above-described embodiment, the plurality of electrode terminals are drawn from one side surrounding the opening of the case, but the electrode terminals do not necessarily have to be arranged on one side as long as the lid can be slid on the case. However, it is preferable to dispose the electrode terminals on one side as in the above-described embodiment because the structure in which the lid is slid on the case can be simplified. In this regard, in the above embodiment, the electrode terminal 34 has been described as three P terminals, N terminals, and one AC terminal, but in the case of a semiconductor power module including P terminals, N terminals, and three AC terminals, If these five electrode terminals are drawn out from one side that surrounds the opening of the case, it becomes relatively easy to take a configuration in which the lid is slidably attached to the case.

[0039]

According to the first aspect of the present invention, wire bonding can be performed with the electrode terminals bent, so that the bonding tool can be shortened.

According to the present invention as set forth in claim 2 or 4, by disposing the nut for joining with the electrode terminal on the lid side, a space for accommodating the nut on the case side can be omitted. Can be realized.

According to the third aspect of the present invention, since the plurality of electrode terminals are drawn out from one side of the castle wall surrounding the opening of the case, the lid is slidably mounted along the opening end of the case. Can be relatively simple.

According to the fifth aspect of the present invention, when the nut support portion provided on the lid side interferes with the storage component, first,
The lid is placed on the case so that the nut support is located between the electrode terminal and the storage component in the sliding direction, and then the lid is slid toward the electrode terminal side and attached to the case. It is possible to avoid increasing the thickness of the module in order to secure the passage of the nut support portion.

According to the present invention as set forth in claim 6 or 7, when the nut support portion provided on the lid side interferes with the storage component, the shape of the lid and the case is set in the case with respect to the sliding direction of the nut support portion. When the lid is slid toward the electrode terminals with the housing parts placed on the open end of the box so that they are located on the opposite side of the electrode terminals, interference between the nut support and the housing parts By designing to prevent it, the degree of freedom in arranging the storage components in the case can be increased.

[Brief description of drawings]

FIG. 1 is an external view showing a semiconductor power module according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the internal structure of the module shown in FIG.

FIG. 3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view similar to FIG. 3 with the lid attached to the case.

FIG. 5 is a cross-sectional view showing an example of engagement between the lid and the case for guiding the lid along the upper end of the case.

FIG. 6A is a schematic side view showing an example of a bonding apparatus. (B) An enlarged perspective view showing the vicinity of the tip of the bonding tool.

FIG. 7 is a side view showing a state of interference when wire bonding is performed in a state where the electrode terminals are erected, and is partially cut away.

FIG. 8 is a cross-sectional view showing a semiconductor power module according to a second embodiment of the present invention, showing a state in which the lid is being closed.

FIG. 9 is an external view showing the semiconductor power module according to the second embodiment of the present invention, showing a state immediately before the lid is completely attached to the case.

FIG. 10 is a sectional view showing a semiconductor power module according to a second embodiment of the present invention, showing a state in which a lid is completely attached to a case.

FIG. 11A is a schematic top view showing an example of a conventional semiconductor power module. (B) The side view of the semiconductor power module of FIG. 11 (a).

FIG. 12 (a) is a schematic top view showing another example of the conventional semiconductor power module. (B) The side view of the semiconductor power module of FIG. 12 (a).

FIG. 13 (a) is a schematic top view showing still another example of a conventional semiconductor power module. (B) FIG. 13 (a)
The side view of the semiconductor power module of FIG.

[Explanation of symbols]

2: semiconductor power module, 4: heat sink, 6: case, 8: lid, 16: semiconductor chip, 34: electrode terminal (electrode plate), 38: nut, 40: nut support portion, 60: semiconductor power module, 68 : First horizontal guide of case, 72: Second horizontal guide of case, 74: Storage component.

Claims (7)

[Claims] 1. A case having an upper end opened and a power semiconductor chip disposed therein, and a lid for closing the opening of the case, and an electrode terminal electrically connected to the power semiconductor chip is drawn to the outside. In the semiconductor power module, the electrode terminal is pulled out from the case and bent along the upper surface of the lid, and the lid is configured to be attached to the case by sliding along the opening end of the case. The semiconductor power module characterized by. 2. A nut supporting portion for supporting a nut that penetrates the electrode terminal and is screwed with a screw for fastening an external wiring to the electrode terminal is provided in the lid. The semiconductor power module described. 3. A plurality of electrode terminals electrically connected to the power semiconductor chip, the case having a case having an upper end opened and having a power semiconductor chip disposed therein, and a lid closing the opening of the case. In the semiconductor power module drawn out to the outside, the plurality of electrode terminals are drawn out from one side of the upper wall surrounding the opening of the case and bent along the upper surface of the lid, and the lid is formed along the opening end of the case. A semiconductor power module configured to be mounted on a case by sliding toward the electrode terminal side. 4. The nut supporting portion for supporting a nut which penetrates the electrode terminal and is screwed into a screw for fastening an external wiring to the electrode terminal is provided in the lid. The semiconductor power module described. 5. The lid is directed toward the electrode terminal side in a state where the nut support portion is arranged on the opening end of the case so as to be located between the plurality of electrode terminals and the housing component in the case in the sliding direction. The semiconductor power module according to claim 4, wherein the semiconductor power module is mounted on the case by sliding. 6. The shape of the lid and the case is such that the nut support is arranged on the opening end of the box so as to be located on the side opposite to the plurality of electrode terminals with the housing component in the case sandwiched therebetween in the sliding direction. The semiconductor power module according to claim 4, which is designed to prevent interference between the nut support portion and the housing component when the lid is slid toward the electrode terminal side. 7. The upper wall surrounding the opening of the case is a first wall.
And a second portion that is higher than the first height by a predetermined height, and the lid has a nut support from the upstream side of the storage component in the case with respect to the sliding direction. 7. The semiconductor power module according to claim 6, wherein when it moves to the downstream side, it slides on the second portion and then slides on the first portion to be mounted on the case.