JP2017005129A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device that can achieve both a high insulation property between a main terminal and a radiator and a high heat radiation property.SOLUTION: A semiconductor device comprises a radiator 3, an insulation member 5 including a conductor, a semiconductor chip 7, a heat dissipation insulation member 11, a terminal 9, and a housing 1. The insulation member 5 including a conductor is arranged in at least a part of a region on one principle surface of the radiator 3. The semiconductor chip 7 is arranged at an opposite side to the radiator 3, of the insulation member 5 including a conductor. The heat dissipation insulation member 11 is arranged so as to include the other region different from a region where the semiconductor chip 7 is arranged, on the one principle surface of the radiator 3. The terminal 9 is arranged in the other region at an opposite side to the radiator 3, of the heat dissipation insulation member 11, and can be electrically connected with the semiconductor chip 7. The housing 1 surrounds the semiconductor chip 7. The heat dissipation insulation member 11 includes an insulation material and has a thermal conductivity higher than that of the housing 1.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a semiconductor device, and more particularly to a power module structure.

  Conventionally, there is a power module structure in which a main terminal is soldered or ultrasonically bonded to a conductor on an insulating substrate. However, with the increase in current density of the power module structure, there may be a problem of lowering reliability, for example, the connection part peels off while being used in the connection part that connects the main terminal and the insulating substrate. From the viewpoint of dealing with such a problem, for example, an insert case type power module structure disclosed in Japanese Unexamined Patent Application Publication No. 2014-11236 (Patent Document 1) has the following configuration. The main terminal is fixed not to the conductor on the insulating substrate but to the base plate which is a heat radiating body through the housing.

JP 2014-11236 A

  When the main terminal is fixed on the housing on the radiator as in JP-A-2014-11236, the casing has high insulation, so high insulation between the main terminal and the radiator is ensured. Is done. However, in Japanese Patent Application Laid-Open No. 2014-11236, since the thermal resistance for propagating the heat of the main terminal to the radiator is not considered, the thermal resistance from the main terminal to the radiator is often increased. If a large current is applied to increase the current density during driving of the power module structure, the amount of heat generated not only by the semiconductor chip constituting the power module structure but also by the main terminal increases. Further, when the external wiring connected to the main terminal becomes high temperature, heat may be transmitted to the main terminal. In these cases, for example, if a thick resin casing is sandwiched between the main terminal and the base plate, the heat dissipation from the main terminal to the radiator is reduced, and heat is trapped in the power module. As a result, the reliability of the power module structure may be reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor device capable of realizing both high insulation between a main terminal and a radiator and high heat dissipation. is there.

  The semiconductor device of the present invention includes a heat radiator, an insulating member including a conductor, a semiconductor chip, a heat insulating member, a terminal, and a housing or a sealing material. The insulating member including the conductor is disposed in at least a part of the region on the one main surface of the radiator. The semiconductor chip is disposed on the opposite side of the heat dissipating member of the insulating member including the conductor. The heat dissipating insulating member is disposed on one main surface of the heat dissipating member so as to include another region different from the region where the semiconductor chip is disposed. The terminal is disposed in another region on the opposite side of the heat dissipating member of the heat insulating member and can be electrically connected to the semiconductor chip. The housing or the sealing material surrounds the semiconductor chip. The heat dissipating insulating member includes an insulating material and has a higher thermal conductivity than the casing or the sealing material.

  The semiconductor device of the present invention includes a heat radiator, an insulating member including a conductor, a semiconductor chip, a heat insulating member, a terminal, and a housing or a sealing material. The insulating member including the conductor is disposed in at least a part of the region on the one main surface of the radiator. The semiconductor chip is disposed on the opposite side of the heat dissipating member of the insulating member including the conductor. The heat dissipating insulating member is disposed on one main surface of the heat dissipating member so as to include another region different from the region where the semiconductor chip is disposed. The terminal is disposed in another region on the opposite side of the heat dissipating member of the heat insulating member and can be electrically connected to the semiconductor chip. The housing or the sealing material surrounds the semiconductor chip. The heat dissipating insulating member includes an insulating material, has a lower thermal conductivity than the casing or the sealing material, and has a higher dielectric strength than the casing or the sealing material.

  According to the present invention, since the heat dissipating insulating member includes an insulating material and has a higher thermal conductivity than the housing or the sealing material, the heat resistance of the heat dissipating insulating member is included in the housing or the sealing. It can reduce compared with the case where material is arrange | positioned. For this reason, by arrangement | positioning of the insulating member for heat dissipation, both high insulation and high heat dissipation are realizable in the area | region between a main terminal and a heat radiator.

  According to the present invention, the heat dissipating insulating member includes an insulating material, and has a lower thermal conductivity and higher dielectric strength than the casing or the sealing material. The thermal resistance of the part can be reduced as compared with the case where the housing or the sealing material is arranged in this part. Since the dielectric strength of the heat dissipating insulating member is high, both high insulation and high heat dissipating properties can be realized in the region between the main terminal and the heat dissipating member by arranging the heat dissipating insulating member.

1 is a schematic projection diagram of an entire power module of a first example of Embodiment 1. FIG. 1 is a schematic plan view of an entire power module of a first example of a first embodiment. FIG. 2 is a schematic projection view showing only a region on the left side in the X direction of FIG. 1 of the power module of the first example of the first embodiment. FIG. 3 is a schematic plan view showing only a half region on the left side in the X direction of FIG. 2 of the power module of the first example of the first embodiment. FIG. 4 is a schematic projection view showing only a region on the left half of the X direction of the power module of the second example of the first embodiment as in FIG. 3. FIG. 4 is a schematic projection view showing only a region on the left half of the X direction of the power module of the third example of the first embodiment as in FIG. 3. It is a schematic projection figure which shows only the area | region of the X direction left side about the half of the power module of the 4th example of Embodiment 1 similarly to FIG. FIG. 10 is a schematic projection view showing only a region on the left side in the X direction of the power module of the fifth example of the first embodiment as in FIG. 3. It is a schematic projection figure which shows only the area | region of the X direction left side about the half of the power module of the 6th example of Embodiment 1 similarly to FIG. It is a schematic projection figure which shows only the area | region of the X direction left side about the half of the power module of Embodiment 2 similarly to FIG. It is a schematic projection figure which shows only the area | region of the X direction left half about the power module of Embodiment 3 similarly to FIG. FIG. 5 is a schematic plan view showing only a half region on the left side in the X direction of the power module according to the third embodiment as in FIG. 4. FIG. 13 is a schematic plan view (A) of the main terminal on the upper side in the Z direction in FIG. 12, and a schematic plan view (B) of the main terminal on the lower side in the Z direction in FIG. FIG. 10 is a schematic projection view of a whole power module of a first example of a fourth embodiment. FIG. 6 is a schematic plan view of an entire power module of a first example of a fourth embodiment. FIG. 15 is a schematic projection view showing only a region on the left side in the X direction of FIG. 14 of the power module of the first example of the fourth embodiment. FIG. 16 is a schematic plan view showing only a region on the left side in the X direction of FIG. 15 of the power module of the first example of the fourth embodiment. FIG. 17 is a schematic projection view showing only the region on the left half of the X direction of the power module of the second example of the fourth embodiment as in FIG. 16. FIG. 17 is a schematic projection view showing only the region on the left half of the X direction of the power module of the third example of the fourth embodiment as in FIG. 16. FIG. 17 is a schematic projection view showing only the region on the left half of the X direction of the power module according to the fifth embodiment, similar to FIG. 16.

Hereinafter, an embodiment will be described with reference to the drawings.
(Embodiment 1)
First, the configuration of the power module of the first example of the present embodiment will be described with reference to FIGS. 1 and 3 are schematic cross-sectional views of a portion along a straight line extending in the left-right direction in the power module. However, in this case, all the components to be listed are not included. In FIG. 4, a schematic projection view as seen from the front is shown. For convenience of explanation, an X direction, a Y direction, and a Z direction are introduced.

  Referring to FIGS. 1 and 2, power module 101 of the first example of the present embodiment has, for example, a box-like (substantially rectangular parallelepiped) appearance, and includes housing 1 and a base as a heat radiator. It mainly includes a plate 3, an insulating substrate 5 as an insulating member, a semiconductor chip 7, a main terminal 9 as a terminal, and a high heat dissipating insulator 11 as a heat dissipating insulating member.

  The housing 1 has an aspect like a box surrounding the whole by being arranged at the outermost part of the power module 101. Conversely, the housing 1 is configured as a side wall surface of a box that houses the semiconductor chip 7 and the like constituting the power module 101 so as to surround the X and Y directions in total. The casing 1 is formed of an insulating material having high mechanical strength and high insulating properties, and is formed of generally known PPS (Poly Phenylene Sulfide Resin) or liquid crystal polymer. The thermal conductivity of PPS is about 0.5 W / (m · K). The housing 1 is arranged not only at the outermost part of the power module 101 but also at a part of the inside (for example, surrounding the main terminal 9) as will be described later.

  The base plate 3 is a flat plate-shaped member that is disposed on the lower side in the Z direction of the housing 1 and has a main surface that extends along the horizontal direction as a base of the entire power module 101 in a normal mounting state. For example, it has a rectangular shape. The base plate 3 is made of a metal material having excellent thermal conductivity such as copper or aluminum. The base plate 3 has a role of radiating heat downward (outside) of the power module 101 by connecting, for example, a heat sink 4 on the main surface on the lower side in the Z direction. As shown in FIGS. 2 and 4, the power module 101 basically has a configuration in which the base plate 3 can be placed as a base (each member is mounted on the upper side of the base plate 3 in the Z direction). ing).

  An insulating substrate 5 is disposed in at least a part of the main surface (on one main surface) on the upper side in the Z direction of the base plate 3 (the central portion in FIGS. 1 and 2). The insulating substrate 5 includes an insulating substrate body 5a, a lower conductor 5b (conductor) bonded on the lower main surface of the insulating substrate body 5a in the Z direction, and an upper main surface of the insulating substrate body 5a in the Z direction. And an upper conductor 5c (conductor) joined to each other.

  The insulating substrate 5 is a substrate on which a main circuit arranged outside the semiconductor chip 7 is formed in the power module 101, and the upper conductor 5c and the lower conductor 5b are made of copper or the like constituting the main circuit, for example It is a metal plate made of aluminum. The insulating substrate body 5a is a plate-like member formed of an insulating material made of ceramics such as alumina or silicon nitride. In particular, the main circuit formed by the upper conductor 5c, the semiconductor element formed on the semiconductor chip 7, and the base plate 3 is electrically insulated.

  A plurality of conductor members may be bonded to the insulating substrate 5 such that two conductor members of the lower conductor 5b and the upper conductor 5c are bonded to the insulating substrate body 5a.

  As described above, the insulating substrate 5 includes the lower conductor 5b made of a conductive material. However, since the insulating substrate 5 includes at least the insulating substrate main body 5a, the insulating substrate main body 5a and the lower conductor 5b are included here for convenience. Are collectively referred to as an insulating substrate 5 as an insulating member.

  The semiconductor chip 7 is disposed on the opposite side (upper side) to the side (lower side) on which the base plate 3 of the insulating substrate 5 is disposed. In particular, referring to FIG. 2 and FIG. 4, here, as an example, semiconductor chip 7 includes two semiconductor chips 7a and 7b spaced apart from each other in the Y direction.

  The semiconductor chip 7 is formed of a semiconductor crystal such as silicon. Although not shown, the semiconductor chip 7 is formed with a rectifying element such as a diode and switching elements such as an IGBT (Insulated Gate Bipolar Transistor) and a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Although not shown, electrodes are provided on the upper and lower main surfaces of the semiconductor chip 7, whereby the various elements are electrically connected to, for example, the main circuit or the main terminal 9 included in the insulating substrate 5. It is connected.

  Although not shown, the switching element and the rectifying element are electrically connected to each other by a bonding wire or a lead frame. In addition, since a parasitic diode exists in the MOSFET, a parasitic diode included in the MOSFET may be used as the rectifying element. The semiconductor chip 7 may have a plurality of rectifying elements and switching elements, or a plurality of the semiconductor chips 7 may be mounted in the power module 101.

  The main terminal 9 is arranged for electrically connecting, for example, the main circuit constituted by the various elements of the semiconductor chip 7 and / or the upper conductor 5c of the insulating substrate 5 and various circuits outside the power module 101. It is formed as a part of the arranged wiring. As shown in FIGS. 1 and 2, the main terminals 9 are arranged on both sides in the X direction with a space from the region where the insulating substrate 5 is placed, for example (in FIGS. 3 and 4). The main terminal 9 on the right side of FIGS. 1 and 2 is not shown). The main terminal 9 has lateral components 9a and 9x extending in a substantially horizontal direction (X direction and Y direction) along the main surface of the base plate 3 in the schematic projection view, and the main surface of the base plate 3 in the schematic projection view. It has an L-shaped shape that is bent so as to have longitudinal components 9b and 9y extending substantially in the intersecting vertical direction (Z direction).

  In order to facilitate electrical connection with various circuits outside the power module 101, the main terminal 9 has one end (upper side) of the longitudinal components 9b and 9y extending above the uppermost part of the housing 1. The power module 101 extends so as to protrude and is exposed to the outside of the box-shaped main body of the power module 101. As a result, the main terminal 9 can be electrically connected to the outside. The main terminal 9 is made of a metal material such as copper. Electrical connection between the main terminal 9 and the semiconductor chip 7 or between the main terminal 9 and the insulating substrate 5 (upper conductor 5c) is made by bonding wires 13 (13a, 13b, 13c). The bonding wire 13 is a thin wire formed of any one selected from the group consisting of aluminum, copper, and gold.

  In FIG. 1 and FIG. 2, the main terminal 9 is arranged in another area (including at least a part) different from (not overlapping with) the area where the semiconductor chip 7 is arranged. The left main terminal 9 and the semiconductor chip 7 are electrically connected by a bonding wire 13a, and the right main terminal 9 and the upper conductor 5c are electrically connected by a bonding wire 13b. Thereby, the main terminal 9 can transmit an electrical signal from the semiconductor chip 7 and the insulating substrate 5 to the outside of the power module 101.

  The highly heat-dissipating insulator 11 is disposed on the upper main surface of the base plate 3 so as to be in contact with the lower main surface of the main terminal 9. Therefore, the main terminal 9 is disposed on the side opposite to the base plate 3 when viewed from the high heat dissipation insulator 11 (in other words, the high heat dissipation insulator 11 is disposed between the base plate 3 and the main terminal 9). The high heat dissipating insulator 11 is disposed in another region (including at least a part thereof) different from (not overlapping with) the region where the semiconductor chip 7 is disposed in a plan view. In FIG. 1, similarly to the main terminal 9, the high heat dissipation insulator 11 is disposed on both sides of the insulating substrate 5 and the semiconductor chip 7 in the X direction.

  The high heat dissipation insulator 11 includes a high heat dissipation insulator body 11a and a high heat dissipation insulator-attached conductor 11b. The high heat dissipation insulator body 11 a and the high heat dissipation insulator accessory conductor 11 b have a flat plate shape having a plane along the main surface of the base plate 3. As shown in FIGS. 1 and 3, the high heat-dissipating insulator-attached conductor 11b has a structure in which it is laminated so as to be in contact with the main surface on the lower side (base plate 3 side) of the high-heat dissipating insulator body 11a. doing.

  In the present embodiment, the high heat dissipation insulator body 11a is formed of an insulating material having a higher thermal conductivity than the casing 1, such as alumina or silicon nitride. Specifically, the heat conductivity of the high heat dissipation insulator body 11a is about 20 W / (m · K) or more and 200 W / (m · K) or less. The high heat-dissipating insulator-attached conductor 11b is formed of a conductor material having a high thermal conductivity such as copper.

  In the first example of FIGS. 1 to 4, it is assumed that the high heat dissipation insulator body 11a is basically formed of the same material as the insulating substrate body 5a. However, the high heat dissipation insulator body 11a of the first example of the present embodiment only needs to have a thermal conductivity higher than at least the housing 1, and is an inexpensive ceramic material (zirconia or the like having a lower thermal conductivity than the insulating substrate body 5a). ) May be used. In the power module 101, the semiconductor chip 7 generates the largest amount of heat, and the main terminal 9 does not generate as much heat as the semiconductor chip 7. For this reason, the high heat-dissipation insulator main body 11a arrange | positioned just under the main terminal 9 may have a heat conductivity lower than the insulated substrate main body 5a. However, it is more preferable that the high heat dissipation insulator body 11a has a higher thermal conductivity than the insulating substrate body 5a.

  Although not shown, the high heat dissipation insulator 11 has an upper portion of the high heat dissipation insulator body 11a made of a ceramic material and the main terminal 9 fixed by a jig, and is placed under the high heat dissipation insulator attached conductor 11b by a spacer or the like. Is provided by forming an insert case with a space for sandwiching a bonding material described later. As a result, the casing 1 surrounds the main terminal 9 from both the X direction and the Y direction, and the main terminal 9 and the high heat dissipation insulator 11 are connected to each other. After being assembled in this manner, the joining material described later is supplied to a desired location, thereby joining the members.

  From the viewpoint of preventing the high heat dissipating insulator 11 from dropping when the top and bottom in the Z direction are reversed with respect to the state shown in FIGS. The casing 1 in a form capable of pressing a part of the lateral component 9a of the main terminal 9 downward in the Z direction may be insert-molded.

  The inside of the housing 1 on which each member described above is mounted is sealed by being filled with a sealing material 21 such as gel. 2 and FIG. 4, the illustration of the sealing material 21 is omitted.

  A pair of control signal electrodes 17 (control signal electrodes 17a and 17b) are formed on a part of the outermost part of the housing 1. The control signal electrodes 17a and 17b are used to input a control signal to be input to a gate wiring included in a switching element such as IBGT or MOSFET formed on the semiconductor chip 7 from the outside, or to output a control signal from the switching element. It is an electrode for doing. For this reason, the semiconductor chip 7 and the control signal electrode 17 are electrically connected by the bonding wire 13c. The control signal electrode 17 extends so that a part of the control signal electrode 17 protrudes to the upper side of the uppermost portion of the housing 1, thereby enabling electrical connection with the outside. Although not shown, the number of control signal electrodes may be increased for the purpose of protecting the semiconductor chip 7 from overcurrent, excessive chip temperature rise, and the like.

  The members described above are connected to each other by a bonding material such as solder. For example, solder 23a is provided between the base plate 3 and the insulating substrate 5, solder 23b is provided between the insulating substrate 5 and the semiconductor chip 7, and solder 23c is provided between the base plate 3 and the high heat dissipation insulator 11. Are arranged to electrically connect the two members. That is, here, the high heat dissipation insulator accessory conductor 11b is provided to enable the high heat dissipation insulator 11 and the base plate 3 to be joined by the solder 23c. As the bonding material, for example, high thermal conductive grease may be used instead of solder, as will be described later.

  In addition, although not shown, an adhesive or the like is also supplied between the housing 1 and the base plate 3, and the housing 1 and the base plate 3 are thereby joined. Further, other insulating members (not shown) included in the power module 101 are connected so as to maintain an insulating state between these members.

  In the following various modifications and the like, from the viewpoint of simplifying the drawing, the illustration is omitted in the right half region of FIGS. 1 and 2, as in FIGS. 3 and 4. In the following drawings, the heat sink 4 is not shown, but the heat sink 4 is arranged in the same manner as the power module 101 in the following various modifications.

  Referring to FIG. 5, power module 102 of the second example of the present embodiment has basically the same configuration as power module 101, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. However, the power module 102 is different from the power module 101 in that the high heat dissipation insulator 11 is formed by a high heat dissipation insulator body 11c made of an insulating sheet. The high heat dissipation insulator body 11c made of an insulating sheet has a flat plate shape having a flat surface along the main surface of the base plate 3, like the high heat dissipation insulator body 11a made of alumina or the like. The insulating sheet is made of various ceramic material fillers filled with pulverized silicon particles, and is electrically insulating. The thermal conductivity of the insulating sheet is about 5 W / (m · K) to 20 W / (m · K). The thermal conductivity of the insulating sheet is at least higher than the thermal conductivity of the housing 1.

  In the second example, from the viewpoint of preventing the high heat-dissipating insulator body 11c from dropping when the top and bottom in the Z direction are reversed with respect to the state shown in FIG. The casing 1 in a form capable of pressing a part of the lateral component 9a of the main terminal 9 downward in the Z direction from the upper side in the direction is insert-molded.

  Further, the same material as that of the thin casing 1 is used to fix the high heat-dissipating insulating main body 11c as an insulating sheet on the lower side in the Z direction of the high heat-dissipating insulating main body 11c (position 23d in FIG. 5). The flat plate member is insert-molded. The high heat-dissipating insulator main body 11c as an insulating sheet having a high thermal conductivity is inserted thereon to ensure insulation between the main terminal 9 and high thermal conductivity. With this high heat dissipation insulator body 11c, the portion of the casing 1 on the lower side in the Z direction (low thermal conductivity) of the high heat dissipation insulator body 11c is thinned, and the region on the lower side in the Z direction of the main terminal 9 is reduced. Compared with the case where all the casings 1 are configured, the thermal conductivity can be increased equivalently, and the heat of the main terminals 9 can be easily released downward in the Z direction.

  In addition, since the high heat dissipation insulator 11 of the second example is composed of only one layer of the high heat dissipation insulator body 11c of the insulating sheet, the bonding material between this and the base plate 3 is a high heat conductive grease 23d instead of the solder 23c. Is preferably used.

  Referring to FIG. 6, power module 103 of the third example of the present embodiment has basically the same configuration as power module 102, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. Also in the power module 103, as in the power module 102, a high heat dissipation insulator body 11 c made of an insulating sheet is used as the high heat dissipation insulator 11. However, the power module 103 is different from the power modules 101 and 102 in that the main terminal 9 and the high heat dissipation insulator 11 are connected, and the high heat dissipation insulator 11 and the base plate 3 are connected in the following manner. ing.

  That is, as shown in FIG. 6, the base plate 3, the high heat dissipation insulator 11, and the main terminal 9 are stacked in this order, and the upper side of the lateral component 9 a of the main terminal 9 is directed downward in the Z direction. High pressure is applied to such an extent that can be bonded. Thereby, the base plate 3, the high heat dissipation insulator 11, and the main terminal 9 are joined to each other. For this reason, in the third example, no bonding material is disposed between the base plate 3 and the high heat dissipation insulator 11.

  In this way, the high heat dissipation insulator 11 made of an insulating sheet can be joined to the base plate 3 and the main terminal 9 so as not to be displaced in plan view. Further, a bonding material such as the high thermal conductive grease 23d is not sandwiched between the base plate 3 and the high heat dissipation insulator 11 or the like. For this reason, the thermal resistance between the base plate 3, the high heat dissipation insulator 11 and the main terminal 9 can be further reduced, and the heat dissipation of the main terminal 9 is enhanced.

  Referring to FIG. 7, power module 104 of the fourth example of the present embodiment has basically the same configuration as power module 102, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. However, the power module 104 does not have an L-shape that is bent so that the main terminal 9 extends in the Z direction, and is a flat plate that extends in a substantially horizontal direction (X direction and Y direction) along the main surface of the base plate 3. It has the form which has only the shape component 9c. The main terminal 9 protrudes from the left side surface of the housing 1 in the X direction and extends to the outside. In this respect, the power module 104 is different from the power module 102.

  As a result, the main terminal 9 can be electrically connected to various external circuits similarly to the power module 101 and the like. As described above, the main terminal 9 does not necessarily have to be taken out from the upper side in the Z direction with respect to the housing 1. It may be in the form of taking out.

  A main terminal 9 having a plate-like component 9c may be used for the power modules 101 and 103.

  Referring to FIG. 8, power module 105 of the fifth example of the present embodiment has basically the same configuration as power module 101, and therefore the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. However, unlike the high heat dissipation insulator 11 of the power module 101, the power module 105 is not provided with the high heat dissipation insulator accessory conductor 11b, and the high heat dissipation insulator 11 is formed only by the high heat dissipation insulator body 11a. It is configured. Further, as the bonding material between the base plate 3 and the high heat dissipation insulator 11, high thermal conductive grease 23d is used instead of the solder 23c. In this respect, the power module 105 is different from the power module 101.

  Referring to FIG. 9, power module 106 of the sixth example of the present embodiment has basically the same configuration as power module 101, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. In the power module 106, the high heat dissipation insulator 11 includes a high heat dissipation insulator body 11d and a high heat dissipation insulator-attached conductor 11b. The high heat-dissipating insulator body 11d is formed of an electrically insulating material such as steatite that has higher thermal conductivity than the housing 1 and higher dielectric strength than the housing 1. The high heat dissipation insulator 11 may have such a high heat dissipation insulator body 11d. Conversely, the high heat dissipation insulator body 11 a of the power module 101 may be formed of a material having a higher thermal conductivity than the housing 1 and a lower dielectric strength than the housing 1.

  In each example of the present embodiment described above, an insulating sheet made of the same material as the insulating sheet constituting the high heat dissipation insulator body 11c may be used instead of the insulating substrate body 5a.

Next, the effect of this Embodiment is demonstrated.
In the present embodiment, in any of the above-described examples, the highly heat-dissipating insulator 11 includes an insulating material between the base plate 3 and the main terminal 9 and has a higher thermal conductivity than the housing 1. Is placed. For this reason, compared with the case where PPS etc. of the same material as the housing | casing 1 is arrange | positioned between the base board 3 and the main terminal 9, for example, the thermal resistance of the area | region between the main terminal 9 and the base board 3 is reduced. can do. Therefore, the heat generated at the main terminal 9 and the heat transferred from the external wiring of the power module to the main terminal 9 can be transmitted to the base plate 3 and radiated from the base plate 3 to the outside. For this reason, the temperature of the main terminal 9 can be lowered more efficiently. If the temperature of the main terminal 9 decreases, the amount of heat transferred from the semiconductor chip 7 to the main terminal 9 via the bonding wire 13 increases, so that the temperature of the semiconductor chip 7 can also be lowered.

  The minimum area of the cross section of the main terminal 9 (for example, the longitudinal component 9b cut so as to intersect the extending direction) is determined so as to depend on the amount of heat generated by the main terminal 9. In order to allow a larger amount of current to flow through the main terminal 9, it is necessary to increase the cross-sectional area of the main terminal 9 to reduce the amount of heat generated. However, if the temperature of the main terminal 9 can be lowered using the high heat dissipation insulator 11 as described above, the cross-sectional area of the main terminal 9 can be reduced, so that the power module can be further downsized.

  Moreover, the high heat dissipation insulator 11 includes an insulating material (expanding in the direction along the main surface of the base plate 3) in any of the embodiments. For this reason, the heat of the main terminal 9 can be reliably radiated toward the base plate 3 while ensuring the insulation between the main terminal 9 and the base plate 3. That is, both high insulation between the main terminal 9 and the base plate 3 and high heat dissipation can be achieved.

  Further, for example, if the high heat-dissipating insulator body 11d is formed of a material having higher thermal conductivity and higher dielectric strength than the housing 1 as in the power module 106 of FIG. 9, the thickness in the Z direction is very thin. Thus, even if the thermal resistance is lowered, the insulation can be sufficiently secured. For this reason, the effect which combines both the high heat conductivity of the high heat dissipation insulator 11 and electrical insulation is securable.

  In each example of the present embodiment described above, the semiconductor chip 7 may be formed of a wide band gap semiconductor such as silicon carbide (SiC) instead of silicon. By doing so, the current density of the main terminal 9 increases and the temperature becomes higher, so that the effect of high heat dissipation by using this embodiment becomes more remarkable.

(Embodiment 2)
Referring to FIG. 10, power module 201 of the present embodiment has basically the same configuration as power module 102 of the second example of the first embodiment, and therefore the same elements are denoted by the same reference numerals. The description will not be repeated. However, in the power module 201, the high heat dissipation insulator 11 is configured by a high heat dissipation insulator body 11e instead of the high heat dissipation insulator body 11c.

  The high heat dissipation insulator body 11e is electrically insulative like the high heat dissipation insulator bodies 11a, 11c, and 11d of the first embodiment. Further, the high heat dissipation insulator body 11 e is formed of a material such as insulating paper having a lower thermal conductivity than that of the housing 1 and a higher dielectric strength than that of the housing 1.

  In this respect, the power module 201 is different from the power modules of the first embodiment, but the other points are basically the same as those of the power modules of the first embodiment. That is, the power module 201 also includes the base plate 3 and the insulating substrate 5 arranged in a partial region on the main surface on the upper side of the base plate 3, and the insulating substrate 5 includes the insulating substrate body 5a. The lower conductor 5b and the upper conductor 5c are provided. A semiconductor chip 7 is disposed above the insulating substrate 5 in the Z direction. The highly heat-dissipating insulator 11 is disposed so as to at least partially include another region different from the region where the semiconductor chip 7 is disposed in plan view. The main terminal 9 is disposed in the other region on the upper side in the Z direction of the high heat dissipation insulator 11, that is, on the side opposite to the base plate 3, and has a configuration that can be electrically connected to the semiconductor chip 7. A housing 1 is provided so as to surround the semiconductor chip 7.

Next, the effect of this Embodiment is demonstrated.
The high heat dissipation insulator body 11e constituting the high heat dissipation insulator 11 of the present embodiment has a higher dielectric strength than the housing 1. For this reason, even if the thickness in the Z direction is considerably reduced, for example, high insulation can be ensured in the portion, that is, the region between the main terminal 9 and the base plate 3. Therefore, by reducing the thickness, the thermal resistance of the portion of the high heat-dissipating insulator body 11e can be reduced as compared with the case where it is thick. Thereby, if the thickness is reduced, even if the thermal conductivity of the high heat dissipation insulator 11 is lower than that of the housing 1, the thermal resistance can be reduced, and heat dissipation from the main terminal 9 to the base plate 3 can be achieved. Can be performed more efficiently. Further, the power module 201 can be further miniaturized by reducing the thickness of the high heat dissipation insulator 11.

Here, for example, the thickness T1 in the Z direction of the high heat dissipation insulator body 11e is T2 when the portion is formed of the same material as that of the housing 1, and the high heat dissipation insulator body 11e is configured. If the thermal conductivity of the material to be made α1 and the thermal conductivity of the material constituting the housing 1 is α2,
T1 <T2 × (α1 / α2) (1)
It is preferable that

  However, in this case, it is preferable to secure a creeping insulation distance from the main terminal 9 to the base plate 3 by the sealing material 21 covering the main terminal 9, the high heat dissipation insulator 11 and the base plate 3.

  In other words, when the high heat-dissipating insulator 11 having higher thermal conductivity than the housing 1 is used as in the first embodiment, even if the thickness of the portion is increased, the heat of the portion is increased. The possibility that the resistance becomes so high that the heat radiation efficiency from the main terminal 9 is extremely lowered can be reduced.

(Embodiment 3)
Referring to FIGS. 11 to 12, power module 301 of the present embodiment has basically the same configuration as power module 102 of the second example of the first embodiment, and therefore the same elements are the same. Reference numerals will be given and description thereof will not be repeated. However, the power module 301 includes at least part of a region in which a plurality (two in this case) of the main terminals are arranged at intervals with respect to the Z direction in which the main terminal intersects the main surface of the base plate 3. It has a configuration. In other words, main terminals whose potentials during operation are different from each other (to a degree that cannot be ignored) are spaced apart from each other in the Z direction.

  Specifically, as shown in FIG. 12, the power module 301 has two main terminals 91 and a main terminal 92. As shown in FIG. 11, the main terminal 91 has a horizontal component 9a1 and a vertical component 9b1, and the main terminal 92 has a horizontal component 9a2 and a vertical component 9b2. The horizontal components 9a1 and 9a2 extend in a substantially horizontal direction (X direction and Y direction) along the main surface of the base plate 3, and the vertical components 9b1 and 9b2 are in a substantially vertical direction intersecting the main surface of the base plate 3 ( Z direction). That is, the main terminals 91 and 92 have a bent L-shape in the schematic projection view, like the main terminal 9 of the first embodiment.

  However, referring to FIG. 12 and FIG. 13, main terminal 91 and main terminal 92 have an L-shaped shape that is bent even in plan view. Specifically, the main terminal 91 has a vertical component 9b1 disposed in the lower left region of FIGS. 12 and 13A, and the horizontal component 9a1 extends to the right in the X direction and then bends to Y It is configured to extend upward in the direction. The main terminal 92 has a vertical component 9b2 arranged in the upper left region of FIGS. 12 and 13B, and the horizontal component 9a2 extends to the right in the X direction and then bends to the lower side in the Y direction. It has an extending form. The region in which the lateral component 9a1 of the main terminal 91 extends upward in the Y direction and the region in which the lateral component 9a2 of the main terminal 92 extends downward in the Y direction are aligned with each other in the Z direction so as to overlap each other in plan view. Has been placed.

  Here, as an example, the lateral component 9a1 of the main terminal 91 and the semiconductor chip 7b are electrically connected by the bonding wire 13a, and the lateral component 9a2 of the main terminal 92 and the semiconductor chip 7a are electrically connected by the bonding wire 13b. Yes.

  Referring to FIG. 11 again, the main terminal closest to the base plate 3 among the plurality of main terminals 91 and 92 (lateral components 9a1 and 9a2) arranged so as to overlap each other in plan view is a high heat dissipation insulator. 11 is arranged. Here, with respect to the Z direction, the horizontal component 9a1 of the main terminal 91 is arranged to overlap the horizontal component 9a2 of the main terminal 92. That is, the main terminal 92 (lateral component 9a2) arranged below the main terminal 91 (lateral component 9a1) in the Z direction is arranged (to be placed) on the high heat dissipation insulator 11. ing.

  Here, the high heat dissipation insulator 11 may be composed of a high heat dissipation insulator body 11c, such as the power module 102, and connected to the high thermal conductive grease 23d. Alternatively, the high heat radiating insulator 11 may be a high heat radiating insulator 11a and a high heat radiating insulator attached conductor 11b having a higher thermal conductivity than the housing 1, such as the power module 101, for example. In this case, the connection between the base plate 3 and the base plate 3 may be the high thermal conductive grease 23d shown in FIG. 11, but may instead be the solder 23c (see FIG. 3).

  In addition, the high heat-dissipating insulator 11 in the present embodiment is a high heat-dissipating insulator body 11e having a lower thermal conductivity than the housing 1 and a higher dielectric strength than the housing 1, for example, as in the second embodiment. It may be. In the case where the high heat dissipation insulator body 11e is used, from the same viewpoint as in the second embodiment, by reducing the thickness in the Z direction, the portion (between the main terminal 92 and the base plate 3) is reduced. It is preferable to make the creeping distance from the main terminal 92 to the base plate 3 as long as possible. In addition, the highly heat-dissipating insulator 11 of each modification of the first and second embodiments and the configuration of the present embodiment can be combined as appropriate. Although not shown, for example, as in the power module 104 of FIG. 7, the main terminals 91 and 92 including regions overlapping each other in a plane have a plate-like component 9 c and are external to the housing 1 from the left in the X direction. Alternatively, the wiring may be taken out.

  On the other hand, the main terminal 91 (lateral component 9a1) arranged above the main terminal 92 (lateral component 9a2) in the Z direction is arranged on the insulator 12. The insulator 12 may be made of the same material as the high heat dissipation insulator 11, but may be made of a different material. The insulator 12 is arranged to extend in the Z direction so as to fill a region between the lateral component 9a1 and the lateral component 9a2. The insulator 12 maintains electrical insulation between the lateral component 9a1 and the lateral component 9a2.

Next, the effect of this Embodiment is demonstrated.
In the present embodiment, for example, if the high heat dissipation insulator 11 has a higher thermal conductivity than the insulating material of the housing 1 (high heat dissipation insulator bodies 11a, 11c, 11d, etc.), The thermal resistance between the base plate 3 can be lowered. Therefore, it is possible to increase the amount of heat transferred from the main terminal 92 to the base plate 3 through the highly heat-dissipating insulator 11, and from the heat generated in the main terminal 92 and the wiring outside the power module 301 to the main terminal 92. The transmitted heat can be transferred more to the base plate 3 and radiated from the base plate 3 to the outside. For this reason, the temperature of the main terminal 92 can be lowered more efficiently. If the temperature of the main terminal 92 decreases, the amount of heat transferred from the semiconductor chip 7 to the main terminal 92 via the bonding wire 13 increases, so that the temperature of the semiconductor chip 7 can also be lowered. Since the heat dissipation efficiency from the main terminal 92 is increased as described above, the area of the cross section intersecting with the extending direction of the main terminals 91 and 92 is reduced as in the first embodiment, and the heat generation amount of the main terminal 92 is reduced. Even if there is an increase in the number of people, it can be said that there is a system in place for heat dissipation. For this reason, the cross-sectional area of the main terminals 91 and 92 can be reduced, and the power module can be further downsized.

  When the insulator 12 is formed of the same material as the insulating material included in the housing 1, for example, the insulator 12 fixes the upper portion of the main terminal 92 and the lower portion of the high heat dissipation insulator 11 with a jig. By doing so, the insulator 12 can be molded together with the casing 1. Therefore, in this case, for example, the manufacturing process can be reduced and the cost can be reduced as compared with the case where the insulator 12 is formed of a material different from that of the housing 1.

  Further, when the insulator 12 is formed of the same material as the insulating material included in the high heat dissipation insulator 11, heat generated at the main terminal 91 and heat transmitted to the main terminal 91 (lateral component 9a1), etc. It is transmitted to the main terminal 92 (lateral component 9a2) thereunder through the insulator 12 as a high heat dissipation insulator. Further, the heat is dissipated from the main terminal 92 through the high heat dissipating insulator 11 to the underlying base plate 3. Therefore, the temperature of the main terminal 91 can be lowered similarly to the main terminal 92.

  However, the heat generated at the main terminal 91 on the upper side is present in the middle of the heat dissipation path toward the heat radiating body such as the lower base plate 3 in the same way as the main terminal 91 such as the main terminal 92. Therefore, the propagation of heat from the main terminal 91 to the main terminal 92 is easily blocked. Therefore, the cooling effect of the main terminal 91 is weaker than that of the main terminal 92 even if the highly heat-dissipating insulator 11 is disposed so as to be in contact therewith. For this reason, for example, even when the insulator 12 is formed of an insulating material that is different from the high heat dissipation insulator 11 (having a thermal conductivity not as high as that of the high heat dissipation insulator body 11c), the cooling effect does not change much. By doing so, the manufacturing cost may be reduced in some cases. In other words, by adopting a configuration having a plurality of main terminals 91 and 92 as in the present embodiment, it is possible to devise methods such as assigning different insulator materials to different places depending on the priority of the necessity of cooling. If so, the cost may be reduced.

(Embodiment 4)
First, the configuration of the power module of the first example of the present embodiment will be described with reference to FIGS. FIG. 14 and FIG. 16 are schematic cross-sectional views of a portion along a straight line extending in the left-right direction in the power module. However, in this case, all the components to be listed are not included. In FIG. 4, a schematic projection view as seen from the front is shown.

  Referring to FIGS. 14 and 15, power module 401 of the first example of the present embodiment has a box-like (substantially rectangular parallelepiped) appearance, for example, heat sink 4 as a heat radiator, and insulating member. As a main component, a member 6 with an insulating sheet, a semiconductor chip 7, a high heat dissipation insulator 11 as a heat dissipation insulating member, and a lead frame 10 as a terminal are mainly provided.

  However, in the power module 401, the housing 1 like the power module 101 is not arranged. Therefore, the sealing material 22 is exposed toward the outside in the region above the heat sink 4 in the Z direction. In this respect, the present embodiment is greatly different from the power modules of the first to third embodiments including the housing 1.

  In the power module 401, only the heat sink 4 is provided as a heat radiating body. However, as in the first to third embodiments, the base plate 3 and the heat sink 4 connected on the main surface below the Z direction are provided. The structure which has may be sufficient. As shown in FIGS. 14 and 16, the power module 401 basically has a configuration in which the heat sink 4 can be mounted as a base (each member is mounted on the upper side of the heat sink 4 in the Z direction). ).

  In the power module 401, the member 6 with an insulating sheet constituting the main circuit is disposed. The member 6 with an insulating sheet is arranged between a semiconductor chip 7 and a high heat-dissipating insulator 11 (to be described later) and the heat sink 4 in the Z direction by spreading over almost the entire XY plane. The insulating sheet member 6 is formed on the insulating sheet 6a made of the same material as the insulating sheet used for the high heat dissipation insulator body 11c and the like on the first embodiment, and on the main surface on the lower side in the Z direction of the insulating sheet 6a. And a heat spreader 6c (conductor) bonded to the main surface on the upper side in the Z direction of the insulating sheet 6a. The insulating sheet 6 a, the copper foil 6 b, and the heat spreader 6 c are spread almost over the entire main surface on the upper side of the heat sink 4. That is, the member 6 with an insulating sheet is assumed to contain a conductor material here, like the insulating substrate 5.

  The member 6 with an insulating sheet is a substrate that forms a main circuit formed outside the semiconductor chip 7 in the same manner as the insulating substrate 5 of the first embodiment. The copper foil 6 b is formed of a copper thin film and corresponds to the lower conductor 5 b of the insulating substrate 5. The heat spreader 6c is made of copper, for example, and corresponds to the upper conductor 5c of the insulating substrate 5. However, in the power module 401, as in the power module 101 and the like, the insulating substrate 5 having the insulating substrate body 5a and the lower conductor 5b and the upper conductor 5c as metal plates provided on the upper and lower surfaces thereof is used. May be.

  The semiconductor chip 7 is arranged on the side (lower side) opposite to the side (lower side) where the heat sink 4 is arranged of the member 6 with insulating sheet. Here, as an example, two semiconductor chips 7a and 7b are arranged at an interval in the X direction.

  The high heat dissipation insulator 11 is a region (here, a semiconductor) different from the region where the semiconductor chip 7 is disposed on the main surface on the upper side of the member 6 with the insulating sheet (also on the main surface on the upper side of the heat sink 4). It is arranged on the left side in the X direction of the chip 7. Here, any of the high heat dissipating insulators 11 in each of the embodiments of the first embodiment may be used, but here, as an example, a state in which the pressure is used and the heat spreader 6c is connected as shown in FIG. A high heat-dissipating insulator body 11c is shown. Therefore, here, from the left side in the X direction, the highly heat-dissipating insulator 11, the semiconductor chip 7a, and the semiconductor chip 7b are arranged on the member 6 with the insulating sheet at intervals from each other.

  In the present embodiment, the high heat dissipation insulator (for example, the high heat dissipation insulator 11 c) included in the high heat dissipation insulator 11 is an insulating material having a higher thermal conductivity than the sealing material 22. Therefore, the insulating sheet 6a is also an insulating material having a higher thermal conductivity than the sealing material 22 (because it is the same material as the high heat dissipation insulator 11c).

  The lead frame 10 corresponds to the main terminal 9 in the first embodiment or the like. The lead frame 10 is connected to the main surface on the upper side in the Z direction of the high heat dissipating insulator 11 and also connected to the main surface on the upper side in the Z direction of the semiconductor chips 7a and 7b. That is, the lead frame 10 extends in the X direction so as to straddle the high heat dissipation insulator 11, the semiconductor chip 7a, and the semiconductor chip 7b. Furthermore, the lead frame 10 extends so as to penetrate the left end portion of the sealing material 22 for sealing these members in the X direction and project to the left, thereby enabling electrical connection with the outside. As shown in the plan views of FIGS. 15 and 17, the lead frame 10 also has a width comparable to the dimension in the Y direction of the high heat dissipation insulator 11 in the Y direction, for example. Accordingly, the lead frame 10 has a plate-like shape extending in the X direction in plan view.

  As described above, the lead frame 10 is directly connected to both the semiconductor chips 7a and 7b and the high heat dissipation insulator 11 here. However, the lead frame 10 is directly connected to the heat spreader 6c instead of the semiconductor chips 7a and 7b, and is electrically connected to the semiconductor chip 7 by connecting the heat spreader 6c and the semiconductor chip 7 with bonding wires (not shown). There may be.

  The lead frame 10 is usually made of copper. However, the lead frame 10 may be formed using a material in which an iron-nickel alloy material called invar is sandwiched between a pair of copper materials.

  A plurality of control signal electrodes 17 (for example, five control signal electrodes 17a, 17b, 17c, 17d, and 17e) are formed on a part of the outermost portion of the sealing material 22. In the same manner as in the first embodiment, a control signal to be input to a gate wiring (not shown) included in a switching element such as IBGT or MOSFET formed on the semiconductor chip 7 is input from the outside, and is controlled from the switching element. It is an electrode for outputting a signal. Therefore, the semiconductor chip 7 and the control signal electrode 17 are electrically connected by the bonding wire 13.

  A pair of main terminals 18a and 18b are arranged spaced apart from each other with respect to the lead frame 10 in the Y direction. These are connected on the heat spreader 6c of the member 6 with an insulating sheet, for example. In FIG. 15, these main terminals 18 a and 18 b extend almost in parallel with the lead frame 10 in the X direction, and a part of them is exposed from the sealing material 22. Thereby, the electrical connection with the exterior is enabled. The main terminals 18a and 18b are different in potential from the lead frame 10.

  The members described above are connected to each other by a bonding material such as solder. For example, a solder 23 a is provided between the heat sink 4 and the insulating sheet member 6, a solder 23 b is provided between the insulating sheet member 6 and the semiconductor chip 7, and a solder 23 e is provided between the semiconductor chip 7 and the lead frame 10. Are arranged to electrically connect the two members. Furthermore, solder 23f is arranged between the main terminal 18 and the member 6 with an insulating sheet, and these are connected. Silver may be used instead of these solders, for example, high heat conductive grease 23d (see FIG. 5) may be used instead of the solder 23a. Further, the creeping insulation distance between the members to be electrically insulated from each other is ensured to be as long as possible.

  In assembling the above embodiment, first, the high heat dissipating insulator 11 is disposed at a desired position on the heat spreader 6c, and the semiconductor chips 7a and 7b are disposed at desired positions on the heat spreader 6c via the solder 23b. Be placed. Solder 23e is supplied on the main surface on the upper side in the Z direction of the semiconductor chips 7a and 7b so as to have a desired thickness in the Z direction.

  Next, the lead frame 10 is disposed so as to overlap both the high heat dissipation insulator 11 and the solder 23e (semiconductor chips 7a and 7b). At this time, the lead frame 10 is bent so as to face upward in the Z direction in a region between the semiconductor chips 7 a and 7 b and the high heat dissipation insulator 11. As a result, the lead frame 10 can be disposed above the high heat dissipating insulator 11 in the Z direction according to the thickness of the solder 23e on the semiconductor chips 7a and 7b.

  For example, if the thickness of the solder 23e that joins the semiconductor chips 7a and 7b and the lead frame 10 increases, the thermal resistance of heat transfer from the semiconductor chips 7a and 7b to the lead frame 10 increases, and the semiconductor chips 7a and 7b. The amount of heat transferred from the lead frame 10 to the lead frame 10 decreases. For this reason, from the viewpoint of increasing the heat dissipation efficiency from the semiconductor chip 7 to the lead frame 10, the lead frame 10 is adapted to the height of the upper surface of the solder 23e while the solder 23e is thin rather than the solder 23e being thick. Sometimes it is better to bend.

  The lead frame 10 is also disposed on the upper surface of the highly heat-dissipating insulator 11, but at this time, the jig is adjusted so that a pressure is applied to the extent that both can be bonded with a jig. In this state, the members are joined together by the solders 23a, 23b, 23e, and 23f in a reflow process. At this time, when the solders 23a, 23b, 23e, and 23f are melted, the weight of the lead frame 10 strengthens the connection between the lead frame 10 and the high heat dissipation insulator 11, thereby reducing the thermal resistance therebetween. Can do.

  Next, a sealing material such as an epoxy resin is used for the sealing material 22 that seals the member 6 with an insulating sheet and each member on the upper side in the Z direction mounted as described above. Since the sealing material 22 has an aspect in which the outermost surface is exposed, the hardness is extremely higher than that of the gel-like sealing material 21. As in the case of the housing 1 such as the power module 101, the sealing material 22 is a box type (for example, a rectangular parallelepiped type) that houses the semiconductor chip 7 constituting the power module 201 so as to surround the X and Y directions in total. have. Each member is sealed using the sealing material 22 after joining using the solders 23a, 23b, 23e, and 23f as described above.

  In addition, since the structure of this Embodiment other than this is as substantially the same as the structure of Embodiment 1, the same code | symbol is attached | subjected about the same element and the description is not repeated.

  Referring to FIG. 18, power module 402 of the second example of the present embodiment has basically the same configuration as power module 401, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. Similarly to the power module 401, the power module 402 uses the lead frame 10 as a terminal instead of the main terminal 9 (see FIG. 1). However, in the power module 402, the high heat dissipation insulator 11 includes a high heat dissipation insulator body 11a, a lower conductor 11f bonded on the lower main surface in the Z direction, and a high heat dissipation insulator body 11a. The upper conductor 11g is joined to the upper main surface in the Z direction. In this respect, the power module 402 is different from the power module 401 in which the high heat dissipation insulator 11c is joined to the lead frame 10 using pressure.

  The high heat dissipation insulator 11 may have the above-described configuration. The lower conductor 11f and the upper conductor 11g are, for example, copper or aluminum metal plates.

  The lower conductor 11f and the heat spreader 6c are joined together by, for example, solder 23g. Similarly, the upper conductor 11g and the heat spreader 6c are joined by, for example, solder 23h.

  In FIG. 18, the heights of the Z-direction uppermost surface of the solder 23 h on the upper conductor 11 g and the Z-direction uppermost surface of the solder 23 e on the semiconductor chip 7 are substantially equal. Therefore, the lead frame 10 joined so as to straddle both extends substantially in a flat plate shape without bending in the Z direction. However, also here (as in the first example), the lead frame 10 is bent in the Z direction as necessary while adjusting the height of the insulating sheet 6a in the Z direction and the thickness of the solders 23b, 23e, 23g, and 23h. May be. For example, from the viewpoint of increasing the heat dissipation efficiency from the semiconductor chip 7 to the lead frame 10, the lead frame 10 is bent to match the height of the upper surface of the solder 23e while the solder 23e is thin, rather than the solder 23e being thick. It may be better.

  When the power module 402 is formed, the solder 23a on the heat sink 4, the solders 23b and 23e on the upper and lower surfaces of the semiconductor chip 7, and the solders 23g and 23h in contact with the upper and lower surfaces of the high heat dissipation insulator 11 are all collectively. Then, it is fixed by a reflow process. Thereby, the members in contact with the solders 23a, 23b, 23e, 23g, and 23h are joined.

  Referring to FIG. 19, power module 403 of the third example of the present embodiment has basically the same configuration as power module 401, and thus the same elements are denoted by the same reference numerals, and the description thereof is repeated. Absent. However, in the power module 403, the lead frame 10 bends substantially at a right angle at a position just above the end on the left side in the X direction of the high heat dissipating insulator 11, breaks through the sealing material 22 and is above the uppermost portion. It extends to protrude. This enables electrical connection with the outside. Thus, the lead frame 10 may protrude outside the sealing material 22 in the X direction, or may protrude outside the sealing material 22 in the Z direction.

Next, the effect of this Embodiment is demonstrated.
In the present embodiment, instead of the main terminal 9 (see FIG. 1), a plate-like lead frame 10 is used in plan view as a terminal, and a high heat dissipation insulator 11 is disposed between the lead frame 10 and the heat sink 4 ( Connected). Compared with the first embodiment in which the main terminal 9 is connected to the semiconductor chip 7 via the bonding wire 13 by the lead frame 10, the heat generated in the semiconductor chip 7 is immediately below the Z direction via the lead frame 10. The heat spreader 6c and the heat sink 4 can radiate heat. That is, the heat dissipation efficiency of the semiconductor chip 7 is further improved by the lead frame 10.

  As in the first embodiment, the heat radiating insulator 11 transmits a large amount of heat generated in the lead frame 10 and heat transferred from the external wiring of the power module to the lead frame 10 to the heat sink 4 and the heat spreader 6c. From there, heat can be dissipated to the outside. Therefore, the cooling efficiency of the lead frame 10 can be increased. The high heat-dissipating insulator 11 can be realized so as to satisfy both of such high heat dissipation and high insulation.

  Since a large amount of heat is easily generated in the lead frame 10 by flowing a large current through the lead frame 10, the heat dissipation system of the present embodiment is particularly beneficial. The semiconductor chip 7 may be formed of a wide band gap semiconductor such as silicon carbide (SiC) instead of silicon. By doing so, the current density of the lead frame 10 increases and the temperature becomes higher, so that the effect of high heat dissipation by using this embodiment becomes more remarkable.

  The heat radiation efficiency from the semiconductor chip 7 to the lead frame 10 can be further increased by the thickness of the solder 23e connecting the semiconductor chip 7 and the lead frame 10.

  Moreover, the insulating sheet 6a and the heat spreader 6c are spread as a part (upper conductor) of the member 6 with the insulating sheet over the (almost) entire surface of the member 6 with the insulating sheet in a plan view. In other words, the insulating sheet 6 a and the heat spreader 6 c are arranged between the semiconductor chips 7 a and 7 b and the high heat dissipation insulator 11 and the heat sink 4 in the Z direction. As described above, the insulating sheet 6 a has higher thermal conductivity than the sealing material 22, and naturally, the heat spreader 6 c also has higher thermal conductivity than the sealing material 22 because it is copper. This also has the effect of further increasing the heat radiation efficiency from the lead frame 10 to the insulating sheet 6a, the heat spreader 6c, the heat sink 4 immediately below, and the like.

  The lead frame 10 generates less heat than the semiconductor chip 7. For this reason, in this embodiment using the lead frame 10, if a high heat dissipation insulator body (including the high heat dissipation insulator 11) having a higher thermal conductivity than the sealing material 22 such as epoxy resin is used, It is sufficient to dissipate relatively little heat generated by the lead frame 10. By using an inexpensive material as the material for such a high heat-dissipating insulator body, the manufacturing cost can be reduced.

  In addition, also in the present embodiment, as in the first embodiment, in order to flow a larger amount of current through the lead frame 10, it is necessary to increase the cross-sectional area of the lead frame 10 and reduce the amount of heat generation. There is. However, if the temperature of the lead frame 10 can be lowered using the high heat dissipating insulator 11 as described above, the cross-sectional area of the lead frame 10 can be reduced, so that the power module can be further downsized.

(Embodiment 5)
Referring to FIG. 20, power module 501 of the present embodiment has basically the same configuration as power module 402 of the second example of the fourth embodiment, and therefore the same elements are denoted by the same reference numerals. The description will not be repeated. That is, the lead frame 10 connected to the wiring outside the power module 501 is provided as a terminal. However, the power module 501 has the base plate 3 instead of the heat sink 4 as a radiator. However, the heat sink 4 may also be used here, and both the base plate 3 and the heat sink 4 may be provided as shown in FIG. Further, the power module 501 is an insulating substrate that covers only a part (the region on the right side in the X direction in FIG. 20) on the upper main surface of the base plate 3, similar to the first embodiment, instead of the member 6 with an insulating sheet. 5 are joined via the solder 23a. A semiconductor chip 7 is bonded onto the insulating substrate 5 via solder 23b.

  As with the power module 402, the high heat dissipation insulator 11 of the power module 501 includes a high heat dissipation insulator body 11a, a lower conductor 11f bonded on the lower main surface in the Z direction, and a high heat dissipation. The upper conductor 11g is bonded to the upper main surface in the Z direction of the conductive insulator body 11a. However, the high heat dissipating insulator 11 in FIG. 20 has a narrower width in the X direction than the high heat dissipating insulator 11 in FIG. 18, and the insulating substrate 5 is disposed (similar to the first embodiment or the like). On the main surface on the upper side of the base plate 3 in a region other than the region to be bonded, it is joined via solder 23g.

  Further, the semiconductor chip 7 and the lead frame 10 are joined by solder 23e, and the high heat dissipation insulator 11 and the lead frame 10 are joined by solder 23h, respectively. Further, all the solders shown in the figure are solidified together by a reflow process, so that the members are joined to each other.

Next, the effect of this Embodiment is demonstrated.
For example, when a sufficient area in a plan view for forming the high heat dissipation insulator body 11a cannot be secured, the plane area of the high heat dissipation insulator body 11a may be smaller than that in FIG. Depending on the structure of the power module and the like, it is preferable to appropriately select and determine whether to design as the power module 402 or the power module 501.

  Also in the present embodiment, as in the fourth embodiment, the power module 501 includes the lead frame 10 and does not include the housing 1. Therefore, a material having higher thermal conductivity than at least the sealing material 22 may be used as the high heat dissipation insulator body 11a. By using an inexpensive material as the material for such a high heat-dissipating insulator body, the manufacturing cost can be reduced.

  The aspects of each embodiment described above can be combined as appropriate within a technically consistent range. For example, the high heat dissipation insulator body 11e shown in Embodiment 2 is used in Embodiments 4 and 5, and the high heat dissipation insulator body 11e has a lower thermal conductivity than the sealing material 22 and a higher dielectric strength. It may be.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Case, 3 Base board, 4 Heat sink, 5 Insulation board | substrate, 5a Insulation board body, 5b, 11f Lower conductor, 5c, 11g Upper conductor, 6 Insulation sheet member, 6a Insulation sheet, 6b Copper foil, 6c Heat spreader, 7, 7a, 7b Semiconductor chip, 9, 18a, 18b, 91, 92 Main terminal, 9a, 9a1, 9a2, 9x Horizontal component, 9b, 9b1, 9b2, 9y Vertical component, 9c Flat component, 10 Lead frame, 11 High heat dissipation insulator, 11a, 11c, 11d, 11e High heat dissipation insulator body, 11b High heat dissipation insulator accessory conductor, 12 Insulator, 13, 13a, 13b, 13c Bonding wire, 17, 17a , 17b, 17c, 17d, 17e Control signal electrode, 21, 22 Sealing material, 23a, 23b, 23c, 23e, 23 , 23g, 23h solder, 23d high thermal conductivity grease, 101,102,103,104,105,106,201,301,401,402,403,501 power module.

Claims (7)

A radiator,
An insulating member including a conductor, disposed in at least a part of the region on one main surface of the radiator,
A semiconductor chip disposed on the opposite side of the heat dissipating member of the insulating member including the conductor;
An insulating member for heat dissipation disposed on one main surface of the heat dissipating member so as to include another region different from the region where the semiconductor chip is disposed,
A terminal disposed in the other region on the opposite side of the heat dissipating member of the heat dissipating insulating member and electrically connectable to the semiconductor chip;
A housing or a sealing material surrounding the semiconductor chip,
The heat dissipation insulating member includes an insulating material and has a higher thermal conductivity than the casing or the sealing material.   The semiconductor device according to claim 1, wherein the heat dissipating insulating member is formed of a material having a higher dielectric strength than the casing. The terminals are arranged so as to be aligned in a direction intersecting the main surface at intervals from each other,
3. The semiconductor device according to claim 1, wherein the terminal closest to the heat dissipating member among the plurality of terminals is disposed on the insulating member for heat dissipation.   The semiconductor device according to claim 1, wherein the terminal is connected to both the semiconductor chip and the insulating member for heat dissipation and has a plate shape in plan view. The insulating member is disposed between the semiconductor chip and the heat dissipating insulating member and the heat dissipating body,
The semiconductor device according to claim 4, wherein the insulating member includes an insulating sheet. A radiator,
An insulating member including a conductor, disposed in at least a part of the region on one main surface of the radiator,
A semiconductor chip disposed on the opposite side of the heat dissipating member of the insulating member including the conductor;
An insulating member for heat dissipation disposed on one main surface of the heat dissipating member so as to include another region different from the region where the semiconductor chip is disposed,
A terminal disposed in the other region on the opposite side of the heat dissipating member of the heat dissipating insulating member and electrically connectable to the semiconductor chip;
A housing or a sealing material surrounding the semiconductor chip,
The semiconductor device, wherein the heat dissipating insulating member includes an insulating material, has a lower thermal conductivity than the casing or the sealing material, and has a higher dielectric strength than the casing or the sealing material. The terminals are arranged so as to be aligned in a direction intersecting the main surface at intervals from each other,
The semiconductor device according to claim 6, wherein the terminal that is closest to the heat radiating body among the plurality of terminals is disposed on the insulating member for heat dissipation.

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