DE1085262B - Process for the production of sintered bodies provided with vacuum-tight seals which serve as bases for electrical arrangements, in particular semiconductor arrangements - Google Patents

Description

GERMAN

The invention relates to a method for the production of seals provided with vacuum-tight seals Sintered bodies that serve as a base for electrical assemblies, in which a fusible, insulating Material of granular consistency around those arranged in a specific mutual position in a mold Distributed leads and then subjected to a pressing and sintering process.

The production of such sintered bodies, which in itself and with regard to the fusing of metallic Complete supply lines vacuum-tight, has recently been particularly in connection with the development in the semiconductor field, in particular with the transistor production, increased importance won. Because of the moisture and contamination sensitivity of semiconductor devices it is desirable to place them in vacuum-tight enclosures. Common embodiments of such covers have one on one End open cup-shaped metal jacket which partially encloses the semiconductor device and on its open side with a suitable end part, for example a base, which has a having insulating core made of sintered, ceramic or other material, is closed. By This insulating core must be the electrical leads to the semiconductor device located inside be passed through in a vacuum-tight manner. Usually the base is like that executed that the mentioned sintered body is surrounded by a metallic collar, which with the sintered body closes vacuum-tight and at the same time a simple connection with the cup-shaped metal jacket allowed.

In the production of such bases with a collar and sintered body, there is one task, precisely the required amount of the insulating, fusible used for the manufacture of the sintered body Material to be provided. If the amount used is too large, the material may be damaged during the Sintering flows over the edge or the circumferential flange of the federal government, whereby the vacuum-tight seal is made difficult or prevented with the metal casing; when using too low a Amount of the fusible material results in insufficient mechanical strength, which is also the Can affect the tightness of the closure.

Another problem in the production of such sintered bodies is the maintenance of the for the correct position of the supply lines during the entire manufacturing process.

Another problem arises with regard to achieving a truly vacuum-tight seal between the sintered body and the melted-down method of manufacture
of sintered bodies provided with vacuum-tight seals, which serve as bases

for electrical arrangements,

in particular semiconductor arrangements

to serve

Applicant:

Philco Corporation,

Philadelphia, Pa. (V. St. A.)

Representative: Dipl.-Ing. C. Wallach, patent attorney,
Munich 2, Kaufingerstr. 8th

Claimed priority:
V. St. v. America April 24, 1957

Henry Paul Beerman, Skokie, 111.,

and Ford Kenyon Clarke, Chalfonte, Pa. (V. St. A.),

have been named as inventors

Supply lines and optionally between the sintered body and the surrounding metallic Federation.

There are processes for the production of such sintered bodies provided with vacuum-tight fuses, which can be used as a base for electrical assemblies, are known in which a fusible, insulating material of a granular consistency, such as glass powder, in order to reduce the in certain mutual position in a press mold arranged supply lines distributed and then a press and subjected to sintering processes.

There is a method of this type known in which the granular material without binding substance before Sintering in the cold state is sufficient while maintaining the predetermined position of the leads strongly pressed and then sintered under pressure.

There is also known a similar method which differs from the aforementioned one in that the granular material has a binding substance before sintering is strongly pressed in the cold state and then sintered without pressure.

Finally, there is also a method of this type for the production of vacuum-tight seals

009 550/273

3 4

provided sintered bodies known, in which the Sinte manufacturing process reproduces, the section

tion without additional pressure and without binding substance in a containing the longitudinal axis of the device

he follows. Level is led,

In all of these known methods, there is a Fig. 4 the pressing process during the manufacturing difficulty in finding the correct position of the supply line,

gen within the sintered core during the production Fig. 5 the self-supporting, mechanically assembled

to ensure the solution process. For this purpose it was up-to-date base before firing or sealing

necessary to close the desired position of the supply lines.

during the entire manufacturing process, in particular the present manufacturing process can so

special also during the sintering process, carried out by io that a mixture of materials

special external devices in the form of different melting points with at least

of teachings or the like. This results in a dissolvable component in granular form,

special in those processes in which the, for example, glass powder in order to be in a certain

Sintering under pressure or with a pressure mutual position arranged in a press mold

follows, to trouble; but also with the method 15 leads are compressed, whereby through the

With sintering without pressure, the necessary mechanical assembly of the particles makes it possible to

dignity, external teachings to maintain the sufficient intimate contact between the supply lines

correct position of the leads to use and the core material is achieved.

This is particularly true in the case of It should be noted that the following

the production of sintered bodies for bases of 20 used designation »glass« a broad meaning

Semiconductor arrangements are due to the fact that they are often extremely clothing; it closes glasses, fries, glazes

nen dimensions and the associated narrow and other materials of a similar nature.

Tolerances. These cold-pressed units are then converted into

The invention is based on the object of bringing a furnace and one between the drive to create in which the disadvantages mentioned 25 melting points of the substances forming the conclusion the known method can be avoided and the lying temperature is heated, with the designation particularly for use in establishing melting point with respect to glass by the range Semiconductor devices, d. H. at high requirements the temperature is given, in which usually The accuracy and the degree of purity in the case of seal closures must be carried out. Through the small dimensions of the overall arrangement suitable- 30 application between the melting points of the is net and, on the other hand, a firing temperature for other components in the manufacturing process large-scale simplicity, the lead wires with the lower, the melting part of the core is hermetically sealed

For this purpose, the method of the opening is connected while the material is closed named type according to the invention so carried out, 35 higher melting point in the form of individual, miteindaß to produce the sintered core a mixture of other and with the supply lines through the cement materials At least particles with different melting points are connected with a sintered core a liquefiable component remains used, this conglomerate to maintain the det is and that this mixture during sintering on for the correct wire holding during the sealing Above the melting point of the liquefiable phase, the desired mechanical rigidity is used. These Component, but below the melting point of the regulation of the degree of fluidity of the rest Components lying at temperature, set mass by suitable dimensioning of the application, part of high and low melting components

With this measure, the equipments become a simple procedure for the correct mounting

right maintenance of the correct position of the supply lines at 45 of the supply lines during the sealing and is unnecessary

the previously known methods associated difficulties thus the need for external furnishing means for

problems avoided. Namely, it then forms during the supply lines.

During the sintering process, a dispersion in which only the correct mixture, i.e. H. of each to receive

partially liquefied sintered core, which thereby provides the required hermetic seal and the

for the automatic maintenance of the correct 50 necessary mechanical for cable support

Location of the supply lines sufficient mechanical rigidity suitable percentage of the individual substances,

Retains rigidity even during sintering. can easily be determined experimentally in each individual case

According to a particularly advantageous embodiment, be agreed.

Form of the invention it is provided that for the production, in particular, the mixture forming the core must

ment of the sintered core a homogeneous mixture of 55 the correct proportion of heat-resistant and an

Glass powders with different melting points have low-melting materials so

is used, which in the subsequent sintering during the sealing process a solid-liquid component

process on a between the melting points of the plex is formed, which is sufficiently viscous to the

The temperature lying between the various components is used to maintain the prescribed

heats up. 60-sided position of the supply lines during firing

To have further advantages and details of the invention required mechanical rigidity, while

result from the description of the embodiment, on the other hand, at the same time a usable

for example on the basis of the drawing; in this shows metic sealing permitted.

Fig. 1 is a view of a semiconductor device, the In Fig. 1 is a hermetically sealed transi-

embodies an embodiment of the invention, where- 65 sturgeon 10 is shown. This version has a

broken away when parts, transistor 12 enveloping cup-shaped metal sleeve

FIG. 2 shows an 11 as well as a according to the present method produced during the production of this.

Pieces of existing base serving device in provided base 13, the two parts

disassembled, long the connecting surfaces of their peripheral flanges

Fig. 3 is a cross-section showing the initial phase of the yu 14 and 15 being hermetically sealed.

In Fig. 2, 19 designates a mold which has a cavity 20 in the bottom openings 21 are provided in a suitable arrangement, which receive the lines 18 and in in their correct position. The cavity 20 is of such a depth that the collar 16 when inserted into this cavity rests on the bottom 22, while the underside of the RandHansches 15 of the federal government comes straight against the top of the cube 19 to rest. ίο

The initial step of the manufacturing process is simply that suitable lines, for example the leads designated by 18 of about 0.4 mm thickness, and the steel collar 16 in the they are introduced into each receiving openings. When these parts are in their position as shown in Fig. 3, take, in the subsequent process step, the cavity 20 is covered with a powdery Glass mixture 23 filled. A preferred composition of this mixture in the present Embodiment contains 15 to 20 percent by weight of a powdered glass frit with low melting point, which form a tight seal at a temperature in the range from 600 to 650 ° C supplies. Otherwise, the mixture contains a more heat-resistant frit that can be used at high temperatures between 800 and 825 ° C normally results in a tight seal.

This mixture of glass powder or frits is then suitably prepared using the oven provided cylinder 24 compressed by means of hydraulic or other devices is brought into contact with the mixture under pressure, the openings 25 in the Printing cylinders 24 are directed and arranged so that they are provided with those provided in the cube or the mold 22 Line guides fit together so that the correct position of the lines during the Compression of the mixture is retained, as shown in FIG. 4.

The preferably made of approximately 0.25 mm material Collar 16 has an inside diameter of about 3.8 mm. It was found that a means of the cylinder 24, which can slide in the collar 16, exerted a force of about 1360 kg on the mixture a sufficient mechanical connection of the particles causes to the feed lines during the following Steps of the manufacturing process to keep in place, and that the pressure an intimate contact between the leads and the core ensured, so that a sufficient A tight seal is achieved in the subsequent firing. In addition, this is used by pressure induced mechanical connection of the particles to the fusible core material in the To fasten the collar so that the whole consisting of collar and compressed core is after when it is removed from the mold it is a self-supporting, well-assembled structure. This cold Pressed base of the type of Fig. 5 are then placed in an electric furnace or with another Device heated to a temperature of about 765 ° C, with this temperature being quite satisfactory Results have been achieved. However, this firing temperature is not critical, but lies between the temperatures at which one of the glass components would melt if alone would be used, so that a core is formed in which the low-melting frit as the glassy Phase serves, which with the homogeneously distributed heat-resistant material to form a solid Joint mass united, while the non-sintered particles of the core serve to increase the strength of the composite mixture to the extent that the mater is all during the sealing process withstands occurring distortion forces and thus maintaining the desired position of the supply lines always guaranteed.

Claims (5)

Patent claims: 1. A process for the production of sintered bodies provided with vacuum-tight seals, which serve as a base for electrical arrangements, in particular semiconductor arrangements, in which a fusible, insulating Material of granular consistency around those arranged in a specific mutual position in a mold Distributed leads and then subjected to a pressing and sintering process, thereby characterized in that a mixture of materials with different for the production of the sintered core Melting points is used with at least one liquefiable component and that this mixture during sintering to a temperature above the melting point of the liquefiable component, however, the temperature is below the melting point of the other components will. 2. The method according to claim 1, characterized in that a for the production of the sintered core homogeneous mixture of glass powders with different melting points is used, which in the subsequent sintering process to one between the melting points of the various Components lying temperature is heated. 3. The method according to any one of claims 1 or 2, characterized in that the components of the mixture with different melting points can be chosen in such a ratio, that the core in the subsequent sintering process a dispersion of unsintered particles in the partially liquefied mixture forms, so that the core during sintering one to maintain the correct mutual position of the supply lines has sufficient mechanical rigidity and that at the same time a hermetically sealed connection between the supply lines and the sintered core is achieved. 4. The method according to any one of claims 1 to 3, characterized in that the mixture from substances with different melting points before sintering to a self-supporting, firmly bonded one Mass is pressed, which is the location of the. maintains supply lines arranged therein. 5. The method according to any one of claims 1 to 4, characterized in that the sintered core is made in a metallic collar of substantially cylindrical shape. Considered publications: German utility model No. 1764699; Swiss patents No. 222 880, 242035. 1 sheet of drawings © 009 550/273 7.60