JP2014183256A - Joining body, semiconductor device using the same, and manufacturing method for them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining body that is able to relax stress and is excellent in electrical conductivity and thermal conductivity, to provide a semiconductor device using this, and to provide a manufacturing method for them.SOLUTION: A joining body 21 has a wound part 31 and a stress relaxing part/parts 41, and joins a base material 10 and an element 15 such that electrical current is supplied and heat can be transmitted. A wound part 31 is wound up from a wind start end 121, which is one end in the longitudinal direction thereof, to a wind final end 131, which is the other end in the longitudinal direction. Thus, winds are densely layered in the direction of thickness. The stress relaxing part/parts 41 is/are formed on one side or both sides of the wound part 31 in the lateral direction thereof, and has/have a plurality of teeth 51 capable of being bent by stress caused between the base material 10 and the element 15. A joining body 21 is disposed between the base material 10 and the element 15 in a state where the joining body 21 is wound up. The joining body 21 joins to the base material 10 on one side 101 in the lateral direction, and joins to the element 15 on the other side 111 in the lateral direction. Thus, while a stress relaxing function is maintained, electric conductivity and thermal conductivity can be ensured.

Description

  The present invention relates to a bonded body, a semiconductor device using the same, and a method for manufacturing the same.

In recent years, low loss of switching elements such as inverters has been demanded. For example, by changing the switching element from conventional silicon (Si) to silicon carbide (SiC), the resistance of the element can be lowered when the withstand voltage is equivalent, so that the switching efficiency can be increased. Further, the SiC element can operate at a higher temperature than the Si element. For this reason, a mounting technique that can withstand high temperatures as a whole semiconductor device is required.
By the way, when a temperature change occurs due to element heat generation or the like in the semiconductor device, when materials having different linear expansion coefficients are bonded, stress due to the difference in linear expansion coefficient is applied to the bonding site. Therefore, for example, in Patent Document 1, the heat dissipation member and the semiconductor chip are connected by an array-shaped connection member.

JP 2007-142461 A

The connecting member of Patent Document 1 can be formed by solder printing, reflow, or the like. However, since the array cannot be densely arranged, there is a problem that electrical resistance and thermal resistance increase.
The present invention has been made in view of the above-described problems, and provides a bonded body that can relieve stress and that can reduce electrical resistance and thermal resistance, a semiconductor device using the same, and a method of manufacturing the same. It is to provide.

  The present invention is a joined body that joins a first member and a second member in a semiconductor device so as to be capable of energization and heat transfer, and includes a winding part and a stress relaxation part. The winding portion is wound from a winding start end that is one side in the longitudinal direction to a winding end that is the other end in the longitudinal direction. The stress relaxation portion is formed on one side or both sides in the width direction of the winding portion, and has a plurality of tooth portions that can be bent by the stress generated between the first member and the second member. The joined body is disposed between the first member and the second member in a wound state, joined to the first member on one side in the width direction, and the second member on the other side in the width direction. Join.

  In the present invention, for example, when stress is generated between the first member and the second member due to a difference in linear expansion coefficient, the stress is relieved by bending of the tooth portion. Moreover, since the joined body is wound and formed, it can be stacked with a high density in the thickness direction, so that a sufficient area for joining the first member and the second member can be ensured. Thereby, electrical resistance and thermal resistance can be reduced.

  Moreover, this invention is a manufacturing method of the conjugate | zygote which joins a 1st member and a 2nd member in a semiconductor device so that electricity supply and heat transfer are possible, Comprising: A stress relaxation part formation process and a winding process are provided. In the stress relaxation portion forming step, a stress relaxation portion having a plurality of tooth portions that can be bent by the stress generated between the first member and the second member is formed on one side or both sides of the winding portion in the width direction. In the winding step, the winding portion is wound from a winding start end that is one side in the longitudinal direction to a winding end that is the other end in the longitudinal direction.

In the present invention, since the stress relaxation portion is formed in the stress relaxation portion forming step, the stress generated between the first member and the second member can be relaxed. In addition, for example, by winding the winding portion while applying tension with a winding machine or the like, the joined body can be easily laminated with high density in the thickness direction, so the first member and the second member are joined. A sufficient area can be secured. As a result, it is possible to manufacture a joined body and a semiconductor device that have a stress relaxation function due to bending of the tooth portion of the stress relaxation portion and can reduce electrical resistance and thermal resistance.
Note that the order of the stress relaxation portion forming step and the winding step may be interchanged.

1 is a cross-sectional view of a joined body and a semiconductor device according to a first embodiment of the present invention. It is a figure explaining the manufacturing method of the zygote and semiconductor device by a 1st embodiment of the present invention. It is a top view which shows the joined body before the winding by 1st Embodiment of this invention. It is the figure which expanded a part of joined body before winding by a 1st embodiment of the present invention. 1 is a plan view of a joined body and a semiconductor device according to a first embodiment of the present invention. It is a top view of the zygote and semiconductor device by a 2nd embodiment of the present invention. It is a top view which shows the joined body before winding by 3rd Embodiment of this invention. It is a top view which shows the joined body before winding by 4th Embodiment of this invention. It is a top view which shows the joined body before winding by 5th Embodiment of this invention. It is a top view which shows the joined body before winding by 6th Embodiment of this invention. It is a top view which shows the joined body before winding by 7th Embodiment of this invention. It is a top view which shows the joined body before winding by 8th Embodiment of this invention. It is a top view which shows the joined body before winding by 9th Embodiment of this invention. It is sectional drawing which shows the conjugate | zygote and semiconductor device by 10th Embodiment of this invention.

Hereinafter, a bonded body according to the present invention, a semiconductor device using the same, and a manufacturing method thereof will be described with reference to the drawings. Hereinafter, in a plurality of embodiments, substantially the same configuration is denoted by the same reference numeral, and description thereof is omitted.
(First embodiment)
1 to 5 show a joined body according to a first embodiment of the present invention and a semiconductor device using the joined body. 1 to 5 are all schematic views. The same applies to the drawings according to other embodiments. FIG. 1 is a cross-sectional view taken along the line II of FIG.
As shown in FIGS. 1 and 2, the semiconductor device 1 includes a base material 10 as a first member, an element 15 as a second member, a joined body 21, and the like.

The base material 10 is a copper-based substrate or a lead frame.
Element 15 is a SiC element.
In this embodiment, since the base material 10 and the element 15 are formed of different materials, the linear expansion coefficients are different.

  The joined body 21 is formed of a material having high electrical conductivity and heat conductivity such as aluminum, and is used for joining the base material 10 and the element 15. The base material 10 and the element 15 are joined by the joined body 21 so as to be capable of energization and heat transfer. Since the base material 10 and the element 15 are joined so that heat can be transferred, for example, heat generated by driving the element 15 can be radiated to the base material 10 side.

Here, a method for manufacturing the bonded body 21 and the semiconductor device 1 will be described with reference to FIG.
The joined body 21 is formed from a base foil F shown in FIG. 2A as a strip-like foil-like material having a longer longitudinal direction than the width direction. Of course, a foil-like material previously formed in a strip shape may be used.
In the stress relaxation portion forming step shown in FIG. 2B, the stress relaxation portion 41 is formed.

FIG. 3 is an enlarged view of the joined body 21 in the state of FIG. FIG. 4 is an enlarged view of a part of FIG. As shown in FIGS. 3 and 4, the joined body 21 of the present embodiment includes a winding part 31 and a stress relaxation part 41.
The winding part 31 is formed on one side 101 of the bonded body 21 in the width direction. The winding part 31 is continuously formed in the longitudinal direction on one side 101 in the width direction.

The stress relaxation part 41 is formed on the other side 111 in the width direction of the bonded body 21 by, for example, a roll press. In other words, the stress relaxation part 41 is formed on one side of the winding part 31.
The stress relaxation part 41 has a plurality of tooth parts 51 formed so as to protrude from the winding part 31. A slit portion 61 is formed between the plurality of tooth portions 51. That is, the stress relaxation part 41 is formed in a comb shape by alternately forming the tooth parts 51 and the slit parts 61 in the longitudinal direction.

In the present embodiment, the height T <b> 1 of the tooth portion 51 is formed substantially constant from the winding start end 121 to the winding end 131. Further, the width W11 of the tooth portion 51 is formed to be substantially constant from the winding start end 121 to the winding end 131. Furthermore, the width W12 of the slit portion 61 is formed to be substantially constant from the winding start end 121 to the winding end 131. The width W12 of the slit portion 61 corresponds to “the interval between adjacent tooth portions”.
The height T1 of the tooth portion 51 is the length in the width direction of the joined body 21, and the width W11 of the tooth portion 51 and the width W12 of the slit portion 61 are taken as the length in the longitudinal direction of the joined body 21. You can also.

  Returning to FIG. 2, in the winding step shown in FIG. 2C, the joined body 21 of this embodiment is wound so that the winding start end 121, which is one end in the longitudinal direction of the joined body 21, is the winding center. It is formed by being wound from the start end 121 side to the winding end end 131 side which is the other end in the longitudinal direction while applying tension with a winding machine or the like. In this embodiment, since the joined body 21 is formed in a substantially cylindrical shape, it is formed in a substantially circular shape when viewed from above (see FIG. 5). By winding the foil-like material while applying tension, the foil-like material is laminated and integrated at a high density. Further, in view of subsequent bonding with the brazing material, the surface of the wound bonded body 21 is metallized with nickel.

In the first joining step and the second joining step shown in FIGS. 2 (d) and 2 (e), the joined body 21 is aligned with the base material 10 so that the axis is substantially perpendicular to the surfaces of the base material 10 and the element 15. It arrange | positions between the elements 15. In the present embodiment, one side 101 in the width direction where the winding part 31 of the joined body 21 is formed is the base material 10 side, and the other side 111 in the width direction where the stress relaxation part 41 is formed is the element 15 side. Placed in.
A phosphor copper brazing foil 11 (see FIG. 1) is disposed between one side 101 in the width direction of the joined body 21 and the base material 10 and heated to 800 [° C.] in N _2. One side 101 of the body 20 in the width direction and the substrate 10 are joined.
Also, the solder foil 16 (see FIG. 1) is disposed between the other side 111 in the axial direction of the joined body 21 and the element 15, and the other side 111 in the width direction of the joined body 21 and the element 15 are joined by reflow. Is done.
Thereby, the base material 10 and the element 15 are joined via the joined body 21.
In FIG. 2, the phosphor copper brazing foil 11 and the solder foil 16 are omitted.

  The joined body 21 in a wound state will be described with reference to FIGS. 1 and 5. In FIG. 5, the element 15 and the solder foil 16 are omitted. In FIG. 5, the slit portion 61 is shown with a satin finish for the description of the tooth portion 51 and the slit portion 61. The same applies to FIG. 6 described later.

As shown in FIG. 1 and FIG. 5, in the joined body 21 in a state where the foil-like material is wound, one side 101 in the width direction in which the winding part 31 is formed is the base material 10 side, and the stress relaxation part 41 is It arrange | positions so that the other side 111 of the width direction formed may turn into the element 15 side.
When the element 15 generates heat due to energization or the like and a stress is generated between the base material 10 and the element 15, the tooth 51 of the stress relaxation part 41 is bent to relieve the stress. In particular, the stress applied from the central portion of the element 15 toward the outer peripheral portion can be preferably alleviated by bending the tooth portion 51 in the radial direction of the bonded body 21 (the thickness direction when viewed as a foil-like object). .

Moreover, in this embodiment, since the joined body 21 is formed by winding up a foil-like object, the foil-like object is in a state of being laminated with high density in the radial direction. Therefore, since a sufficient area for joining the base material 10 and the element 15 can be ensured, electrical resistance and thermal resistance can be reduced.
Therefore, it can be said that the bonded body 21 of this embodiment is excellent in electrical conductivity and thermal conductivity while maintaining the stress relaxation function.

Here, in terms of stress relaxation, the thickness of the foil-like material is preferably thin. On the other hand, when the thickness of the foil-like material is reduced, the number of layers (the number of turns) increases in order to cover a certain area (for example, the area defined by the outer periphery of the joined body 21 in FIG. 5) with the joined body 21. . In view of these points, the thickness D of the foil can be appropriately set according to the stress to be relaxed, and is preferably 0.5 [mm] or less, for example.
Further, when the width of the foil-like material is increased, the electrical and thermal resistance between the substrate 10 and the element 15 is increased. For this reason, the width of the foil is preferably small, for example, 2 [mm] or less. The length of the foil is sufficiently long compared to the width so that it can be wound.

Furthermore, the stress relaxation effect is higher as the height T1 of the tooth portion 51 shown in FIGS. 3 and 4 is larger and as the width W11 of the tooth portion 51 is smaller. Further, the smaller the area of the formed slit portion 61, the higher the electrical conductivity and thermal conductivity. The area of the slit portion 61 is represented by the product of the height T1 of the tooth portion 51 and the width W12 of the slit portion 61.
In view of these points, the shape of the tooth part 51 and the slit part 61 of the stress relaxation part 41 can be appropriately designed according to the stress to be relaxed.

  In the present embodiment, a SiC element capable of high temperature operation is used as the element 15. When the element 15 is operated at a high temperature, the temperature range of the heat cycle to be ensured is widened, so that the stress generated between the substrate 10 and the element 15 is increased. Therefore, by using the bonded body 21 having a stress relaxation function, it is possible to relieve stress generated between the base material 10 and the element 15 when the element 15 is operated at a high temperature. Therefore, the element 15 is operated at a high temperature. Even so, the occurrence of cracks or the like between the substrate 10 and the element 15 can be suppressed, and the bonding state can be appropriately maintained.

If the element 15 which is a SiC element can be operated at a high temperature, the element 15 can be miniaturized and the cost can be reduced. In addition, for example, a device that requires water cooling can be realized even with air cooling, which leads to simplification of the configuration related to cooling and heat dissipation.
Further, since the SiC element has higher switching efficiency than the Si element, for example, when the semiconductor device 1 using the element 15 that is an SiC element is applied to an inverter of a vehicle main machine, it contributes to an improvement in fuel consumption of the vehicle.

As described above in detail, the joined body 21 of the present embodiment includes the winding part 31 and the stress relaxation part 41, and joins the base material 10 and the element 15 so as to allow conduction and heat transfer. The winding part 31 is wound from a winding start end 121 which is one end in the longitudinal direction to a winding end 131 which is the other end in the longitudinal direction. The stress relaxation portion 41 is formed on one side or both sides of the winding portion 31 in the width direction, and has a plurality of tooth portions 51 that can be bent by the stress generated between the base material 10 and the element 15. In the present embodiment, the stress relaxation part 41 is formed on one side of the winding part 31. The joined body 21 is disposed between the base material 10 and the element 15 in a wound state, joined to the base material 10 on one side 101 in the width direction, and on the other side 111 in the width direction. Join with.
In the present embodiment, the height T1 of the tooth portion 51, the width W11 of the tooth portion 51, and the width W12 of the slit portion 61 that is the distance between the adjacent tooth portions 51 are from the winding start end 121 to the winding end. It is formed uniformly over 131.
The semiconductor device 1 includes a bonded body 21, a base material 10 provided on one side 101 in the width direction of the bonded body 21, and an element 15 provided on the other side 111 in the width direction of the bonded body 21.

In the present embodiment, when a stress is generated between the base material 10 and the element 15 due to a difference in linear expansion coefficient, the tooth portion 51 is bent, so that the stress is relieved and generation of a crack or the like can be suppressed. .
In addition, since the joined body 21 is formed by winding, it can be stacked with a high density in the thickness direction (the radial direction in the wound state), so that a sufficient area for joining the base material 10 and the element 15 is sufficient. Can be secured. Thereby, electrical resistance and thermal resistance can be reduced. Therefore, the joined body 21 of the present embodiment is excellent in electrical conductivity and thermal conductivity while maintaining the stress relaxation function.

  The manufacturing method of the joined body 21 in the present embodiment includes a stress relaxation part forming step and a winding step. In the stress relaxation part forming step, the stress relaxation part 41 having the tooth part 51 that can be bent by the stress generated by the difference in linear expansion coefficient between the base material 10 and the element 15 is formed on one side or both sides of the winding part 31 in the width direction. (See FIG. 2 (b)). In the winding process, the winding portion 31 is wound from the winding start end 121 that is one end in the longitudinal direction to the winding end 131 that is the other end in the longitudinal direction (see FIG. 2C).

  Moreover, the manufacturing method of the semiconductor device 1 in the present embodiment is a first bonding step in which the one side 101 in the width direction of the bonded body 21 manufactured by the above manufacturing method and the base material 10 are bonded so as to allow current and heat transfer. And a second joining step of joining the other side 111 of the joined body 21 in the width direction and the base material 10 and the element 15 having a different linear expansion coefficient so as to be capable of energization and heat transfer (FIG. 2D). (See (e)).

  In the present embodiment, since the stress relaxation part 41 is formed in the stress relaxation part forming step, the stress generated between the base material 10 and the element 15 can be relaxed. Further, for example, by winding the winding part 31 while applying tension by a winding machine or the like, the joined body 21 can be easily laminated at a high density in the thickness direction (the radial direction in the wound state). . Thereby, electrical resistance and thermal resistance can be reduced. Therefore, in this embodiment, it is possible to manufacture a bonded body and a semiconductor device that are excellent in electrical conductivity and thermal conductivity while maintaining the stress relaxation function.

(Second Embodiment)
FIG. 6 shows a joined body according to the second embodiment of the present invention. FIG. 6 is a diagram corresponding to FIG. 5 of the above embodiment.
The joined body 22 of the present embodiment has the same shape before winding as that of the above embodiment, and the wound shape is different. That is, in the above embodiment, the joined body 21 is wound to form a substantially cylindrical shape, and is substantially circular in top view as shown in FIG. The joined body 22 of this embodiment is wound to form a substantially rectangular parallelepiped shape, and has a substantially rectangular shape in top view as shown in FIG.
Even if it forms in this way, the stress which arises between the base material 10 and the element 15 can be relieve | moderated because the tooth | gear part 51 of the stress relaxation part 41 bends. In particular, the stress applied in the outer peripheral direction from the winding center of the joined body 22 can be relaxed by bending the tooth portion 51 in the thickness direction of the foil.
The winding shape is not limited to a substantially circular shape in a top view as in the first embodiment or a substantially rectangular shape in a top view as in this embodiment, and may be any shape such as a triangular shape in a top view.
Thereby, there exists an effect similar to 1st Embodiment.

(Third to ninth embodiments)
Hereinafter, the third to ninth embodiments shown in FIGS. 7 to 13 are variations in the shape of the joint. 7 to 13 are views corresponding to FIG. 3 of the first embodiment, and show the joined bodies 23 to 29 before being wound. The joined bodies 23 to 29 have winding portions 33 to 39 and stress relaxation portions 43 to 49 as in the above embodiment, and the other ends in the longitudinal direction from the winding start ends 123 to 129 that are one end in the longitudinal direction. It is formed by being wound around winding ends 133 to 139 which are ends. Moreover, it joins with the base material 10 on the one side 103-109 side of the width direction of the joined bodies 23-39, and it joins with the element 15 on the other side 113-119 of the width direction.
Further, the stress relaxation parts 43 to 49 have tooth parts 53 to 59 that can be bent by the stress generated between the base material 10 and the element 15. Slit portions 63 to 69 are formed between the adjacent tooth portions 53 to 59.

(Third embodiment)
As shown in FIG. 7, the joined body 23 according to the third embodiment of the present invention has a winding portion 33 formed at substantially the center in the width direction. Further, the stress relaxation parts 43 are formed on both sides of the winding part 33.
In this embodiment, the height T3 of the tooth portion 53, the width W31 of the tooth portion 53, and the width W32 of the slit portion 63 that is the distance between the adjacent tooth portions 53 are substantially from the winding start end 123 to the winding end 133. It is formed uniformly.
Even if comprised in this way, there exists an effect similar to 1st Embodiment.

(Fourth embodiment)
As shown in FIG. 8, the joined body 24 according to the fourth embodiment of the present invention has winding portions 34 formed at both ends in the width direction. Moreover, the stress relaxation part 44 is formed in the approximate center of the width direction. In other words, the stress relaxation portion 44 is formed between the two winding portions 34 formed at both ends in the width direction. Further, it can be considered that the stress relaxation portion 44 is formed on one side of the winding portion 34.
In this embodiment, the height T4 of the tooth portion 54, the width W41 of the tooth portion 54, and the width 42 of the slit portion 64, which is the distance between the adjacent tooth portions 54, are substantially from the winding start end 124 to the winding end end 134. It is formed uniformly.
Even if comprised in this way, there exists an effect similar to 1st Embodiment.

(Fifth embodiment)
As shown in FIG. 9, in the joined body 25 according to the fifth embodiment of the present invention, the stress relaxation portion 45 is formed on one side of the winding portion 35.
In this embodiment, the width W51 of the tooth portion 55 of the stress relaxation portion 45 and the width W52 of the slit portion 65, which is the distance between the adjacent tooth portions 55, are formed substantially constant from the winding start end 125 to the winding end end 135. Is done.

Further, the height T5 of the tooth portion 55 is formed to be different from the winding start end 125 to the winding end end 135. In particular, in this embodiment, the height T5 of the tooth portion 55 is formed smaller on the winding start end 125 side and larger on the winding end end 135 side.
Here, when winding is performed so that the winding start end 125 is the winding center, the height T5 of the tooth portion 55 on the winding center side is small, and the height T5 of the tooth portion 55 on the outer peripheral side is large. As a result, the stress relaxation function on the outer peripheral side where stress tends to concentrate can be enhanced, and the thermal resistance of the central portion of the element 15 where the heat density becomes high can be reduced.
In addition, the same effects as those of the first embodiment are obtained.

(Sixth embodiment)
As shown in FIG. 10, in the joined body 26 according to the sixth embodiment of the present invention, the stress relaxation part 46 is formed on one side of the winding part 36.
In this embodiment, the width W61 of the tooth portion 56 of the stress relaxation portion 46 and the width W62 of the slit portion 66, which is the interval between the adjacent tooth portions 56, are formed substantially constant from the winding start end 126 to the winding end 136. Is done.

Further, the height T6 of the tooth portion 56 is formed to be different from the winding start end 126 to the winding end 136. The height T6 of the tooth portion 56 in this embodiment is small on the winding start end 126 and winding end 136 side, and is large at the intermediate portion 146.
Even if comprised in this way, there exists an effect similar to 1st Embodiment.

(Seventh embodiment)
As shown in FIG. 11, in the joined body 27 according to the seventh embodiment of the present invention, the stress relaxation portion 47 is formed on one side of the winding portion 37.
In this embodiment, the width W71 of the tooth portion 57 of the stress relaxation portion 47 and the width W72 of the slit portion 67, which is the distance from the adjacent tooth portion 57, are formed substantially constant from the winding start end 127 to the winding end 137. Is done.

Further, the height of the tooth portion 57 is formed to be different from the winding start end 127 to the winding end end 137. In this embodiment, a section A in which the height of the tooth portion 57 is T71 and a section B in which the height of the tooth portion 57 is a height T72 smaller than T71 are repeated.
Even if comprised in this way, there exists an effect similar to 1st Embodiment.

(Eighth embodiment)
As shown in FIG. 12, in the joined body 28 according to the eighth embodiment of the present invention, the stress relaxation portion 48 is formed on one side of the winding portion 38.
In this embodiment, the height T8 of the tooth portion 58 of the stress relaxation portion 48 and the distance W82 between the adjacent tooth portions 58 are formed substantially constant from the winding start end 128 to the winding end end 138.

Further, the width W81 of the tooth portion 58 is formed to be different from the winding start end 128 to the winding end 138. The width W81 of the tooth portion 58 in this embodiment is formed larger on the winding start end 128 side and smaller on the winding end end 138 side.
As a result, the stress relaxation function on the outer peripheral side where stress tends to concentrate can be enhanced, and the thermal resistance of the central portion of the element 15 where the heat density becomes high can be reduced.
In addition, the same effects as those of the first embodiment are obtained.

(Ninth embodiment)
As shown in FIG. 13, in the joined body 29 according to the ninth embodiment of the present invention, the stress relaxation portion 49 is formed on one side of the winding portion 39.
In this embodiment, the height T9 of the tooth portion 59 of the stress relaxation portion 49 and the width W91 of the tooth portion 59 are formed to be substantially constant from the winding start end 129 to the winding end end 139.
Further, the width W92 of the slit portion 69, which is an interval between the adjacent tooth portions 59, is formed to be different from the winding start end 129 to the winding end end 139. The width 92 of the slit portion 69 of this embodiment is formed to be small on the winding start end 129 side and large on the winding end end 139 side.
As a result, the stress relaxation function on the outer peripheral side where stress tends to concentrate can be enhanced, and the thermal resistance of the central portion of the element 15 where the heat density becomes high can be reduced.
In addition, the same effects as those of the first embodiment are obtained.

(10th Embodiment)
FIG. 14 shows a semiconductor device according to the tenth embodiment of the present invention.
The semiconductor device 2 according to this embodiment is a double-sided heat dissipation semiconductor device. That is, the substrate 10 is provided not only on the first surface 151 side of the element 15 but also on the second surface 152 side via the joined body 21.
In FIG. 14, the joined body 21 of the first embodiment is illustrated, but the joined bodies 22 to 29 of the second to ninth embodiments may be employed. The joined body on the first surface 151 side and the joined body on the second surface 152 side of the element 15 may have different shapes.
Even if the joined bodies 21 to 29 are applied to the double-sided heat dissipation semiconductor device 2 as in the present embodiment, the same effects as those of the first embodiment are obtained.

(Other embodiments)
In the said embodiment, the 1st member which a joined body joins was a copper base base material, and the 2nd member was a SiC element. In other embodiments, the first member and the second member are not limited to the combination of the base material and the element, but may be the base materials, the elements, or another member. Moreover, in the said embodiment, the element was a SiC element. In other embodiments, any element such as a Si element may be used.

  In addition, even if the first member and the second member are formed of the same material and the linear expansion coefficient of the member alone is equal, for example, when one is mounted on the substrate and the other is not mounted on the substrate, etc. Stress may occur between the first member and the second member due to factors other than the material. Also in such a case, it is considered that “the linear expansion coefficients of the first member and the second member are different”.

In the said embodiment, aluminum was illustrated as a raw material of a joined body. In another embodiment, as long as the material has high thermal conductivity and electrical conductivity, a metal such as copper or nickel may be used instead of aluminum. Further, for example, a non-metallic material such as a carbon nanotube may be used.
In the said embodiment, the metallization process was performed after winding of a conjugate | zygote. In other embodiments, the metallization process may be performed before winding the bonded body, or the metallization process may not be performed.

  In the above embodiment, phosphor copper solder is used for joining the base material and the joined body, and solder is used for joining the element and the joined body. In another embodiment, for bonding the first member and the second member to the bonded body, a conductive adhesive containing a metal nanomaterial in addition to a general brazing material as long as it is a material capable of transmitting electricity and heat. An agent or the like may be used. Further, depending on the material, if possible, bonding may be performed directly without using a brazing material or a conductive adhesive.

  For example, in 1st Embodiment, the winding part was formed in the one side of the width direction joined to a base material, and the stress relaxation part was formed in the other side of the width direction joined to an element. In another embodiment, the stress relaxation portion may be formed on one side in the width direction to be bonded to the base material, and the winding portion may be formed on the other side in the width direction to be bonded to the element.

In the said embodiment, a slit part is formed between adjacent tooth parts. In other embodiments, the stress relief portion may be formed in any manner as long as the tooth portion can be bent by the stress generated between the first member and the second member.
For example, as in the above embodiment, a slit portion (space) may be provided between adjacent tooth portions. In this case, the brazing material or conductive adhesive used for joining to the first member or the second member enters the space between the tooth portions to the extent that the tooth portions can be bent by stress on the tip side of the tooth portion. Is acceptable. Moreover, the width | variety of a slit part may be as small as possible, and it may be in the state where adjacent tooth parts contact.

Further, for example, the slit portion formed between adjacent tooth portions may be filled with a filling member having an elastic modulus such that the tooth portion can be bent by stress. The elastic modulus of the filling member is preferably 20 [GPa] or less, which is the elastic modulus of tin (Sn), for example.
Furthermore, for example, the tooth portion may be formed by forming a connecting portion obtained by thinly processing between adjacent tooth portions with a press or the like.
Further, the stress relaxation portion is not limited to pressing, and may be formed by any method such as etching.

In the said embodiment, a stress relaxation part is formed in the state before winding, and a joined body is formed by winding up the foil-like object in which the stress relaxation part was formed. That is, a winding process is performed after a stress relaxation part formation process. In another embodiment, after winding up the foil, a stress relaxation part may be formed to form a joined body. That is, you may make it perform a stress relaxation part formation process after a winding process. Moreover, if a 1st joining process and a 2nd joining process are implemented after a stress relaxation part formation process and a winding process, the order may be replaced and may be performed simultaneously.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

1, 2 ... Semiconductor device 10 ... Base material (first member)
15 ... Element (second member)
21-29 ... joined body 31, 33-39 ... winding part 41, 43-49 ... stress relaxation part 51, 53-59 ... tooth part

Claims (10)

A joined body (21-29) for joining the first member (10) and the second member (15) in the semiconductor device (1, 2) so as to be capable of energization and heat transfer,
Winding portions (31, 33-39) wound from the winding start end (121, 123-129) which is one end in the longitudinal direction to the winding end (131, 133-139) which is the other end in the longitudinal direction;
A stress relieving part that is formed on one or both sides in the width direction of the winding part and has a plurality of tooth parts (51, 53 to 59) that can be bent by the stress generated between the first member and the second member. (41, 43-49),
With
It is arrange | positioned between the said 1st member and the said 2nd member in the wound state, and it joins with the said 1st member at one side (101, 103-109) of the width direction, and the other side of the width direction (111, 113 to 119) A joined body characterized by joining to the second member.   The height of the teeth (51, 53, 54, 58, 59) is from the winding start end (121, 123, 124, 128, 129) to the winding end (131, 133, 134, 138, 139). The joined body (21 to 24, 28, 29) according to claim 1, wherein the joined body is formed uniformly over the distance.   The height of the tooth portion (55) is formed smaller on the winding start end (125) side and larger on the winding end end (135) side. The joined body (25).   The teeth (51, 53-57, 59) have a constant width from the winding start end (121, 123-127, 129) to the winding end (131, 133-137, 139). The joined body (21-27, 29) as described in any one of Claims 1-3 characterized by the above-mentioned.   The width of the said tooth | gear part (58) is formed large in the said winding start end (128) side, and is formed small in the said winding termination | terminus (138) side, The one of Claims 1-3 characterized by the above-mentioned. The joined body (28) according to one item.   An interval between the adjacent tooth portions (51, 53 to 58) is formed to be constant from the winding start end (121, 123 to 128) to the winding end (131, 133 to 138). The joined body (21 to 28) according to any one of claims 1 to 5.   An interval between the adjacent tooth portions (59) is formed smaller on the winding start end (129) side and larger on the winding end end (139) side. The joined body (29) according to any one of 5 above. The joined body according to any one of claims 1 to 7,
The first member joined to one side in the width direction of the joined body in a wound state;
The second member joined to the other side in the width direction of the joined body in the wound state;
A semiconductor device comprising: A method of manufacturing a joined body (21-29) for joining a first member (10) and a second member (15) in a semiconductor device (1, 2) so as to allow conduction and heat transfer,
Winding portions (31, 33) include stress relaxation portions (41, 43-49) having a plurality of tooth portions (51, 53-59) that can be bent by the stress generated between the first member and the second member. To 39) a stress relaxation portion forming step formed on one side or both sides in the width direction;
A winding step of winding the winding part from a winding start end (121, 123-129) which is one end in the longitudinal direction to a winding end (131, 133-139) which is the other end in the longitudinal direction;
A method for producing a joined body comprising: A first joining step of joining one side (101, 103 to 109) in the width direction of the joined body produced by the production method according to claim 9 and the first member so that energization and heat transfer are possible;
A second joining step for joining the other side (111, 113 to 119) in the width direction of the joined body and the second member having a linear expansion coefficient different from that of the first member so as to allow conduction and heat transfer;
A method for manufacturing a semiconductor device, comprising:

Images