JP2015109394A - Semiconductor device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a thickness of a solder and parallelism of the thickness after bonding and inhibit deformation occurring in the solder when a switching element of a small plane area and a terminal board are bonded by using the solder.SOLUTION: Provided are a semiconductor device 10 having a switching element chip 16 bonded with a substrate 12 and a manufacturing method of the semiconductor device 10. The semiconductor device manufacturing method comprises the steps of: arranging a sheet solder 32 (solder 14) and a porous body 18 having a certain thickness between an undersurface or a top face of the switching element chip 16 and the substrate 12; heating and melting the sheet solder 32 and impregnating the entire porous body 18 from a top edge to a bottom edge in a thickness direction with the sheet solder 32 to bond the switching element chip 16 and the substrate 12.

Description

  The present invention relates to a semiconductor device including a switching element joined to a terminal plate and a method for manufacturing the same.

  For example, Patent Documents 1 and 2 disclose a technique of manufacturing a semiconductor device by bonding a switching element to a terminal plate.

  In Patent Document 1, a plurality of bumps are formed on a transfer substrate by a wire bonder, and each bump is transferred to a terminal electrode of an electronic circuit element (switching element). It is disclosed to use a connection surface for (terminal plate). In this case, the electronic circuit element is connected to the circuit board via a plurality of bumps, so that each bump electrically connects the electronic circuit element and the circuit board, and the gap between the electronic circuit element and the circuit board. It functions as a spacer for filling an anisotropic conductive resin.

  In Patent Document 2, metal protrusions are provided on a plurality of electrode pads of a first semiconductor element (switching element) and a plurality of connection pads of a second semiconductor element (terminal plate), respectively. And connecting the metal protrusions in a state where the protrusion provided on one of the second semiconductor elements has a pointed tip and the protrusion provided on the other has a flat top. Is disclosed. In this case, the first semiconductor element is connected to the second semiconductor element via the plurality of metal protrusions, so that each metal protrusion electrically connects the first semiconductor element and the second semiconductor element. And functions as a spacer for filling the gap between the first semiconductor element and the second mounted object with the sealing resin.

JP-A-10-135216 JP 2003-197672 A

  By the way, as a next-generation switching element, a switching element having a smaller plane area than the conventional one is assumed. However, when the plane area of the switching element is reduced, it is difficult to form a plurality of bumps as in Patent Document 1 and a plurality of metal protrusions as in Patent Document 2 on the switching element. As a result, the planar area of the switching element to which the techniques of Patent Documents 1 and 2 can be applied is limited (the planar area of the switching element that can be manufactured is limited), and the size of the switching element that can be mounted on the semiconductor device (flat area) Area) will be limited.

  Such a problem is similarly caused even when the material for joining the switching element and the terminal plate is changed from the resin disclosed in Patent Documents 1 and 2 to solder.

  That is, when joining the switching element and the terminal plate using solder, a plurality of spacers (for example, bonding wires or protrusions formed on the terminal plate facing the switching element) are provided in advance on the switching element or the terminal plate, It is conceivable to join the switching element and the terminal plate by laminating the terminal plate, the sheet solder, and the switching element in this order and heating and melting the sheet solder in a reflow furnace. In this case, if a plurality of spacers are provided, the thickness and parallelism of the solder after joining can be ensured. However, as described above, since the next-generation switching element has a small plane area, it is difficult to ensure a size enough to provide a plurality of spacers.

  Therefore, it is conceivable that a plurality of balls made of metal of a certain size are mixed in the sheet solder so that each ball functions as a spacer during heating in the reflow furnace. However, when a ball having a large sphere diameter is mixed with the sheet solder in order to ensure the thickness of the solder after joining, the volume ratio of the solder is lowered. In addition, in the case of a switching element with a small flat area, the bonding area with the terminal plate is small, so that the thickness of the solder is restricted in relation to the volume ratio of the solder.

  In addition, when the switching element and the terminal plate are joined by pressing the switching element against the terminal plate using a weight that is a pressing body during heating in the reflow furnace, the outer periphery of the weight is overhanged. It is conceivable that the flange portion is provided in contact with a jig that holds the switching element and the terminal plate. In this case, in the reflow process, when the switching element is pushed down by the weight, the flange portion comes into contact with the jig, and the height of the weight is regulated. Thereby, the inclination of the solder is suppressed, and the thickness and parallelism of the solder are ensured.

  However, since it is necessary to form a flange on the weight, there is a limit to the connection between the switching element having a small flat area and the terminal plate. Moreover, while the upper limit of the solder thickness is defined by the weight height, the lower limit cannot be defined. As a result, due to the tolerance of each member used for joining, a certain amount of inclination must be allowed for the solder after joining.

  Thus, when the plane area of the switching element is reduced, it becomes difficult to provide a plurality of spacers on the switching element or the terminal plate, and it becomes difficult to ensure the parallelism of the solder thickness after joining. Even if a plurality of spacers can be provided on the switching element or the terminal board, the parallelism of the solder thickness depends on each spacer, and it is difficult to ensure the parallelism.

  In addition, since the plane area becomes small, it becomes difficult to adjust the parallelism of the solder thickness using a jig, and the solder overflows to the side of the switching element, so that the thickness of the solder after joining is reduced. There is a possibility that it cannot be secured or the thickness of the solder becomes non-uniform.

  Furthermore, if the thickness of the solder is reduced, the stress due to the distortion of the solder increases, and the durability of the joint portion (solder) between the switching element and the terminal board may be reduced.

  The present invention has been made in consideration of such various problems. When a switching element having a small flat area and a terminal plate are joined using solder, the thickness of the solder after joining and the parallel of the thicknesses are combined. The present invention relates to a semiconductor device and a method for manufacturing the same that can secure the degree and suppress distortion generated in solder.

  The present invention relates to a semiconductor device including a switching element bonded to a terminal plate and a method for manufacturing the same.

  In the semiconductor device, a lower surface or an upper surface of the switching element is joined to the terminal plate by solder, a porous body having a certain thickness is disposed between the switching element and the terminal plate, and the solder is Impregnation is performed throughout the thickness direction from the upper end to the lower end of the porous body.

  Further, in the manufacturing method, solder and a porous body having a certain thickness are disposed between the lower surface or the upper surface of the switching element and the terminal plate, and the solder is melted to form the porous body. The switching element and the terminal plate are joined by impregnating the solder over the entire thickness direction from the upper end to the lower end of the switch.

  As described above, when the conventional technique is applied, the size of the switching element mounted on the semiconductor device (the planar area of the next-generation switching element) is limited. Therefore, when a switching element having a small flat area is joined to the terminal board, adjustment with a jig is difficult. In addition, when the switching element and the terminal plate are joined using solder, the solder overflows to the side of the switching element, making it impossible to ensure the thickness of the solder, or the thickness of the solder is not uniform. There is a risk of becoming. In the portion where the thickness of the solder is reduced, the stress due to strain increases. As a result, the durability of the solder after joining may be reduced.

  On the other hand, according to the present invention, since the porous body is disposed between the terminal plate and the switching element, when the solder is heated and melted, the solder is impregnated inside the porous body, As a result, the thickness of the solder after joining can be ensured by an amount equivalent to the thickness of the porous body. Therefore, in this invention, it can suppress that the thickness of solder becomes thin or the thickness of solder becomes non-uniform | heterogenous, and a switching element inclines. Thereby, the distortion which generate | occur | produces in the junction part of a switching element and a terminal board can be suppressed.

  As described above, the present invention, when impregnating the porous body disposed between the switching element and the terminal plate having a small plane area with the solder, and joining the switching element and the terminal plate using the solder, It is possible to secure the thickness of the solder after joining and the parallelism of the thickness, and to suppress distortion generated in the solder.

  When the solder is heated and melted, if the switching element and the porous body are pressed to the terminal plate side using the pressing body, the distance between the terminal plate and the switching element is maintained at the thickness of the porous body, The porous body can be easily impregnated with solder.

  And in this invention, it is preferable that the area of a porous body is smaller than the area of a switching element by planar view. When the plane area of the porous body is the same as the plane area of the switching element (the size of the porous body is the same as the shape of the switching element in plan view), it is necessary to impregnate the entire porous body with solder Therefore, some solder may be pushed out around the porous body and overflow to the side of the switching element. Therefore, in the present invention, by making the plane area of the porous body smaller than the plane area of the switching element, it is easy to spread the solder in the space around the porous body while ensuring the thickness of the solder. It is possible to suppress a part of the solder from overflowing locally to the side of the switching element.

  In this case, the switching element is formed in a rectangular shape in plan view, and the lengths of the porous body in the vertical direction and the horizontal direction are each longer than the length from the outer periphery to the center of gravity of the switching element. It is preferable. As a result, in addition to the above-described effect obtained by making the plane area of the porous body smaller than the plane area of the switching element, even if the position of the porous body is shifted between the switching element and the terminal plate, If the center of gravity of the switching element is located inside the porous body, the thickness of the solder can be ensured more reliably.

  Furthermore, it is preferable that the outer periphery of the porous body is formed in an arc shape or is chamfered in a plan view. Thereby, it can position so that a porous body may not overlap with the corner | angular part of a switching element by planar view. As a result, it is possible to stably distribute the solder to corners where stress is likely to concentrate, and to more effectively suppress a decrease in durability of the solder after joining.

  According to the present invention, when the switching element and the terminal plate are joined using the solder while the porous body disposed between the switching element and the terminal plate having a small plane area is impregnated with the solder, It is possible to ensure the thickness of the solder and the parallelism of the thickness, and to suppress distortion generated in the solder.

It is sectional drawing of the semiconductor device which concerns on this embodiment. It is sectional drawing of the manufacturing apparatus for manufacturing the semiconductor device of FIG. It is sectional drawing of the manufacturing apparatus which concerns on a comparative example. It is sectional drawing of the semiconductor device which concerns on the comparative example manufactured with the manufacturing apparatus of FIG. It is a graph which shows the relationship between the thickness of solder and stress. It is sectional drawing which illustrated the positional relationship of the gravity center of a weight or a switching element chip | tip, and a porous body. It is sectional drawing according to arrangement | positioning shown in FIG. It is sectional drawing which shows the modification of this embodiment.

  A preferred embodiment of the semiconductor device and the manufacturing method thereof according to the present invention will be described below in detail with reference to FIGS.

[Semiconductor Device 10 According to this Embodiment]
FIG. 1 is a cross-sectional view of a semiconductor device 10 according to this embodiment.

  The semiconductor device 10 includes a substrate 12 and a switching element chip 16 bonded to the upper surface of the substrate 12 via solder 14. The substrate 12 is a terminal plate of the switching element chip 16 made of a metal plate such as a copper plate, a ceramic-bonded electrode such as a DBC substrate, a metal block, or a beam lead (press-molded electrode). The switching element chip 16 is a power module semiconductor element chip such as a MOSFET using SiC, and is a next-generation switching element chip having a relatively small flat area (narrow area of several mm square or less).

  In the semiconductor device 10, a block-shaped porous body 18 having a certain thickness and functioning as a spacer is disposed between the substrate 12 and the switching element chip 16. The porous body 18 has a narrower width (smaller planar area) than the switching element chip 16, and the pores 20 (see FIG. 2) formed inside the porous body 18 are impregnated with the solder 14. Yes. FIG. 1 illustrates a state in which a porous body 18 is disposed at a substantially central portion between the substrate 12 and the switching element chip 16, and a side portion of the porous body 18 is surrounded by the solder 14. Yes.

  The porous body 18 is a porous metal (for example, a foamed metal made of copper or silver) or a porous ceramic with good wettability with the solder 14 in which the solder 14 is easily impregnated into the pores 20. In addition, the volume ratio of the porous body 18 is about several percent so that the electrical resistivity and thermal conductivity of the entire porous body 18 after impregnation do not greatly change from the electrical resistivity and thermal conductivity of the solder 14. It is preferable that it is set. Therefore, the porosity of the porous body 18 is preferably 90% or more.

  The air holes 20 preferably include open air holes in consideration of electric conduction between the substrate 12 and the switching element chip 16. Therefore, in the porous body 18, the solder 14 is impregnated over the entire thickness direction (vertical direction in FIGS. 1 and 2) from the upper end to the lower end of the porous body 18.

  As a result, the side surface of the porous body 18 is surrounded in a state where the upper surface of the substrate 12 and the lower surface of the switching element chip 16 are maintained at a predetermined interval (for example, an interval of several hundred μm or more) by the porous body 18. The substrate 12 and the switching element chip 16 are joined by the solder 14 and the solder 14 impregnated in the holes 20 and exposed at the upper and lower ends of the porous body 18. That is, the porous body 18 is impregnated with the solder 14, and the substrate 12 and the switching element chip 16 are joined in a state where the porous body 18 is cast and integrated by the surrounding solder 14.

[Method of Manufacturing Semiconductor Device 10 According to this Embodiment]
A method of manufacturing the semiconductor device 10 configured as described above will be described with reference to FIG.

  FIG. 2 is a cross-sectional view illustrating a part of the manufacturing apparatus 22 that performs the method of manufacturing the semiconductor device 10 according to this embodiment.

  The manufacturing apparatus 22 is an apparatus including a heating apparatus such as a reflow furnace, and includes a jig 26 made of carbon or SUS having a recess 24 and having heat resistance. The substrate 12 is accommodated in the recess 24. The depth of the recess 24 is set to such a depth that the upper surface of the substrate 12 is slightly above the upper surface of the jig 26 when the substrate 12 is accommodated in the recess 24. Further, the manufacturing apparatus 22 has an opening 28 having a size that allows the switching element chip 16 to be inserted, and has a heat-resistant carbon or SUS lid 30 that holds the substrate 12 accommodated in the recess 24 from above. Is further provided.

  In this embodiment, when manufacturing the semiconductor device 10, first, the substrate 12 is placed in the recess 24 of the jig 26. Next, the lid 30 is lowered from above the jig 26 to hold the upper surface of the substrate 12. Thereby, when the lid 30 is viewed from above, only a predetermined portion of the upper surface of the substrate 12 is exposed through the opening 28.

  Next, the sheet solder 32 that becomes the solder 14, the porous body 18 before impregnation, the switching element chip 16, and the weight (pressing body) 34 are stacked in that order on the upper surface of the substrate 12 through the opening 28. . In this case, the sheet solder 32 is disposed on the upper surface of the substrate 12 so as to cover the predetermined portion. In FIG. 2, the substantially central portion of the upper surface of the substrate 12 is defined as the predetermined location, and the sheet solder 32, the porous body 18 before impregnation, the switching element chip 16 and the weight 34 are laminated substantially coaxially with respect to the predetermined location. The case is shown.

  Next, after the jig 26 and the lid 30 described above are placed in a reflow furnace, the sheet solder 32 is melted by heating to a predetermined temperature. In this case, when the sheet solder 32 is heated and melted, the switching element chip 16 and the porous body 18 are lowered by the pressing force from the weight 34. As a result, the molten sheet solder 32 is impregnated in the pores 20 of the porous body 18.

  As described above, the porous body 18 has a certain thickness along the vertical direction. Therefore, when the porous body 18 is lowered to the upper surface of the substrate 12 by the pressing force from the weight 34, the porous body 18 is held at a predetermined position on the upper surface of the substrate 12 by the pressing force, and the substrate 12 and the switching element chip 16 are The interval is maintained at the thickness of the porous body 18. In this state, the melted sheet solder 32 (solder 14) is impregnated in the holes 20. That is, the porous body 18 is impregnated with the solder 14 in the pores 20 and cast and integrated with the surrounding solder 14.

  Thereafter, when the heat treatment in the reflow furnace is stopped, the solder 14 is cooled and solidified. Thereby, between the switching element chip 16 and the substrate 12, the porous body 18 in which the pores 20 are impregnated with the solder 14 has a predetermined thickness of the solder 14 solidified at the side of the porous body 18. It functions as a spacer for equalizing the thickness (thickness of the porous body 18). Therefore, the substrate 12 and the switching element chip 16 are joined together with the solder 14 having a uniform thickness. In this way, the semiconductor device 10 is manufactured.

  Finally, the jig 26 and the lid 30 are pulled out from the reflow furnace, the weight 34 and the lid 30 are removed, and the manufactured semiconductor device 10 is taken out.

[Effects of this embodiment]
Next, effects of the semiconductor device 10 and the manufacturing method thereof according to this embodiment will be described.

  Here, the effects of this embodiment will be described in comparison with the conventional manufacturing method (comparative example) shown in FIGS. In FIG. 3 and FIG. 4, the same components as in this embodiment will be described with the same reference numerals.

  FIG. 3 illustrates a manufacturing apparatus 36 according to a comparative example, in which a sheet solder 32, a switching element chip 16, and a weight 34 are sequentially stacked at predetermined positions on the upper surface of the substrate 12. Therefore, the comparative example is different from this embodiment in that the semiconductor device 38 (see FIG. 4) is manufactured without using the porous body 18.

  In the comparative example, after the sheet solder 32, the switching element chip 16, and the weight 34 are sequentially laminated at predetermined positions on the upper surface of the substrate 12 through the opening 28, and the jig 26, the lid 30 and the like are disposed in the reflow furnace. Then, the sheet solder 32 is melted by heating to a predetermined temperature. Thereby, the switching element chip 16 is lowered by the pressing force from the weight 34, and when the heat treatment in the reflow furnace is stopped, the solder 14 is cooled and solidified. As a result, the substrate 12 and the switching element chip 16 are joined via the solder 14, and the semiconductor device 38 is manufactured.

  However, when the switching element chip 16 is a next-generation switching element chip having a small plane area, the solder 14 of the semiconductor device 38 is caused by tolerances of the jig 26, the lid 30 and the weight 34 constituting the manufacturing apparatus 36. A certain amount of inclination must be allowed.

  That is, as described in [Problems to be Solved by the Invention], since the next generation switching element chip 16 has a small plane area, a plurality of spacers may be provided on the switching element chip 16 or the substrate 12. Have difficulty. Therefore, when the conventional technique is applied and the substrate 12 and the switching element chip 16 are bonded using the solder 14, it is difficult to ensure the parallelism of the thickness of the solder 14 after bonding. Even if a plurality of spacers can be provided on the switching element chip 16 or the substrate 12, the parallelism of the thickness of the solder 14 depends on each spacer, so that it is difficult to ensure the parallelism. .

  Further, when the plane area is reduced, it becomes difficult to adjust the parallelism of the thickness of the solder 14 using the jig 26 and the lid 30, and the solder 14 overflows to the side of the switching element chip 16. The thickness of the later solder 14 cannot be ensured, or the thickness of the solder 14 becomes non-uniform.

  Further, when the thickness of the solder 14 is reduced, the stress due to the distortion of the solder 14 is increased as shown in FIG. As a result, in the solder 14 having a non-uniform thickness, stress due to distortion is generated in the thinned portion (the left portion in FIG. 4), and the durability of the solder 14 is reduced.

  On the other hand, in this embodiment, in the semiconductor device 10, the porous body 18 having a certain thickness is disposed between the lower surface of the switching element chip 16 and the upper surface of the substrate 12, and from the upper end of the porous body 18. The solder 14 is impregnated over the entire thickness direction up to the lower end, and the substrate 12 is switched by the solder 14 surrounding the side of the porous body 18 and the solder 14 exposed at the upper and lower ends of the porous body 18. The element chip 16 is joined.

  In this embodiment, in the manufacturing method of the semiconductor device 10, after the sheet solder 32 and the porous body 18 having a certain thickness are disposed between the lower surface of the switching element chip 16 and the upper surface of the substrate 12, The sheet solder 32 is heated and melted, and the switching element chip 16 and the substrate 12 are joined by the solder 14 while impregnating the sheet solder 32 (solder 14) over the entire thickness direction from the upper end to the lower end of the porous body 18. .

  Thus, in this embodiment, since the porous body 18 is disposed between the substrate 12 and the switching element chip 16, the porous body 18 is obtained when the solder 14 (sheet solder 32) is heated and melted. As a result, the thickness of the solder 14 after joining can be ensured by an amount equivalent to the thickness of the porous body 18. Therefore, in this embodiment, the thickness of the solder 14 is reduced, or the thickness of the solder 14 is not uniform, and the switching element chip 16 can be prevented from being inclined. Thereby, the distortion which generate | occur | produces in the solder 14 which is a junction part of the board | substrate 12 and the switching element chip | tip 16 can be suppressed.

  As described above, in this embodiment, the porous element 18 disposed between the switching element chip 16 having a small plane area and the substrate 12 is impregnated with the solder 14, and the switching element chip 16 and the substrate 12 are soldered. When joining using the solder 14, it is possible to ensure the thickness of the solder 14 after joining and the parallelism of the thickness, and to suppress distortion generated in the solder 14.

  In this embodiment, when the sheet solder 32 is heated and melted, the distance between the substrate 12 and the switching element chip 16 can be obtained by pressing the switching element chip 16 and the porous body 18 toward the substrate 12 using the weight 34. Can be easily impregnated with the sheet solder 32 (solder 14) in a state where the thickness of the porous body 18 is maintained.

  In this embodiment, the plane area of the porous body 18 is set smaller than the plane area of the switching element chip 16. When the plane area of the porous body 18 is equal to the plane area of the switching element chip 16 (the size of the porous body 18 is the same as the shape of the switching element chip 16), the entire porous body 18 is soldered. Since it is necessary to impregnate 14, as described above, a part of the solder 14 may be pushed out around the porous body 18 and overflow to the side of the switching element chip 16.

  Therefore, in this embodiment, the solder 14 is placed in the space around the porous body 18 while ensuring the thickness of the solder 14 by making the plane area of the porous body 18 smaller than the plane area of the switching element chip 16. It is possible to prevent the solder 14 from partially overflowing to the side of the switching element chip 16 by facilitating the spread.

[Modification of this embodiment]
The present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

  As shown in FIGS. 6 and 7, in this embodiment, the center of gravity 40 of the weight 34 (or the switching element chip 16) only needs to be inside the porous body 18 inside the opening 28 of the lid 30. .

  As described above, when the planar area of the porous body 18 is equal to the planar area of the switching element chip 16 (the porous body 18 has the same size as the shape of the switching element chip 16 in plan view). Since the entire porous body 18 needs to be impregnated with the solder 14, a part of the solder 14 may be pushed out around the porous body 18 and overflow to the side of the switching element chip 16.

  Therefore, the planar area of the porous body 18 is made smaller than the planar area of the switching element chip 16 (the original planar area of the porous body 18a indicated by the two-dot chain line is changed to the porous body 18 having a small planar area indicated by the solid line. Thus, while ensuring the thickness of the solder 14, it is easy to spread the solder 14 in the space around the porous body 18, and a part of the solder 14 is locally located on the side of the switching element chip 16. It is possible to suppress overflowing.

  Further, in the plan view of FIG. 6, the switching element chip 16 is formed in a rectangular shape, and the length L1 in the vertical direction and the length L2 in the horizontal direction of the porous body 18 are respectively weights 34 (switching element chip 16). ) Is set longer than the lengths L3, L4, and L41 from the outer periphery to the center of gravity 40 (L1> L3, L2> L4, L2> L41).

  As a result, in addition to the above-described effect obtained by making the plane area of the porous body 18 smaller than the plane area of the switching element chip 16, even if the position of the porous body 18 is shifted between the substrate 12 and the switching element chip 16. 6, if the center of gravity 40 of the switching element chip 16 is located inside the porous body 18 in the plan view of FIG. 6, the porous body 18 is surely impregnated with the solder 14 without tilting the weight 34, The thickness of the solder 14 can be ensured more reliably.

  Thus, even if the plane area of the porous body 18 is reduced, it is possible to achieve both the reliable impregnation of the solder 14 into the porous body 18 and the securing of the parallelism of the thickness of the solder 14.

  Further, since the weight 34 and the center of gravity 40 of the switching element chip 16 need only be inside the porous body 18 in a plan view, the porous body 18 has an annular cross section as shown in FIG. There may be. Thereby, the center of gravity 40 can be included in the inside of the porous body 18 with a smaller plane area.

  In this case, by setting the porous body 18 to have an annular cross section (a cylindrical porous body 18), the porous body 18 can be positioned so as not to overlap the corners of the switching element chip 16. As a result, it is possible to stably spread the solder 14 to corners where stress is likely to concentrate, and to more effectively suppress a decrease in durability of the solder 14 after joining.

  Further, in this embodiment, the porous body 18 is not limited to the block shape or the cylindrical shape described above, and any material can be used as long as the thickness of the solder 14 and the parallelism of the thickness can be secured. The shape can also be adopted.

  That is, in this embodiment, if the center of gravity 40 is inward of the porous body 18 and the porous body 18 is not located at a position overlapping the corner of the switching element chip 16, the porous body 18 is Any cross-sectional shape can be used. For example, the porous body 18 may have an arc shape with a perfect circular shape, an elliptical shape, or an oval cross section, or may have a cross-sectional shape in which the outer periphery of the porous body 18 is chamfered. By adopting these cross-sectional shapes, the same effects as the cross-sectional annular configuration of FIG. 8 can be obtained.

  In this embodiment, as described above, the upper surface of the substrate 12 and the lower surface of the switching element chip 16 are held between the upper surface of the substrate 12 and the lower surface of the switching element chip 16 by the porous body 18 at a predetermined interval. And the solder 14 are impregnated, and the holes 20 of the porous body 18 are impregnated with the solder 14.

  This embodiment is not limited to this description, and the porous body 18 holds a gap between the lower surface of a substrate (not shown) (for example, the same substrate as the substrate 12) and the upper surface of the switching element chip 16 at a predetermined interval. On the other hand, the lower surface of the substrate and the upper surface of the switching element chip 16 may be joined with the solder 14, and the pores 20 of the porous body 18 may be impregnated with the solder 14. Even in this case, each effect by this embodiment mentioned above can be acquired easily.

  In the above description, the case where the manufacturing apparatus 22 manufactures one semiconductor device 10 has been described. However, in this embodiment, the jig 26 is provided with a plurality of recesses 24 and the lid 30 has a plurality of openings. It is also possible to provide a plurality of semiconductor devices 10 at the same time. Even in this case, by applying the manufacturing method of this embodiment described above and simultaneously manufacturing each semiconductor device 10 using the porous body 18, stable and good bonding quality (a certain level) can be obtained for all the semiconductor devices 10. The thickness of the solder 14 and the parallelism of the thickness) can be ensured.

DESCRIPTION OF SYMBOLS 10, 38 ... Semiconductor device 12 ... Board | substrate 14 ... Solder 16 ... Switching element chip | tip 18, 18a ... Porous body 20 ... Hole 22, 36 ... Manufacturing apparatus 24 ... Recessed part 26 ... Jig 28 ... Opening part 30 ... Cover 32 ... Sheet solder 34 ... weight 40 ... center of gravity

Claims (6)

In a semiconductor device comprising a switching element joined to a terminal plate,
The lower surface or upper surface of the switching element is joined to the terminal board by solder,
Between the switching element and the terminal plate, a porous body having a certain thickness is disposed,
The solder is impregnated over the entire thickness direction from the upper end to the lower end of the porous body. The semiconductor device according to claim 1,
The semiconductor device, wherein an area of the porous body is smaller than an area of the switching element in a plan view. The semiconductor device according to claim 2,
In a plan view, the switching element is formed in a rectangular shape,
The length of the said porous body in the vertical direction and a horizontal direction is respectively formed longer than the length from the outer periphery of the said switching element to a gravity center. The semiconductor device characterized by the above-mentioned. The semiconductor device according to any one of claims 1 to 3,
The semiconductor device, wherein the outer periphery of the porous body is formed in an arc shape or is chamfered in a plan view. In a method for manufacturing a semiconductor device for manufacturing a semiconductor device by bonding a switching element to a terminal plate,
Between the lower surface or upper surface of the switching element and the terminal plate, a solder and a porous body having a certain thickness are disposed,
The switching element and the terminal plate are joined by melting the solder and impregnating the solder over the entire thickness direction from the upper end to the lower end of the porous body. Production method. In the manufacturing method of the semiconductor device according to claim 5,
When the solder is melted, the switching element and the porous body are pressed toward the terminal plate using a pressing body, so that the distance between the terminal plate and the switching element is set to the thickness of the porous body. The method for manufacturing a semiconductor device, wherein the porous body is impregnated with the solder while being held.

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