JP2010171096A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device in which high stress reduction performance and heat radiation performance are compatible with each other, for both high reliability and adaptivity to large power. <P>SOLUTION: In the semiconductor device, a semiconductor chip, a lead electrode and a base electrode facing each other across the semiconductor chip, and a junction layer for electrically joining them are stacked. The semiconductor device is used with a heatsink member to be abutted with the base electrode. The base electrode includes a heat propagation part and a thermal expansion constricting part as a laminate. The semiconductor chip is joined to the heat propagation part of the base electrode via the junction layer, with the heat propagation part abutting against the heatsink member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device, and more particularly to a power semiconductor device suitably used for rectification of a large current in a vehicular rotary generator or the like.

  The power semiconductor device is a high-power semiconductor device used to control electric devices such as motors and generators and to convert electric power. In recent years, the demand for power semiconductor devices has been rapidly increasing due to demands for energy saving and environmental load reduction for electric devices. In addition, due to the high efficiency and large capacity of the electrical equipment, the operating environment of power semiconductor devices has further increased with higher voltage and higher current (higher power), and the required operating temperature conditions have become increasingly severe. It is coming. Under such circumstances, it is important for power semiconductor devices that are used for a long period of time not to cause a decrease in reliability. In particular, ensuring reliability in a bonding layer (for example, a solder bonding layer) between electronic members. (For example, the bonding layer is not damaged) is an important issue.

A rectifier used as a type of power semiconductor device and used in a vehicular rotary generator or the like is generally a semiconductor chip and a pair of electrodes facing each other across the semiconductor chip are laminated by solder bonding, and the lamination is made of silicon. The structure is sealed with resin or the like. As described above, power semiconductor devices are often operated at a high voltage and a large current (high power). Therefore, during operation, a large amount of Joule heat is generated in a semiconductor chip or the like, resulting in a high temperature of 200 ° C. or higher. is there. On the other hand, it is cooled down to the ambient temperature during stoppage. That is, the power semiconductor device has a particularly large temperature difference between operation and stop among various semiconductor devices, and as a result, a large thermal stress is repeatedly generated inside the semiconductor device. Specifically, silicon (Si, linear expansion coefficient: about 3 × 10 ⁻⁶ / ° C.), which is the main material of the semiconductor chip, and copper (Cu, linear expansion coefficient: about 17 × 10 ⁻⁶ ), which is the main material of the electrode. / ° C), resulting in thermal stress due to the difference in thermal expansion.

  This repeated thermal stress tends to cause a shearing stress in a solder joint layer having a relatively low mechanical strength and cause fatigue cracks. The occurrence / progress of fatigue cracks (that is, fatigue failure) in the solder joint layer may cause a conduction failure or a heat radiation failure in the semiconductor chip, and may cause the power semiconductor device to stop functioning. Therefore, in order to prevent fatigue failure of the solder joint layer, it is important to reduce the shear stress caused by the difference in thermal expansion of the electronic member (for example, semiconductor chip / electrode).

  As a structure for reducing the shear stress applied to the solder joint layer, for example, a structure as shown in Patent Document 1 has been proposed. In Patent Document 1, the linear expansion coefficient is larger than the linear expansion coefficient of the semiconductor chip between the semiconductor chip and the first electrode, and between the semiconductor chip and the second electrode, and the first and second electrodes. A rectifier having a stress buffer plate made of a material smaller than the material linear expansion coefficient is disclosed.

  Patent Document 2 proposes a semiconductor rectifier element having the following structure. In Patent Document 2, a semiconductor chip having a rectifying function is soldered to the inner bottom of a bowl-shaped metal heat dissipation container with an electrode on one main surface, and soldered to one end of a lead wire with an electrode on the other main surface. In addition, a semiconductor rectifying element in which the inside of the heat dissipation container is resin-sealed, the semiconductor rectification element is disclosed in which the heat dissipation container is made of a three-layer clad material of copper, Kovar, and copper.

U.S. Pat. No. 4,349,831 JP-A-63-252457

  Due to the rapid electrification of automobiles in recent years, the power capacity of vehicular rotary generators and the like has been increasing, and accordingly, the amount of heat generated in power semiconductor devices has increased, and the heat load and thermal stress inside the semiconductor devices have also been increasing. is there. In contrast, in the semiconductor device described in Patent Document 1, a stress buffer plate is provided between the semiconductor chip and both electrodes to relieve the shear stress caused by the difference in linear expansion coefficient. Since the heat conductivity is low, the heat dissipation from the semiconductor chip is lowered, and it is difficult to cope with further increase in the amount of heat generation. Moreover, although the semiconductor rectifier described in Patent Document 2 uses a clad material of copper, kovar and copper close to the linear expansion coefficient of silicon as a heat radiating container, it relieves the shear stress applied to the solder joint layer. Since the heat conductivity of the Kovar in the clad material is low, the heat dissipation in the thickness direction of the heat radiating container is reduced, so that the increase in the amount of heat generated can be dealt with similarly to the semiconductor device described in Patent Document 1. Is difficult.

  That is, in order to ensure reliability equal to or higher than that of a conventional semiconductor device (a power semiconductor device such as a rectifier) and to cope with an increase in power, further measures are required. Accordingly, an object of the present invention is to provide a semiconductor device having both high reliability and high power handling capability by making high stress relaxation performance and heat dissipation performance compatible.

In order to achieve the above object, the present invention provides a semiconductor device in which a semiconductor chip and a base electrode opposed to each other with the semiconductor chip interposed therebetween, and a lead electrode and a bonding layer that electrically connects them are stacked, and the base electrode A semiconductor device used by contacting a heat radiating member to
The base electrode is composed of a laminated body of a heat transfer portion and a thermal expansion restraint portion, and the semiconductor chip is bonded to the heat transfer portion of the base electrode via the bonding layer, and the heat transfer portion A semiconductor device, wherein the semiconductor device is in contact with the heat dissipating member.

In order to achieve the above object, the present invention can make the following improvements and changes in the semiconductor device according to the present invention.
(1) The heat transfer portion of the base electrode includes a first heat transfer portion that is bonded to the semiconductor chip and transfers heat in an in-plane direction of the base electrode, and a heat transfer portion that transfers heat in the thickness direction of the base electrode. 2 heat transfer sections.
(2) The heat transfer portion of the base electrode further includes a third or fourth heat transfer portion that is connected to the second heat transfer portion and transfers heat in an in-plane direction of the base electrode.
(3) The thermal expansion restraining portion of the base electrode is embedded in the base electrode.
(4) The base electrode has a bottom part and a wall part formed on the outer edge of the bottom part, and has a concave shape as a whole.
(5) The thermal expansion restricting portion of the base electrode is made of a material having a linear expansion coefficient of 12 × 10 ⁻⁶ / ° C. or less.
(6) The thermal expansion restraint portion of the base electrode is made of molybdenum (Mo), tungsten (W), iron-nickel alloy (Fe-Ni alloy), or iron-nickel-cobalt alloy (Fe-Ni-Co alloy). Consists of.
(7) The heat transfer portion of the base electrode is made of a material having a thermal conductivity of 150 W / m · K or more.
(8) The heat transfer portion of the base electrode is made of copper (Cu), aluminum (Al), or an alloy containing one of them as a main constituent element.
(9) The bonding layer is made of an alloy containing tin (Sn) and copper (Cu) as main constituent elements and having a Cu concentration of 7% by mass or less and no lead (Pb).

  ADVANTAGE OF THE INVENTION According to this invention, the high stress relaxation performance and heat dissipation performance can be made compatible in a power semiconductor device, and the semiconductor device which has high reliability and the response | compatibility to high power can be provided.

It is a longitudinal cross-sectional schematic diagram which shows an example of the semiconductor device which concerns on the 1st Embodiment of this invention. It is a longitudinal cross-sectional schematic diagram which shows the other example of the semiconductor device which concerns on the 1st Embodiment of this invention. It is the result of having analyzed the semiconductor chip temperature on the energization conditions in the conventional power semiconductor device and the power semiconductor device according to the first embodiment. It is the result of having analyzed the equivalent plastic strain ratio in the 1st joint layer under energization conditions in the conventional power semiconductor device and the power semiconductor device concerning a 1st embodiment. It is a longitudinal cross-sectional schematic diagram which shows an example of the semiconductor device which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional schematic diagram which shows an example of the semiconductor device which concerns on the 3rd Embodiment of this invention. It is a cross-sectional schematic diagram which shows one example of the semiconductor device which concerns on the 4th Embodiment of this invention, (a) is a longitudinal cross-sectional schematic diagram, (b) is the cross section cut | disconnected by the AA line in (a). It is a schematic diagram. It is a cross-sectional schematic diagram which shows another example of the semiconductor device which concerns on the 4th Embodiment of this invention, (a) is a longitudinal cross-sectional schematic diagram, (b) cut | disconnected by the BB line in (a). It is a cross-sectional schematic diagram. It is a longitudinal cross-sectional schematic diagram which shows an example of the conventional semiconductor device.

  First, a conventional semiconductor device will be briefly described. FIG. 9 is a schematic longitudinal sectional view showing an example of a conventional semiconductor device. A conventional power semiconductor device 600 includes, for example, a semiconductor chip 10, a pair of electrodes (a base electrode 61 and a lead electrode 12) that are opposed to each other with the semiconductor chip 10 interposed therebetween, and a bonding layer (first electrode) that electrically connects them. The bonding layer 63 and the second bonding layer 64) are laminated, and the entire structure is sealed with the sealing material 15. The semiconductor device 600 is used with the heat radiating member 16 in contact with the base electrode 61. In FIG. 9, the base electrode 61 is a generally concave electrode having a bottom portion 611 and a wall portion 612 formed on the outer edge of the bottom portion, and the lead electrode 12 enlarges the contact area with the lead portion 12a. The case of an electrode including the electrode portion 12b for performing the above is shown.

  As described above, in the conventional semiconductor device 600, the base electrode 61 is made of the three-layer clad material of the copper material 61a, the Kovar material 61b, and the copper material 61c. Since the three-layer clad material of copper-kovar-copper has a smaller coefficient of linear expansion up to 0 to 200 ° C. than that of a single copper material, it absorbs the difference in thermal expansion accompanying the temperature change of the semiconductor device. It is said that shear stress (thermal shock) applied to the bonding layer 63 can be reduced. However, the thermal conductivity (about 17 W / m · K) of the Kovar material 61b used for the three-layer clad material is significantly smaller than the thermal conductivity (about 400 W / m · K) of the copper materials 61a and 61c. Therefore, there is a problem that heat conduction in the thickness direction of the three-layer clad material is hindered. This is because when the power capacity of the semiconductor device is increased (that is, when the amount of heat generated in the semiconductor chip is increased), the temperature change amount (temperature amplitude) also increases, and as a result, fatigue cracks due to the difference in thermal expansion are induced. Will lead to.

  Therefore, in addition to the conventional semiconductor device as described above, if the heat generated in the semiconductor chip can be positively released (transmitted) to the outside, the temperature change amount (temperature amplitude) of the semiconductor device itself can be reduced. As a result, it was considered that the shear stress applied to the bonding layer could be further reduced. The present invention has been completed by the inventors' extensive research and research on thermal stress and heat transfer in semiconductor devices.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment taken up here, and may be appropriately combined. In addition, the same code | symbol is attached | subjected to the part which is synonymous in drawing, and the overlapping description is abbreviate | omitted.

[First embodiment of the present invention]
(Structure of semiconductor device)
FIG. 1 is a schematic longitudinal sectional view showing an example of a semiconductor device according to the first embodiment of the present invention. Similar to the conventional power semiconductor device 600, the power semiconductor device 100 according to the present embodiment includes the semiconductor chip 10, a pair of electrodes (base electrode 11A and lead electrode 12) opposed to each other with the semiconductor chip 10 interposed therebetween, and A bonding layer (first bonding layer 13 and second bonding layer 14) to be electrically bonded is laminated, and the entire structure is sealed with a sealing material 15, and the base electrode 11A has The heat radiating member 16 is used in contact therewith. Further, the base electrode 11A is configured by a laminated body of the first thermal expansion restraint portion 11a, the heat transfer portion 11b, and the second thermal expansion restraint portion 11c.

  On the other hand, as shown in FIG. 1, in the power semiconductor device 100 according to the present embodiment, the semiconductor chip 10 is joined to the heat transfer part 11b via the first bonding layer 13, and the heat transfer part 11b dissipates heat. It differs from the conventional power semiconductor device 600 in that it is in contact with the member 16. Although FIG. 1 shows a base electrode 11A having a three-layer structure, the base electrode is not limited to a three-layer structure, and may have a structure of four or more layers. Further, in the figure, the base electrode 11A is a generally concave electrode having a bottom 111 and a wall 112 formed on the outer edge of the bottom, and the lead electrode 12 enlarges the contact area with the lead 12a. However, the wall portion 112 and the electrode portion 12b may be omitted.

  FIG. 2 is a schematic longitudinal sectional view showing another example of the semiconductor device according to the first embodiment of the present invention. In FIG. 2, illustration of the heat radiating member 16 is omitted. In FIG. 2 (a), the base electrode 11B has a four-layer structure of a laminate of a first thermal expansion restraint portion 11a, a heat transfer portion 11b, a second thermal expansion restraint portion 11c, and a sub heat transfer portion 11d. This is an example (the power semiconductor device 101 according to the present embodiment). In FIG. 2B, the base electrode 11C is a laminated body of the first thermal expansion restraint part 11e, the heat transfer part 11f, and the second thermal expansion restraint part 11c, and the first thermal expansion restraint part 11e is a wall part. This is an example formed on the outer peripheral side of 112 (the power semiconductor device 102 according to the present embodiment). In FIG. 2C, the base electrode 11D is a laminate of the first thermal expansion restraint portion 11g, the heat transfer portion 11h, and the second thermal expansion restraint portion 11c, and the wall 112 is the first thermal expansion restraint portion. This is an example (power semiconductor device 103 according to the present embodiment) configured only with 11g. FIG. 2D shows a structural example in which the base electrode 11E is a laminate of the first thermal expansion restraint portion 11i, the heat transfer portion 11j, and the second thermal expansion restraint portion 11c and does not have the wall portion 112 (this embodiment). The power semiconductor device 104) according to FIG.

Thermal expansion restraining portion 11a, 11c, 11e, 11g, 11i, it is desirable that the linear expansion coefficient of a material is 12 × 10 ^-6 ℃ ^-1 or less. Specifically, Mo (linear expansion coefficient: about 5 × 10 ^-6 / ° C), W (linear expansion coefficient: about 4.5 × 10 ^-6 / ° C), Fe-Ni alloy (for example, Fe-42% Ni alloy) , Linear expansion coefficient: about 5 × 10 ^-6 / ° C, Fe-36% Ni alloy, linear expansion coefficient: about 1.2 × 10 ^-6 / ° C, Cu and Mo composite (equivalent linear expansion coefficient: for example about 7 × 10 ⁻⁶ ° C.− ¹ ), Fe—Ni—Co alloy (for example, Fe-29% Ni-17% Co alloy, linear expansion coefficient: about 5 × 10 ⁻⁶ / ° C.), etc. can be preferably used. . Note that the first thermal expansion restraint portion and the second thermal expansion restraint portion do not need to use the same material and can be appropriately selected.

  On the other hand, the material of the heat transfer portions 11b, 11d, 11f, 11h, and 11j is preferably a metal having a thermal conductivity of 150 W / m · K or more. Specifically, Cu (thermal conductivity: about 400 W / m · K), Al (thermal conductivity: about 240 W / m · K), or an alloy containing one of them as a main constituent element (for example, C194 And A6101) can be preferably used. In addition, the thickness ratio (or volume ratio) of the first thermal expansion restraint portion, the heat transfer portion, and the second thermal expansion restraint portion in the base electrode, and the height / thickness dimensions of the wall portion are selected. It is designed as appropriate according to the physical property value of the material and the power consumption (design operating temperature) of the semiconductor chip.

  In the power semiconductor devices 100 to 104 according to the present embodiment, the surface of the base electrode bottom 111 at the time of temperature rise is provided by providing the first thermal expansion restraining portion and the second thermal expansion restraining portion with respect to the heat transfer portion. Since the thermal expansion in the inward direction (the in-plane direction of the semiconductor chip 10 and the horizontal direction in FIGS. 1 and 2) can be restricted and the difference in thermal expansion from the semiconductor chip 10 becomes small, the first bonding layer The shear stress applied to 13 can be reduced. In addition, the semiconductor chip 10 is bonded to the metal member having a high thermal conductivity serving as the heat transfer portion via the first bonding layer 13, and the heat transfer portion is in contact with the heat radiating member 16. The heat generated in the semiconductor chip 10 can be transmitted to the heat radiating member 16 more efficiently (with a lower thermal resistance) than before. As a result, the temperature rise of the entire semiconductor device can be suppressed and heat can be radiated with high responsiveness to the temperature rise, and as a result, the shear stress applied to the first bonding layer 13 can be further reduced.

  In addition, the mechanical properties of the material to be the stress suppressing part (for example, Mo Young's modulus: about 330 GPa, W Young's modulus: about 410 GPa, Invar alloy Young's modulus: about 140 GPa, Kovar alloy's Young's modulus: about 130 GPa) is higher than the mechanical properties of the metal member that becomes the heat transfer part (for example, Young's modulus of Cu: about 120 GPa, Young's modulus of Al: about 70 GPa). It also functions as a reinforcing material for the electrodes. This suppresses deformation of the base electrode when the base electrode is brought into contact with the heat radiating member 16 (for example, when the base electrode is press-fitted into the heat radiating member 16). As a result, the semiconductor chip 10 or the first bonding is suppressed. This leads to the effect of preventing the generation of cracks in the layer 13. Since the power semiconductor devices 100 to 104 according to the present embodiment have a structure in which the heat transfer portion to which the semiconductor chip 10 is bonded is sandwiched between the first thermal expansion restraint portion and the second thermal expansion restraint portion, the base electrode It is more effective in suppressing the deformation of.

  There are no particular limitations on the bonding material used for the first bonding layer 13 and the second bonding layer 14, but lead-free solder (for example, Sn and Cu as main constituent elements and a Cu concentration of 7 mass from the viewpoint of environmental protection) It is particularly preferable to use an alloy that is not more than% and does not contain Pb. Further, the material of the sealing material 15 is not particularly limited, and a commonly used material (for example, silicon resin) can be used.

(Method for manufacturing semiconductor device)
The manufacturing method of the semiconductor device according to the present invention is not limited as long as a desired structure can be formed as a result, and the conventional method can be used. As an example, a base electrode that is a laminate of a heat transfer section and a thermal expansion restraint section can be manufactured by sintering, powder metallurgy, welding, or the like of a plate material.

(Analysis of heat dissipation performance and stress relaxation performance)
Using the conventional power semiconductor device 600 shown in FIG. 9 and the power semiconductor device 100 according to the present embodiment shown in FIG. 1, the heat dissipation performance and the stress relaxation performance were compared and examined. “The thickness of the copper material 61a: the thickness of the Kovar material 61b: the thickness of the copper material 61c” in the base electrode 61 of the conventional power semiconductor device 600 and “the heat” in the base electrode 11A of the power semiconductor device 100 according to the present embodiment. The thickness of the expansion restraint portion 11a: the thickness of the heat transfer portion 11b: the thickness of the thermal expansion restraint portion 11c "was set to" 1: 1: 1 ". The other conditions are the same. The heat generation condition of the semiconductor chip 10 was that the heat generation continued from the initial temperature of 50 ° C. to 35 W. The results are shown in FIGS.

  FIG. 3 shows the result of analyzing the semiconductor chip temperature under energization conditions in the conventional power semiconductor device and the power semiconductor device according to the first embodiment. As shown in FIG. 3, the semiconductor chip temperature in the power semiconductor device according to the first embodiment is about 5 ° C. lower than that in the conventional power semiconductor device. This indicates that the heat dissipation performance of the power semiconductor device is improved by the feature of the present invention. In addition, this temperature difference is very large when lead-free solder (for example, Sn-Cu solder, Sn-Ag-Cu solder) is used as the bonding layer (first bonding layer and second bonding layer). This is a significant difference (temperature margin).

  FIG. 4 is a result of analyzing the equivalent plastic strain ratio in the first bonding layer under a current-carrying condition in the conventional power semiconductor device and the power semiconductor device according to the first embodiment. As shown in FIG. 4, the equivalent plastic strain ratio in the first bonding layer in the power semiconductor device according to the first embodiment is dramatically reduced to about 60% of that in the conventional power semiconductor device. It was confirmed. This can be understood that the increase in the temperature of the entire semiconductor device is suppressed by the improvement of the heat dissipation performance described above, and as a result, the equivalent plastic strain ratio in the first bonding layer can be reduced.

  As described above with reference to FIGS. 3 and 4, it was confirmed that the power semiconductor device according to the present embodiment can achieve both high heat dissipation performance and high stress relaxation performance as compared with the conventional power semiconductor device. . It can be said that these lead to a power semiconductor device having both high reliability and compatibility with high power.

[Second Embodiment of the Present Invention]
(Structure of semiconductor device)
FIG. 5 is a schematic longitudinal sectional view showing an example of a semiconductor device according to the second embodiment of the present invention. The power semiconductor device 200 according to the present embodiment has substantially the same configuration as the semiconductor device 100 according to the first embodiment, and the base electrode 21 includes a first thermal expansion restraining portion 21a, a heat transfer portion, It is comprised with the laminated body with the 2nd thermal expansion restraint part 21c. In addition, the heat transfer section includes a first heat transfer section 21b that is bonded to the semiconductor chip 10 and transfers heat in the in-plane direction of the base electrode 21 and contacts the heat radiating member 16, and heat transfer in the thickness direction of the base electrode 21. And a second heat transfer section 21d.

  In the semiconductor device 200 according to the present embodiment, in addition to the same effects as those of the first embodiment, the second heat transfer portion 21d that transfers heat in the thickness direction of the base electrode 21 is present. It is possible to dissipate heat to the member that comes into contact with the bottom surface 211 ′ of the bottom portion 211, and to exhibit higher heat dissipation performance. In FIG. 5, the base electrode 21 is a generally concave electrode having a bottom portion 211 and a wall portion 212 formed on the outer edge of the bottom portion, and the lead electrode 12 enlarges the contact area with the lead portion 12a. Although the case of the electrode comprising the electrode portion 12b for the purpose has been shown, the same modification as that of the first embodiment may be made (see FIG. 2). Also, the manufacturing method of the semiconductor device according to the present embodiment is not particularly limited, and a conventional method can be used.

[Third embodiment of the present invention]
(Structure of semiconductor device)
FIG. 6 is a schematic longitudinal sectional view showing an example of a semiconductor device according to the third embodiment of the present invention. In the power semiconductor device 300 according to the present embodiment, in addition to the semiconductor device 200 according to the second embodiment, the base electrode 31 includes a first thermal expansion restraint portion 31a, a heat transfer portion, and a second heat A heat transfer unit that includes a first heat transfer unit 31b that is bonded to the semiconductor chip 10 and transfers heat in the in-plane direction of the base electrode 31 and contacts the heat radiating member 16; A second heat transfer portion 31d that transfers heat in the thickness direction of the electrode 31 and a third heat transfer that is connected to the second heat transfer portion 31d and transfers heat in the in-plane direction of the base electrode 31 and contacts the heat radiating member 16 And a heat part 31e.

  The semiconductor device 300 according to the present embodiment is transmitted through the second heat transfer section 31d due to the presence of the third heat transfer section 31e in addition to the same effects as the first and second embodiments. Heat can be dissipated to the member that contacts the bottom surface 311 ′ of the bottom 311 ′ of the base electrode 31 and the heat dissipating member 16, and higher heat dissipating performance can be exhibited. In FIG. 6, the base electrode 31 is a generally concave electrode having a bottom 311 and a wall 312 formed on the outer edge of the bottom, and the lead electrode 12 expands the contact area with the lead 12a. Although the case of the electrode comprising the electrode portion 12b for the purpose has been shown, the same modification as that of the first embodiment may be made (see FIG. 2). Also, the manufacturing method of the semiconductor device according to the present embodiment is not particularly limited, and a conventional method can be used.

[Fourth Embodiment of the Present Invention]
(Structure of semiconductor device)
7A and 7B are schematic cross-sectional views showing an example of a semiconductor device according to the fourth embodiment of the present invention, where FIG. 7A is a schematic vertical cross-sectional view, and FIG. 7B is an AA line in FIG. It is the cut cross-sectional schematic diagram. The power semiconductor device 400 according to the present embodiment has substantially the same configuration as that of the semiconductor device 300 according to the third embodiment, and the base electrode 41 includes a first thermal expansion restraint portion 41a, a heat transfer portion, and the like. And a second heat expansion restraining portion 41c, and the heat transfer portion transfers the heat in the in-plane direction of the base electrode 41 to which the semiconductor chip 10 is bonded, and contacts the heat radiating member 16. A portion 41b, a second heat transfer portion 41d that transfers heat in the thickness direction of the base electrode 41, a third heat transfer portion 41d 'that transfers heat in the thickness direction of the base electrode 41 and contacts the heat radiating member 16, A fourth heat transfer portion 41e connected to the second and third heat transfer portions 41d and 41d 'and transferring heat in the in-plane direction of the base electrode 41 and contacting the heat radiating member 16 is provided.

  8A and 8B are schematic cross-sectional views showing another example of the semiconductor device according to the fourth embodiment of the present invention. FIG. 8A is a schematic vertical cross-sectional view, and FIG. 8B is a cross-sectional view taken along line BB in FIG. It is a cross-sectional schematic diagram cut | disconnected by the line. In the power semiconductor device 500 according to the present embodiment, the base electrode 51 is configured by a laminated body of a first thermal expansion restraint portion 51a, a heat transfer portion, and a second thermal expansion restraint portion 51c, and the heat transfer The first heat transfer portion 51b is connected to the semiconductor chip 10 and transfers heat in the in-plane direction of the base electrode 51 and contacts the heat radiating member 16. The heat transfer portion 51b transfers heat in the thickness direction of the base electrode 51 and contacts the heat radiating member 16. A second heat transfer section 51d ′ and a third heat transfer section 51e connected to the second heat transfer section 51d ′ and transferring heat in the in-plane direction of the base electrode 51 and contacting the heat radiating member 16; Features. Other configurations are the same as those of the semiconductor device 100 according to the first embodiment described above.

  Both the semiconductor devices 400 and 500 according to the fourth embodiment shown in FIGS. 7 and 8 have a structure in which the second thermal expansion restraint portions 41c and 51c are buried in the base electrodes 41 and 51, respectively.

  The semiconductor device 400 according to the present embodiment has a third heat transfer portion 41d ′ that transfers heat in the thickness direction of the base electrode 41 and contacts the heat radiating member 16 in addition to the same effects as the above-described embodiment. Thus, heat can be transferred to the fourth heat transfer portion 41e while radiating heat to the heat radiating member 16, and higher heat dissipation performance can be exhibited. Similarly, in the semiconductor device 500 according to the present embodiment, the second heat transfer portion 51d ′ that transfers heat in the thickness direction of the base electrode 51 and contacts the heat dissipation member 16 exists. Heat can be transferred to the third heat transfer portion 51e while radiating heat, and high heat dissipation performance can be exhibited.

  In FIGS. 7 and 8, the base electrodes 41 and 51 are generally concave electrodes having bottom portions 411 and 511 and wall portions 412 and 512 formed on the outer edges of the bottom portions, respectively. Shows the case of an electrode composed of the lead portion 12a and the electrode portion 12b for expanding the contact area, but may be modified similarly to the first embodiment (see FIG. 2). Also, the manufacturing method of the semiconductor device according to the present embodiment is not particularly limited, and a conventional method can be used.

100 to 104, 200, 300, 400, 500, 600 ... power semiconductor device, 10 ... semiconductor chip,
11A to 11E, 21, 31, 41, 51, 61 ... base electrode,
11a, 11e, 11g, 11i, 21a, 31a, 41a, 51a ... the first thermal expansion restraint part,
11c, 21c, 31c, 41c, 51c ... second thermal expansion restraint portion,
11b, 11f, 11h, 11j ... Heat transfer section, 11d ... Sub heat transfer section,
21b, 31b, 41b, 51b ... 1st heat transfer part, 21d, 31d, 41d, 51d '... 2nd heat transfer part,
31e, 41d ', 51e ... 3rd heat transfer part, 41e ... 4th heat transfer part,
111, 211, 311, 411, 511, 611 ... bottom, 211 ', 311', 411 ', 511' ... bottom,
112, 212, 312, 412, 512, 612 ... the wall,
12 ... Lead electrode, 12a ... Lead part, 12b ... Electrode part,
13, 63: first bonding layer, 14, 64: second bonding layer, 15: sealing material, 16: heat dissipation member.

Claims (10)

A semiconductor device in which a semiconductor chip and a base electrode opposed to each other with the semiconductor chip interposed therebetween, and a lead electrode and a bonding layer that electrically connects them are stacked, and is used by bringing a heat dissipation member into contact with the base electrode A semiconductor device,
The base electrode is composed of a laminate of a heat transfer part and a thermal expansion restraint part,
The semiconductor chip is bonded to the heat transfer portion of the base electrode via the bonding layer,
The semiconductor device, wherein the heat transfer portion is in contact with the heat radiating member. The semiconductor device according to claim 1,
The heat transfer section of the base electrode includes a first heat transfer section that is bonded to the semiconductor chip and transfers heat in an in-plane direction of the base electrode, and a second heat transfer section that transfers heat in the thickness direction of the base electrode. A semiconductor device comprising a heat part. The semiconductor device according to claim 2,
The heat transfer portion of the base electrode further includes a third or fourth heat transfer portion that is connected to the second heat transfer portion and transfers heat in an in-plane direction of the base electrode. . The semiconductor device according to claim 3.
The semiconductor device, wherein the thermal expansion restraining portion of the base electrode is embedded in the base electrode. 5. The semiconductor device according to claim 1, wherein:
The base electrode has a bottom part and a wall part formed on the outer periphery of the bottom part, and has a concave shape as a whole. The semiconductor device according to claim 1, wherein:
Wherein the thermal expansion restraining portion of the base electrode, a semiconductor device which is characterized in that its linear expansion coefficient is a material is 12 × 10 ^-6 / ℃ or less. The semiconductor device according to claim 6.
The semiconductor device according to claim 1, wherein the thermal expansion restraining portion of the base electrode is made of Mo, W, Fe-Ni alloy, or Fe-Ni-Co alloy. The semiconductor device according to any one of claims 1 to 7,
The semiconductor device according to claim 1, wherein the heat transfer portion of the base electrode is made of a material having a thermal conductivity of 150 W / m · K or more. The semiconductor device according to claim 8,
The heat transfer portion of the base electrode is made of Cu, Al, or an alloy having one of them as a main constituent element. 10. The semiconductor device according to claim 1, wherein:
The semiconductor device is characterized in that the bonding layer is made of an alloy containing Sn and Cu as main constituent elements and a Cu concentration of 7% by mass or less and containing no Pb.

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