JPS59214245A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent crack and exfoliation of semiconductor element without deteriorating heat radiation characteristic by constituting a support with a metal material having a high thermal conductivity and a metal body having a low thermal expansion coefficient. CONSTITUTION:A semiconductor element 204 is fixed to a metal support 205 and a metal support 205 is fixed to a heat radiating base 201. A metal support 205 is composed of a first metal material 206 having a high thermal conductivity, for example, copper or copper alloy and a second metal material 207 having a low thermal expansion coefficient, for example, consisting of alloy of iron- nickel, iron-cabalt-nickel attrached to the side surface thereof. Heat generated by semiconductor element 204 is radiated to a heat radiating base 201 through the metal material 206. Thermal expansion of metal material 206 is suppressed by the metal material 207. Therefore, a stress generated by difference of thermal expansion coefficient between semiconductor element 204 and support 205 can be alleviated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat dissipation structure for a semiconductor device, particularly a high-power semiconductor device.

In general, semiconductor devices, especially high-power semiconductor devices,
In order to obtain high output, the semiconductor element #7 is removed during operation of the semiconductor device.
It is important to allow the grazing to take advantage of the heat generated by the grass. In addition, in conventional high-output semiconductor devices, semiconductor elements are directly bonded to a heat-dissipating base made of a metal with high thermal conductivity, such as copper, using a brazing material, such as an alloy material such as gold-silicon or lead-tin silver. It was layered. In such conventional semiconductor equipment,
Stress caused by the difference in thermal expansion coefficient between the heat dissipation base and the semiconductor element often causes accidents such as cracks in the semiconductor element with weaker mechanical strength, or separation of the element from the heat dissipation base. Was. In particular, as output increases and semiconductor element chips themselves become larger, the occurrence of such accidents has become more prominent. Therefore, in order to prevent such accidents, a metal support made of a metal such as tungsten or molybdenum, which has a smaller coefficient of thermal expansion than the heat dissipation base, is fixed to the heat dissipation base. Semiconductor devices have been proposed in which stress caused by differences in thermal expansion coefficients of elements is alleviated.

However, in a conventional semiconductor device having such a metal support, the heat generated by the semiconductor element.

Since the heat is radiated through the metal support which has a lower thermal conductivity than the heat radiating base (the heat radiating base), it has the disadvantage that heat radiation is inhibited by the metal support. Furthermore, since a brown value material such as molybdenum or tungsten must be used as the metal support, it has the disadvantage that semiconductor devices cannot be provided at low cost.

The purpose of F-16 Meiji is to provide an inexpensive semiconductor device with excellent heat dissipation and no chip cracking.

The present invention uses a first metal body, such as copper, which has high thermal conductivity as a metal support, and a metal body, such as iron, which has a low coefficient of expansion.
Secondary materials such as Nisokel, iron-cobalt-nickel alloys, etc.
and a second metal body on the side of the first metal body.
The structure has a structure in which a metal body is attached to the first metal body, and a semiconductor element is attached to the first metal body.
It is characterized by being fixed to the upper end surface of the metal body.

In such a half-quad mounting according to the present invention, the semiconductor element is mounted on the first metal body of the highly thermally conductive metal support. ! 1
Since the heat generated by the semiconductor element during operation of the semiconductor device can be dissipated from the surface heat dissipation base via the highly thermally conductive tenth metal body, sufficient heat dissipation can be achieved. Further, the semiconductor element is fixed on the first metal body having a large coefficient of thermal expansion.
A second metal body with a small coefficient of thermal expansion attached to the il1 surface acts to suppress thermal expansion of the first metal body.

For this reason, it is possible to alleviate the stress applied to the semiconductor element caused by the difference in thermal expansion coefficient between the semiconductor element and the first metal body, and it is possible to completely prevent cracking of the semiconductor element and peeling from the metal body. Also, the metal support is copper.

It also has the advantage that it can be constructed from a combination of inexpensive materials such as iron-nickel alloy.

As described above, the inventive semiconductor device has excellent heat dissipation properties, eliminates defects such as cracking of the semiconductor element and peeling from the support, and can be easily provided during operation of the semiconductor device.

Next, the invention will be explained in more detail using one box.

Figure 1 is a vertical cross-sectional view showing a conventional semiconductor device;
The figure is a longitudinal sectional view showing an embodiment of the invention.

FIGS. 3(a) and 3(b) are schematic diagrams showing an example of the manufacturing method of the metal support according to the invention.

In FIG. 1 (FIG. 2), 101 (201) is a heat dissipation base made of a metal with high thermal conductivity such as copper, and the heat dissipation base 101 (201) is made of a metal such as alumina. Hole 102 (202) in the center of the insulator
A wall member 103 (203) is attached.

The metal grinding support 105 (205) for mounting the semiconductor device 104 (204) is attached to the heat dissipating metal base 1 at the opening m1 opening 02 (202) of the wall member 1.03 (203).
It is fixed at 01 (201). Semiconductor element 101 (
201) is fixed to the metal support 105 (205),
Each electrode is connected to a metal layer formed on the wall member 103 (203) by a thin metal wire 1.08 (208), and is electrically connected to an external lead 109 (209) via the metal layer.

In the conventional semiconductor device shown in FIG. 1, the metal support 105 on which the semiconductor element 1 rl 4 is mounted includes:
In order to prevent the semiconductor element 304 from cracking or peeling from the metal support 105 due to the difference in thermal expansion coefficient with the semiconductor element 104, a material having a smaller thermal expansion coefficient than that of the heat dissipation base 101, such as tungsten, Metals such as molybdenum are used.

In such a conventional semiconductor device, the half body part 104
The generated heat is transferred to the heat dissipation base 101 via the metal support 105 which has lower thermal conductivity than the heat dissipation base 101.
Therefore, the metal support 105 has the disadvantage that heat dissipation is impaired. Further, the metal support 105 is made of tungsten.

Since all expensive materials such as molybdenum must be used, the semiconductor device has the disadvantage that it cannot provide a low-cost V'c.

On the other hand, in the actual phase example shown in FIG.
The all-pole support 205 for fixing 04 is a first all-pole support 206 made of copper, copper alloy, etc., which has high thermal conductivity.
and, for example, iron-nickel having a low expansion coefficient on the side surface of the first metal body 206.

It has a structure in which a second metal body 207 made of an alloy such as iron-cobalt-nickel is attached, and the semiconductor element 204 is attached to the first metal body 207.
is fixed to the upper end surface of the metal body 206.

In such an uninvented semiconductor device, the semiconductor element 2
Since the heat generated from the heat dissipation base 201 is dissipated through the first metal body 206 having high thermal conductivity, it is possible to dissipate the heat by the amount of light.

Further, the semiconductor element 204 is fixed on a first metal body 206 with a large coefficient of thermal expansion, and a second metal body 206 with a low coefficient of thermal expansion is attached to the side surface of the first metal body 206.
07 acts to completely suppress the thermal expansion of the first metal body 206. For this reason, the semiconductor element 204 and the first metal body 206
It is possible to alleviate the stress caused by the difference in the coefficient of thermal expansion between the semiconductor element 204 and the first metal body 206, thereby preventing the semiconductor element 204 from cracking and peeling from the first metal body 206. In addition, the metal support 20
5 can be made of an inexpensive material such as copper or an iron-nickel alloy, and as shown in FIG. A strip clad with a metal plate 207 having a coefficient,
It can be easily obtained by cutting as shown by diagonal lines in the figure. Further, as shown in FIG. 3 (tb), a metal wire 206 made of thermally conductive material such as copper is coated with a wire such as iron.
It can also be easily obtained by cutting a wire clad with a metal 207 having a low coefficient of expansion, such as a nickel alloy, perpendicular to the axial direction as shown by diagonal lines in the figure.

As described above, according to the semiconductor device assembly of the present invention, a semiconductor device that has excellent heat dissipation properties and has all defects such as cracks in the semiconductor element 204 and peeling from the metal support 205 removed can be provided at low cost and easily.

The effect of non-invention has been explained above with reference to the drawings,
The effect of the invention is that the metal support is a rectangular parallelepiped-shaped metal support shown in Figure 31 (a) with a second metal body attached to two sides of the first metal body, or as shown in Figure 3 (b). There are no restrictions on the shape of the first metal wire, such as a cylindrical one with a second metal body attached to the outer periphery of the first metal wire, or the attachment of the first metal body and the second metal body. It is clear that the scope of the patent application covers all semiconductor devices.

Margin below: 17 yen, s;, \ 2, -1 １ノ″7　°・　l′ 15. −hi

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing a conventional semiconductor device), Fig.
The figure is a longitudinal sectional view showing an embodiment of the invention. No. 31.
J(a) and (b) are schematic diagrams showing an example of a method for manufacturing a metal support according to the invention. 101.201...Base for heat dissipation, 102.20
2... Wall member opening portion, 103, 203...
・Wall parts. 104.204...Semiconductor element, 105,205
...Metal support, 206...First metal body, 207...Second metal body, 108,208.
...Thin metal wire. 1.09,209...External lead. /θ2 /θ5 lθ41θ1 Figure 1 Koshirae 3 figure ＾ Figure 2 Figure 3 6

Claims (1)

[Claims] In a semiconductor device in which a semiconductor element is mounted on a metal support fixed to a heat sink, the metal support includes a first metal body having high thermal conductivity and a side surface of the first metal body. 1. A semiconductor device comprising: a second metal body having a low expansion coefficient attached to the semiconductor device;