JP2019009328A - Power semiconductor device - Google Patents

Abstract

To obtain a power semiconductor device capable of realizing compaction/weight saving, heavy-current/high breakdown voltage, and low cost/high reliability, by making the flow of flux component contained in solder paste controllable.SOLUTION: In a power semiconductor device in which a power semiconductor element is chip mounted by Ag sinter, and comprising a metal wiring board, a main terminal, and a frame, the main terminal is provided at one end to be solder joined, with an opening for injecting solder paste containing flux, and has a notch for flowing out the solder paste at a part of a circumference forming the opening. The notch is provided at a position where the solder paste injected into the opening flows out in a direction deviated from the power semiconductor element and the Ag sinter, thus allowing flow control of the flux component contained in the solder paste.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power semiconductor device that includes a main terminal for a current path and a signal terminal, in which a power semiconductor element, a terminal, and a wire connecting the power semiconductor element are sealed with a sealing material, and in particular, bonding with a solder paste is applied. The present invention relates to a power semiconductor device.

  Power semiconductor devices for power conversion are incorporated in various products from transportation equipment to household appliances. In addition, products that have not been provided with a power semiconductor device have been increasingly incorporated from the viewpoint of power saving and high efficiency. These products are required to be further reduced in size and improved in durability, and downsizing and high durability are indispensable also in the power semiconductor device to be mounted.

  A power semiconductor device can operate at a high voltage, a large current, and a high frequency as compared with a semiconductor element used in household appliances or computers. On the other hand, power semiconductor devices generate significant heat during operation and tend to become high temperature.

  For example, a switching power supply widely used as a power converter controls power by continuously opening and closing a large current circuit at high speed. By performing such control, the switching power supply generates heat due to the power loss due to the on-resistance and forward voltage drop of the power semiconductor used as the switching element. For this reason, the solderability of the main terminal, which is a large current path of the power semiconductor element, is one of the factors that greatly affects the durability and reliability of the module product.

  In a power module, connection of components by a reflow process is common, and a solder paste containing a flux component is used at that time. When the electrode area is increased as in a power module, the wet spreadability of the solder paste is not improved even if the temperature during reflow is increased. Therefore, solderability is secured by using a large amount of solder paste. However, using a large amount of solder paste causes problems such as generation of voids, scattering of flux and solder particles.

  As a conventional technique for preventing a failure of a connection terminal in a power module component due to heat, there is a technique in which a hole is formed in a central portion of a lead electrode surface and a gas (void) of a solder joint portion is released using a chimney effect. (For example, refer to Patent Document 1).

JP 2007-335767 A

  However, this conventional technique has the following problems. In the semiconductor power module component connection terminal described in Patent Document 1 described above, the hole formed in the central portion of the lead electrode surface is for the purpose of releasing the gas in the solder connection portion to the outside. For this reason, the shape of this hole is a reverse taper type in which the opening on the lower surface of the terminal is widened and becomes narrower upward. In Patent Document 1, a solder paste is applied in advance for connecting components, and the components are placed thereon.

  In this case, the pressing force for placing the component on the solder paste causes extrusion of the solder paste applied in advance, scattering of the flux and solder particles, and the like. For this reason, the molten solder paste may come into contact with the adjacent chip or wiring and cause an electrical short circuit. Furthermore, there is also a problem that the amount of solder necessary for obtaining sufficient solder meltability does not remain due to scattering of flux and solder particles.

  Further, when solid solder such as plate solder is used, the wettability at the time of melting the solder is remarkably deteriorated due to the surface oxidation of the solder or the joining member. Therefore, it is necessary to apply a fluxing agent in advance or to perform solder melting in a reducing atmosphere such as formic acid.

  On the other hand, when flux is applied and the solder is melted, a flux residue cleaning step is required after the solder is melted due to reliability problems. As a result, an additional work process or an additional worker is required, leading to an increase in cost.

  Furthermore, there may be a case where the flux residue cannot be completely removed when a small part is arranged or when the structure is complicated. For this reason, the concern about reliability deterioration remains.

  In the case of solder melting in a formic acid atmosphere, handling of formic acid, management problems, and the introduction of an atmosphere forming device dedicated to formic acid are necessary. Therefore, in the case of solder melting in a formic acid atmosphere, there is a problem that workability is deteriorated in addition to an increase in cost.

  The present invention has been made in order to solve such a problem, and enables the flow of the flux component contained in the solder paste to be controlled when performing the joining using the solder paste, thereby reducing the size and weight, An object of the present invention is to obtain a power semiconductor device capable of realizing high breakdown voltage and low cost and high reliability.

  A power semiconductor device according to the present invention includes a metal wiring board having a power semiconductor element mounted on a chip by an Ag sinter and having a land portion for solder joint, and a main terminal in which the land portion and one end are electrically connected by solder joint. And a resin frame that covers the periphery of the metal wiring board on which the power semiconductor element is mounted, and is incorporated so that the other end of the main terminal protrudes to the outside. The main terminal is provided with an opening for injecting a solder paste containing flux at one end where the solder is joined, and a notch for allowing the solder paste to flow out to the outside in a part of the periphery forming the opening. The notch is provided at a position where the solder paste injected into the opening flows out in a direction shifted from the power semiconductor element and the Ag sinter. It is, and makes it possible to flow control of the flux component contained in the solder paste.

  According to the present invention, at one end of the main terminal, by providing an opening having a notch for allowing the solder paste to flow out in a specific direction, even when a large amount of solder paste is applied, the main terminal leaks. A structure that can guide and discharge the solder paste properly is realized. As a result, when joining using solder paste, the flow of flux components contained in the solder paste can be controlled, and it is possible to achieve small size, light weight, high current, high pressure resistance, and low cost and high reliability. A power semiconductor device can be obtained.

It is a figure which shows the structure of the semiconductor device for electric power which concerns on Embodiment 1 of this invention. It is a figure which shows the specific structure of the upper surface and cross section of the power semiconductor device which concerns on Embodiment 1 of this invention. It is the figure which showed the cross section along the upper surface and III-III line | wire of the main terminal of the power semiconductor device which concerns on Embodiment 1 of this invention. It is a figure which shows typically the flow-out of the solder paste in the power semiconductor device which concerns on Embodiment 1 of this invention. It is the figure which expanded the cross section of the main terminal of the semiconductor device for electric power which concerns on Embodiment 1 of this invention. It is an example of the shape of the main terminal of the semiconductor device for electric power which concerns on Embodiment 1 of this invention. It is a figure which shows the specific structure of the upper surface and cross section of the power semiconductor device which concerns on Embodiment 2 of this invention. It is a figure which shows typically the flow-out of the solder paste in the power semiconductor device which concerns on Embodiment 2 of this invention. It is a figure which shows the cross section at the time of mounting the concrete mortar jig | tool mounted on the main terminal of the power semiconductor device which concerns on Embodiment 3 of this invention, and a jig | tool on a main terminal. It is a figure which shows the cross section of the frame frame integrated jig | tool mounted on the main terminal of the semiconductor device for electric power which concerns on Embodiment 3 of this invention. It is a flowchart which shows the manufacturing process of the semiconductor device for electric power in Embodiment 4 of this invention.

  Hereinafter, preferred embodiments of a power semiconductor device of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a power semiconductor device according to the first embodiment of the present invention. The power semiconductor device according to the first embodiment is configured to include a main terminal 5 and a plurality of signal terminals 6 which are formed to protrude from the resin frame 2 of the module.

  The main terminal 5 is a power supply terminal for inputting a main power supply of the power semiconductor device. The main terminal 5 is made of metal, and is formed of, for example, an alloy based on copper or stainless steel. The metal of the base material may be exposed on the surface of the main terminal 5, or at least a part of the surface may be plated.

  One end of the signal terminal 6 protrudes from the frame of the module. The signal terminal 6 is a terminal for inputting a signal for controlling the operation of the power semiconductor element 3 from the outside. Similarly to the main terminal 5, the signal terminal 6 is made of metal and is formed of an alloy. The signal terminal 6 may be plated on at least a part or the entire surface of the lead.

  The frame 2 can be injection-molded and is made of a high heat resistant resin. Specific examples of the high heat resistant resin include PPS (polyphenylene sulfide), fluorine resin, and the like. The frame 2 incorporates a main terminal 5 which is a power supply terminal of the semiconductor element, a signal terminal 6 for operation control, and a terminal for wire bonding.

  The frame 2 is bonded to the substrate 1 on which the semiconductor element is mounted with an adhesive. The adhesive is generally a silicone-based or epoxy-based thermosetting adhesive.

  The power semiconductor element 3 includes an upper surface electrode provided on the upper surface of the power semiconductor element 3 and a lower surface electrode provided on the lower surface of the power semiconductor element 3. The lower surface electrode of the power semiconductor element 3 is mechanically and electrically connected to the wiring board by being joined to terminals of the wiring board via a conductive member.

  Further, the upper surface electrode of the power semiconductor element 3 is mechanically and electrically connected to the lower portion of the main terminal 5 through a conductive member. Further, the power semiconductor element 3 is connected to a lead as an external terminal by a wire. The power semiconductor element 3 is characterized in that a current flows in the thickness direction when the power semiconductor element 3 is on and the current is interrupted when the power semiconductor element 3 is off.

  As a material of the power semiconductor element 3, for example, not only Si but also a compound semiconductor such as SiC, GaN, GaAs may be used. Moreover, a layer capable of being soldered, such as a Ni plating layer, may be provided on the surface of the upper surface electrode of the power semiconductor element 3.

  The power semiconductor device is a semiconductor device that controls or supplies power, and is characterized by handling a large voltage and current. Power semiconductor devices are used for power conversion applications such as voltage conversion, frequency conversion, DC to AC conversion, or AC to DC conversion. Power semiconductor devices are used in inverters for home appliances such as air conditioners, refrigerators, washing machines, electric / hybrid vehicles, drive systems for electric railway vehicles, and illumination control applications for lighting equipment.

  The conductive members are respectively disposed between the upper surface electrode or the wiring substrate of the power semiconductor element 3 and the main terminal 5 and between the lower surface electrode of the power semiconductor element 3 and the wiring substrate. For example, a silver (Ag) paste is used for the conductive member. Ag paste has been used for power semiconductor products as one of die bond materials excellent in high temperature durability and heat dissipation.

  The Ag paste is a paste obtained by adding an organic solvent to Ag nanoparticles. Ag nanoparticles have high conductivity among metals and are excellent in heat resistance, high temperature durability and reliability. Further, the Ag nano-particles are made fine to the nano-scale to increase the reactivity, and thereby the bonding material is sintered at a low temperature without melting to form a metal bonding layer.

  Silicone gel covers the power semiconductor element 3 and terminals, wires, and the like, and is used as a sealing material for modules for the purpose of protecting the power semiconductor element from external environmental factors such as light, heat, humidity, and vibration.

  Silicone gel has excellent heat resistance and cold resistance unique to silicone, has no corrosive properties, has low shrinkage upon curing, and has excellent adhesiveness and adhesiveness resulting from low crosslink density, sealing properties, and moisture resistance. It has the property to have sex. Furthermore, silicone gel has excellent characteristics in vibration absorption and is widely used as a sealing / protecting material and a filler.

  The wiring board has an insulating layer and a conductor layer, and is joined to the lower surface electrode of the power semiconductor element 3 via a conductive member. The wiring substrate is a ceramic material wired with copper or aluminum.

  The mortar-shaped jig 12 is made of a heat-resistant material that exceeds the solder melting temperature. Similar to the frame 2, the mortar-shaped jig 12 is made of PPS (polyphenylene sulfide) or fluorine resin, and ceramic can also be used.

  The mortar-shaped jig 12, which is the jig of the present invention, is set on the terminal portion in the solder application step, and is removed after the solder application. Alternatively, the mortar-shaped jig 12 can be removed after the solder is melted in the reflow process, or can be sealed with a silicone gel in the subsequent process without being removed as it is.

  Further, in the manufacturing process of the frame 2, a shape corresponding to the mortar-shaped jig 12 can be formed by injection molding at the upper position of the main terminal 5 in advance when the frame is manufactured. In this case, since the frame frame 2 and the mortar shape are integrated, it is not necessary to install the mortar-shaped jig 12 on the main terminal 5 in the assembly process of the power semiconductor element. As a result, it is possible to reduce time and costs such as process reduction and worker reduction.

  FIG. 2 is a diagram showing a specific configuration of the upper surface and cross section of the power semiconductor device according to the first embodiment of the present invention. The substrate 1 used in the power semiconductor device shown in FIG. 2 is composed of an insulating layer such as ceramic, a front conductor layer such as Cu, and a back conductor layer. Two power semiconductor elements 3 (IGBT; Insulated Gate Bipolar Transistor and free wheel diode) are die-bonded to the surface conductor layer of the substrate 1 by Ag paste.

  Further, the back surface of the substrate 1 is bonded to a heat sink having an effect of releasing heat generated when the power semiconductor operates.

  The frame frame 2 is adhered to the outer peripheral portion of the chip on the substrate surface using a silicone adhesive or the like, and is thermally cured. In the frame frame 2, a main terminal 5 serving as a path for a large current for operating the power semiconductor and eight signal terminals 6 for power control protrude in the vertical direction (Z-axis direction) of the frame frame. .

  Further, in the horizontal direction (XY direction) of the frame frame, a main terminal 5 for soldering and bonding to the substrate 1 and a signal terminal 6 for connecting to the electrode pad of the power semiconductor element 3 by wire bonding, respectively, It protrudes.

  When the frame frame 2 is bonded and cured to the substrate 1 with an adhesive, the land on the substrate 1 and the main terminal 5 protruding from the frame frame 2 are positioned. The power semiconductor device for power bonded and hardened is set on a jig in a solder application process after the electrodes on the chip and the terminals on the frame are connected by an aluminum wire.

  The dispenser unit is moved to the opening on the main terminal 5 and solder paste is injected. The solder paste can be adjusted so that an optimum application amount can be obtained with the air pressure of the dispenser unit, the moving speed of the head portion, and the distance (GAP) between the tip of the dispenser and the main terminal as variables.

  The solder paste to be used is a residue-free or low-residue type that does not require a cleaning step, so that flux application before soldering and melting in a formic acid reducing atmosphere after solder application can be avoided. Therefore, by using such a solder paste, the solder paste can be melted in a low oxygen concentration atmosphere in a general-purpose nitrogen reflow apparatus.

  FIG. 3 is a diagram showing a top surface of main terminal 5 and a cross section taken along line III-III of the power semiconductor device according to the first embodiment of the present invention.

  The main terminal 5 is a terminal for applying solder that protrudes in the XY direction from the frame 2. This terminal has a so-called tapered shape 10 in which the opening size of the upper surface of the terminal in the Z direction is wider than the opening size of the lower surface.

  Next, the case where the solder paste is applied from above the terminal using the dispenser unit will be described.

  According to the structure of the main terminal 5 according to the present invention, it is possible to prevent the solder paste from remaining on the upper surface of the terminal or leaking from the upper surface of the terminal to the outside of the terminal. Further, the applied solder paste flows while being melted to the land portion 15 (see FIG. 2) on the lower surface of the terminal. Therefore, it is possible to fill the land portion 15 of the substrate 1, the lower surface of the terminal, and the side surface with an amount of solder paste necessary to form a good fillet.

  FIG. 4 is a diagram schematically showing the flow of solder paste in the power semiconductor device according to the first embodiment of the present invention. As shown in FIG. 3, the main terminal 5 has a C-shaped cut 9 in which a part of the tip is cut. In FIG. 4, the cut portion is located between two semiconductor chips 3 mounted side by side on the substrate 1. Solder paste 14 is injected into the main terminal 5.

  When injecting the solder paste 14 with the dispenser unit, if the amount of the solder paste 14 increases, excess solder paste 14 leaks from the opening of the main terminal 5. At this time, the C-shaped cut 9 introduced at the tip of the main terminal 5 induces the flow of the solder paste 14 in the direction perpendicular to the opening, thereby flowing into the semiconductor element (chip) 3 and the Ag sintering area 8. The amount of the solder paste 14 can be reduced. That is, the flow control of the flux component contained in the solder paste 14 can be realized by having the C-shaped cut 9.

  By this effect, an electrical short circuit due to the leaked solder paste 14 can be prevented. Furthermore, the occurrence of Ag ion migration caused by the flux component contained in the solder paste 14 adhering to the Ag sintering area 8 can be avoided, and the reliability of the product can be improved.

  FIG. 5 is an enlarged view of the cross section of the main terminal 5 of the power semiconductor device according to the first embodiment of the present invention. In FIG. 5, the cross section of the frame 2 is also drawn. As in FIG. 3, the main terminal 5 has a taper that has a wide opening on the upper surface of the terminal and becomes narrower toward the lower surface. Further, the outer side of the lower surface of the main terminal 5 has a structure having a key part 11 bent in a key shape (L-shape) toward the substrate.

  When the solder paste 14 is injected from the dispenser unit, the solder paste 14 that has flowed to the lower surface of the terminal may be pushed out of the land as it is due to the viscosity of the solder paste 14 or the distance between the terminal and the board land. Therefore, the key portion 11 is provided to serve as a breakwater for preventing the solder paste 14 from being pushed out of the land.

  With the structure of the main terminal 5 according to the first embodiment, it is possible to avoid the solder paste 14 and the flux contained therein from flowing out around the terminals and lands and being electrically short-circuited with the semiconductor element (chip) 3. it can. As a result, it is possible to reduce the size and weight of the module by narrowing the distance between the solder bonding land, chip and wiring. Furthermore, the flow control of the flux component contained in the solder paste can be realized by a simple configuration of the main terminal 5, so that the number of members used can be reduced and the cost can be reduced.

  FIG. 6 is a shape example of the main terminal 5 of the power semiconductor device according to the first embodiment of the present invention. In this example, a part of the terminal is cut out in accordance with the application in order to guide and control the flowing direction of the solder paste 14.

  FIG. 6A illustrates a terminal in which the lateral direction of the terminal is cut. FIG. 6B illustrates a terminal cut at an arbitrary angle. The shape of the terminal is not limited to the shape shown in FIGS. 6 (a) and 6 (b).

  Depending on the distance or mutual arrangement of the terminal and the semiconductor element (chip) 3, the size of the land, the area required for solder bonding, the amount of solder paste applied, etc. It is possible to design the position and cutting width. As a specific example, FIG. 6C illustrates a diamond-shaped terminal, and FIG. 6D illustrates a triangular terminal.

Embodiment 2. FIG.
FIG. 7 is a diagram showing a specific configuration of the upper surface and cross section of the power semiconductor device according to the second embodiment of the present invention. In FIG. 7, one power semiconductor element (IGBT and a free wheel diode) 3 is made of Ag paste on the surface conductor layer of the substrate 1 made of an insulating layer such as ceramic, a surface conductor layer such as Cu, and a back surface conductor layer. Die bonded. The frame frame 2 is adhered to the outer peripheral portion of the chip on the substrate surface using a silicone adhesive or the like, and is thermally cured.

  In the frame frame 2, a main terminal 5 serving as a path for a large current for operating the power semiconductor and five signal terminals 6 for power control protrude in the vertical direction (Z-axis direction) of the frame frame 2. Yes. Further, in the horizontal direction (XY direction) of the frame frame 2, there are a main terminal 5 for soldering and joining to the substrate 1, and a signal terminal 6 for connecting to the electrode pad of the power semiconductor element 3 by wire bonding, Each protrudes.

  After the frame frame 2 is bonded and cured to the substrate 1 with an adhesive, the chip electrodes and terminals on the frame are connected with aluminum wires. Next, the solder paste 14 is injected into the terminal opening by the dispenser unit. The solder paste 14 can be prevented from melting in a flux coating or formic acid reducing atmosphere by using a residue-free or low-residue type that does not require a cleaning process. Therefore, by using such a solder paste 14, the solder paste 14 can be melted in a low oxygen concentration atmosphere in a general-purpose nitrogen reflow apparatus.

  FIG. 8 is a diagram schematically showing the flow of the solder paste 14 in the power semiconductor device according to the second embodiment of the present invention. The main terminal 5 has a shape in which a lateral side on one side of the terminal is notched. When the amount of the solder paste 14 increases, the solder paste 14 leaked from the opening of the terminal is guided to flow in a direction perpendicular to the cut of the terminal, and moves toward the semiconductor element (chip) 3 and the Ag sintering area 8. The cuts of the main terminals are arranged so that there is no.

  Thereby, a short circuit between the solder paste that has flowed out and the chip can be prevented. That is, in the Ag sintering area 8, it is possible to avoid the occurrence of Ag ion migration caused by the adhesion of the flux component contained in the solder paste, and to improve the reliability of the product.

Embodiment 3 FIG.
FIG. 9 is a diagram showing a cross section when a concrete mortar jig 12 and jig to be mounted on the main terminal 5 of the power semiconductor device according to the third embodiment of the present invention are mounted on the main terminal 5. . The mortar-shaped jig 12 in the third embodiment is made of an injection-moldable resin such as PPS (polyphenylene sulfide) made of the same material as the frame 2.

  Before the solder paste 14 is applied from the top of the terminal by the dispenser unit, the mortar-shaped jig 12 is mechanically controlled or manually positioned on the top of the terminal, and then the solder paste 14 is applied.

  Usually, in order to inject the solder paste 14 into the terminal opening by the dispenser unit and fill the solder paste 14 between the board land portion 15 and the terminal gap, several nozzles (or needles) at the tip of the dispenser head are provided on the upper surface of the terminal. A positioning accuracy close to a distance of 10 to several hundred microns is required.

  However, when a mass production process is assumed, the relative position between the nozzle tip of the dispenser unit and the terminal opening varies depending on the member tolerance, assembly tolerance, and conveyance positioning accuracy of the power semiconductor device.

  Therefore, the mortar-shaped jig 12 is used in the second embodiment so as not to be affected by variations in positioning accuracy between the nozzle tip and the terminal opening in the mass production process. Specifically, the mortar-shaped jig 12 is installed on the upper surface of the terminal, and a nozzle tip for injecting solder paste into the opening of the mortar-shaped jig 12 is disposed. Here, as shown in FIG. 9, the mortar-shaped jig 12 is formed in a shape such that the cross-sectional area of the opening of the mortar-shaped jig 12 is larger than the cross-sectional area of the upper surface opening of the main terminal 5. ing.

  By using the mortar-shaped jig 12 having such a shape, the positioning accuracy of the nozzle at the tip of the dispenser head is eased, the sagging and leakage at the time of pouring the solder paste are prevented, the solder paste on the chip and wiring, and the solder paste included therein Therefore, it is possible to prevent electrical short-circuiting.

  FIG. 10 is a view showing a cross section of the frame-frame-integrated jig 13 placed on the main terminal 5 of the power semiconductor device according to the third embodiment of the present invention. The frame frame integrated jig 13 shown in FIG. 10 is different from that shown in FIG. 9 in that the mortar-shaped jig 12 is integrally formed with the resin frame by the mold design. As a result, an alignment mechanism for the frame 2 and the mortar-shaped jig 13 is not necessary.

  The frame 2 is made of a resin such as PPS (polyphenylene sulfide), for example. Therefore, by designing a mold having a mortar-shaped part and using a mold having a mortar-shaped part in the manufacturing process of the frame frame 2, the frame frame integrated jig 13 can be injection-molded. As a result, product quality and yield are stable, and mass production is possible without increasing costs.

  The mortar-shaped jig 13 according to Embodiment 3 can alleviate the positioning accuracy of the dispenser unit when the solder paste is applied from the upper part of the terminal by the dispenser unit. As a result, solder paste sagging, leakage, and protrusion due to relative displacement between the terminal and dispenser unit can be suppressed, and the required amount of solder paste can be applied to the gap between the terminal opening, the terminal, and the board land. It becomes.

  Furthermore, even if a large amount of solder paste is applied in order to form a sufficient fillet and ensure good meltability of the solder paste, the solder paste leaks out to the chip and the wiring part and is electrically connected by the solder bridge. It is possible to prevent product quality defects caused by causing a short circuit.

  The heat-resistant mortar-shaped jig can be recycled after being applied after the solder paste is applied or after the solder paste is melted in the reflow process and then re-installed in a subsequent module. However, if it is judged that the cost will be high considering the manpower and equipment for removing and re-installing the heat-resistant jig, it flows to the subsequent process with the heat-resistant jig attached, and the semiconductor elements and terminals It is also possible to fill the heat-resistant jig with silicone gel together with the wire.

Embodiment 4 FIG.
In the fourth embodiment, a series of manufacturing steps of the power semiconductor device according to the present invention will be specifically described with reference to a flowchart. FIG. 11 is a flowchart showing manufacturing steps of the power semiconductor device according to the fourth embodiment of the present invention.

  First, an Ag paste is printed on the ceramic substrate (substrate 1) (step S1101), and the power semiconductor element 3 (chip 3) is die-bonded (step S1102).

  Next, an epoxy-based adhesive is applied to the back surface of the frame frame 2, and the substrate 1 and the frame frame 2 are overlapped and assembled, and then the substrate 1 and the frame frame 2 are cured in a curing furnace (step S1103).

  Next, the electrode (pad) of the chip 3 and the electrode terminal on the surface of the frame frame 2 are connected by wire bonding with an aluminum wire (step S1104).

  Next, the solder paste 14 is applied to the soldering portion provided on the main terminal 5 where the main terminal lead 4 protrudes from the frame 2, and the solder is melted and cooled in a low oxygen concentration atmosphere in a reflow process. Then, the main terminal 5 and the substrate 1 are joined (step S1105).

  In this step, as described in the first to third embodiments, the main terminal 5 having an opening having a notch for allowing the solder paste 14 to flow out in a specific direction is applied at one end. By applying such a main terminal 5, even when a large amount of solder paste 14 is applied, the solder paste 14 leaking from the main terminal 5 can be appropriately guided and discharged, and the flux component contained in the solder paste 14 Flow control is possible.

  Next, solder is placed on the heat sink, and a plurality of power semiconductor devices are placed thereon. Solder is placed on the electrode on the chip of the power semiconductor device, and a lead (a metal part similar to the terminal) is placed on the solder. (Step S1106).

  Next, the gel is injected into the frame frame 2 with a silicone gel, and the gel is cured in a curing furnace (step S1107).

  Next, the support is attached, and the main terminal is TIG (Tungsten Inert Gas) welded (step S1108), and the entire inside of the support on which the power semiconductor device is mounted is gel-sealed with silicone gel (step S1109).

  After the gel sealing, a cooling pipe is press-fitted (step S1110), and the characteristics are inspected (step S1111).

  Although not described in this assembly process flow, quality inspection processes such as visual appearance inspection, ultrasonic flaw detection inspection (SAT / C-SAM), X-ray inspection, electrical characteristic inspection, or reduction / cleaning processes are the processes. It is assumed that it is performed at a predetermined timing in the middle of the flow.

  The preferred embodiment has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications and replacements are made to the above-described embodiment without departing from the scope described in the claims. Can be added.

  DESCRIPTION OF SYMBOLS 1 Board | substrate, 2 Frame frame, 3 Power semiconductor element (semiconductor chip), 4 Main terminal lead, 5 Main terminal (Soldering part), 6 Signal terminal, 7 Positioning pin, 8 Ag sintering area, 9 Terminal notch part, 10 Tapered part, 11 key (¬) part, 12 mortar-shaped jig, 13 frame-frame-integrated mortar-shaped jig, 14 solder paste, 15 land part.

Claims (5)

A metal wiring board on which a power semiconductor element is mounted by Ag sintering and has a land portion for soldering;
A main terminal electrically connected to the land portion and one end by solder bonding;
A power semiconductor device configured to include a resin frame that covers the periphery of the metal wiring board on which the other end of the main terminal protrudes to the outside and covers the power semiconductor element. There,
The main terminal is provided with an opening for injecting a solder paste containing flux at the one end where the solder is joined, and the solder paste flows out to a part of the periphery forming the opening. Has a notch,
The notch is provided at a position where the solder paste injected into the opening flows out in a direction deviated from the power semiconductor element and the Ag sinter, and can control the flow of flux components contained in the solder paste. Power semiconductor device. 2. The main terminal has a tapered shape in which a longitudinal cross-sectional shape of the opening portion is wider on an upper surface side than a lower surface side to be solder-bonded to the land portion, and the opening portion is widened toward the upper surface direction. The power semiconductor device according to the above. The power semiconductor device according to claim 1, wherein the main terminal has a key shape in which a longitudinal cross-sectional shape of a tip portion of the one end is bent in a direction of a lower surface side to be solder-bonded to the land portion. 4. The power semiconductor device according to claim 1, further comprising: a jig mounted on an upper surface of the opening and having a mortar shape that expands a cross-sectional area of the upper surface of the opening. The power semiconductor device according to claim 4, wherein the jig is integrally formed with the frame frame.

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