DE2157145A1 - Composite body and process for its manufacture - Google Patents

Description

PATENT Attorneys ^ » O / I 4 O

DIPL.-ING. LEO FLEUCHAUS DR.-ING. HANS LEYH

Munich 71,

Melchiorstrasse 42 11/16/1971

Our reference: A 12 360

PLESSEY HANDEL UND INVESTMENTS A.G. 6300 Zug / Switzerland Gartenstrasse 2

Composite body and process for its manufacture

The invention relates to a composite body and a method for its production.

The composite body according to the invention is characterized in that it comprises at least a portion of a microcrystalline and substantially impermeable carbon material which is connected to another Part is connected by means of an intermediate layer of an element forming a carbide.

If the second part is made of metal, it is expedient to have a metallic layer between the layer of the carbide former and this Part of a metal coating arranged.

Foal <? .- ^r 1materialian with a microcrystalline structure, which are essentially impermeable, e.g. vitreous, vitreous and pyrolytic coals are electrically conductive, mechanically very strong, resistant to numerous chemicals, as well as chemically, biologically and physically compatible with human tissue, which is why they to a large extent for applications in electronics, for example, ■

Lh / fi as well

209822/0996

BATH

A 12 36O

Govrie are suitable in biological and chemical engineering. However, it is difficult in practice to establish an effective bond between a part made of such a carbon material and another part the same or a different material the chemical inactivity of the carbon material.

To produce the aforementioned composite body, it is expedient to use a carbide-forming element is applied to the part consisting of carbon in order to form an intermediate layer, which in turn connected to the other part.

Is this other part a metal part and should it be with the carbide layer are connected by soldering, brazing or the like, then the carbide layer is expediently covered with a metal coating, for example made of nickel. Vitreous or vitreous coal is advantageously used as the carbon material, while silicon is advantageously used as carbide former.

The invention is explained in detail below with reference to the drawings described.

Fig. 1 shows schematically in section part of an inventive Composite body.

Fig. 2 also shows a further embodiment in section. Fig. 3 shows another embodiment in section.

In the production of the composite body according to the invention according to FIG. is first a part 1 of the desired shape made of a carbon material, for example vitreous or vitreous coal or pyrolytic Formed coal.

Vitreous or vitreous coal is produced by the thermal decomposition of organic substances. A method of making impermeable Body of coal is described in U.S. Patent No. 3,1109,712 and British Patent No. 956,452. as

- 2 - bulk goods

209822/0996 bad orig.nal

A 12 360

In bulk, vitreous coal has a density of about 1.5; she is not porous and shows a shell-like break.

Pyrolytic charcoal becomes more organic by charring certain simple ones Connections created.

After the production of the part 1, a layer 2 is made of a Carbide-forming element in a suitable known manner, for example by precipitation from the vapor phase on the desired area of the Part 1 applied. Suitable carbide formers are, for example, silicon, tungsten, boron and titanium.

During the production of layer 2 by precipitation from the vapor phase a mask is expediently applied to the coal part 1, which only leaves the areas free on which a precipitate is desired, whereupon the coal part 1 in an atmosphere of silane is heated to a temperature in the range of about 1000 ° C. A silicon layer forms on the exposed surfaces Process that bonds firmly to the underlying carbon material.

Then the part 3 is connected to the SdIcht 2. If the part 3 consists of a material which has essentially the same temperature coefficient as the carbon material of the part 1 has, for example hard glass (Pyrex glass), then the part 3 is directly with connected to layer 2. The connection between a part 3 made of hard glass and the silicon layer 2 is made by heating the two Parts brought about to an elevated temperature, whereby one obtains a solid vacuum-tight connection, the considerable thermal Shocks averted. Will a seal of this type with compressed air loaded with a pressure difference of about 1 kg per square centimeter over a period of about 15 hours, one only obtains a loss of less than 0.00005 cm of air per hour.

Fig. 2 shows a preferred composite body made of a coal part 4, for example vitreous coal, one end of which is sealed in one end of a tube 5 made of Pyrex glass by means of a layer 6 of silicon is attached. The silicon is with part 4 in the above

- 3 - wrote

209822/0996

2157U5

A 12 3CO

scbriebonen T ^T else been connected before ^. as Part 4 ™ .it>T'nrie the "ear was 5, respectively. Kin ^v erbund3-" been rrer this ^a rt spell used in various ways, such as electric power, with the aid of the part · * an enclosed in pipe 5 substance be supplied or discharged from this substance, since the part 4, as stated above, is electrically conductive and corrosion-resistant to numerous substances.

If the part 3 is tested from a "lethal and should it be connected to the part 1 by ^{T <7} calibration soldering, hard soldering or the like connected", then, as FIG. 3 shows, the layer 2 with a metal coating 7, for example made of nickel, provided ore *, -Hie connection with de ^r i part 3 is -Obtained.

Beirr j'berziehen 2 rit of the silicon layer, the layer of nickel about 5 "'inutes on a hot plate in a solution of Ii _n ^c 0./HO in" (^ rhältnis gereiniat 5: 1. ~ M_r> surface of the silicon layer 2 is "ater then entionisinrtem ^T- gowarchen. Thereafter, v-ith the ausgewaschone surface -i.er riliciumschicht 2 a ^v tivated namely before the part 1 is brought Hickel-plating solution with the Fchicht 2 in an electrodeless, din at a temperature of about The surface of the layer is exposed to the nickel coating solution for a period of time which depends on the desired thickness of the coating 7, but in practice it has been found that about 5 minutes are sufficient to obtain a suitably thick coating After the coating has been formed, the part 1 is removed from the piling solution and washed.

^T. Use may also equally ^v eramisch ^f r parts such as to be connected from AIuwiniumoxyd with other bodies, to which end a silicon layer is applied before production of the connection to the other bodies on the ceramic part. A metallic layer is arranged between the silicon layer and the other body if this other grain is made of metal. This structure is also suitable for numerous applications

- 4 - dungsf "He

2 09822/0996

BAD ORiGiNAL

2157U5

A 12 360

dunrrsf. "1Ie, ζ.P. on the packaging of semiconductor devices. Here the semiconductor device is attached to a ceramic carrier and a cover made of metal is placed over the semiconductor device and connected to the ceramic carrier, which is connected to a Silicon and a "lethal layer is provided to protect the connection, ζ.Ρ ·, lightly tinker with a low-melting solder to be able to.

BATH ORIGINAL

- 5 - Claims

209822/0996

Claims (12)

A N S P R ίί C H E 2157H5 A 12 360 Composite body, characterized by at least one part (1, 4) made of a substantially impermeable, microcrystalline carbon material, which by means of an intermediate layer (2, 6) of an element forming a carbide with connected to another part. 2. Composite body according to claim 1, characterized in that that the charcoal material is vitreous or vitreous charcoal or pyroIytic charcoal. 3. Composite body according to claim 1 or 2, characterized in that the carbide-forming element silicon, Is tungsten, boron or titanium. 4. Composite body according to one of the preceding claims, wherein the other part is made of metal, characterized in that between this other part (3) and the Layer (2) of the carbide-forming element a metallic layer (7) is arranged to connect the two parts (1, 3) to facilitate. 5. Composite body according to one of the preceding claims, characterized by a part (4) made of vitreous Carbon, which is connected to the other part (5) by means of an intermediate layer (6) made of silicon. 6. Composite body according to one of the preceding claims, characterized characterized in that the part (5) is in the form of a Tube is made of hard glass and that the part (4) is in the form of a rod, one end of which in a 209822/0996 2157U5 A 12 360 opening of the ear (5) by means of an intermediate layer (6) is tightly attached to a carbide-forming element, the rod-shaped part (4) extends into the tube (5). 7. A method for producing a composite body according to a of the preceding claims, characterized in that that a layer (2, 6) of a carbide-forming element is applied to the carbon part (1, 4), and that this Layer is connected to the other part (3, 5). 8. The method according to claim 7, characterized in that that the carbide-forming element is deposited from a vapor phase on the coal part · (1, 4). 9. The method according to claim B, wherein the carbide-forming element is filiciur », characterized in that a '4as3'e is attached to the carbon part (1, 4) which only leaves the puddles free on which the silicon is deposited, and that the .Kohleteil (1, 4) is heated to a temperature of about 1000 ⁰ C in a silane atmosphere. 10. The method according to any one of claims 7 to 9, wherein all of the above Part - a "<? Tall part is characterized by that the layer (2) is provided with a coating (7) made of Fickel before it is connected to the metal part. 11. Verf aViruses according to claim 10, characterized in that that the layer (2) to which the part (3) is connected is cleaned and then activated, that afterwards in a plating bath the nickel layer (7) is formed on the cleaned surface and the body thus formed is then washed. 12. The method according to claim 11, characterized in that that the surface of the layer (2) is heated on a hot plate 209822/0996 ^ß AD original 2157U5 A. and about 5 Hinuten is immersed in a solution of P ^ SO. / Fo ^ in the ratio 5: 1, is washed with deionized preceded the ^c chicht setter. BATH ORIGINAL 209822/0996