Patent Description:
Research into and development of hybrid or electric vehicles has been actively conducted. These types of vehicle are environmentally friendly and consider fuel efficiency, for example in contrast to a vehicle using a combustion engine.

Hybrid vehicles are driven with two power sources by linking an existing engine and a motor driven by electric energy to each other, and electric vehicles are driven only with a motor driven by electric energy. Therefore, these vehicles are regarded, in territories such as the United States and Japan, as realistic alternative next-generation vehicles due to effects such as a decrease of environmental pollution from exhaust gases and improvement of fuel efficiency.

These vehicles are mounted with a high-capacity battery to supply power to the electric motor when necessary and charge the battery with electric energy generated from a regenerative power source when the hybrid vehicle or the electric vehicle is decelerated or stopped. The electric motor for a vehicle may mainly include a rotor having a plurality of magnetic materials such as permanent magnets and a stator generating an electromagnetic force to rotate the rotor.

In addition, the hybrid vehicle and electric/fuel cell vehicles have used an inverter converting high-voltage direct current (DC) power generated from batteries or fuel cells into three-phase (U, V, and W phases) alternating current (AC) power in the electric motor for a vehicle to charge/discharge internally produced electrical energy.

In addition, the inverter includes a power module in which power semiconductors are integrated. Since an amount of heat generated by the power module is large due to torque transfer for quick starting of the inverter, an engine room of a high temperature, and the like, at the time of starting of the inverter, the power module is disposed on an inverter heat sink provided in an inverter housing for heat dissipation, such that the heat generated by the power module is cooled. <CIT> relates to a semiconductor module that uses pin bonding and can improve cooling capacity. <CIT> relates to a semiconductor module which is used in vehicles such as an electric car or a hybrid car. <CIT> relates to a semiconductor device housing package for housing a semiconductor device such as an LSI Circuit.

In one general aspect, a power module pack includes a first cooling plate, a second cooling plate stacked on and coupled to the first cooling plate, and power modules interposed between the first cooling plate and the second cooling plate. Each of the power modules has a lower surface soldered to an upper surface of the first cooling plate.

A preform solder may be disposed between the lower surface of each of the power modules and the upper surface of the first cooling plate, and each of the power modules may be soldered to the first cooling plate by the preform solder.

An upper surface of the preform solder may have the same shape and width as a lower surface of a circuit board of each of the power modules.

An engraved pattern recessed inward may be formed at a position corresponding to a position where each of the power modules is disposed, on the upper surface of the first cooling plate.

One or more engraved grooves recessed inward are formed in an upper surface of each of the power modules. Embossed projections protruding outward are formed, respectively, at positions each corresponding to the one or more engraved grooves of each of the power modules on a lower surface of the second cooling plate. Each embossed projection of the second cooling plate is inserted into each engraved groove of each of the power modules, such that a position of the power module is fixed.

A plurality of heat dissipation fins protruding outward may be provided on a lower surface of the first cooling plate.

The power module pack may further include a first cover stacked on and coupled to a lower surface of the first cooling plate to form a first coolant flow channel through which a coolant flows between the first cooling plate and the first cover, and a second cover stacked on and coupled to an upper surface of the second cooling plate to form a second coolant flow channel through which a coolant flows between the second cooling plate and the second cover.

The first cover, the first cooling plate, the second cooling plate, and the second cover may be provided with bolt coupling parts protruding laterally, respectively, and the bolt coupling parts of the first cover, the first cooling plate, the second cooling plate, and the second cover may be stacked and arranged in a line and be coupled to each other at a time through one bolt.

In another general aspect, a cooling plate has one or more power modules soldered to one surface of the cooling plate, and an engraved pattern recessed inward is formed at a position corresponding to a position at which each of the power modules is disposed, on the one surface of the cooling plate.

The engraved pattern may include a first line, a second line, a third line, and a fourth line sequentially connected to each other to form a frame having a rectangular shape, first cross lines formed perpendicular to the line and crossing the first line, and third cross lines formed perpendicular to the third line and crossing the third line, the first line, the second line, the third line, and the fourth line formed along edges of a circuit board of each of the power modules, the first cross lines formed to extend in one side direction from the outermost one side of chips mounted in each of the power modules, and the third cross lines formed to extend in the other side direction from the outermost other side of the chips mounted in each of the power modules.

A plurality of first cross lines may be formed and disposed at equal intervals, a plurality of third cross lines may be formed and disposed at equal intervals, and the respective lines of the engraved pattern may be mirror-symmetrical to each other with respect to the center between the first line and the third line.

Widths of the first line and the third line may be greater than widths of the second line, the fourth line, the first cross lines, and the third cross lines.

When any two adjacent power modules of the one or more power modules are referred to as a first power module and a second power module, respectively, an engraved pattern corresponding to a position where the first power module is disposed and an engraved pattern corresponding to a position where the second power module is disposed may be separated from each other.

In still another general aspect, a soldering pressure jig for soldering a power module pack includes a lower jig on which one or more power modules are disposed; and an upper jig fastened to the lower jig. A plurality of through holes passing through the upper jig are formed at positions of the upper jig corresponding to a position of each of the one or more power modules, and ball plungers penetrate through the through holes to pressurize an upper portion of each of the power modules.

A pressure applied to each of the power modules may be adjustable using the ball plunger.

A plurality of vent holes penetrating through the upper jig may be formed in the upper jig, and the plurality of vent holes may be formed outside each of the power modules.

<FIG> is a perspective view of an inverter according to an embodiment of the present invention, and <FIG> is an exploded perspective view of <FIG>. An inverter <NUM> has a structure in which various components including a power module pack <NUM> are accommodated in a housing <NUM>.

The present invention relates to a structure and a manufacturing method of the power module pack <NUM> capable of improving performance of the inverter, a power module <NUM> accommodated in the power module pack, and a metal clip <NUM> applied to the power module.

First, the power module <NUM> according to the present invention will be briefly described below. <FIG> is a perspective view of a power module according to an embodiment of the present invention, and <FIG> is a top view and a bottom view of the power module. The power module <NUM> has a structure in which components including the circuit board <NUM> are molded by a molding part <NUM>. In this case, as illustrated in <FIG>, a lower portion of the circuit board <NUM> is exposed to the outside of the molding part <NUM>, and an upper portion of the circuit board <NUM> is occluded by the molding part <NUM>. In the power module according to the present invention, most of the heat generated by the power module is transferred to the circuit board disposed at a lower portion of the power module, and accordingly, heat of the lower portion of the power module needs to be intensively dissipated. Forming a heat dissipation path of the power module downward is to improve a manufacturing property, performance, and the like, of the power module itself, and more detailed contents will be described later.

Hereinafter, respective components according to the present invention will be described with reference to such characteristics of the power module.

<FIG> is an exploded perspective view of a power module pack according to an embodiment of the present invention, and is an exploded view of the power module pack of <FIG>. The power module pack <NUM> mainly includes a heat sink <NUM> and a heat sink cover <NUM>, and has a structure in which the power modules <NUM> are interposed between the heat sink <NUM> and the heat sink cover <NUM>.

The heat sink <NUM> includes a first cooling plate <NUM> and a first cover <NUM>, and the first cover <NUM> is stacked on and coupled to one surface of the first cooling plate <NUM> to form a first coolant flow channel C1 through which a coolant flows between the first cooling plate <NUM> and the first cover <NUM>.

The heat sink cover <NUM> includes a second cooling plate <NUM> and a second cover <NUM>, and the second cover <NUM> is stacked on and coupled to one surface of the second cooling plate <NUM> to form a second coolant flow channel C2 through which a coolant flows between the second cooling plate <NUM> and the second cover <NUM>.

That is, the heat sink <NUM> and the heat sink cover <NUM> correspond to structures in which coolants flow to cool the power modules <NUM> interposed therebetween. A flow path of the coolant is as follows. A first through hole <NUM>-H penetrating through the first cooling plate <NUM> is formed at one end portion of the first cooling plate <NUM>, a second through hole <NUM>-H penetrating the second cooling plate <NUM> is formed at one end portion of the second cooling plate <NUM>, and the first coolant flow channel C1 and the second coolant flow channel C2 communicate with each other through the first through hole <NUM>-H and the second through hole <NUM>-H. In addition, a first cover through hole <NUM>-H penetrating through the first cover <NUM> is formed at the other end portion of the first cover <NUM>, and an inlet is provided in the first cover through hole <NUM>-H, such that the coolant is introduced from the outside through the inlet and the first cover through hole <NUM>-H, and a second cover through hole <NUM>-H penetrating through the second cover <NUM> is formed at the other end portion of the second cover <NUM>, and an outlet is provided in the second cover through hole <NUM>-H, such that the coolant is discharged to the outside through the outlet and the second cover through hole <NUM>-H.

Here, as illustrated in <FIG>, a plurality of heat dissipation fins <NUM>-P protruding outward are provided on one surface of the first cooling plate <NUM> (upper surface of the first cooling plate in <FIG>). A heat sink structure including the plurality of heat dissipation fins is provided, such that heat dissipation performance of heat transferred from the power module may be improved. Meanwhile, as described above, in the power module according to the present invention, the heat dissipation path is formed downward, and accordingly, a heat dissipation fin structure may not be provided on one surface of the second cooling plate <NUM> (lower surface of the second cooling plate in <FIG>) unlike the first cooling plate <NUM>. By forming the heat dissipation path of the power module in one direction and installing the heat dissipation fin structure in only one direction as described above, a manufacturing cost may be reduced.

In addition, as illustrated in <FIG>, the first cover <NUM>, the first cooling plate <NUM>, the second cooling plate <NUM>, and the second cover <NUM> are provided with bolt coupling parts <NUM>-C, <NUM>-C, <NUM>-C, and <NUM>-C protruding laterally, respectively, and the bolt coupling parts <NUM>-C, <NUM>-C, <NUM>-C, and <NUM>-C of the first cover, the first cooling plate, the second cooling plate, and the second cover are stacked and arranged in a line and are coupled to each other at a time through one bolt. The numbers of each of bolt coupling parts may be plural, and the first cover, the first cooling plate, the second cooling plate, and the second cover are configured to be fastened to each other at a time through one bolt as described above, such that manufacturing convenience of the power module pack may be improved.

<FIG> is a perspective view illustrating a first cooling plate, a second cooling plate, and power modules separated from each other. As illustrated in <FIG>, one or more power modules <NUM> are provided in the power module pack, and each of the power modules <NUM> is interposed between the first cooling plate <NUM> and the second cooling plate <NUM>. A plurality of power modules <NUM> may be provided and disposed side by side in a line. That is, the plurality of power modules may be disposed in a single-layer parallel structure.

A lower surface of the power module <NUM> is soldered to the other surface of the first cooling plate <NUM> (upper surface of the first cooling plate in <FIG>). Here, since the heat dissipation path of the power module <NUM> is formed downward, an upper surface of the power module <NUM> may not be bonded to the other surface of the second cooling plate (lower surface of the second cooling plate in <FIG>).

In this case, in the present invention, the power module <NUM> and the first cooling plate <NUM> may be soldered to each other using a preform solder. More specifically, the preform solders <NUM> are disposed between lower surfaces of the power modules <NUM> and the other surface of the first cooling plate <NUM>, respectively, and the power modules <NUM> are soldered to the first cooling plate <NUM> by the preform solders <NUM>.

The preform solder is a metal alloy bonding material, and is a sheet-type solder having a predetermined size and shape, unlike a polymer-based adhesive according to the related art. The polymer-based adhesive according to the related art has a thermal conductivity of <NUM> to <NUM> W, and thus, has a difficulty in securing sufficient thermal performance in an inverter system that requires a high power density and heat dissipation performance, but the preform solder has a thermal conductivity of <NUM> to <NUM> W higher than the thermal conductivity of the polymer-based adhesive according to the related art, and thus, excellent thermal performance may be secured by applying the preform solder.

<FIG> is a view for describing a preform solder according to an embodiment of the present invention. The preform solder <NUM> has a shape corresponding to the power module <NUM>. Specifically, an upper surface of the preform solder <NUM> has the same shape and width as a lower surface of the circuit board <NUM> of the power module <NUM>. That is, the preform solder is in direct surface-contact with the lower surface of the circuit board of the power module, and since the preform solder is formed in the same size and shape as the circuit board of the power module, solder overflow at the time of soldering may be prevented, and the use of an unnecessary solder may be decreased.

Meanwhile, as the preform solder melts and flows at the time of soldering, the power module put on the preform solder moves along the flow of the preform solder, such that a position or a posture of the power module may be misaligned, and a problem that voids are generated inside the preform solder at the time of soldering may occur. In order to solve such a problem, the present invention adopts the following configuration.

<FIG> is a view illustrating the other surface of the first cooling plate. As illustrated in <FIG>, engraved patterns GP recessed inward are formed at positions corresponding to positions where the respective power modules <NUM> are seated (for example, disposed), on the other surface of the first cooling plate <NUM>, that is, the upper surface of the first cooling plate <NUM> facing the lower surfaces of the power modules <NUM>. Since the engraved pattern is formed as described above, voids generated inside the solder at the time of soldering are discharged to the outside along the engraved pattern, such that it is possible to prevent generation of a gap in a soldering part due to the voids, and accordingly, a defect in heat dissipation performance may be decreased.

<FIG> is views illustrating photographs of a soldering part. A left photograph of <FIG> is a photograph when an engraved pattern is not applied, and a right photograph of <FIG> is a photograph when the engraved pattern is applied. As illustrated in <FIG>, it may be confirmed that when the engraved pattern is not applied, a great gap is generated in the soldering part, whereas when the engraved pattern is applied, a gap is significantly decreased in the soldering part.

<FIG> is views illustrating various embodiments of an engraved pattern. As illustrated in <FIG>, the engraved pattern may be configured in various shapes. In this case, the engraved pattern of <FIG> is an engraved pattern illustrated on the lower right of <FIG>, and corresponds to a preferable example among various engraved patterns. The engraved pattern will be described below with reference to <FIG> and <FIG>.

The engraved pattern GP includes a first line L1, a second line L2, a third line L3, and a fourth line L4 sequentially connected to each other to form a frame having a rectangular shape, first cross lines LC1 formed perpendicular to the line L1 and crossing the first line L1, and third cross lines LC3 formed perpendicular to the third line L3 and crossing the third line L3.

In this case, the first line L1, the second line L2, the third line L3, and the fourth line L4 are formed along edges of the circuit board <NUM> of each power module <NUM>, the first cross lines LC1 are formed to extend in one side direction from the outermost one side (left side in <FIG>) of chips <NUM> mounted in each power module <NUM>, and the third cross lines LC3 are formed to extend in the other side direction from the outermost other side (right side in <FIG>) of the chips <NUM> mounted in each power module <NUM>.

In addition, the second line L2 is formed to extend in one side direction so that one end thereof exceeds the first line L1 and is formed to extend in the other side direction so that the other end thereof exceeds the third line L3, and the fourth line L4 is formed to extend in one side direction so that one end thereof exceeds the first line L1 and is formed to extend in the other side direction so that the other end thereof exceeds the third line L3.

In addition, a plurality of first cross lines LC1 are formed and disposed at equal intervals, a plurality of third cross lines LC3 are formed and disposed at equal intervals, and the respective lines (i.e., the first to the fourth line, the first cross lines, and the third cross lines) are mirror-symmetrical to each other with respect to the center between the first line L1 and the third line L3.

In addition, widths of the first line L1 and the third line L3 are greater than widths of the second line L2, the fourth line L4, the first cross lines LC1, and the third cross lines LC3. In addition, the widths of the first line L1 and the third line L3 may be the same as each other, and the widths of the second line L2, the fourth line L4, the first cross lines LC1, and the third cross lines LC3 may be the same as each other.

Since the engraved pattern corresponding to each power module has the shape as described above, it is possible to prevent the generation of the gap due to the voids in the soldering part.

Furthermore, as illustrated in <FIG>, it is preferable that the engraved patterns GP each corresponding to two adjacent power modules are separated from each other. More specifically, when any two adjacent power modules of one or more power modules are referred to as a first power module and a second power module, respectively, an engraved pattern GP-<NUM> corresponding to a position where the first power module is seated and an engraved pattern GP-<NUM> corresponding to a position where the second power module is seated are separated from each other. Accordingly, an adverse effect between the two adjacent power modules may be prevented.

Referring to <FIG> again, one or more engraved grooves <NUM> recessed inward are formed in the upper surface of each power module <NUM>, and embossed projections <NUM>-B protruding outward are formed, respectively, at positions each corresponding to one or more engraved grooves <NUM> of each power module <NUM> on the other surface of the second cooling plate <NUM>. <FIG> is a view illustrating the other surface of the second cooling plate. As illustrated in <FIG>, the embossed projections <NUM>-B protruding downward are formed on the other surface of the second cooling plate <NUM>, that is, the lower surface of the second cooling plate <NUM> facing the upper surface of the power module <NUM>.

In addition, each embossed projection <NUM>-B of the second cooling plate is inserted into each engraved groove <NUM> of each power module, such that a position of the power module <NUM> is fixed. This may allow the power module to be maintained at its original position by preventing a phenomenon in which the power module seated on the solder is misaligned because the solder melts at the time of soldering.

Hereinafter, a soldering pressure jig for manufacturing a power module pack will be described.

<FIG> is a view illustrating a soldering pressure jig according to an embodiment of the present invention, and <FIG> is a view illustrating a photograph of the pressure jig of <FIG>. The soldering pressure jig <NUM> according to the present invention includes an upper jig <NUM> and a lower jig <NUM>.

The first cooling plate <NUM>, the preform solders <NUM>, and the power modules <NUM> may be sequentially stacked on the lower jig <NUM>, the upper jig <NUM> may be bolted to the lower jig <NUM> using bolts, and soldering may be then performed. In this case, a plurality of through holes <NUM> penetrating through the upper jig may be formed at positions of the upper jig <NUM> corresponding to each power module <NUM>, and ball plungers <NUM> may penetrate through the corresponding through holes <NUM> to pressurize an upper portion of each power module <NUM>. In this case, the ball plungers <NUM> penetrate through the upper jig <NUM>, such that end portions of the ball plungers <NUM> may be inserted into the engraved grooves <NUM> formed in the upper surface of the power module described above to pressurize the power module <NUM>.

When a pressure applied to the solder at the time of soldering is excessively weak, many voids are generated inside the solder, and thus, it is preferable to perform the soldering while applying a predetermined level of pressure to the solder. By appropriately pressurizing and balancing the power module at multiple points at the same time, it is possible to prevent the power module from being inclined to one side at the time of soldering, and accordingly, soldering characteristics may be improved and a thickness of the soldering may be evenly maintained.

That is, the present invention may provide the above-described advantages by forming the through holes <NUM> in the upper jig <NUM> and adjusting a pressure applied to the solder through the ball plungers <NUM>. Here, screw threads may be formed in each of the ball plunger <NUM> and the through hole <NUM> of the upper jig to appropriately adjust a desired pressure using a wrench or the like.

Furthermore, referring to <FIG> again, a plurality of vent holes <NUM> penetrating through the upper jig <NUM> are formed in the upper jig <NUM>. The vent holes <NUM> function as passages through which the voids generated inside the solder at the time of soldering may be discharged to the outside to assist in improving soldering characteristics. In this case, the plurality of vent holes <NUM> may be formed outside each power module <NUM>, that is, may be formed to be misaligned with each power module.

<FIG> is a view illustrating a power module according to the related art, and <FIG> is an exploded perspective view of the power module according to the related art. The power module according to the related art has a structure in which a lower substrate and mounted components and an upper substrate and mounted components are primarily soldered to each other, and the primarily soldered lower substrate and upper substrate are secondarily soldered to each other, which has a problem that a manufacturing cost and a manufacturing cycle time increase. In addition, since defects of products occur in each soldering process, there is a problem that a defective rate is increased at the time of the secondary soldering process as described above.

The power module according to the present invention has been made in an effort to solve such a problem, and provides an integrated soldering process capable of integrating primary and secondary soldering processes according to the related art and a power module structure based on the integrated soldering process.

<FIG> is a perspective view of a power module according to an embodiment of the present invention, and <FIG> is an exploded perspective view of <FIG>. The power module according to the present invention includes a circuit board <NUM>, chips <NUM>, and metal clips <NUM>, chip solders <NUM> are disposed between the circuit board <NUM> and the chips <NUM>, such that the circuit board <NUM> and the chips <NUM> are soldered to each other by the chip solders <NUM>, and clip solders <NUM> are disposed between the chips <NUM> and the metal clips <NUM>, such that the chips <NUM> and the metal clips <NUM> are soldered to each other by the clip solders <NUM>.

The circuit board <NUM> is an insulating substrate on which metal circuits are formed and onto which electric components are attached, and may be a directed bonded copper (DBC) substrate.

The chips <NUM> are disposed on the circuit board <NUM>. Each chip is an integrated circuit formed of a semiconductor, and corresponds to a bare chip. The chips may be disposed in a structure in which they are arranged in a row on the circuit board <NUM>, and may be formed in a plurality of rows.

The metal clips <NUM> are disposed on the chips and correspond to a kind of metal plates connected to the chips <NUM>. The metal clips <NUM> electrically connect the chips <NUM> to each other and at the same time, electrically connect the chips <NUM> and the circuit board <NUM> to each other. That is, current paths between the chips <NUM> and the circuit board <NUM> are formed through the metal clips <NUM>.

In this case, the metal clip <NUM> dissipates heat of the chips <NUM>. The heat of the chips is emitted in all directions, and heat transferred to an upper portion in the heat of the chips is dissipated through the metal clip <NUM>.

In the related art, another circuit board is provided on the chips and metal spacers are put between another circuit board and the chip to dissipate heat, whereas in the present invention, another circuit board according to the related art is removed, the metal clips are applied, and a heat dissipation path is formed through the metal clips, and thus, the number of components and an assembling man-hour may be decreased as compared with the related art. More specifically, the power module according to the related art includes four types of mounted components such as a lower substrate, solders, chips, and a lead frame, and three types of mounted components such as an upper substrate, solders, and spacers, whereas the power module according to the present invention includes four types of mounted components such as a substrate, solders, chips, and a lead frame to have a very simple structure, and thus, the number of components and an assembling man-hour may be decreased as compared with the related art, such that a manufacturing process of the power module may be simplified and a manufacturing yield of the power module may be improved.

The metal clip <NUM> may be formed of copper (Cu). Since copper has a high conductivity, it may improve heat dissipation performance of the power module due to its excellent heat dissipation properties, and may lower a manufacturing cost of the power module due to its low cost.

Referring to <FIG> again, the metal clips <NUM> may include extension parts <NUM>-C formed to extend from the metal clip <NUM> and in contact with an upper surface of the circuit board <NUM>. Since the metal clips include the extension parts as described above, the heat transferred to the metal clips is transferred to the circuit board, such that heat dissipation performance may be improved. As described above, the heat transferred to the circuit board may be dissipated through the heat sink.

In addition, at least one of both end portions of the metal clip <NUM> may be coupled to a lead frame <NUM>. Since the lead frame <NUM> has a structure in which at least a portion thereof is exposed to the outside, the heat transferred to the metal clip <NUM> is transferred to the lead frame <NUM> and dissipated to the outside, such that heat dissipation performance may be improved.

Referring back to <FIG>, the power module according to the present invention further includes a molding part <NUM> for molding the mounted components, that is, the circuit board <NUM>, the chips <NUM>, the metal clips <NUM>, and the like. In this case, the upper portion of the circuit board <NUM> is occluded by the molding part <NUM>. That is, in the related art, the heat transferred from the chip to the upper portion is dissipated through the upper substrate, and thus, the upper substrate is exposed to the outside, whereas in the present invention, the heat transmitted from the chip to the upper portion is dissipated by the metal clip or is transferred to and dissipated by the lower substrate and the lead frame through the metal clip, and thus, the upper portion does not need to be exposed, and accordingly, the upper portion of the molding part <NUM> may be occluded. As described above, since the molding part is configured to cover all of the upper portions of the mounted components, protection performance of the mounted components from the outside by the molding part may be increased, and structural robustness of the power module may be improved.

Referring to <FIG> and <FIG> again, each of the chip solders <NUM> and the clip solders <NUM> is configured as a preform solder. In this case, the chip solder <NUM> and the clip solder <NUM> have the same melting point. That is, the chip solder <NUM> and the clip solder <NUM> are configured as the same solder. In addition, the chip solders <NUM> and the clip solders <NUM> are fused simultaneously in one process, such that the circuit board <NUM> and the chips <NUM>, and the chips <NUM> and the metal clips <NUM> are simultaneously soldered to each other.

As described above, the power module according to the present invention is manufactured by using the same solders in order to solder the respective components to each other and soldering the respective solders at the same time and in an integrated manner, and thus, the number of soldering processes may be decreased as compared with the related art in which each of the lower substrate and the upper substrate is primarily soldered to the mounted components, and the primarily soldered lower substrate and upper substrate are secondarily soldered to each other, such that a manufacturing process may be simplified. In addition, as the number of soldering processes is decreased, a predetermined defective rate occurring in each soldering process is also decreased, such that a manufacturing yield of the power module may be improved.

A specific embodiment of the present power module will be described below with reference to <FIG> and <FIG> again. The chips include first-row chips including a plurality of chips arranged in a row and second-row chips including a plurality of other chips arranged in a row, and the metal clip may include a first metal clip disposed on the first-row chips and electrically connecting the first-row chips to each other and a second metal clip disposed on the second-row chips and electrically connecting the second-row chips to each other.

In addition, the first metal clip may include an extension part formed to extend from one side of the first metal clip and in contact with the upper surface of the circuit board, and at least one of both end portions of the second metal clip may be in direct contact with the lead frame. In this case, the extension part of the first metal clip may be formed between the first metal clip and the second metal clip spaced apart from each other. As described above, the extension portion is formed between the first metal clip and the second metal clip, which may be directly or indirectly assist in heat dissipation of the first metal clip and the second metal clip.

<FIG> is an exploded perspective view of a power module soldering jig according to an embodiment of the present invention, and <FIG> is views illustrating an upper jig and a lower jig, respectively. As illustrated in <FIG>, a soldering jig <NUM> includes a lower jig <NUM> and an upper jig <NUM>. In addition, <FIG> is a view illustrating a power module manufactured through the soldering jig, and corresponds to internal components of the power module before the molding part <NUM> is provided.

A structure <NUM> including a circuit board <NUM>, a chip solder <NUM>, chips <NUM>, and a clip solder <NUM> is seated on the lower jig <NUM>. The structure <NUM> may further include an external frame <NUM> for fixing the circuit board <NUM> and the lead frame <NUM>, and may be seated on the lower jig <NUM> in a state in which the respective components are fixed to the external frame <NUM>. A seating groove <NUM> may be formed in the center of the lower jig <NUM> so that the circuit board may be mounted on the lower jig <NUM>.

The upper jig <NUM> is fastened to the lower jig <NUM>, and the metal clip <NUM> is fixed to a lower portion of the upper jig <NUM>. As described above, the metal clip <NUM> is fixed to the upper jig <NUM>, and thus, a position of the metal clip <NUM> in a vertical direction is fixed by the upper jig.

More specifically, a lower portion of the upper jig <NUM> includes a ring (not illustrated) protruding downward, the metal clip <NUM> includes a ring groove <NUM> to which the ring of the upper jig may be hooked, and the metal clip <NUM> is hung on and fixed to the upper jig <NUM> using the ring. The ring groove <NUM> of the metal clip may correspond to some of through holes <NUM> penetrating through the metal clip <NUM>, and these through holes <NUM> may function as passages through which a molding material flows later. More detailed contents thereof will be described later.

In such a jig configuration, when the upper jig <NUM> to which the metal clip <NUM> is fixed is fastened to the lower jig <NUM> on which the structure <NUM> is seated, the upper jig <NUM> correctly positions the metal clip <NUM> at a position spaced apart from the chips <NUM> in a gravity direction.

That is, with the present device, when soldering the metal clip to upper portions of the chips using the preform solder, the metal clip is not seated on the upper portions of the chips by gravity, but a position of the metal clip in the vertical direction is fixed in a state in which the metal clip is hung on the upper jig. Accordingly, even though the solder is fused, the position of the metal clip in the vertical direction is fixed, and thus, it is possible to prevent the metal clip from being inclined, and it is possible to keep a thickness of the soldering part constant, such that a power module of a certain standard may be manufactured.

Meanwhile, at the time of a soldering process, heat loss may occur through the upper jig and the lower jig, and the upper jig and the lower jig may also be expanded by heat to be thermally deformed. In order to solve such a problem, the present invention adopts the following configuration.

Referring to <FIG> again, the upper jig has a plurality of punched parts <NUM> formed to penetrate through the upper jig. Accordingly, heat dissipated through the upper jig may be minimized, a manufacturing cost of the upper jig may be decreased, and structural robustness of the upper jig may be improved.

In addition, in order to prevent thermal deformation of the power module, each of the upper jig and the lower jig may be formed of a material having a low coefficient of thermal expansion and having a high mechanical strength. Specifically, each of the upper jig and the lower jig may have a coefficient of thermal expansion of <NUM> ppm/°C or less and a tensile strength of <NUM> MPa or more.

Furthermore, a volume may be optimized in order to increase heat transfer efficiency conducted from a lower portion, and as a preferable example, the lower jig may be manufactured to have a volume <NUM> times or more the volume of the power module.

<FIG> is a flowchart of a power module soldering method according to an embodiment of the present invention. The soldering method according to an embodiment of the present invention includes a lower jig configuring step, an upper jig configuring step, a jig fastening step, and an integrated soldering step.

In the lower jig configuring step, the circuit board, the chip solder, the chips, and the clip solder are sequentially stacked on the lower jig. In the upper jig configuring step, the metal clip is fixed to the lower part of the upper jig. In the jig fastening step, the lower jig and the upper jig are fastened to each other. In addition, in the integrated soldering step, the chip solder and the clip solder are soldered simultaneously in one process. Here, the order of the lower jig configuring step and the upper jig configuring step may be changed.

Furthermore, in the lower jig configuring step, a lead frame solder and the lead frame may be further sequentially stacked on one side of the circuit board, and a pin solder and signal pins may further be sequentially stacked on the other side of the circuit board. In this case, in the integrated soldering step, the lead frame solder and the pin solder may be simultaneously soldered together with the chip solder and the clip solder in one process.

With the soldering method according to an embodiment of the present invention described above, all the solders in the power module are simultaneously soldered in one process, such that a manufacturing process of the power module may be simplified and a manufacturing yield of the power module may be significantly improved.

Referring to <FIG> again, a product of <FIG> is internal components of the power module in which mounted components of the power module are soldered through a soldering process, and a power module of a final product is manufactured by forming the molding part <NUM> for protecting the internal components. The molding part <NUM> corresponds to a housing or cover accommodating and protecting the internal components.

<FIG> is views illustrating a molding part manufacturing mold according to the related art, and illustrates an upper mold and a lower mold. In the molding part manufacturing mold according to the related art, a molding material injection port and a molding material discharge port are formed as an intaglio in the upper mold, and it is impossible to change an injection position and a discharge position of a molding material. Accordingly, when design structures of the internal components of the power module are changed, there is a problem that a mold should be newly manufactured by redesigning positions of an injection port and a discharge port suitable for the changed design structures. The change in the design structures of the internal components of the power module may mean a change in a size of the power module, a change in positions of the internal components, a change in structures of the internal components, and the like.

<FIG> is views illustrating whether or not a molding part is peeled according to an injection position and a discharge position of a molding material. In a left drawing of <FIG>, an injection position of the molding material is positioned on the lower right side of the left drawing and a discharge position of the molding material is positioned on the upper left side of the left drawing. In this case, as indicated by dotted lines, the molding material is not uniformly dispersed between the internal components of the power module, such that peeling of the molding part occurs. In a right drawing of <FIG>, an injection position of the molding material is positioned at the right center of the right drawing and a discharge position of the molding material is positioned on the upper left side of the right drawing. In this case, as illustrated in the right drawing of <FIG>, the molding material is uniformly dispersed between the internal components of the power module, such that peeling of the molding part does not occur. As described above, there is an injection position and a discharge position of the molding material optimized for each of the design structures of the internal components of the power module. To the end, injection and discharge positions of the molding part need to be appropriately designed according to the design structures of the internal components of each power module. However, as described above, the molding part manufacturing mold according to the related art is manufactured in a form in which the molding material injection port and the molding material discharge port are fixed, and thus, it is impossible to change positions of the molding material injection port and the molding material discharge port.

The present invention has been made in an effort to solve such a problem, and provides a molding part manufacturing mold in which positions of a molding material injection port and a molding material discharge port may be changed.

<FIG> is a view illustrating a molding part manufacturing mold according to an embodiment of the present invention. The molding part manufacturing mold <NUM> according to an embodiment of the present invention includes an upper mold <NUM> and a lower mold <NUM>, and further includes an injection part mounting mold <NUM> and a discharge part mounting mold <NUM>.

The upper mold <NUM> and the lower mold <NUM> are stacked and fastened to each other to form a molding space <NUM> into which the internal components of the power module are put therebetween. A molding material is injected into the molding space <NUM> into which the internal components are put, such that the molding part of the power module is manufactured. The molding material may be an epoxy molding compound (EMC).

The injection part mounting mold <NUM> is mounted in a first mounting groove (not illustrated) formed inside the upper mold <NUM> or the lower mold <NUM>, and includes one or more injection ports <NUM> injecting the molding material into the molding space <NUM>. That is, a mounting groove into which the injection part mounting mold may be inserted and mounted is formed in the upper mold or the lower mold, and the injection part mounting mold <NUM> is inserted and mounted into the mounting groove. The injection part mounting mold <NUM> is detachably mounted in the first mounting groove. <FIG> illustrates that the mounting groove is formed in the upper mold and the injection part mounting mold is mounted in the mounting groove.

The discharge part mounting mold <NUM> is mounted in a second mounting groove (not illustrated) formed inside the upper mold <NUM> or the lower mold <NUM>, and includes one or more discharge ports discharging the molding material injected into the molding space. That is, a mounting groove into which the discharge part mounting mold may be inserted and mounted is formed in the upper mold or the lower mold, and the discharge part mounting mold is inserted and mounted into the mounting groove. The discharge part mounting mold <NUM> is detachably mounted in the second mounting groove. <FIG> illustrates that the mounting groove is formed in the upper mold and the discharge part mounting mold is mounted in the mounting groove.

The injection part mounting mold <NUM> is one injection part mounting mold in an injection part mounting mold set <NUM> including various types of injection part mounting molds <NUM> having different injection port structures, and the discharge part mounting mold <NUM> is one discharge part mounting mold in a discharge part mounting mold set <NUM> including various types of discharge part mounting molds <NUM> having different discharge port structures. <FIG> is views illustrating an injection part mounting mold set and a discharge part mounting mold set. As illustrated in <FIG>, the injection part mounting molds <NUM> of the injection part mounting mold set <NUM> are formed so that at least one of positions, the numbers, and sizes of injection ports <NUM> are different from each other, and the discharge part mounting molds <NUM> of the discharge part mounting mold set <NUM> are formed so that at least one of positions, the numbers, and sizes of discharge ports <NUM> are different from each other. More detailed contents thereof will be described later.

In addition, any one of the injection part mounting molds <NUM> of the injection part mounting mold set <NUM> is mounted in the first mounting groove, and any one of the discharge part mounting molds <NUM> of the discharge part mounting mold set <NUM> is mounted in the second mounting groove. Accordingly, an injection position at which the molding material is injected into the molding space <NUM> and a discharge position at which the molding material is discharged from the molding space may be freely changed.

That is, as compared with the molding part manufacturing mold according to the related art in which the positions of the molding material injection port and the molding material discharge port are fixed and may not be changed, the molding part manufacturing mold according to the present invention is manufactured so that the injection position and the discharge position of the molding material may be freely changed by separately manufacturing an injection part mold and a discharge part mold and mounting each of the injection part mold and the discharge part mold on the upper mold or the lower mold. Accordingly, the molding part manufacturing mold according to the present invention may easily cope with changes in designs of the internal components of the power module of various structures, such that utilization efficiency of the molds may be increased, and a degree of freedom of the changes in the designs of the internal components of the power module may be secured without considering the molding part manufacturing mold.

Here, the injection part mounting mold <NUM> may be inserted into and bolted to the first mounting groove, and the discharge part mounting mold <NUM> may be inserted into and bolted to the second mounting groove. To this end, bolting holes <NUM>-H and <NUM>-H may be formed in the injection part mounting mold and the discharge part mounting mold, respectively. The injection part mounting mold and the discharge part mounting mold may be easily and firmly fixed to bolting holes through the bolting.

Hereinafter, a specific embodiment of the molding part manufacturing mold <NUM> will be described.

Referring to <FIG> again, the injection part mounting mold <NUM> has a structure in which the injection ports <NUM> are formed as an intaglio on a mold body 630B, and the discharge hole mounting mold <NUM> has a structure in which the discharge ports <NUM> are formed as an intaglio on a mold body 640B.

The molding space <NUM> has a rectangular shape, the injection part mounting mold <NUM> has a shape in which it extends to be elongated along one side surface (right side surface in <FIG>) of the molding space <NUM>, and the discharge hole mounting mold <NUM> has a shape in which it extends to be elongated along the other side surface (left side surface in <FIG>) of the molding space <NUM>. In addition, the injection part mounting mold <NUM> and the discharge part mounting mold <NUM> are disposed to face each other with the molding space <NUM> interposed therebetween. As described above, the injection part mounting mold and the discharge part mounting mold are disposed to face each other, such that the injection position and the discharge position of the molding material are disposed to face each other, which is preferable in terms of fluidity of the molding material in the molding space.

Referring to <FIG> again, a collection groove <NUM> which is formed to be elongated as an intaglio along a length direction of the injection part mounting mold <NUM> and in which the molding material provided from the outside is collected is formed at a place spaced apart from the molding space <NUM> in the injection part mounting mold <NUM>, and a storage groove <NUM> which is formed to be elongated as an intaglio along a length direction of the discharge part mounting mold <NUM> and in which the molding material discharged to the outside is stored is formed at a place spaced apart from the molding space <NUM> in the discharge part mounting mold <NUM>.

In addition, one side outer groove <NUM> which is formed to be elongated as an intaglio along the length direction of the injection part mounting mold <NUM> and of which a side surface facing one side surface of the molding space <NUM> directly communicates with one side surface of the molding space <NUM> is formed at a place close to the molding space <NUM> in the injection part mounting mold <NUM>. In addition, the other side outer groove <NUM> which is formed to be elongated as an intaglio along the length direction of the discharge part mounting mold <NUM> and of which a side surface facing the other side surface of the molding space <NUM> directly communicates with the other side surface of the molding space <NUM> is formed at a place close to the molding space <NUM> in the discharge part mounting mold <NUM>. These outer grooves <NUM> and <NUM> are formed in order to prevent injection pressures from being concentrated on the injection port <NUM> or the discharge port <NUM>, and may prevent the molding material from flowing out due to the concentration of the injection pressures.

In addition, the injection port <NUM> has an outer side communicating with the collection groove <NUM> and an inner side communicating with one side outer groove <NUM>, and the discharge port <NUM> has an inner side communicating with the other side outer groove <NUM> and an outer side communicating with the storage groove <NUM>. In this case, the injection port <NUM> has an inner diameter increasing from the outside to the inside, that is, as it becomes closer to the molding space <NUM>, and the discharge port <NUM> has an inner diameter decreasing from the inside to the outside, that is, as it becomes more distant from the molding space <NUM>. For example, each of the injection port and the discharge port may be formed in a triangular shape. This is advantageous in dispersing the injection pressures at the injection port and the discharge port.

Referring to <FIG> again, as described above, the injection part mounting mold set <NUM> and the discharge part mounting mold set <NUM> include various types of injection part mounting molds <NUM> and discharge part mounting molds <NUM>, respectively. In this case, the injection part mounting mold <NUM> and the discharge part mounting mold <NUM> are formed so that positions, the numbers, sizes, and the like, of injection ports <NUM> and discharge parts <NUM> are different from each other, respectively. That is, a flow of the molding material in the molding space may be adjusted by freely changing the injection ports and the discharge parts, and as a result, molding optimized for the design structures of the internal components of each power module may be performed.

More specifically, the injection part mounting mold <NUM> includes one or two more injection ports <NUM>, and each of the one or two more injection ports <NUM> is formed in one of the center of the injection part mounting mold <NUM> in the length direction, a position eccentric from the center to one side, and a position eccentric from the center to the other side. In addition, the discharge part mounting mold <NUM> includes one or two or more discharge ports <NUM>, and each of the one or two or more discharge ports <NUM> is formed in one of the center of the discharge part mounting mold <NUM> in the length direction, a position eccentric from the center to one side, and a position eccentric from the center to the other side.

Simultaneously with or separately from this, the injection part mounting mold <NUM> includes two or more injection ports <NUM>, and the two or more injection ports <NUM> are formed to have the same inner diameter or different inner diameters. In addition, the discharge part mounting mold <NUM> includes two or more discharge ports <NUM>, and the two or more discharge ports <NUM> are formed to have the same inner diameter or different inner diameters.

That is, the injection part mounting mold and the discharge part mounting mold may be variously designed by making positions, sizes, the numbers, and the like of injection ports and discharge ports different from each other, respectively, and the molding part manufacturing mold may be modified and designed so as to be appropriate for the design structures of the internal components of the power module by appropriately combining and selecting any one of these various types of injection part mounting molds and any one of these various types of discharge part mounting molds with each other. Accordingly, it is possible to cope with power modules having various design structures, and it is possible to freely change the design regardless of the molding part manufacturing mold at the time of designing the power module.

As described above, the metal clip is applied to the power module according to the present invention. Hereinafter, the metal clip will be described in detail.

<FIG> is a view illustrating a connection structure between a substrate and a chip of the power module according to the related art. As illustrated in <FIG>, in the related art, a chip and a substrate are connected to each other through metal wires at the time of packaging the power module, and aluminum wires are generally used as the metal wires. In a case of connection through the aluminum wires, there are advantages such as a simple structure and a low cost, but there are problems such as relatively low bonding reliability, high thermal resistance, and high parasitic inductance, and furthermore, there is a problem that the number of wires required for a high current increases, such that it is difficult and a long process time is required to connect dozens of wires to each other.

The present invention has been made in an effort to solve such a problem, and provides a metal clip of a power module capable of improving thermal performance of the power module and securing structural stability of the power module by applying the metal clip instead of the wire according to the related art.

<FIG> is a view illustrating a connection structure between a board and a chip of the power module according to an embodiment of the present invention. As illustrated in <FIG>, the metal clips <NUM> are disposed on and connected to the chips <NUM>, and the chips <NUM> and the circuit board <NUM> are connected to each other through the metal clips <NUM>. By applying the metal clips as described above, a bonding area with the chips is increased, such that efficient heat dissipation is achieved to decrease thermal resistance, bonding reliability between the metal clips and the circuit board is increased, and a current density is increased, and thus, a high current may flow. In addition, as compared with a wire bonding technology according to the related art, at the time of applying the metal clips, the chips and the board may be connected to each other at a time, such that a manufacturing process may be simplified, and the metal clips support the internal components of the power module, such that thermal deformation of the power module may be decreased.

<FIG> is a top view of a metal clip according to an embodiment of the present invention, <FIG> is a cross-sectional view taken along line A-A of <FIG>, and <FIG> is a cross-sectional view taken along line B-B of <FIG>. The metal clip <NUM> according to the present invention electrically connects the chips <NUM> of the power module <NUM> to each other, and includes a bonding part <NUM> and an outer side part <NUM>.

A plurality of bonding parts <NUM> are provided to correspond to the respective chips, and a lower surface of each of the plurality of bonding parts <NUM> is bonded to an upper surface of each of the chips.

The outer side part <NUM> is formed to extend upward from at least a portion of an outer side of the bonding part <NUM> to have a step from the bonding part <NUM>. That is, the outer side part <NUM> corresponds to a partition wall formed at the outer side part of the bonding part <NUM>.

Here, a pressing groove <NUM> recessed inward is formed along a boundary between an upper surface of the bonding part <NUM> and the outer side part <NUM>, on the upper surface of the bonding part <NUM>. That is, the lower surface of the bonding part <NUM> corresponds to a bonding surface with the chip <NUM>, and in order to maintain a height of the metal clip <NUM> at the time of soldering, the lower surface of the bonding part <NUM> should have a flatness of a predetermined level or higher. The metal clip according to the present invention has a structure in which a flatness is easily managed because an edge portion of the upper surface of each bonding part <NUM> is formed to be thin.

More specifically, the bonding part <NUM> and the outer side part <NUM> of the metal clip <NUM> have a structure in which a metal plate is bent. In this case, the metal clip <NUM> has a structure in which the outer side part <NUM> is bent at an edge of the bonding part <NUM>, such that the center of the lower surface of the bonding part <NUM> may be convexly formed. This structure is disadvantageous for soldering, and thus, needs to be planarized.

In order to make the lower surface of the bonding part <NUM> flat, the pressing groove <NUM> is formed at the edge of the bonding part <NUM>. The pressing groove <NUM> of the bonding part <NUM> is formed through a punching process. <FIG> is a view illustrating a bonding part punching process. As illustrated in <FIG>, in the bonding part <NUM>, the pressing groove <NUM> is formed in the upper surface of the bonding part <NUM> by punching and pressing a region in which the pressing groove <NUM> of the bonding part <NUM> is formed, from above. In this process, a pressed metal structure (e.g., copper) is pushed toward a mold of the bonding surface, such that it becomes possible to secure a flatness of the bonding surface. That is, the lower surface of the bonding part <NUM> is formed to be flat, and accordingly, the height of the metal clip <NUM> at the time of soldering may be maintained as a desired height.

In addition, as described above, the metal clip <NUM> has the structure in which the metal plate is bent, and accordingly, the entire region of the metal plate is formed to have a constant thickness. That is, the bonding part <NUM> and the outer side part <NUM> are formed to have the same thickness. Furthermore, since the metal clip <NUM> has the structure in which the metal plate is bent, a lower portion of the outer side part <NUM> is formed as an empty space, and the outer side part <NUM> is bent at a predetermined angle from the bonding part <NUM> and extends upward. In this case, an angle θ formed by a lower surface of the outer side part <NUM> and the lower surface of the bonding part <NUM> is smaller than a right angle.

<FIG> is a view illustrating a flow of solder at the time of a soldering process. As illustrated in <FIG>, the clip solder <NUM> flows along the lower surface of the outer side part <NUM> by an adhesive force of the solder itself at the time of the soldering process. In this case, in the present invention, the outer side part <NUM> is bent at a predetermined angle, such that the solder may easily climb on the lower surface of the outer side part <NUM>, and thus, wettability of the solder is improved, and the lower portion of the outer side part <NUM> is formed as the empty space, and the solder is stored in the empty space, such that it is possible to prevent the solder from overflowing an upper portion of the metal clip <NUM>.

In addition, since the outer side part <NUM> has a structure in which it bent at a predetermined angle, the metal clip performs a support function when the power module is thermally deformed, which may assist in withstanding stress caused by thermal deformation.

Meanwhile, the chips positioned below the solder may also move along with the solder while the solder flows at the time of soldering. In the present invention, the outer side part <NUM> is formed in a symmetrical shape in order to prevent the chip from moving at the time of soldering. Accordingly, the solder flows symmetrically along the outer side part <NUM>, such that amounts of movement of the solder from the center toward both sides are the same as each other, and thus, the movement of the chips at the time of the soldering may be prevented.

Specifically, referring to <FIG> and <FIG> again, the bonding part <NUM> is formed in a rectangular shape when viewed from above, and the outer side parts <NUM> are formed at edges of the bonding part <NUM> in three directions among edges of the bonding part <NUM> in four directions or are formed at all of the edges of the bonding part <NUM> in the four directions. For passivation of the chips <NUM>, the outer side part <NUM> may not be formed at an edge of the bonding part <NUM> in any one direction among the edges of the bonding part <NUM> in the four directions. In this case, the outer side parts <NUM> are formed to be symmetrical to each other with respect to the center of the bonding part <NUM> when the bonding part <NUM> is viewed from above. That is, the outer side parts <NUM> in each direction formed at an outer side of the bonding part <NUM> may have the same height and bending angle, and may be formed in a structure in which they are mirror-symmetrical to each other with respect to a center line of the chip in a direction perpendicular to a direction in which the chips are arranged.

<FIG> is a view illustrating a soldered state when outer side parts are asymmetrically formed in the metal clip. As illustrated in <FIG>, it may be confirmed that solder overflow to an upper portion of the metal clip occurs, and lower chips are moved and rotated. <FIG> is a view illustrating a soldered state when outer side parts are symmetrically formed in the metal clip. As illustrated in <FIG>, it may be confirmed that solder overflow to an upper portion of the metal clip does not occur and lower chips are not moved and rotated.

Meanwhile, referring to <FIG> and <FIG> again, one or more through holes <NUM> penetrating through the metal clip <NUM> are formed in the metal clip <NUM>. In this case, one or more through holes <NUM> are formed in a connection part connecting two adjacent bonding parts <NUM> of the plurality of bonding parts <NUM> to each other. The connection part may correspond to a portion of the outer side part <NUM>. The through hole <NUM> formed in the connection part is a hole for securing fluidity of the molding material at the time of manufacturing the molding part described above, and may be formed in a size of <NUM>% or more of a particle size of the molding material. In addition, in order to satisfy such a condition, at least one of one or more through holes <NUM> may be formed in an elliptical shape. In this case, the through hole <NUM> having the elliptical shape may correspond to the ring groove <NUM> described above, and the metal clip may be fixed to the upper jig <NUM> of the soldering jig <NUM> at the time of soldering the power module through the through hole <NUM> having the elliptical shape.

Various embodiments of the present disclosure do not list all available combinations but are for describing a representative aspect of the present disclosure, and descriptions of various embodiments may be applied independently or may be applied through a combination of two or more.

The scope of the present disclosure may include software or machine-executable instructions (for example, an operation system (OS), applications, firmware, programs, etc.), which enable operations of a method according to various embodiments to be executed in a device or a computer, and a non-transitory computer-readable medium capable of being executed in a device or a computer each storing the software or the instructions.

The present disclosure has been made in an effort to solve problems in the related art, and the present disclosure is directed to a power module pack applied to an inverter, the power module accommodated in the power module pack, and the structure and the manufacturing method of the clip applied to the power module, through which performance of the inverter may be improved, manufacturing convenience may be secured, and a manufacturing yield may be increased. This is in contrast to prior processes in which a soldering process is divided into a primary process and a secondary process, such that a defective rate according to each soldering process increases, and types of mounted components of the power module are many, such that there is a difficulty in manufacturing the power module.

Claim 1:
A power module pack (<NUM>) comprising:
a first cooling plate (<NUM>);
a second cooling plate (<NUM>) stacked on and coupled to the first cooling plate (<NUM>); and
one or more power modules (<NUM>) interposed between the first cooling plate (<NUM>) and the second cooling plate (<NUM>),
wherein each of the one or more power modules (<NUM>) has a lower surface soldered to an upper surface of the first cooling plate (<NUM>),
characterized in that one or more engraved grooves (<NUM>) recessed inward are formed in an upper surface of each of the one or more power modules (<NUM>),
in that embossed projections (<NUM>-B) protruding outward are formed, respectively, at positions each corresponding to the one or more engraved grooves (<NUM>) of each of the one or more power modules (<NUM>) on a lower surface of the second cooling plate (<NUM>), and
wherein each embossed projection (<NUM>-B) of the second cooling plate (<NUM>) is inserted into each engraved groove (<NUM>) of each of the one or more power modules (<NUM>), such that a position of each of the one or more power modules (<NUM>) is fixed.