JP2008098559A - Semiconductor mounting structure, and its mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor mounting structure and its mounting method, capable of mounting a semiconductor component on a bus bar and a cooling metal substrate while suppressing complication of mounting work. <P>SOLUTION: A semiconductor component 1 is placed on bus bars 2, 3 and is connected thereto. The bus bars 2, 3 are mounted on a cooling metal substrate 4 via an electric insulating sheet 5. A resin made nail shaped body 8 penetrates through holes of the bus bars 2, 3 and the electric insulating sheet 5 and is collectively pressed into a bottomed hole 41 of the cooling metal substrate 4. Hereby, the bus bars 2, 3 are fixed while being electrically insulated to the cooling metal substrate 4 by a bar-shaped resin member 9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mounting structure of semiconductor components such as a semiconductor chip and a semiconductor module (abbreviated as a semiconductor mounting structure) and an improvement of the mounting method.

  When semiconductor components are used in a high-temperature environment such as a vehicle engine room, and when semiconductor components that require high power such as a motor are used, a mounting structure with excellent heat dissipation is required.

  As one of the conventional semiconductor mounting structures, a method is known in which a semiconductor module having a semiconductor chip inside is fastened to a cooling metal substrate or a metal member corresponding thereto via an electrical insulating sheet with a screw. A metal plate is disposed on the back surface (surface on the cooling metal substrate side) of the semiconductor module, and a semiconductor chip is mounted on the metal plate. The heat of the semiconductor chip is dissipated to the cooling metal substrate through the metal plate and the electrical insulating sheet. The semiconductor module has lead terminals connected to external wiring.

As another conventional semiconductor mounting structure, a semiconductor module having a semiconductor chip inside is solder-bonded to a wiring board (also referred to as an insulating metal board), and the wiring board is cooled by a screw or a metal corresponding thereto. A method of fastening to a member is known. Preferably, the wiring board has a metal plate whose back surface is in close contact with the cooling metal substrate, and a copper foil wiring pattern patterned on the surface of the metal plate via an electric insulating layer. The lead terminals of the semiconductor module are soldered to the copper foil wiring. This type of semiconductor mounting structure is described in Patent Document 1 below.
JP 2005-512345 A

  However, in the conventional semiconductor mounting structure described above, it is conceivable that a large number of bus bars are fastened on the cooling metal substrate in the same manner as the semiconductor module and the wiring substrate. Thereby, reduction of wiring loss and good cooling of the semiconductor module through the bus bar are expected.

  However, in this case, since it becomes necessary to fasten a large number of bus bars to the cooling metal substrate with screws while securing electrical insulation, the mounting work becomes very troublesome.

  In order to solve this problem, it can be considered that each bus bar is bonded to a cooling metal substrate. In this case, however, the adhesive layer leads to the problem of increasing the thermal conductivity between the bus bar and the cooling metal substrate.

  The present invention has been made in view of the above problems, and an object thereof is to provide a semiconductor mounting structure and a mounting method thereof capable of mounting a semiconductor component on a bus bar and a cooling metal substrate while suppressing complicated mounting work. It is said.

  A first invention that solves the above-described problems includes a semiconductor component having a semiconductor element, a plurality of bus bars to which the semiconductor component is connected and arranged in a plane in a predetermined pattern, and the bus bar group capable of being electrically insulated and having good heat conduction. A cooling metal substrate in close contact with the anti-element mounting surface, a planar first electrical insulating member interposed between each of the bus bars and the cooling metal substrate, and penetrating through the first electrical insulating member The bus bar is mechanically coupled to the cooling metal substrate by a deformation action, and a fixing member electrically insulated from the bus bar by a second electrical insulation member is provided.

  That is, according to the present invention, each bus bar to which the semiconductor component is connected is coupled and fixed to the cooling metal substrate by utilizing the deformation of the fixing member or the cooling metal substrate that is the counterpart member. For this reason, semiconductor components can be connected to a bus bar having low electrical resistance and low wiring loss, and fixing of each bus bar is much easier than conventional screw fastening. Further, the heat generated by the semiconductor component can also be radiated to the cooling metal substrate satisfactorily.

  In a preferred aspect, the fixing member comprises a blind rivet that is caulked through the bus bar, the first electrical insulating member, and the cooling metal substrate in the thickness direction. In this way, the bus bar can be fixed to the cooling metal substrate easily and reliably by rivet caulking.

  In a preferred aspect, the fixing member is made of a nail-like body that is press-fitted or driven into the cooling metal substrate through the bus bars and the first electrical insulating member. In this way, the bus bar can be fixed to the cooling metal substrate easily and reliably by the combination of the nail-like body or the cooling metal substrate due to the deformation. A hole into which the nail-like body is pushed into the cooling metal substrate may be provided in advance. In this way, the nail-like body can be driven easily. Of course, in this case, the inner diameter of the hole is preferably slightly smaller than the outer diameter of the nail-like body.

  In a preferred aspect, the fixing member is formed integrally with the cooling metal substrate and protrudes from the cooling metal substrate through the bus bar, and a caulking ring caulked by the protrusion. Have. In this way, the bus bar can be fixed to the cooling metal substrate easily and reliably by caulking a crown-shaped caulking ring, for example.

  In a preferred aspect, the fixing member has a protrusion that is formed integrally with the cooling metal substrate and protrudes beyond the bus bar from the cooling metal substrate, and a tip portion of the protrusion is plastically deformed. And pressed against the bus bar. For the plastic deformation of the protrusion, for example, the head of the protrusion may be crushed, or a long protrusion may be bent sideways and pressed against the bus bar.

  In a preferred aspect, the fixing member is a rod-shaped resin member that penetrates the bus bar and the first electrical insulating member and is fixed to the cooling metal substrate by self-deformation. The self-deformation of the rod-shaped resin member may be plastic deformation by mechanical force, or may utilize thermal deformation. In this case, since the fixing member also serves as the second electric insulating member that electrically insulates the fixing member and the bus bar, the number of parts can be reduced.

  In a preferred aspect, the fixing member is made of an electrically insulating resin. In this case, since the fixing member also serves as the second electrical insulating member, it is possible to reduce the number of components and simplify the mounting operation.

  In a preferred embodiment, the fixing member has an electrically insulating resin film attached to the surface. This deposition can be realized by, for example, coating and drying. In this case, since the fixing member also serves as the second electrical insulating member, it is possible to reduce the number of components and simplify the mounting operation.

  In a preferred embodiment, the bus bars and the cooling metal substrate are fixed all at once by the fixing member. In this way, the mounting process can be greatly shortened and simplified as compared to fastening each bus bar with screws one by one.

  According to a second invention for solving the above-described problems, a semiconductor component having a semiconductor element, a plurality of bus bars to which the semiconductor component is connected and arranged in a plane in a predetermined pattern; A cooling metal substrate in close contact with the anti-element mounting surface, a planar first electrical insulating member interposed between each of the bus bars and the cooling metal substrate, and penetrating through the first electrical insulating member A fixing member that mechanically couples each bus bar to the cooling metal substrate and is electrically insulated from the bus bar by a second electric insulating member, and the fixing member penetrates the bus bar. A plurality of legs that are pressed against the cooling metal substrate, and a connecting plate portion that presses the semiconductor component mounted on the bus bar against the bus bar and connects the plurality of legs. A portal member having, and its characterized by having a pressing biasing member that presses and biases the portal member to the cooling metal substrate.

  That is, according to the present invention, the fixing member is a gate-shaped member formed by integrating the leg portion that presses each bus bar against the cooling metal substrate and the plate portion that presses the semiconductor component against the cooling metal substrate via the bus bar. Is pressed against the metal substrate for cooling by the pressing biasing member. As the pressing urging member, an elastic body (such as a clip) fixed to the cooling metal substrate, a cover plate of the casing to which the cooling metal substrate is fixed, or an elastic material fixed thereto can be used. In addition, these elasticity is for absorbing the dimensional tolerance of each part.

  A preferred embodiment of the present invention will be described below.

(Embodiment 1)
The semiconductor mounting structure of Embodiment 1 will be described with reference to FIG. FIG. 1 is a cross-sectional view showing this semiconductor mounting structure.

  The semiconductor mounting structure includes a semiconductor component 1 containing a semiconductor element, a plurality of bus bars 2 and 3 to which the semiconductor component 1 is connected and arranged in a plane in a predetermined pattern, and a bus bar 2 that can be electrically insulated and has good heat conduction. 3, a cooling metal substrate 4 that is in close contact with the anti-element mounting surface, and an electric insulating sheet (planar first electric insulating member) 5 interposed between the bus bars 2 and 3 and the cooling metal substrate 4, The bus bars 2 and 3 are mechanically coupled to the cooling metal substrate 4 through the electric insulating sheet 5 by deformation and are electrically insulated from the bus bars 2 and 3 by the resin ring plate (second electric insulating member) 6. Two blind rivets (fixing members) 7.

  In this embodiment, a thin heat conductive sheet is used as the electrical insulating sheet 5, but a resin film is formed on the upper surface of the cooling metal substrate 4, or a resin film is formed on the surfaces of the bus bars 2 and 3. You may employ | adopt well-known alternative methods, such as doing.

  In this embodiment, the semiconductor component 1 is composed of a semiconductor module having a necessary number of lead terminals including the lead terminals 11 and 12 shown in the figure and bonded to the bus bar 2 by soldering or bonding with an adhesive. Is not to be done. For example, a semiconductor chip resin-molded on the bus bar 2 may be used. Alternatively, a card-like semiconductor module in which metal plates forming electrodes on both sides are exposed may be used. The lead terminal 11 is soldered to the bus bar 2 and the lead terminal 12 is soldered to the bus bar 3.

  Two sets of through holes are formed in the bus bars 2 and 3, the electrical insulating sheet 5, and the cooling metal substrate 4, and blind rivets 7 are respectively fitted and caulked into the two sets of through holes. More specifically, 70 is the head of the blind rivet 7, and 71 is the tip of the blind rivet 7. The head portion 70 of the blind rivet 7 is in contact with the surface (semiconductor module side) of the bus bars 2 and 3 via the resin wheel plate 6. In this state, the bus bars 2 and 3 are firmly fixed to the cooling metal substrate 4 by applying an axial force to the blind rivet 7 and caulking the tip 71.

  Although not shown between the outer peripheral surface of the blind rivet 7 and the through holes of the bus bars 2 and 3 facing the blind rivet 7, an electrically insulating resin material (second electrical insulating member) for insulating the rivet peripheral wall is interposed. It is installed. The electrically insulating resin material for insulating the rivet peripheral wall may be a resin sleeve, and may be a liquid resin that has been injected into the through hole in advance and solidified after rivet caulking. In addition, it is good also as the resin film previously apply | coated to the surface of the through-hole of the bus-bars 2 and 3, and the resin film previously apply | coated to the outer peripheral surface of the blind rivet 7. FIG. In addition, the blind rivet 7 may be made of resin, and in this case, the second electrical insulating member described above can be omitted.

(Embodiment 2)
A semiconductor mounting structure according to the second embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view showing this semiconductor mounting structure.

  This semiconductor mounting structure is different in that instead of the resin wheel plate 6 and the blind rivet 7 in FIG. The cooling metal substrate 4 has a bottomed hole 41 in place of the through hole, but may be a through hole. However, the inner diameter of the bottomed hole 41 of the cooling metal substrate 4 is slightly smaller than the outer diameter of the resin-made nail-like body 8. The resin-made nail-like body 8 is press-fitted into the bottomed hole 41 of the cooling metal substrate 4 through the through holes of the bus bars 2 and 3 and the through holes of the electrical insulating sheet 5. The bus bars 2 and 3 are satisfactorily fixed to the cooling metal substrate 4 by plastic deformation of the tip end portion of the resin-made nail-like body 8 by this press-fitting. This resin-made nail-like body 8 also serves as the second electrical insulating member referred to in the present invention. The resin nail 8 may have a metal core, or the metal nail 8 may be electrically insulated from the bus bars 2 and 3 in the same manner as in the first embodiment. .

(Embodiment 3)
A semiconductor mounting structure of the third embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional view showing this semiconductor mounting structure.

  This semiconductor mounting structure is different from that in FIG. 2 in that the resin-made nail-like body 8 is changed to a rod-like resin member 9 obtained by melting and solidifying. This rod-shaped resin member 9 cools the bus bars 2 and 3 by injecting a molten resin liquid into the bottomed holes 41 of the cooling metal substrate 4 through the through holes of the bus bars 2 and 3 and the through holes of the electrical insulating sheet 5 and solidifying them. Fixed to a metal substrate. Even if it does in this way, there can exist an effect similar to Embodiment 2. FIG. The rod-shaped resin member 9 is obtained by softening the rod-shaped resin member 9 that has been previously pressed into the bottomed hole 41 of the cooling metal substrate 4 through the through-holes of the bus bars 2 and 3 and the through-holes of the electrical insulating sheet 5 with heat. Also good.

(Embodiment 4)
A semiconductor mounting structure according to the fourth embodiment will be described with reference to FIG. FIG. 4 is a cross-sectional view showing this semiconductor mounting structure.

  In this semiconductor mounting structure, the blind rivet 7 in FIG. 1 is omitted, and instead, a rod-like protrusion 42 protruding from the upper surface of the cooling metal substrate 4 and a resin ring plate (second electrical insulating member) on the rod-like protrusion 42. 6, a metal ring 10 made of easy deformation is fitted, and the metal ring 10 is plastically deformed to fix the bus bars 2 and 3 to the cooling metal substrate 4. The metal ring 10 can have various forms, but may be formed in a crown shape and covered with the rod-shaped protrusion 42, for example. Also in this embodiment, the inner peripheral surface of the through hole of the bus bars 2 and 3 and the outer peripheral surface of the rod-shaped protrusion 42 are electrically insulated by the method described above. Also in this embodiment, the bus bars 2 and 3 can be satisfactorily fixed to the cooling metal substrate 4.

(Embodiment 5)
A semiconductor mounting structure according to the fifth embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view showing this semiconductor mounting structure.

  This semiconductor mounting structure omits the easily deformable metal ring 10 in FIG. 4, bends the bar-shaped protrusion 42 substantially at a right angle, and presses the bus bars 2 and 3 with their tip portions, whereby the bus bars 2 and 3 are cooled. It is fixed to the substrate 4. In FIG. 5, the rod-shaped protrusion 42 is formed at the end of the cooling metal substrate 4, but may be provided at the center of the cooling metal substrate 4. Further, in FIG. 5, the rod-like protrusions 42 are arranged at the ends of the bus bars 2 and 3, but of course, they may be fitted into the through holes of the bus bars 2 and 3. Also in this embodiment, a resin member 61 similar to the resin ring plate 6 shown in FIG. 4 is interposed between the rod-shaped protrusion 42 and the bus bars 2 and 3. The resin member 61 is preferably formed in a flange shape and its cylindrical portion is fitted to the rod-shaped protrusion 42. In this way, it is possible to easily fix the bus bars 2 and 3 to the cooling metal substrate 4 simply by bending the tip of the rod-like protrusion 42.

(Embodiment 6)
A semiconductor mounting structure of the sixth embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view showing this semiconductor mounting structure.

  In this semiconductor mounting structure, the through hole of the cooling metal substrate 4 is omitted in FIG. 1, and a resin-made gate-shaped member 101 instead of the blind rivet 7 and a pressing bias that presses and biases the portal-shaped member 101 are used. The feature is that the member 102 is employed.

  The gate-shaped member 101 includes a pair of leg portions 101a and 101b and a connecting plate portion 101c that is formed integrally with the leg portions 101a and 101b and extends in parallel with the upper surface of the cooling metal substrate 4. It is formed into a shape. Since the gate-shaped member 101 is pressed and biased toward the cooling metal substrate 4 by the pressing and biasing member 102, the distal ends of the leg portions 101 a and 101 b of the gate-shaped member 101 are inserted into the through holes of the bus bars 2 and 3. The cooling metal substrate 4 is pressed through the electrical insulating sheet 5. It is not essential to insert the tip portions of the leg portions 101a and 101b into the through holes of the bus bars 2 and 3, and the through holes of the bus bars 2 and 3 may be used as bottomed holes.

  The pressing biasing member 102 may be, for example, a U-shaped clip whose one end presses and biases the gate-shaped member 101 and whose other end presses and biases the back surface of the cooling metal substrate 4. Instead, the pressing and urging member may be constituted by a cover plate of a housing in which the semiconductor mounting structure is accommodated or an elastic plate provided on the back surface of the cover plate.

(Mounting method)
In each of the above-described embodiments, the bus bars 2 and 3 are fixed together using a dedicated lowering pressing jig. In this way, the mounting work time can be significantly shortened compared to fastening the bus bars 2 and 3 one by one. Further, since no screw thread is required in the insertion hole of the cooling metal substrate 4, the processing cost can be reduced.

1 is a longitudinal sectional view showing a semiconductor mounting structure of Embodiment 1. FIG. FIG. 6 is a longitudinal sectional view showing a semiconductor mounting structure of a second embodiment. It is a longitudinal cross-sectional view which shows the semiconductor mounting structure of Embodiment 3. It is a longitudinal cross-sectional view which shows the semiconductor mounting structure of Embodiment 4. FIG. 10 is a longitudinal sectional view showing a semiconductor mounting structure of a fifth embodiment. It is a longitudinal cross-sectional view which shows the semiconductor mounting structure of Embodiment 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor component 2 Bus bar 3 Bus bar 4 Cooling metal board 5 Electrical insulation sheet 6 Resin ring plate 7 Blind rivet 8 Nail-like body 9 Rod-shaped resin member 10 Metal ring 11 Lead terminal 12 Lead terminal 41 Bottom hole 42 Rod-shaped protrusion 61 Resin member 70 head 71 distal end 101 portal member 101a leg 101b leg 101c connecting plate part 102 pressing member

Claims (10)

A semiconductor component having a semiconductor element;
A plurality of bus bars connected to the semiconductor component and arranged in a plane in a predetermined pattern;
A cooling metal substrate that is insulative and has good thermal conductivity and is in close contact with the anti-element mounting surface of the bus bar group;
A planar first electrical insulating member interposed between each bus bar and the cooling metal substrate;
A fixing member that penetrates through the first electrical insulating member and mechanically couples each bus bar to the cooling metal substrate by a deformation action and is electrically insulated from the bus bar by a second electrical insulating member;
A semiconductor mounting structure comprising: The semiconductor packaging structure according to claim 1,
The fixing member is
A semiconductor mounting structure comprising a blind rivet that is caulked through the bus bar, the first electrical insulating member, and the cooling metal substrate in a thickness direction. The semiconductor packaging structure according to claim 1,
The fixing member is
A semiconductor mounting structure comprising a nail-like body that is press-fitted or driven into the cooling metal substrate through the bus bars and the first electrical insulating member. The semiconductor packaging structure according to claim 1,
The fixing member is
A protrusion that is formed integrally with the cooling metal substrate and protrudes from the cooling metal substrate through the bus bar;
A semiconductor mounting structure having a caulking ring caulked on the protrusion. The semiconductor packaging structure according to claim 1,
The fixing member is
A protrusion that is formed integrally with the cooling metal substrate and protrudes beyond the bus bar from the cooling metal substrate;
A semiconductor mounting structure in which a tip portion of the protruding portion is plastically deformed and pressed against the bus bar. The semiconductor packaging structure according to claim 1,
The fixing member is
A semiconductor mounting structure comprising a rod-shaped resin member that penetrates the bus bar and the first electrical insulating member and is fixed to the cooling metal substrate. The semiconductor packaging structure according to claim 1,
The fixing member is
A semiconductor mounting structure made of electrically insulating resin. The semiconductor packaging structure according to claim 1,
The fixing member is
A semiconductor mounting structure with an electrically insulating resin film deposited on the surface. In the mounting method of the semiconductor mounting structure in any one of Claims 1 thru | or 8,
A mounting method for a semiconductor mounting structure, wherein the fixing of the bus bars and the cooling metal substrate by the fixing member is performed at once. A semiconductor component having a semiconductor element;
A plurality of bus bars connected to the semiconductor component and arranged in a plane in a predetermined pattern;
A cooling metal substrate that is insulative and has good thermal conductivity and is in close contact with the anti-element mounting surface of the bus bar group;
A planar first electrical insulating member interposed between each bus bar and the cooling metal substrate;
A fixing member penetrating the first electrical insulation member to mechanically couple each bus bar to the cooling metal substrate and electrically insulated from the bus bar by a second electrical insulation member;
With
The fixing member is
A gate having a plurality of legs that pass through the bus bar and pressed against the metal substrate for cooling, and a connecting plate that presses the semiconductor component mounted on the bus bar against the bus bar and connects the plurality of legs. A shape member;
A pressing urging member that urges the gate-shaped member against the cooling metal substrate;
A semiconductor mounting structure.

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