JP4533152B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, and more particularly to a transfer mold type semiconductor device incorporating a heating element and a control element.

  In recent years, there is an increasing demand for power semiconductor devices (intelligent power modules (hereinafter simply referred to as “IPMs”)) that reliably control large currents flowing in electronic devices such as motors and heaters. Such an IPM is generally controlled so as to safely stop driving when an overcurrent flows through a heating element (eg, an insulated gate bipolar transistor (IGBT)) that generates a large amount of heat during driving. And a control element (for example, a complementary metal oxide semiconductor (CMOS) chip).

  In general, the switching time of a control element varies with its temperature, and in particular increases as the temperature of the control element increases. Therefore, when the heat generated from the heat generating element is transferred to the control element incorporated in the same resin package and the temperature of the control element rises, the switching loss of the IPM increases.

Techniques for suppressing the temperature rise of the control element by improving the heat dissipation of the control element have been proposed. For example, according to the semiconductor device shown in FIG. 1 of JP-A-8-255868, the heat generated from the digital IC chip itself is obtained by mounting and fixing the analog IC chip and the digital IC chip on the insulated die pad metal plates. It is disclosed that heat is efficiently radiated to the outside.
JP-A-8-255868

  However, in general, the heat generated from an analog IC chip such as an IGBT is much larger than the heat generated from a digital IC chip such as a CMOS, and a heat radiating fin is further provided on a metal plate on which the IGBT is mounted. However, in FIG. 2 of the above-mentioned Patent Document 1 showing the prior art, if the heat dissipating fins are arranged on a pair of metal plates, the heat from the analog IC chip is dissipated. The heat dissipation of the digital IC chip is rather deteriorated. In other words, according to the semiconductor device according to this prior art, the radiating fins cannot be provided on the metal plate in order to more efficiently cool the analog IC chip that generates enormous heat.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor device that can be attached with a radiation fin that efficiently dissipates heat generated from a heating element, and that can suppress propagation of heat from the heating element to a control element. And

A semiconductor device according to an aspect of the present invention includes at least one set of first and second lead frames including a front surface and a back surface, a heating element mounted on the front surface of the first lead frame, and the first A control element mounted on the front surface of the second lead frame and generating less heat than the heat generating element; and facing or abutting against the back surface of the first lead frame; and on the back surface of the second lead frame A heat dissipating block that does not oppose, and a heat generating element, the control element, and a resin package that seals the heat dissipating block, the resin package having an upper surface that opposes the surface of the first and second lead frames; A first lower surface facing the back surface of the first lead frame, and a second lower surface facing the back surface of the second lead frame, Having a back surface and a void formed in advance between the plane containing the lower surface of the first lead frame.

  According to one aspect of the present invention, the heat from the heat dissipation block heated by the heating element is prevented from propagating to the second lead frame on which the control element is mounted, and the temperature rise of the control element is minimized. Thus, a semiconductor device with little switching loss can be realized.

  Embodiments of a semiconductor device according to the present invention will be described below with reference to the accompanying drawings. In the description of each embodiment, a term indicating a direction (for example, “X direction”, “Y direction”, “Z direction”, “upward”, “downward”, etc.) is used as appropriate for easy understanding. However, this is for explanation and these terms do not limit the present invention.

Embodiment 1 FIG.
A first embodiment of a transfer mold type semiconductor device according to the present invention will be described below with reference to FIGS. The semiconductor device 1 according to the first embodiment shown in FIG. 1 schematically includes a plurality of first lead frames 10, a plurality of second lead frames 20, and a resin package 30 that seals the entire lead frames 10 and 20. And have.

  In the cross-sectional view shown in FIG. 2, the resin package 30 includes an upper surface 31 that opposes the surface 11 of the first lead frame 10 and the surface 21 of the second lead frame 20, the back surface 13 of the first lead frame 10, and the second surface. A lower surface 33 facing the back surface 23 of the lead frame 20 is provided. Further, on the surface 11 of the first lead frame 10, at least one that generates extremely large heat during switching driving of, for example, a free wheel diode chip (FWD chip) 12a and an insulated gate bipolar transistor chip (IGBT chip) 12b. The heating element 12 is mounted using a conductive adhesive (not shown) such as solder. Similarly, on the surface 21 of the second lead frame 20, for example, when an overcurrent flows through the IGBT chip 12 b, a complementary metal oxide semiconductor (CMOS) that controls the switching drive to be stopped safely is used. A control element 22 such as a chip is mounted using a conductive adhesive (not shown). In the present application, the FWD chip 12a and the IGBT chip 12b are exemplified as the heating element 12, and the CMOS chip 22 is disclosed as an example of the control element 22. However, the heating element 12 is an arbitrary circuit element that generates a large amount of heat. The control element 22 is an arbitrary circuit element that generates less heat than the heating element 12, and the specific functions of the heating element 12 and the control element 22 do not limit the present invention.

  According to the semiconductor device 1 of the first embodiment of the present invention, in the cross-sectional view shown in FIG. 3, the three heating elements 12 are mounted on the surface 11 of the first lead frame 10a on the leftmost side in the drawing. The other first lead frames 10b, 10c, and 10d are illustrated as having one heating element 12 mounted thereon. In addition, the semiconductor device 1 includes a plurality of heat sinks 40a to 40f (FIG. 3) fixed in contact with the back surface 13 (FIG. 2) of the first lead frame 10. These heat sinks 40 are constituted by metal blocks (heat radiating blocks) having good thermal conductivity such as copper or aluminum, and can efficiently transmit heat generated from the respective heat generating elements 12 downward. As described above, the heating element 12, the control element 22, and the heat sink 40 are sealed so as to be entirely surrounded by the resin package 30. Thus, the semiconductor device 1 according to the first embodiment is a transfer mold type IPM having a divided heat sink structure.

  Furthermore, according to the first embodiment of the present invention, each heat sink 40 does not extend in the X direction beyond the first lead frame 10 toward the second lead frame 20 as shown in FIG. The back surface 23 of the frame 20 does not face the heat sink 40.

  In the semiconductor device 1 configured in this manner, the heat generated by the heating element 12 propagates to the heat sink 40 and is efficiently radiated from the lower surface 33 of the resin package 30 through the heat sink 40 immediately. Further, as shown in FIGS. 2 and 3, preferably, the radiation fins 50 are attached so as to contact the lower surface 33 of the resin package 30, and the heat from the lower surface 33 of the resin package 30 is more effectively radiated. Is done. As described above, the heat sink 40 does not extend below the second lead frame 20 and does not face the back surface 23 of the second lead frame 20 (FIG. 2). Therefore, according to the first embodiment, it is possible to suppress the heat from being transmitted from the heat sink 40 heated by the heating element 12 to the second lead frame 20, and to suppress the temperature rise of the control element 22 to a minimum. The semiconductor device 1 with little switching loss can be realized.

  By the way, each independent heat sink 40 is fixed in contact with the back surface 13 of each corresponding first lead frame 10, so that each heat sink 40a to 40f is each first lead frame 10a as shown in FIG. The resin package 30 is transfer-molded in a state of being hung from 10 to 10d. At this time, when the heat sink 40 is fixed to the first lead frame 10, the first lead frame 10 generally tends to sink downward due to the weight of the heat sink 40, but each of the first lead frames 10a to 10d is The heat sink 40 has a difference (variation) in strength or degree of settling with respect to the same weight. Therefore, as shown in FIG. 4, the distance (thickness) between the heat sinks 40a to 40f and the lower surface 33 of the resin package 30 also has a difference (variation) from each other, and the heat sink (for example, 40d) and the resin package sink most greatly. The distance between the 30 lower surfaces 33 must be designed so as to ensure the required minimum withstand voltage.

  However, according to the first embodiment of the present invention, each of the heat sinks 40a to 40f does not extend in the X direction beyond the first lead frame 10 toward the second lead frame 20, and the weight of each of the heat sinks 40a to 40f. Can be made substantially lighter than conventional ones, so that variations in the degree to which each first lead frame 10 sinks can be reduced, and as a result, the thickness between each heat sink 40 and the lower surface 33 of the resin package 30 can be reduced. Can be made thinner. Therefore, according to the first embodiment, the thickness of the semiconductor device 1 in the Z direction can be reduced, and the heat dissipation effect from each heat sink 40 can be improved while ensuring the required minimum withstand voltage.

Modifications 1-4.
Modifications 1 to 4 of the first embodiment according to the present invention will be described below with reference to FIG. The semiconductor device 1 according to the first to fourth modifications is roughly the same as the semiconductor device 1 according to the first embodiment except that the resin package 30 has a gap formed between the second lead frame 20 and the radiation fin 50. Therefore, a detailed description of the overlapping parts is omitted.

Modification 1
In the semiconductor device 1 of Modification 1 shown in FIGS. 5 and 6, the second lead frame 20 and the radiating fin 50 (or the resin package) are removed by cutting off a part of the resin package 30 below the second lead frame 20. A notch (gap) 51 is formed between the lower surface 33 and the XY plane including the lower surface 33. That is, the resin package 30 has a notch 51 formed between the back surface 23 of the second lead frame 20 and the heat radiation fin 50. The notch 51 communicates with the atmosphere and has a lower thermal conductivity than the resin package 30, so that the heat transmitted to the heat generating element 12, the heat sink 40, and the heat radiating fin 50 conversely passes through the resin package 30. Thus, transmission to the control element 22 can be prevented. Therefore, according to the semiconductor device 1 of the first modification, it is possible to suppress the heat propagating from the radiating fins 50 to the control element 22, and to realize the semiconductor device 1 with further less switching loss than the first embodiment. Can do.

Modification 2
Alternatively, as shown in FIGS. 7 and 8, the semiconductor device 1 of Modification 2 includes a passage portion (gap) extending in the Y direction on the lower surface 33 of the resin package 30 below the second lead frame 20. 52 may be formed. The passage portion 52 forms a gap between the second lead frame 20 and the heat radiating fin 50 (or an XY plane including the lower surfaces 33a and 33b of the resin package 30), similarly to the cutout portion 51 of the first modification. . Therefore, according to the semiconductor device 1 of the second modification, similarly to the first modification, it is possible to suppress the heat propagating from the radiating fins 50 to the control element 22, and the switching loss is smaller than that of the first embodiment. The semiconductor device 1 can be realized.

  As a further effect of the semiconductor device 1 according to the modified example 2, as shown in FIG. 7 in particular, the lower surfaces 33a and 33b of the resin package 30 on both sides of the passage portion 52 are on the same plane. It can be placed stably on top. That is, the workability when fixing the semiconductor device 1 to the heat radiation fin 50 can be significantly improved as compared with the first modification.

Modification 3
In still another modified example 3, as shown in FIGS. 9 and 10, the semiconductor device 1 includes a plurality of vertical hole portions (upward in the Z direction) extending from the lower surface 33 of the resin package 30 toward the control element 22 (Z direction). (Void) 53 may be provided. In FIG. 10, each vertical hole portion 53 is illustrated so as to extend in the Z direction below the XY plane region including the peripheral portion of each control element 22. A single vertical hole (not shown) may be provided below the XY plane region including the portion. The vertical hole portion 53 configured as described above includes the second lead frame 20 and the heat radiation fin 50 (or the lower surface 33 of the resin package 30), similarly to the cutout portion 51 of the first modification and the passage portion 52 of the second modification. An air gap is formed between (XY plane). Therefore, according to the semiconductor device 1 of the modified example 3, similarly to the modified examples 1 and 2, it is possible to suppress the heat propagating from the radiating fin 50 heated by the heating element 12 to the control element 22 in reverse. Thus, it is possible to realize the semiconductor device 1 with less switching loss than the first embodiment. Further, unlike the semiconductor device 1 of the first modification, the semiconductor device 1 can be easily and stably fixed to the radiating fin 50 without causing a substantial step on the lower surface 33 of the resin package 30.

Modification 4
According to yet another modification 4, the semiconductor device 1 may have a slit (gap) 54 that extends substantially parallel to the XY plane, as shown in FIG. The slit 54 forms a gap between the second lead frame 20 and the heat radiating fin 50 as in the first to third modifications. Therefore, according to the semiconductor device 1 of the modified example 4, similarly to the modified examples 1 to 3, it is possible to suppress the heat propagating back to the control element 22 from the radiating fin 50 heated by the heat generating element 12. Thus, it is possible to realize the semiconductor device 1 with less switching loss than the first embodiment. In addition, the semiconductor device 1 of Modification 4 can be easily and stably fixed to the radiating fin 50.

Embodiment 2. FIG.
Next, a second embodiment of the transfer mold type semiconductor device according to the present invention will be described below with reference to FIGS. Components similar to those in the first embodiment will be described using the same reference numerals. Similar to the semiconductor device 1 of the first embodiment, the semiconductor device 2 of the second embodiment has a plurality of first lead frames 10 and second lead frames 20. Further, as shown in FIGS. 12 and 13, the semiconductor device 2 according to the second embodiment includes the heating elements 12 a and 12 b mounted on the surface 11 of the first lead frame 10 and the surface of the second lead frame 20. And a single heat sink (heat radiation block) 42 facing the back surface 11 of the first lead frame 10. Furthermore, according to the second embodiment, as shown in the bottom view of FIG. 13, the heat generating element 12, the control element 22, and the resin package 30 that seals the heat sink 42 are provided so that the lower surface 43 of the heat sink 42 is exposed. Is provided. The resin package 30 has an upper surface 31 and a lower surface 33. The heat sink 42 is composed of a metal block (heat dissipation block) having good thermal conductivity such as copper or aluminum. That is, the semiconductor device 2 according to the second embodiment is a transfer mold type IPM having an integral heat sink structure.

  The heat sink 42 according to the second embodiment of the present invention does not extend in the Y direction beyond the first lead frame 10, does not face the back surface 23 of the second lead frame 20, and does not face the back surface 13 of the first lead frame 10. Only oppose.

  According to the semiconductor device 2 configured in this manner, as in the first embodiment, the heat generated in the heating element 12 propagates to the heat sink 42 and is efficiently radiated to the outside from the lower surface 43 thereof. Also, as shown in FIG. 12, the heat radiation fin 50 is preferably attached so as to contact the lower surface 43 of the heat sink 42, and the heat from the lower surface 43 of the heat sink 42 is radiated more effectively. At this time, since the heat sink 42 does not extend below the second lead frame 20 and does not face the back surface 23 of the second lead frame 20 (FIG. 12), heat propagates from the heat sink 42 to the second lead frame 20. The temperature rise of the control element 22 can be suppressed as small as possible. Thus, according to the second embodiment of the present invention, the semiconductor device 2 with less switching loss can be realized.

  As will be readily understood by those skilled in the art, the first to fourth modifications to the first embodiment can be similarly applied to the semiconductor device 2 of the second embodiment. That is, by providing a gap in the resin package 30 between the second lead frame 20 and the heat radiating fins 50, the heat propagated back to the control element 22 from the heat radiating fins 50 heated by the heat generating elements 12 is suppressed. The semiconductor device 2 with a smaller switching loss than that of the mode 2 can be realized. Specifically, the gap of the resin package 30 formed between the second lead frame 20 and the radiating fin 50 (or the XY plane including the lower surface 33 of the resin package 30) is specifically the resin package 30 and the radiating fin 50. Notches 51 (FIGS. 5 and 6) between them, passage portions 52 (FIGS. 7 and 8) extending in the Y direction on the lower surface 33 of the resin package 30, individual control elements 22 or a series of control elements 22 as a whole A plurality of or single longitudinal hole portions 53 (FIGS. 9 and 10) formed below the XY plane region including the peripheral portion, and slits (FIG. 11) extending substantially parallel to the XY plane Any of them may be used.

Embodiment 3 FIG.
Next, a third embodiment of the transfer mold type semiconductor device according to the present invention will be described below with reference to FIGS. Components similar to those in Embodiments 1 and 2 will be described using the same reference numerals. The semiconductor device 3 according to the third embodiment of the present invention includes a plurality of first lead frames 10 and second lead frames 20 like the semiconductor device according to the above-described embodiment. Further, in the semiconductor device 3 of the third embodiment, as schematically shown in FIGS. 14 and 15, the heating elements 12 a and 12 b mounted on the surface 11 of the first lead frame 10, and the second lead frame 20. It has a control element 22 mounted on the surface 21 and a heat sink (heat radiation block) 44 with a through hole. According to the third embodiment, as shown in the bottom view of FIG. 15, the resin package 30 that seals the heating element 12, the control element 22, and the heat sink 42 so that the lower surface 45 of the heat sink 44 with a through hole is exposed. Is provided. The resin package 30 has an upper surface 31 and a lower surface 33. As described above, the semiconductor device 3 according to the third embodiment is a transfer mold type IPM having an integrated heat sink structure as in the second embodiment.

  The heat sink 44 with a through hole according to the third embodiment is made of a metal block (heat radiating block) having good thermal conductivity such as copper or aluminum, and as shown in FIG. 15, in particular, the first and second block portions 44a, 44b and a pair of bridge portions 44c and 44d that connect and support them. As shown in FIG. 14, the first block portion 44 a faces the back surface 13 of the first lead frame 10 and does not extend substantially in the X direction beyond the first lead frame 10. Similarly, the second block portion 44 b faces the back surface 23 of the second lead frame 20 and does not extend toward the first lead frame 10 substantially beyond the second lead frame 20. Thus, in the heat sink 44 with a through hole of the third embodiment, a through hole 46 extending in the Z direction is formed between the first and second lead frames 10 and 20. When the through hole 46 is transfer molded, the inside thereof is filled with a mold resin.

  According to the semiconductor device 3 configured as described above, since the mold resin having lower thermal conductivity than the heat sink 44 is filled in the through hole 46, the heat generated in the heating element 12 and transmitted to the first block portion 44a is the first. Propagation to the two block portions 44b can be suppressed. As a result, the temperature rise of the control element 22 on the second lead frame 20 can be suppressed as much as possible. Therefore, according to the third embodiment of the present invention, it is possible to realize the semiconductor device 3 with little switching loss.

Embodiment 4 FIG.
Next, a fourth embodiment of a transfer mold type semiconductor device according to the present invention will be described below with reference to FIGS. In addition, about the component similar to Embodiment 1-3, it demonstrates using the same code | symbol. The semiconductor device 4 of the fourth embodiment has a plurality of first lead frames 10 and second lead frames 20 as in the semiconductor device of the above-described embodiment. Further, the semiconductor device 4 is mounted on the surface 21 of the second lead frame 20 and the heat generating elements 12a and 12b mounted on the surface 11 of the first lead frame 10, as schematically shown in FIG. The heat generating element 12, the control element 22, and the heat sink 47 are sealed so that the control element 22, the heat sink (heat radiating block) 47 facing the first and second lead frames 10 and 20, and the lower surface 48 of the heat sink 47 are exposed. And a resin package 30 to be stopped. That is, the semiconductor device 4 according to the fourth embodiment is a transfer mold type IPM having an integrated heat sink structure as in the second and third embodiments.

  In the semiconductor device 4 of the fourth embodiment shown in FIGS. 16 and 17, the resin package 30 has an upper surface 31 and a lower surface 33, and a plurality of heat insulations extending downward (−Z direction) from the upper surface 31 toward the lower surface 33. A hole 35 is provided. Each of these heat insulating holes 35 is provided between the heating element 12 and the control element 22 and communicates with the atmosphere having a lower thermal conductivity than that of the resin, so that it directly propagates from the heating element 12 to the control element 22. Heat can be cut off. Thus, according to the fourth embodiment of the present invention, it is possible to realize the semiconductor device 4 that suppresses the temperature rise of the control element 22 as much as possible and has a small switching loss.

  In addition, the heat insulation hole 35 demonstrated above in Embodiment 4 is applicable also to the semiconductor devices 1-3 of Embodiment 1-3, for example, as shown in FIG. 18 (semiconductor device 2). Further, for example, as shown in FIG. 19 (semiconductor device 3), the heat insulating hole 35 can be formed so as to extend upward from the lower surface 33 of the resin package 30 toward the upper surface 31. Since these heat insulating holes 35 are disposed between the heating element 12 and the control element 22, it is possible to block the heat directly transmitted from the heating element 12 to the control element 22. Therefore, similarly, the temperature rise of the control element 22 can be suppressed as much as possible, and the semiconductor device 4 with less switching loss can be realized.

Embodiment 5 FIG.
Next, a fifth embodiment of the transfer mold type semiconductor device according to the present invention will be described with reference to FIG. In addition, about the component similar to Embodiment 1-4, it demonstrates using the same code | symbol. The semiconductor device 5 of the fifth embodiment has a plurality of first lead frames 10 and second lead frames 20 as in the semiconductor device of the above-described embodiment. In addition, as shown in FIG. 20, the semiconductor device 5 includes heating elements 12 a and 12 b mounted on the surface 11 of the first lead frame 10, and a control element 22 mounted on the surface 21 of the second lead frame 20. A heat sink (heat radiating block) 60 facing the first and second lead frames 20, and the heat generating element 12, the control element 22, and the resin package 30 for sealing the heat sink 60 so that the lower surface 61 of the heat sink 60 is exposed. Is provided. The resin package 30 has an upper surface 31 and a lower surface 33. As described above, the semiconductor device 5 according to the fifth embodiment is a transfer mold type IPM having an integrated heat sink structure as in the second to fourth embodiments.

In the semiconductor device 5 of the fifth embodiment according to the present invention shown in FIG. 20, the heat sink 60 faces the first facing region 62 facing the back surface 13 of the first lead frame 10 and the back surface 23 of the second lead frame 20. And a second facing region 64 substantially parallel to the XY plane. The first and second opposing regions 62 and 64 are substantially parallel to the XY plane. In the semiconductor device 5 shown in FIG. 20, the distance h _{1 in} the Z direction between the back surface 13 of the first lead frame 10 and the first facing region 62 is equal to the back surface 23 of the second lead frame 20 and the second facing region 64. Is smaller than the distance h _{2 in} the Z direction (h ₂ > h ₁ ). As described above, according to the semiconductor device 5 of the fifth embodiment, a part of the heat sink 60 below the back surface 23 of the second lead frame 20 is cut away, and the first lead frame 10 and the first opposing region 62 are separated. The resin mold is thicker between the second lead frame 20 and the second facing region 64 than between the two. Therefore, since the thermal conductivity of the mold resin is lower than that of the metal material constituting the heat sink 60, heat transmitted from the heat sink 60 to the second lead frame 20 can be suppressed. In this way, it is possible to realize the semiconductor device 5 in which the temperature rise of the control element 22 is suppressed as much as possible and the switching loss is small.

Embodiment 6 FIG.
Next, a sixth embodiment of the transfer mold type semiconductor device according to the present invention will be described below with reference to FIG. Components similar to those in the first embodiment will be described using the same reference numerals. The semiconductor device 6 of the sixth embodiment has a plurality of first lead frames 10 and second lead frames 20 as in the semiconductor device of the above-described embodiment. Further, as shown in FIG. 21, the semiconductor device 6 includes heating elements 12 a and 12 b mounted on the surface 11 of the first lead frame 10, and a control element 22 mounted on the surface 21 of the second lead frame 20. A heat sink (heat radiating block) 40 that contacts the first lead frame 10 and faces the second lead frame 20, and a heat generating element 12, a control element 22, and a resin package 30 that totally seals the heat sink 40. . That is, the semiconductor device 6 according to the sixth embodiment is a transfer mold type intelligent power module having a divided heat sink structure, as in the first embodiment.

  In the semiconductor device 6 according to the sixth embodiment of the present invention, as shown in FIG. 21, the resin package 30 has an upper surface 31 and a lower surface 33, and a series of concave portions 36 and convex portions on the upper surface 31 of the resin package 30. 37. That is, a plurality of concave portions 36 and convex portions 37 are provided on the upper surface 31 on the control board 70 side of the resin package 30 when attached to the control board 70. Thus, the heat generated from the heating element 12 is efficiently radiated from the upper surface 31 of the resin package 30 on the control board 70 side, and the heat transmitted to the control element 22 can be reduced.

Further, since the heat generating element 12 can be sufficiently radiated without providing another heat sink between the upper surface 31 of the resin package 30 and the heat generating element 12, the thickness of the entire resin package 30 can be reduced, and the semiconductor device 6 can be reduced. It can be thinned.
Furthermore, in FIG. 21, the first and second lead frames 10 and 20 extend upward beyond the upper surface 31 of the resin package 30 so that the upper surface 31 of the resin package 30 and the control board 70 are separated by a distance d. Yes. The semiconductor device 6 configured in this way can secure the mountability to the control board 70 while ensuring the heat dissipation from the upper surface 31 of the resin package 30.

  Preferably, the concave portion 36 and the convex portion 37 are formed above the heat generating element 12 as shown in FIG. 21, and the concave portion 36 is formed directly above the heat generating element 12. Thus, the heat from the heating element 12 can be radiated more effectively. Therefore, according to the sixth embodiment, the temperature rise of the control element 22 can be suppressed as much as possible, and the semiconductor device 6 with little switching loss can be realized.

  The series of recesses 36 and protrusions 37 on the upper surface 31 on the control board 70 side described in this embodiment is not limited to a transfer mold type intelligent power module having a split type heat sink structure, but also an integrated heat sink structure. The transfer mold type intelligent power module having the same structure can be formed in the same manner to realize effective heat dissipation from the heating element 12.

1 is a perspective view of a semiconductor device according to a first embodiment of the present invention. It is sectional drawing seen from the II-II line of FIG. It is sectional drawing seen from the III-III line of FIG. It is sectional drawing similar to FIG. FIG. 5 is a cross-sectional view similar to FIG. 2 illustrating a first modification of the first embodiment. FIG. 6 is a schematic side view showing a first modification. FIG. 6 is a cross-sectional view similar to FIG. 2 showing a second modification of the first embodiment. FIG. 10 is a schematic side view showing a second modification. FIG. 10 is a cross-sectional view similar to FIG. 2 illustrating a third modification of the first embodiment. It is a bottom view of the modification 3 seen from the bottom. FIG. 6 is a cross-sectional view similar to FIG. 2 illustrating a fourth modification of the first embodiment. It is sectional drawing of the semiconductor device of Embodiment 2 which concerns on this invention. It is a bottom view of Embodiment 2 seen from the bottom. It is sectional drawing of the semiconductor device of Embodiment 3 which concerns on this invention. It is a bottom view of Embodiment 3 seen from the bottom. It is sectional drawing of the semiconductor device of Embodiment 4 which concerns on this invention. It is a top view of Embodiment 4 seen from the top. It is sectional drawing similar to FIG. 16 which shows the modification of Embodiment 4. FIG. FIG. 17 is a cross-sectional view similar to FIG. 16, illustrating another modification of the fourth embodiment. It is sectional drawing of the semiconductor device of Embodiment 5 which concerns on this invention. It is sectional drawing of the semiconductor device of Embodiment 6 which concerns on this invention.

Explanation of symbols

1-6 Semiconductor device, 10 1st lead frame, 12 Heating element, 20 2nd lead frame, 22 Control element, 30 Resin package, 31 Upper surface, 33 Lower surface, 40, 42, 44, 47, 60 Heat sink, 46 Through hole , 50 Radiation fin, 51 Notch, 52 Passage, 53 Vertical hole, 54 Slit, 70 Control board.

Claims (1)

At least one set of first and second lead frames including a front surface and a back surface;
A heating element mounted on the surface of the first lead frame;
A control element mounted on the surface of the second lead frame and generating less heat than the heating element;
A heat dissipating block facing or abutting against the back surface of the first lead frame and not facing the back surface of the second lead frame;
A resin package for sealing the heat generating element, the control element, and the heat dissipation block ;
The resin package faces an upper surface facing the front surface of the first and second lead frames, a first lower surface facing the back surface of the first lead frame, and a back surface of the second lead frame. And a second lower surface, and a gap formed between the rear surface of the second lead frame and a plane including the first lower surface .

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