JPS58135647A - Manufacture of copper-carbon fiber compound material - Google Patents

Abstract

PURPOSE:To obtain a Cu-C compound material having almost no difference between the coefficient of thermal expansion on the center part and that on the circumference of the material by a method wherein copper coated carbon fibers, which are made into a bundle and twisted, is used as a core material, other steel coated carbon fibers are wound thereon, and then they are compressed and heated up. CONSTITUTION:The core material 11 is obtained by having a plurality of steel coated carbon fibers made into bundles and twisted. This core material is twisted in a clockwise direction, for example, the tensile dorce at both ends as shown by the arrows A and B, and twisting force as shown by the arrows C and D are added, and the above is formed into a strong stick form body. Nos. 12 and 13 are the side plates provided on the stick type core material 11, and a steel coated carbon fiber bundle 14 is wound around the core material 11 using the side plates 12 and 13. After a prescribed amount of the steel coated carbon fiber 14 has been wound around, the side plates 12 and 13 are removed, and the carbon fiber is soaked into the slurry of copper powder and copper powder is impregnated into the carbon fibers, as occasion demands, for the purpose of regulating the composition ratio between copper and carbon. Then, the wound body is heated and compressed together with the core material 11, copper is formed into matrix and a Cu-C compound material wherein carbon fibers are enbedded can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a copper-carbon fiber composite material, in particular a method for manufacturing a copper-carbon fiber composite material, in which carbon fiber is incorporated into a steel matrix suitable as a TA material for semiconductor devices.
The present invention relates to a method for producing a copper-carbon fiber composite material.

Steel-carbon fiber composite material (hereinafter abbreviated as Cu-Cm composite material).

) is effective in that its properties can be freely changed by changing the composition ratio by taking advantage of the electrical conductivity and thermal conductivity of copper and the low thermal expansion of carbon fiber, and it is particularly useful as a fIL pole material that supports the semiconductor substrate in semiconductor devices. It is effective when used.

Figure 1 shows a semiconductor device using this Cu-,C composite material.
, the semiconductor substrate 2 has a pn junction J and is exposed at its end g3. 'a3 has glass 4
It is baked in as rM stabilizing material.

C is applied to the upper and lower main surfaces of the semiconductor substrate 2 through a brazing material 5.6.
Electrode material 7.8 made of u-C composite material is fixed. The periphery of the semiconductor substrate 2 is molded with an epoxy resin 10 via a silicone rubber 9 and over both electrode plates 7 and 8.

The semiconductor device lf1 having such a structure is called a button type, and is often used with a cooling body (not shown) pressed against both electrode plates 7.8. Since it is a composite material and its composition ratio allows it to have a coefficient of thermal expansion close to that of the semiconductor substrate 2, no thermal stress is applied to the semiconductor substrate 2, and therefore, the semiconductor substrate 2Vi should not rupture.

-However, it was confirmed that the semiconductor substrate 2 cracked from approximately the center toward the periphery and was destroyed.When we investigated the cause of this, we found that there may be a problem in the manufacturing of the CU-C composite material. I got to thinking.

The one that caused the destruction was one in which carbon fiber was spirally wound parallel to the main surface of the semiconductor substrate 2, and the center of the fiber was filled with copper powder and sintered after the core material had been removed. .

In other words, even if the surrounding CU-C composite material is used, the steel in the center itself has a different amount of thermal expansion, and as it is receiving pressing force from the cooling body, an overload is applied to the center of the semiconductor substrate 2. Therefore, the object of the present invention is to ensure that even if the charcoal IA fibers are embedded in a spiral shape, they are sufficiently rolled up to the center, and therefore, The present invention is characterized by providing a method for producing a Cu-C composite material with almost no difference in thermal expansion coefficient between the center and the periphery. The purpose is to apply pressure using a material as a core material.

Hereinafter, the manufacturing method of the present invention will be explained based on the embodiments shown in the drawings.

In FIG. 2, reference numeral 11 is a core material obtained by bundling and twisting a plurality of steel-coated carbon fibers, that is, carbon fibers provided with a steel plating layer. This core material is twisted, for example, in the right direction, and tension is applied at both ends as shown by arrows A and B, and carrying force is applied as shown by arrows C and D, resulting in a strong rod-shaped body. ing.

Reference numerals 12 and 13 denote side plates provided on this rod-shaped core material 11, and a bundle 14 of steel-coated carbon fibers is wound around the core material 11 using the side plates 12 and 13 as guides. After a predetermined amount of the steel-coated carbon fiber bundle 14 has been wound in this way, the side plates 12 and 13 are removed, and if necessary, the side plates 12 and 13 are dipped in copper powder slurry to adjust the composition ratio of steel and carbon. Copper powder is impregnated between carbon fibers. Next, this wound body including the core material 11 is heated and pressurized to obtain a Cu--C composite material in which the steel 1□ is used as a matrix and carbon fibers are embedded therein.

When the core material 11 is heated and pressurized, the core material 11 is carried in, so that the carbon fibers are only stretched and contracted by the pressurizing force, and each carbon fiber is not irregularly deformed.

In the CU-C composite material, the core material 41 itself has carbon fiber,
And since they are integrated, carbon fibers existed between the center and the periphery, and by adjusting the composition ratio of the strip steel plating layer and the carbon fiber of the core material 11 in the center, the center C has an almost uniform coefficient of thermal expansion from the center to the periphery.
It may be made of a U-C composite material. Therefore, expansion and contraction occur almost uniformly in the center and periphery, and no protrusion occurs in the center.

For this reason, when used as an electrode plate of a semiconductor device, even when subjected to pressing force from a cooling body, no overload is applied to a part of the semiconductor substrate, and the steel-coated carbon fiber bundle does not melt when the semiconductor substrate breaks. Instead of 14, a cloth-like weave of copper-coated carbon fiber may be wound around the core material 11. in this case,
By using a biased steel-coated carbon fiber woven fabric, each carbon fiber will not deform irregularly when heated and pressurized.

The CU-C composite material obtained using the steel-coated carbon fiber woven fabric exhibits high resistance not only in the radial direction and circumferential direction, but also in the thickness direction.
The CU-C composite material can have a thermal expansion coefficient similar to that of a semiconductor substrate, and the CU-C composite material has at least one semiconductor substrate brazed between a pair of electrodes, and the surrounding area has a thermal expansion coefficient similar to that of the semiconductor substrate. However, it can be applied as the pair of electrodes of a glass-molded deaf semiconductor device sealed with glass having a surface stabilizing function.

As described above, according to the manufacturing method of the present invention, it is possible to obtain a CU-C composite material in which there is almost no difference in coefficient of thermal expansion between the center and the periphery.

[Brief explanation of the drawings] Figure 1 shows a semiconductor using a Cu-C composite material as an electrode plate!
A cross-sectional view of uJl, FIG. 2 is a diagram illustrating the manufacturing method of the present invention. 1... Semiconductor device, 2... Semiconductor substrate, 5.6...
・Brazing material, 7.8... Electrode plate, 11... Core material, 12
．． 13...￥11 謬2(21 ↑

Claims (1)

[Claims] 1. A copper-carbon fiber composite characterized by further wrapping other steel-coated carbon fibers around a core material obtained by bundling and twisting steel-coated carbon fibers, and then heating and pressurizing the core material. Method of manufacturing wood. 2. Claim 1: Wrapping other steel-coated carbon fibers while applying tensile force and twisting force to the core material!
! Method for manufacturing fine steel-carbon fiber composite material