JPS58135648A - Manufacture of copper-carbon fiber compound material - Google Patents

Abstract

PURPOSE:To accomplish the manufacturing method for a Cu-C compound material generating no difference in the coefficient of thermal expansion between the center part and the circumference of the material by a method wherein, even in the case of carbon fibers which are spirally embedded, the carbon fibers are wound as far as to the center part. CONSTITUTION:The copper-plated layer and the copper powder of each conical body 13 are formed in a copper matrix state, and they function as copper matrix leaving no boundary by applying heat and pressure even when they are used for a laminated adhesive material 17. In other words, in this laminated adhesive material 17, a plurality of carbon fibers are conically wound around in buried form in the copper matrix. Then, said laminated adhesive material 17 is cut into the prescribed size as shown by the dotted lines in the diagram. The carbon fibers are cut too together with the laminated adhesive material 17, but as the carbon fibers are wound and buried in layer form between the center part and the circumference of the Cu-C compound material 18 after cutting, the coefficient of thermal expansion of the carbon fibers can be brought close to that of the semiconductor substrate. Also, as the carbon fibers were wound around and buried as far as the center part in the stage of a conical body 13, the carbon fiber layer is extended to the center part of the Cu-C compound material as well.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aA relates to a method of manufacturing a copper-carbon fiber composite material, particularly a method of manufacturing a steel-carbon fiber composite material in which carbon fibers are embedded in a steel matrix suitable as an electrode material for a semiconductor device. Two steel-carbon fiber composite materials (hereinafter abbreviated as Cu-C composite materials)
) is effective in that its properties can be freely changed by changing the composition ratio by taking advantage of the electrical conductivity and heat conductivity of steel and the low thermal expansion of carbon fiber, and it is particularly useful as an electrode material that supports the semiconductor substrate in semiconductor devices. It will be effective if

FIG. 1 shows a semiconductor device 1 using this C'u-C composite material, in which a semiconductor substrate 2 has a P-joint J and is exposed at its end Fi#13. Glass 4 is baked into the groove 3 as a surface stabilizing material.

A is applied to the upper and lower main surfaces of the semiconductor substrate 2 through a brazing material 5.6.
An electrode material 7.8 made of n-c1 composite material is fixed. The periphery of the semiconductor substrate 2 is molded with a wind box resin 10 through a silicone rubber 9 and over both electrode materials 7 and 8.

A semiconductor device l having such a structure is called a button type.
A cooling body (not shown) is often pressed against both electrode plates 7.8.

Both electrode plates 7.8 are made of a Cu-C composite material, and their composition ratio allows them to have a thermal expansion coefficient extremely close to that of the semiconductor substrate 2, so that no thermal stress is applied to the semiconductor substrate 2.
Therefore, the semiconductor substrate 2 should not be destroyed.

However, it was confirmed that the semiconductor substrate 2 was broken with a curve extending from the center toward the periphery.

After investigating the cause, we came to the conclusion that there may be a problem in the production of the CU-C composite material.

The one that caused the destruction was a large one made of carbon fibers wound in a spiral 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 though the surrounding area is made of CU-C composite material, the center is made of steel itself, which has a different amount of thermal expansion, and is subjected to pressing force from the cooling body, resulting in an overload in the center of the semiconductor substrate 2. It is estimated that this caused cracks to appear from the center to the periphery.

Therefore, the object of the present invention is to ensure that even if the carbon fibers are spirally wound, they are sufficiently wound up to the center, so that there is no difference in the coefficient of thermal expansion between the center and the periphery.
The present invention provides a method for manufacturing a composite material.

Digging carbon fiber in a spiral shape means that when viewed in a plane direction,
Since the coefficient of thermal expansion is the same in both the radial direction and the circumferential direction, this is an effective buried form when considering the matching of the coefficient of thermal expansion with the semiconductor substrate. However, it is necessary to avoid using core materials.

Therefore, in Zero-Hatsu, steel-coated carbon fiber is wound into a conical shape, and once it is hardened, multiple values are prepared, multiplied, and heated and pressurized to integrate. A CU-C composite material is obtained by cutting the CU-C composite material.

2 and 3 show an embodiment of the present invention.

In Fig. 2, the steel-coated carbon fiber is wound around the conical body 12, rotating in the direction shown by the arrow, with the steel-coated carbon fiber directed from the center to the periphery. This shows the state in which you can obtain .

Copper-coated carbon fiber is carbon fiber with a copper layer, which is bundled and impregnated with copper powder slurry. Heat and press as necessary to form a cone-shaped body. In this state, the carbon fibers are sufficiently wound and embedded up to the central tip of the cone.

In Figure #E3, a plurality of such conical bodies 13 are laminated between a cylindrical mold 14 and molds 1.5.16 at both ends, and heated and pressed as they are to form a laminated bonded body of CU-C composite material. 17 is shown. The copper plating layer and copper powder of each pyramidal body 13 form a steel matrix, and the laminated adhesive body 17 also functions as a -steel matrix by heating and pressing without leaving any boundaries.

In other words, it can be said that in this laminated adhesive body 17, a plurality of carbon fibers are each wound in a conical shape in a steel matrix.

Next, this laminated adhesive body 17 is cut into a required size as shown by the dotted line. Although the carbon fibers are also cut by cutting, the carbon fibers are wrapped and buried in layers between the center and the periphery in the Cu-C composite material 18 after cutting, so that the coefficient of thermal expansion is sufficiently close to that of the semiconductor substrate 2. be able to.

In addition, in the central part, carbon fibers have already been wound and dug up to the central part at the pyramid-shaped body 130 stage, so in the Cu-C composite material 18, carbon fibers are similarly present up to the central part. There is no difference in the coefficient of thermal expansion between the center and the periphery in the thickness direction.

Such a Cu-C composite material 18 is used as an electrode plate 7 shown in FIG.
．． 8, and even if a pressing force is applied from the cooling body, it will expand and contract on average during actual use, so no overload will be applied to a part of the semiconductor substrate 2, and therefore the semiconductor substrate will not be destroyed. There isn't.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a semiconductor device using cu-c4@composite material as an electrode plate, Fig. 112, and Fig. 3 show the manufacturing method of the present invention for each piece. It is a front view.

Claims (1)

[Claims] 1. Obtain a dragging anchor shape by rolling and solidifying steel-coated carbon fiber into a conical shape 1
Embed carbon fibers in a steel matrix, which consists of the steps of laminating multiple conical bodies and integrating them by heating and pressing to obtain a nine-layer adhesive, and cutting the laminated adhesive into the required size. Outline - Manufacturing method of carbon fiber composite materials