JP2018195724A - Power module and manufacturing method for the same, and power converter - Google Patents

Abstract

To provide a power module which can achieve further improved reliability; and provide a manufacturing method for the power module; and provide a power converter.SOLUTION: A power module 1 comprises an insulating circuit board 7 and a power semiconductor element 13. The power semiconductor element 13 includes an element body 13a, a surface electrode 13b and a back electrode 13c. The insulating circuit board 7 includes an insulating substrate 7a, circuit patterns 7b, 7c and a conductive member 7d. The power semiconductor element 13 and the insulating circuit board 7 are jointed by a second joint part 5b which forms a planar joint surface 5. In the second junction part 5d, a joint material 9 prevails in a planar state and partitioning members 11 are arranged so as to partition the joint material 9 in a plan view. The partitioning members 11 are formed by a material different from that of the joint material 9.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power module, a manufacturing method thereof, and a power conversion device, and more particularly, a power module in which a power semiconductor element is bonded to an insulating circuit board, a manufacturing method of such a power module, and such a power module. It is related with the power converter device.

  In a power module, a power semiconductor element is mounted on a circuit pattern of an insulated circuit board disposed in a housing. The power semiconductor element is electrically connected to an external terminal via a wiring member or the like. The inside of the housing is insulated and sealed with a sealing material.

  In general, the power semiconductor element has a thin plate shape. In such a power semiconductor element, current flows in a direction substantially perpendicular to a plane (virtual) on which the thin plate-shaped power semiconductor element is located. For this reason, the power semiconductor element is surface-bonded to the circuit pattern on the insulating circuit board.

  In many cases, an insulating circuit board on which a power semiconductor element is mounted is surface-bonded to a base plate serving as a structure support. Thus, in the power module, there is a place where one member and another member are surface-bonded, and the one member and the other member are surface-bonded by the surface bonding portion. Currently, lead-free solder, brazing material, sinterable metal particle paste, conductive adhesive, or the like is used as a bonding material for the surface bonding portion.

  In the power module, as the power semiconductor element is turned on and off, the temperature rises and falls repeatedly (temperature swing). When the temperature of the above-described surface bonding portion changes, thermal stress is generated due to a difference in coefficient of linear expansion of the member or the like, and the surface bonding portion may be damaged. When the surface junction is damaged, it is difficult to release heat generated in the power semiconductor element, which may lead to failure of the power module.

  Conventionally, a structure for preventing damage to such a surface joint has been proposed. For example, Patent Document 1 proposes a structure in which a plurality of slits are provided on a surface (bonding surface) of a circuit board in a structure in which a circuit board and a cooler are bonded.

JP 2008-135511 A

  Conventionally, in a power module having a surface joint, it is required to further improve the reliability of the power module by suppressing damage to the surface joint due to temperature rise and fall and improving heat dissipation. It has been.

  The present invention has been made as part of such development, and one object is to provide a power module that can be further improved in reliability, and the other object is to provide such a power module. It is to provide a manufacturing method, and yet another object is to provide a power conversion device to which such a power module is applied.

  The power module according to the present invention includes a base plate, an insulating circuit board, a power semiconductor element, a wiring member, an external terminal, and a sealing member. The insulating circuit board is bonded to the base plate via the first bonding portion and has a circuit pattern. The power semiconductor element is bonded to the insulating circuit board via the second bonding portion. The wiring member is bonded to the power semiconductor element via the third bonding portion, and is bonded to the circuit pattern via the fourth bonding portion. The external terminal is joined to the insulating circuit board via the fifth joint. The sealing member seals the insulating circuit board, the power semiconductor element, and the wiring member. At least one of the first joint, the second joint, the third joint, the fourth joint, and the fifth joint is a surface joint. The surface bonding portion includes a bonding material that expands in a planar shape, and a partition member that is disposed in the bonding material in a mode of partitioning the bonding material in a plan view.

  The method for manufacturing a power module according to the present invention is a method for manufacturing a power module having a base plate, an insulating circuit board, a power semiconductor element, a wiring member, and an external terminal, and includes the following steps. One member among the base plate, the insulated circuit board, the power semiconductor element, the wiring member, and the external terminal is used as the first member to be joined, and the other member is used as the second member to be joined. A step of joining the joining member. The step of bonding the first bonded member and the second bonded member includes the following steps. A joining material and a separating member for separating the joining material in a plan view are arranged on the first joined member. The second member to be joined is arranged in such a manner that the joining material and the partition member are sandwiched between the second member to be joined and the first member to be joined, and the second member to be joined is joined by the joining material and the separator member. Join the member.

  A power conversion device according to the present invention is a power conversion device to which the power module is applied, and includes a main conversion circuit and a control circuit. The main conversion circuit returns the input power and outputs it. The control circuit outputs a control signal for controlling the main conversion circuit to the main conversion circuit.

  According to the power module of the present invention, at least one of the first joint, the second joint, the third joint, the fourth joint, and the fifth joint is a surface joint. The surface bonding portion includes a bonding material that expands in a planar shape, and a partition member that is disposed in the bonding material in a mode of partitioning the bonding material in a plan view. Thereby, thermal stress is reduced and the reliability can be further improved.

  According to the method for manufacturing a power module according to the present invention, in the step of joining the first member to be joined and the second member to be joined, the joining material and the joining material are divided in plan view on the first member to be joined. A separator member is arranged. The second member to be joined is arranged in such a manner that the joining material and the partition member are sandwiched between the second member to be joined and the first member to be joined, and the second member to be joined is joined by the joining material and the separator member. Join the member. As a result, it is possible to manufacture a power module in which thermal stress is reduced and reliability can be further improved.

  According to the power converter of the present invention, by applying the power module, thermal stress is reduced, and further improvement in reliability can be achieved.

3 is a plan view of the power module according to Embodiment 1. FIG. FIG. 2 is a cross-sectional view of the power module taken along a cross-sectional line II-II shown in FIG. 1 in the same embodiment. In the same embodiment, it is the 1st top view showing the arrangement structure of the joining material in a surface joined part, and a division member. In the same embodiment, it is the 2nd top view showing the arrangement structure of the joining material in a surface joined part, and a division member. In the same embodiment, it is the 3rd top view which shows the arrangement structure of the joining material and the delimiter in the surface joining section. In the same embodiment, it is the 4th top view which shows the arrangement structure of the joining material and the delimiter in the surface joint section. In the same embodiment, it is the 5th top view which shows the arrangement structure of the joining material and the delimiter in the surface joint section. In the same embodiment, it is the 6th top view which shows the arrangement structure of the joining material and the delimiter in the surface joining section. In the same embodiment, it is the 7th top view which shows the arrangement structure of the joining material and the delimiter in the surface joint section. In the embodiment, it is a first partial cross-sectional view showing a cross-sectional shape of a separation member in a surface bonding portion. In the same embodiment, it is the 2nd partial sectional view showing the section shape of the division member in a surface joined part. FIG. 10 is a third partial cross-sectional view showing a cross-sectional shape of a separation member in a surface bonding portion in the embodiment. In the embodiment, it is a fourth partial cross-sectional view showing the cross-sectional shape of the separation member in the surface bonding portion. FIG. 10 is a fifth partial cross-sectional view showing a cross-sectional shape of a separation member in a surface bonding portion in the embodiment. FIG. 10 is a sixth partial cross-sectional view illustrating a cross-sectional shape of a separation member in a surface bonding portion in the embodiment. In the embodiment, it is a fragmentary sectional view which shows the cross-section of the division member in a surface junction part. In the embodiment, it is sectional drawing which shows 1 process of the manufacturing method of a power module. In the embodiment, it is a first partial cross-sectional view showing an arrangement mode of a bonding material and a partition member when surface bonding is performed using a bonding material and a partition member. In the same embodiment, it is the 2nd partial sectional view showing the mode of arrangement of joining material and a separating member at the time of surface joining by a joining material and a separating member. FIG. 10 is a third partial cross-sectional view showing an arrangement mode of the bonding material and the partition member when the surface is bonded by the bonding material and the partition member in the embodiment. FIG. 10 is a fourth partial cross-sectional view showing an arrangement mode of the bonding material and the partition member when the surface is bonded by the bonding material and the partition member in the embodiment. FIG. 10 is a fifth partial cross-sectional view illustrating an arrangement mode of the bonding material and the partition member when surface bonding is performed using the bonding material and the partition member in the embodiment. FIG. 18 is a cross-sectional view showing a step performed after the step shown in FIG. 17 in the same embodiment. FIG. 24 is a cross-sectional view showing a step performed after the step shown in FIG. 23 in the same embodiment. FIG. 25 is a cross-sectional view showing a step performed after the step shown in FIG. 24 in the same embodiment. FIG. 26 is a cross-sectional view showing a step performed after the step shown in FIG. 25 in the same embodiment. FIG. 27 is a cross-sectional view showing a step performed after the step shown in FIG. 26 in the same embodiment. 6 is a plan view of a power module according to Embodiment 2. FIG. FIG. 29 is a cross-sectional view of the power module taken along a cross-sectional line XXIX-XXIX shown in FIG. 28 in the embodiment. In the embodiment, it is sectional drawing which shows 1 process of the manufacturing method of a power module. FIG. 31 is a cross-sectional view showing a step performed after the step shown in FIG. 30 in the same embodiment. FIG. 32 is a cross-sectional view showing a step performed after the step shown in FIG. 31 in the same embodiment. FIG. 33 is a cross-sectional view showing a step performed after the step shown in FIG. 32 in the same embodiment. FIG. 34 is a cross-sectional view showing a step performed after the step shown in FIG. 33 in the same embodiment. FIG. 35 is a cross-sectional view showing a step performed after the step shown in FIG. 34 in the same embodiment. It is a block diagram which shows the structure of the power conversion system to which the power converter device which applied the power module based on Embodiment 3 is applied.

Embodiment 1 FIG.
The power module according to Embodiment 1 will be described.

  As shown in FIGS. 1 and 2, in the power module 1, an insulating circuit board 7 is mounted on the base plate 3. The insulating circuit board 7 includes an insulating board 7a, circuit patterns 7b and 7c, and a conductive member 7d. The circuit patterns 7b and 7c are arranged on the surface of the insulating substrate 7a. The conductive member 7d is disposed on the back surface of the insulating substrate 7a. The conductive member 7d of the insulated circuit board 7 is bonded to the base plate 3 by the first bonding portion 5a. Here, the 1st junction part 5a is a solder, for example.

  A power semiconductor element 13 is mounted on the insulating circuit board 7. The power semiconductor element 13 includes an element body 13a, a front electrode 13b, and a back electrode 13c. The back electrode 13 c of the power semiconductor element 13 is bonded to the circuit pattern 7 b by the surface bonding portion 5. As will be described later, the second bonding portion 5 b forming the surface bonding portion 5 includes a bonding material 9 and a separating member 11.

  The surface electrode 13 b of the power semiconductor element 13 and the circuit pattern 7 c are electrically connected by the wiring member 15. One external terminal 19 and the circuit pattern 7 b are electrically connected by the wiring member 17. Further, the other external terminal 19 and the circuit pattern 7 c are electrically connected by the wiring member 17. A case 21 is attached to the base plate 3. The case 21 is filled with a sealing member 23 so as to insulate and seal the power semiconductor element 13 and the like disposed on the base plate 3.

  In the power module described above, in particular, the power semiconductor element 13 (back electrode 13 c) and the insulating circuit substrate 7 (circuit pattern 7 b) are bonded via the surface bonding portion 5, and the second bonding forming the surface bonding portion 5. The part 5 b includes a bonding material 9 and a separating member 11. Next, the bonding material 9 and the separating member 11 will be described. The bonding material 9 extends in a planar shape. The separating member 11 is arranged so as to separate the bonding material 9 in plan view with respect to the bonding material 9 spreading in a plane. Separating the bonding material 9 in plan view refers to a structure in which the dividing member 11 is arranged to divide the bonding material 9 when the bonding material 9 is viewed from above. The bonding material 9 is not intended to have a structure in which the separating member 11 is completely partitioned on one side and the other side. The partition member 11 is made of a material (different member) different from the bonding material 9.

  Here, the material (material) of the bonding material 9 and the separating member 11 will be described. As the bonding material 9, for example, lead-free solder generally used in recent years can be applied. As the bonding material 9, a conductive adhesive or a metal sintered body can be applied. A metal sintered body is obtained by sintering metal particles by subjecting a paste containing metal particles to a heat treatment (joining step).

  When lead-free solder is applied as the bonding material 9, it is desirable to apply a metal as the first metal that easily wets the lead-free solder as the separating member 11. Examples of metals that easily get wet with lead-free solder include copper, nickel, and gold. By applying a metal that easily wets to lead-free solder as the separating member 11, the joining material 9 and the separating member 11 are joined, and the separating member 11 contributes to heat conduction. As a result, heat generated in the power semiconductor element 13 can be easily released. In addition, as the partition member 11, if the metal is located at least on the surface, it can be joined to the joining material 9 and heat can be released.

  Further, as the separating member 11, the separating member 11 having a mode in which the surface of an arbitrary metal (base material) is covered with a metal different from the bonding material 9 may be applied. For example, there is a partition member 11 in which a relatively soft metal such as pure aluminum is used as a base material, and the surface of the metal is covered with a metal that is easily wetted by lead-free solder.

  In this case, first, since the metal of the base material is relatively soft, thermal stress can be reduced. Moreover, the joining material 9 and the partition member 11 are joined, and the partition member 11 contributes to heat conduction. The thermal conductivity of aluminum is about 200 W / mK, and this thermal conductivity value is higher than the thermal conductivity value of general lead-free solder.

  For this reason, compared with the case where a surface junction part is only lead-free solder, it becomes easy to radiate | generate the generated heat | fever and can improve heat dissipation. Thus, when a material having a thermal conductivity higher than the thermal conductivity of the bonding material 9 is selected as the separating member 11, both the reliability of the bonding and the heat dissipation can be improved. Become bigger.

  Further, when importance is placed on reducing thermal stress, a resin material is selected as the base material of the partition member 11, and the partition member 11 in which a metal as the first metal is formed on the surface of the resin material is applied. May be. As such a metal, it is desirable to apply nickel, copper or gold.

  When a conductive adhesive is applied as the bonding material 9, the resin component contained in the conductive adhesive has an adhesive force. For this reason, compared with the case where solder is used as the bonding material 9, there are more options for the separating member 11 for bringing the bonding material 9 and the separating member 11 into close contact with each other. By selecting various metals as the third metal as the separating member 11, it is possible to improve both the reliability of the bonding and the heat dissipation described above.

  Further, when a metal sintered body is applied as the bonding material 9, and as a more specific example, a silver sintered body or a copper sintered body is applied, the separating member 11 may be a silver sintered paste or copper. It is desirable to select a metal as the fourth metal that has good bondability with the sintered paste. For example, by selecting a metal such as copper, silver, or gold as such a metal, the bonding material 9 and the partition member 11 can be bonded, and both the reliability of the bonding and the heat dissipation can be improved. Can do.

  In addition, the example of the material of the joining material 9 and the partition member 11 mentioned above shows a particularly effective example, and is not limited to these materials. In addition, the bonding or bonding between the bonding material 9 and the partition member 11 is not essential, and even if the bonding material 9 and the partition member 11 are in close contact with each other even if the bonding material 9 or the bonding member 11 does not have a certain bonding force or adhesion, Heat conduction is expected. Furthermore, when a space (gap) exists between the bonding material 9 and the partition member 11, it is disadvantageous from the viewpoint of heat conduction, but from the viewpoint of bonding properties, stress is released to the space. Can contribute to stress reduction.

  Next, the shape of the separation member 11 will be described in detail. When the partition member 11 is viewed in plan with respect to the bonding material 9, the partition member 11 is arranged with an arbitrary shape that partitions the bonding material 9. For example, FIG. 3 shows an arrangement structure in which the separating members 11 are arranged in a lattice pattern with respect to the bonding material 9. FIG. 4 shows an arrangement structure in which the partition members 11 are arranged in a mesh pattern with respect to the bonding material 9.

  FIG. 5 shows an arrangement structure in which the separating member 11 is arranged substantially concentrically with respect to the bonding material 9. FIG. 6 shows an arrangement structure in which closed loop-shaped separating members 11 are arranged in a nested manner with respect to the bonding material 9. FIG. 7 shows an arrangement structure in which the separating member 11 is arranged in a spiral with respect to the bonding material 9. The concentric arrangement structure shown in FIG. 5, the nested arrangement structure shown in FIG. 6, and the spiral arrangement structure shown in FIG. Can be difficult.

  Further, in the region of the bonding material 9, the partition member 11 may be intensively arranged particularly at a place where damage is to be prevented. For example, FIG. 8 shows an arrangement structure in which the partition members 11 are arranged in a concentrated manner in the peripheral region of the bonding material 9. Further, FIG. 9 shows an arrangement structure in which the partition members 11 are intensively arranged in the central region of the bonding material 9. The above-described examples of the shape (arrangement structure) of the separating members are particularly effective examples, and are not limited to these arrangement structures.

  Next, the cross-sectional shape of the separation member 11 will be described. The cross-sectional shape of the separation member 11 can be any cross-sectional shape. For example, FIG. 10 shows a separating member 11 having a rectangular cross-sectional shape. In FIG. 11, a separating member 11 having a circular cross-sectional shape is shown. In FIG. 12, the partition member 11 whose cross-sectional shape is elliptical is shown. FIG. 13 shows a separating member 11 having a polygonal cross-sectional shape.

  Moreover, the partition member 11 may be in contact with the power semiconductor element 13 or may not be in contact. FIG. 14 shows a cross-sectional structure in which the separation member 11 is in contact with the power semiconductor element 13 and is also in contact with the circuit pattern 7b. On the other hand, FIG. 15 shows a cross-sectional structure in which the partition member 11 is not in contact with the power semiconductor element 13 and the circuit pattern 7b. It is desirable to design the cross-sectional shape of the partition member 11 by comprehensively judging the effect of reducing stress, heat dissipation, ease of manufacture of the partition member 11, and the like.

  Further, in the power module 1 described above, the case where the one-layer separation member 11 is disposed in the bonding material 9 has been described as an example, but the number of layers is not limited to one, In order to further increase the reliability, a plurality of layers of bonding materials may be disposed. For example, FIG. 16 shows a cross-sectional structure in which the two-layer separating member 11 is arranged on the bonding material 9.

  Moreover, it is desirable to apply a material having a desired linear expansion coefficient as the material (base material) of the separation member 11. For example, the linear expansion coefficient of solder (22 ppm / K), the linear expansion coefficient of silver (19 ppm / K), the linear expansion coefficient of copper (17 ppm / K), or a linear expansion coefficient smaller than the linear expansion coefficient of resin material. It is desirable to apply the material it has. As such a material, for example, a metal as the second metal or the fifth metal such as molybdenum (Mo) or molybdenum copper (MoCu) alloy can be used.

  Further, as the bonding material 9, solder, a sintered body such as silver or copper, and a conductive adhesive are often used. The linear expansion coefficients of these bonding materials 9 are the expansion coefficient of silicon (Si) (2 ppm / K) or the expansion coefficient of silicon carbide (SiC) (5 ppm / K), which is the constituent material of the power semiconductor element 13. Bigger than.

  In the case where the difference between the linear expansion coefficient of the bonding material 9 and the linear expansion coefficient of the material constituting the power semiconductor element 13 affects the reliability of the power module 1, a section having a relatively low linear expansion coefficient. By burying the member 11 in the bonding material 9, the linear expansion coefficient of the entire (total) surface bonding portion including the bonding material 9 and the partition member 11 is adjusted, and the reliability of the power module 1 is further improved. Can do.

  Next, an example of the manufacturing method of the power module 1 described above will be described. First, an insulating circuit board 7 is prepared. Next, as shown in FIG. 17, the back electrode 13 c of the power semiconductor element 13 is bonded to the circuit pattern 7 b of the insulating circuit substrate 7. For example, as shown in FIG. 18, the bonding material 9 and the separating member 11 are disposed between the circuit pattern 7b (insulating circuit board 7) and the back electrode 13c (power semiconductor element 13). Thereafter, a process (bonding process) for bonding the insulating circuit substrate 7 and the power semiconductor element 13 is performed by the bonding material 9 and the separating member 11.

  Here, for example, when lead-free solder is applied as the bonding material 9, a solder preform, paste solder, and the like are disposed together with the separating member 11. In the joining process, reflow soldering is performed by heat treatment. As the solder reflows, the partition member 11 is buried in the bonding material 9.

  Further, when a conductive adhesive is applied as the bonding material 9, particularly in the case of a conductive adhesive in which the metal particles are contained in the resin, together with the separating member 11, a paste-like conductive adhesive before curing. Agent is placed. At this time, it is desirable to embed the separating member 11 in a paste-like conductive adhesive. In the joining process, curing is performed.

  Furthermore, when a metal sintered body is applied as the bonding material 9, a paste containing metal particles is disposed together with the partition member. In the joining step, heat treatment or heat pressure treatment is performed, the binder component contained in the paste is volatilized, and a metal sintered body is formed. In addition, when not performing a pressurization process, it is desirable to embed the delimiter member 11 in a paste beforehand.

  By the way, when arranging the joining material 9 and the separating member 11 on the insulating circuit board 7, in addition to the manner of arranging the separating member 11 on the joining material 9 shown in FIG. There is. FIG. 19 shows a mode in which the separation member 11 is sandwiched by the bonding material 9 from above and below. In FIG. 20, the aspect which arrange | positions the joining material 9 on the partition member 11 is shown. FIG. 21 shows a mode in which, for example, two layers of bonding material 9 and two layers of separating members 11 are alternately stacked.

  Further, as shown in FIG. 22, a mode in which a gap is provided in advance in the layered bonding material 9 and the separating member 11 is fitted into the gap may be employed. In such an arrangement mode, it is possible to prevent voids from remaining in the bonding material 9 after the bonding step, and it is possible to suppress heat dissipation from being impaired due to the voids remaining.

  As described above, if the bonding material 9 is a paste material, the partition member 11 may be pressed against the paste material. Further, when the bonding material 9 is a solid material, a recess or the like is formed in the bonding material 9 in advance, and the partition member 11 may be fitted into the recess or the like. Thus, the power semiconductor element 13 is bonded to the insulating circuit substrate 7 via the surface bonding portion 5.

  Next, as shown in FIG. 23, one end of the wiring member 15 is joined to the surface electrode 13b of the power semiconductor element 13 by, for example, solder. The other end of the wiring member 15 is joined to the circuit pattern 7c by solder, for example. Next, as shown in FIG. 24, the insulating circuit board 7 is bonded to the base plate 3 by the first bonding portion 5a. For example, solder is applied as the first joint 5a. Next, as shown in FIG. 25, the case 21 is attached to the base plate 3. An external terminal 19 for electrically connecting the power semiconductor element 3 and the like to the outside protrudes from the case 21.

  Next, as shown in FIG. 26, the wiring member 17 electrically connected to one external terminal 19 is joined to the circuit pattern 7b by, for example, solder. Moreover, the wiring member 17 electrically connected to the other external terminals 19 is joined to the circuit pattern 7c by, for example, solder. Next, as shown in FIG. 27, the case 21 is filled with a sealing member 23, and the power semiconductor element 13 and the like are insulated and sealed. Thus, the power module 1 shown in FIGS. 1 and 2 is completed.

  In the power module 1 described above, the partition member 11 is disposed so as to partition the bonding material 9 in plan view in the surface bonding portion 5 that bonds the power semiconductor element 13 and the circuit pattern 7b. Thereby, as mentioned above, the thermal stress accompanying the heat generation of the power semiconductor element 13 can be reduced. Further, when the temperature rise and fall are repeated with the on / off operation of the power semiconductor element 13, the surface bonding portion 5 can be made less likely to be damaged. Furthermore, compared with the case of a conventional power module in which a gap such as a slit is formed in the joint, there is no need to worry about the bonding material flowing into the gap, and the options for the bonding material 9 can be expanded.

Embodiment 2. FIG.
In the power module described above, the case where the bonding material 9 and the separating member 11 are arranged in the second bonding portion 5b (the surface bonding portion 5) for bonding the power semiconductor element 13 and the circuit pattern 7b has been described. Here, a power module in which a bonding member and a separating member are arranged for all of the surface bonding portions will be described.

  As shown in FIGS. 28 and 29, in the power module 1, in addition to the second joint portion 5b for surface-joining the power semiconductor element 13 and the circuit pattern 7b, the first joint portion 5a, the third joint portion 5c, A bonding material 9 and a separating member 11 are arranged as the surface bonding portion 5 in each of the fourth bonding portion 5d and the fifth bonding portion 5e. The conductive member 7d of the insulated circuit board 7 and the base plate 3 are surface-bonded by the first bonding portion 5a.

  The surface electrode 13b of the power semiconductor element 13 and the wiring member 15 are surface-bonded by the third bonding portion 5c. The circuit pattern 7c of the insulating circuit board 7 and the wiring member 15 are surface bonded by the fourth bonding portion 5d. The circuit pattern 7b of the insulating circuit board 7 and the wiring member 17 are surface-bonded by the fifth bonding portion 5e. The arrangement structure, material, and the like described in the first embodiment are applied to the arrangement structure, material, and the like of the separation member 11 with respect to the bonding material 9.

  In addition, since it is the same as that of the power module shown in FIG.1 and FIG.2 about another structure, the same code | symbol is attached | subjected to the same member and the description will not be repeated unless it is required.

  Next, an example of a method for manufacturing the power module described above will be described. First, similarly to the process shown in FIG. 17, as shown in FIG. 30, the back surface electrode 13 c of the power semiconductor element 13 is formed by the second joint portion 5 b including the joining material 9 and the partition member 11. Bonded to the circuit pattern 7b.

  Next, as shown in FIG. 31, one end of the wiring member 15 is bonded to the surface electrode 13 b of the power semiconductor element 13 by the third bonding portion 5 c including the bonding material 9 and the separating member 11. Further, the other end of the wiring member 15 is bonded to the circuit pattern 7 c of the insulating circuit board 7 by the fourth bonding portion 5 d including the bonding material 9 and the partition member 11. Next, as shown in FIG. 32, the conductive member 7 d of the insulated circuit board 7 is bonded to the base plate 3 by the first bonding portion 5 a including the bonding material 9 and the partition member 11. Next, as shown in FIG. 33, the case 21 is attached to the base plate 3.

  Next, as shown in FIG. 34, the wiring member 17 is bonded to the circuit pattern 7 b of the insulating circuit board 7 by the fifth bonding portion 5 e including the bonding material 9 and the partition member 11. In addition, the wiring member 17 is bonded to the circuit pattern 7 c of the insulating circuit board 7 by the fifth bonding portion 5 e including the bonding material 9 and the partition member 11. Next, as shown in FIG. 35, the sealing member 23 is filled in the case 21, and the power semiconductor element 13 and the like are insulated and sealed. Thus, the power module 1 shown in FIGS. 28 and 29 is completed. In each of the steps of joining corresponding members by the surface joining portion 5, a method suitable for joining is applied from the methods described in the first embodiment.

  In the power module 1 described above, the bonding material 9 and the separating member 11 are arranged for all the surface bonding portions 5. Thereby, as described in the first embodiment, the thermal stress accompanying the heat generation of the power semiconductor element 13 can be effectively reduced. In addition, when the temperature rise and fall are repeated with the on and off operations of the power semiconductor element 13, the surface bonding portion 5 can be further prevented from being damaged.

  In the power module described above, the case where the bonding material 9 and the separating member 11 are arranged for all of the surface bonding portions 5 has been described. However, the power module 1 is not limited to this and is not limited to a specific one. A bonding material 9 and a separating member 11 may be disposed on the surface bonding portion 5.

Embodiment 3 FIG.
Here, the power conversion device to which the power module according to Embodiments 1 and 2 described above is applied will be described. Although the present invention is not limited to a specific power converter, hereinafter, a case where the present invention is applied to a three-phase inverter will be described as a third embodiment.

  FIG. 36 is a block diagram showing a configuration of a power conversion system to which the power conversion device according to the present embodiment is applied. The power conversion system illustrated in FIG. 36 includes a power supply 100, a power conversion device 200, and a load 300. The power source 100 is a DC power source and supplies DC power to the power conversion device 200. The power source 100 can be constituted by various types, and can be constituted by, for example, a DC system, a solar battery, or a storage battery. Moreover, you may comprise by the rectifier circuit or AC / DC converter connected to the alternating current system. Further, the power supply 100 may be configured by a DC / DC converter that converts DC power output from the DC system into predetermined power.

  The power conversion device 200 is a three-phase inverter connected between the power supply 100 and the load 300, converts the DC power supplied from the power supply 100 into AC power, and supplies the AC power to the load 300. As shown in FIG. 36, the power conversion device 200 converts a DC power into an AC power and outputs the main conversion circuit 201, and a control circuit 203 outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201. And.

  The load 300 is a three-phase electric motor that is driven by AC power supplied from the power conversion device 200. Note that the load 300 is not limited to a specific application, and is an electric motor mounted on various electric devices. For example, the load 300 is used as an electric motor for a hybrid vehicle, an electric vehicle, a railway vehicle, an elevator, or an air conditioner.

  Hereinafter, details of the power conversion device 200 will be described. The main conversion circuit 201 includes a switching element and a reflux diode (both not shown). When the switching element is switched, the DC power supplied from the power supply 100 is converted into AC power and supplied to the load 300. Although there are various specific circuit configurations of the main conversion circuit 201, the main conversion circuit 201 according to the present embodiment is a two-level three-phase full bridge circuit, and includes six switching elements and respective switching elements. It can be composed of six anti-parallel diodes.

  Each switching element or each free-wheeling diode of the main conversion circuit 201 is configured by the semiconductor module 202 (power module 1) corresponding to any of the first and second embodiments described above. The six switching elements are connected in series for each of the two switching elements to constitute upper and lower arms, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full bridge circuit. The output terminals of the upper and lower arms, that is, the three output terminals of the main conversion circuit 201 are connected to the load 300.

  The main conversion circuit 201 includes a drive circuit (not shown) that drives each switching element. However, the drive circuit may be built in the semiconductor module 202 or a drive circuit separate from the semiconductor module 202. May be provided. The drive circuit generates a drive signal for driving the switching element of the main conversion circuit 201 and supplies the drive signal to the control electrode of the switching element of the main conversion circuit 201. Specifically, in accordance with a control signal from the control circuit 203 described later, a drive signal for turning on the switching element and a drive signal for turning off the switching element are output to the control electrode of each switching element. When the switching element is maintained in the on state, the drive signal is a voltage signal (on signal) that is equal to or higher than the threshold voltage of the switching element. When the switching element is maintained in the off state, the drive signal is a voltage that is equal to or lower than the threshold voltage of the switching element. Signal (off signal).

  The control circuit 203 controls the switching element of the main conversion circuit 201 so that desired power is supplied to the load 300. Specifically, based on the power to be supplied to the load 300, the time (ON time) during which each switching element of the main converter circuit 201 is to be turned on is calculated. For example, the main conversion circuit 201 can be controlled by PWM control that modulates the ON time of the switching element according to the voltage to be output. Then, a control command (control signal) is supplied to the drive circuit included in the main conversion circuit 201 so that an ON signal is output to the switching element that should be turned on at each time point and an OFF signal is output to the switching element that should be turned off. ) Is output. The drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element in accordance with the control signal.

  In the power conversion device according to the present embodiment, since the semiconductor module (power module 1) according to the first and second embodiments is applied as the switching element and the free wheel diode of the main conversion circuit 201, the reliability of the power conversion device is improved. Can be improved.

  In the present embodiment, an example in which the present invention is applied to a two-level three-phase inverter has been described. However, the present invention is not limited to this and can be applied to various power conversion devices. In the present embodiment, a two-level power conversion device is used. However, a three-level or multi-level power conversion device may be used. The invention may be applied. In addition, when power is supplied to a direct current load or the like, the present invention can be applied to a DC / DC converter or an AC / DC converter.

  In addition, the power conversion device to which the present invention is applied is not limited to the case where the load described above is an electric motor. For example, a power supply device for an electric discharge machine, a laser processing machine, an induction heating cooker, or a non-contact power feeding system Furthermore, it can also be used as a power conditioner for a photovoltaic power generation system or a power storage system.

  In addition, about the power module and power converter device which were demonstrated in each embodiment, it is possible to combine variously as needed.

  The embodiment disclosed this time is an example, and the present invention is not limited to this. The present invention is defined by the terms of the claims, rather than the scope described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is effectively used for a power module having a surface joint portion.

DESCRIPTION OF SYMBOLS 1 Power module, 3 base board, 5 surface junction part, 5a 1st junction part, 5b 2nd junction part, 5c 3rd junction part, 5d 4th junction part, 5e 5th junction part, 7 insulation circuit board, 7a insulation Substrate, 7b circuit pattern, 7c circuit pattern, 7d conductive member, 9 bonding material, 11 partition member, 13 power semiconductor element, 13a element body, 13b surface electrode, 13c back electrode, 15, 17 wiring member, 19 external terminal , 21 case, 23 sealing member, 100 power supply, 200 power conversion device, 201 main conversion circuit, 202 semiconductor module, 203 control circuit, 300 load.

Claims (17)

A base plate,
An insulating circuit board bonded to the base plate via a first bonding portion and having a circuit pattern;
A power semiconductor element bonded to the insulating circuit substrate via a second bonding portion;
A wiring member bonded to the power semiconductor element via a third bonding portion and bonded to the circuit pattern via a fourth bonding portion;
An external terminal joined to the insulated circuit board via a fifth joint,
A sealing member for sealing the insulating circuit board, the power semiconductor element, and the wiring member;
At least one of the first joint, the second joint, the third joint, the fourth joint, and the fifth joint is a surface joint,
The surface joint portion is
A bonding material;
A power module comprising: a partition member disposed on the bonding material in a mode of partitioning the bonding material in plan view.   In the surface joining portion, the partition member is arranged concentrically in a plan view with respect to the joining material, a structure in which closed loops are nested, and a spiral shape. The power module according to claim 1, wherein the power module has any one of the structures.   3. The power module according to claim 1, wherein in the surface bonding portion, the bonding material and the partitioning member are either in a bonded state or in a bonded state. The bonding material is solder,
The power module according to claim 1, wherein the first metal is located on at least a surface of the partition member.   The power module according to claim 4, wherein the first metal is any one selected from the group consisting of nickel, copper, and gold.   The power module according to claim 4, wherein a portion made of a material different from the first metal is located inside the partition member.   The power module according to claim 6, wherein the material is a second metal having a linear expansion coefficient smaller than the linear expansion coefficient of the solder, the linear expansion coefficient of silver, the linear expansion coefficient of copper, and the linear expansion coefficient of the resin material. . The bonding material is a conductive adhesive,
The power module according to claim 1, wherein the partition member is a third metal. The bonding material is a sintered body of either silver or gold,
The power module according to claim 1, wherein a fourth metal is located on at least a surface of the partition member.   The power module according to claim 9, wherein the fourth metal is any one selected from the group consisting of copper, silver, and gold.   The power module according to claim 9, wherein a portion made of another material different from the fourth metal is located inside the partition member.   The power according to claim 11, wherein the other material is a fifth metal having a linear expansion coefficient smaller than that of solder, a linear expansion coefficient of silver, a linear expansion coefficient of copper, and a linear expansion coefficient of resin material. module. A method of manufacturing a power module having a base plate, an insulated circuit board, a power semiconductor element, a wiring member, and an external terminal,
One member of the base plate, the insulated circuit board, the power semiconductor element, the wiring member, and the external terminal is a first member to be joined, and the other member is a second member to be joined. A step of joining the joining member and the second joined member,
The step of joining the first member to be joined and the second member to be joined includes
Arranging a bonding material and a separating member for dividing the bonding material in a plan view on the first bonded member;
The second member to be bonded is disposed in a form in which the bonding material and the partition member are sandwiched between the second member to be bonded and the first member to be bonded, and the second member to be bonded is the bonding material and And a step of joining the first member to be joined by the partition member. In the step of joining the first member to be joined and the second member to be joined,
As the bonding material, solder is used,
The method for manufacturing a power module according to claim 13, wherein the second member to be bonded is heat-treated and bonded to the first member to be bonded by reflow soldering. In the step of joining the first member to be joined and the second member to be joined,
As the bonding material, a conductive adhesive is used,
The method for manufacturing a power module according to claim 13, wherein the second member to be bonded is bonded to the first member to be bonded by performing a heat treatment. In the step of joining the first member to be joined and the second member to be joined,
As the bonding material, a paste-like material containing either silver or copper particles is used,
The pasted material becomes a sintered body of one of the silver and the copper by performing at least heat treatment, and the second joined member is joined to the first joined member. Method of manufacturing the power module. A power conversion device to which the power module according to any one of claims 1 to 12 is applied,
A main conversion circuit that returns and outputs input power; and
A power conversion apparatus comprising: a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit.

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