Header Having High-density Conductor Arrangement And Method Of Making Same

Abstract

A header having a high-density density conductor arrangement having a plurality of equally spaced-apart conductors held in place by a sealing, electrical insulating material. A method of forming such a header with a high-density conductor arrangement by chemically milling or stamping the conductors from a single sheet of material, leaving them joined by strips at both ends. The conductors are formed in the shape desired and fused to a base, after which the upper strip is ground off and the conductors are plated. The conductors are now ready for use in the final manufacture of electronic assemblies such as transistors, integrated circuits, etc.

Description

The invention relates to headers having high-density conductor arrangements for use in providing connecting leads for electronic assemblies such as transistors, integrated circuits, microelectronic circuits and the like. In particular, the invention is directed toward providing more precise assembly and higher conductor packing densities than have been attainable heretofore.

In the prior art, the individual conductors were individually sealed in the outer metal ring. This requires large finished sizes because the individual conductors must be held in position during sealing by tooling which is subject to high temperatures, wear and initial machining deviations. In some prior art assemblies, the conductors are joined at one end by a connecting band. Even these assemblies are subjected to positioning inaccuracies due to the bending of the unsupported ends of the conductors.

Moreover, hermetic defects are generated by material handling in the assembly procedures and such handling increases in proportion with the increase in the number of conductors. This increased handling reduces the yield.

To obtain uniform plating of the conductors it is necessary to join them at one end. Except for the prior art assemblies, which are joined by a band at one end, it is necessary to electrically connect the individual conductors by special wiring or racks prior to and during the plating operation.

Operator inaccuracy or machine errors result in defects which proliferate as the number of conductors is increased. Bent conductor ends, missing conductors and uneven spacing either reduce the productive yield or make it difficult for the end user to use the finished product.

It is an important object of the invention to provide a header having a high-density conductor arrangement by creating precise spacing of the individual conductors thus making high-conductor packing densities possible.

It is a further object of the invention to provide a method for making such an arrangement.

These and other objects, features, uses and advantages will be apparent during the course of the following description when taken in conjunction with the accompanying drawings.

Broadly, the invention comprises chemically milling or stamping a plurality of equally spaced conductors from a single sheet, leaving both ends of the conductors joined by conductive strips. The desired number of conductors are severed from the sheet and they are formed into the desired configuration. One end of the conductors is placed in a sealing jig with the strip elevated from the seal area so that the strip remains free when the combination is hermetically sealed. This effectively positions the conductors in the proper relationship. The end strip nearest the hermetic sealing is ground off and the conductor ends are ground to the desired height above the seal.

The combination is then plated in a plating solution (such as gold for semiconductor use). The plating procedure is uniform because the conductors are all connected by the remaining strip or band which also helps to protect the conductors from damage. Now, the electronic components are installed and connected to the individual pins. When assembly is completed, the lower band is removed so that the individual conductors are available for connection in the external electronic system.

It is also within the contemplation of the invention to surround the conductors with an internal or external insulating ring or a combination of both to form a plug to thereby permit the unit to be readily inserted into and removed from a mating receptacle. Moreover, a plurality of conductive sheets may be used and various shapes and configurations of the finished units may be produced utilizing the teaching of the invention.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a plan view of an embodiment of the invention;

FIG. 2 is a sectional view, taken on lines 2--2 of FIG. 1, viewed in the direction of the arrows;

FIG. 3 is an elevational view of a typical, chemically milled or stamped sheet used in carrying out the teachings of the invention:

FIG. 4, on the same sheet as FIGS. 1 and 2, is an exploded view showing the parts used in making the embodiment of FIGS. 1 and 2;

FIG. 5 is an elevational view of an alternative mounting base which may be used with the embodiment of FIGS. 1 and 2;

FIG. 6 is a view similar to that of FIG. 1 of a further embodiment of the invention;

FIG. 7 is a sectional view, taken on the lines 7--7 of FIG. 6, viewed in the direction of the arrows;

FIG. 8 is a view similar to that of FIG. 4 of the embodiment of FIGS. 6 and 7;

FIG. 9 is a view similar to that of FIG. 1 of a two-row embodiment of the invention;

FIG. 10 is a view similar to that of FIG. 6 of a two-row embodiment of the invention;

FIG. 11 is a view similar to that of FIG. 2, but inverted, showing the use of an insulating ring inside the conductors to form a plug-in-type unit;

FIG. 12 is a view similar to that of FIG. 11, showing the use of an insulating ring outside the conductors to form a plug-in-type unit; and

FIG. 13 is a view similar to that of FIG. 11, showing the use of two insulating rings, one inside and one outside the conductors, to form a plug-in-type unit.

In the drawings, wherein, for the purpose of illustration, are shown various embodiments of the invention, the numeral 20 designates an embodiment of conductor arrangement of the invention for use as an electronic component header. Header 20 is seen to comprise (FIGS. 1 and 2) an outer metallic ring 22 and a plurality of conductive pins 24 joined at one extremity by strip or band 26 and sealed within the ring 22 by hermetic seal 28 of glass or other sealing material with the conductor ends 25 projecting above the seal.

Header 20 is formed by chemically milling or stamping a sheet of conductive material 30 so as to form a plurality of individual conductors 24 joined at both ends by strips 26 and 32 (FIG. 3). The required number of conductors are cut from the sheet and are formed into the desired configuration (FIG. 4). Assembly proceeds by placing the upper end of the conductive sheet 31 between glass rings 34 and 36 so that strip 32 and a portion of the individual conductors project above the rings. Metallic base 38 and ring 22 are fitted inside ring 34 and outside ring 36, respectively. Now, the heat required to cause the glass to flow and seal the conductors in place is applied.

For the so-called "matched seal" technology, the conductors, the metallic base and the ring are typically iron-nickel-cobalt alloys such as Kovar and the sealing material is Corning 7052 glass. For the so-called "compression seal" technique, the conductors, and the metallic base are formed of nickel iron alloy such as No. 52 alloy, the outer ring is typically formed of cold rolled steel and the sealing material is Corning 9010 glass. It should be noted, however, that any other sealing material, which is capable of flow, may also be used. This would include plastic, epoxy molding, Mycalex and similar material.

After the combination is assembled, and the conductors are sealed in place, the upper strip 32 is ground off, leaving the ends 25 projecting above the seal. In the same operation, the ends 25 may be ground to uniform height. Next, the assembly is placed in the plating bath and the conductors are plated. Because one of the plating connections is made to strip 26, the plating on the conductors is very uniform. The combination is now ready for internal wiring. The desired electrical circuits are wired to the conductor ends 25 and the strip 26 is removed by cutting the conductors 24 above the upper edge of the strip. This effectively frees and separates the conductors 24, making the finished assembly ready for use.

If desired, base 40 with stud 42 (FIG. 5) may be substituted for base 38. It is noted that whichever base is used, only five parts must be handled in the production of the header 20 of the invention.

FIGS. 6-8 illustrate a further embodiment of a square header 44 in which only eight parts are handled. Header 44 is formed of four sheets 31 of conductors 24 having upper strips 32 and lower strips 26, base 46, sealing rings 48 and 50 and outer ring 52. The combination is assembled as described earlier and the strips 31 are sealed as shown at 54. Then the upper strips 32 are removed and the ends 25 are ground to the correct height. The leads may now be plated as described earlier. Following which, the electronic components are connected to the lead ends 25 and the lower strip 26 is removed.

The embodiment of FIG. 9 is assembled in the same manner as that of FIG. 1. It comprises an outer ring 56, two concentric sets of conductors 24 and a base 58. Assembly and construction follows the same procedure as was described earlier. It should be noted that three, mating, sealing rings are used in order to seal the conductors in place.

The embodiment of FIG. 10 is assembled in the same manner as that of FIG. 6. It comprises an outer ring 60, an inner base 62 and eight sets of conductors 24. Assembly and construction follows the same procedure as was described earlier. It should be noted again that three, mating, sealing rings are used in order to seal the conductors in place.

It can readily be seen that any number of concentric rings of conductors may be used to increase the number of conductors while occupying relatively little space.

The embodiments of FIGS. 11-13 utilize the teaching of the invention to produce a plug-type header for ready insertion into and removal from a mating plug. After the pins of any of the previously described embodiments have been plated, an insulator 64 is formed inside the pins and in contact with them. Then strip 26 is removed. Insulator 64 may be a plastic, epoxy or other material which is applied in liquid form in a jig or it may be a solid ring made of glass, ceramic, plastic, Mycalex or similar material which is bonded into place with epoxy or similar material. FIG. 11 is shown inverted from FIG. 2 since, when solid rings are used, it is easier to put them in place with the bottom of the assembly up. When the unit is finished and the internal wiring is completed, it may be plugged into a receptacle having individual contacts which connect to the outside of the individual pins 24 of the header 20.

Ring 66 of FIG. 12 is formed of material similar to that of ring 64 of FIG. 11. The completed header may make contact by means of the tips of pins 24 in the usual plug-in receptacle. Alternatively, a receptacle may be used which fits inside the header pins and whose individual contacts make contact with the inside of the individual pins 24 of the header 20.

Rings 68 and 70 of FIG. 13 are formed of material similar to that forming rings 64 and 66. Ring 68 is inside the pins and ring 70 is outside the pins and contact is normally made to the protruding tips of pins 24. However, special sockets may be used which will permit contact to be made to the inside and/or the outside of the pins.

It is also within the contemplation of the invention to substitute a disc for either ring 64 or ring 68.

While particular embodiments of the invention have been shown and described, it is apparent to those skilled in the art that modifications are possible without departing from the spirit of the invention or the scope of the subjoined claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A header having high-density conductor arrangements for electronic assemblies comprising:

a metal base whose outer perimeter is shaped in the desired shape of the header;

a metal ring having an internal perimeter larger than that of the outer perimeter of the metal base and disposed outside the metal base;

a sheet of spaced-apart conductors disposed between the metal base and the metal ring and substantially surrounding the metal base;

the sheet of spaced-apart conductors having a first end and a second end;

sealing means sealing the first end of the sheet of spaced-apart conductors between the metal base and the metal ring and insulating the sheet of spaced-apart conductors therefrom;

the individual ends of the conductors at the said first end projecting beyond the sealing means for sufficient distance to permit connections to be made thereto;

the conductors at the said second end of the sheet of spaced-apart conductors being joined together by a single strip of the material thereof.

2. The invention of claim 1 including:

a plurality of sheets of spaced-apart conductors, each such sheet of spaced-apart conductors being of such size so as to conform to the perimeter of the metal base;

no two such sheets of spaced-apart conductors being of the same size;

the sheets of spaced-apart conductors being disposed one inside the other;

the sealing means sealing the plurality of sheets between the metal base and the metal ring with the conductors of one sheet of spaced-apart conductors being spaced from the conductors of every other sheet of spaced-apart conductors.

3. The invention of claim 1 including an insulating ring in contact with the individual conductors adjacent the said second end of the sheet of spaced-apart conductors.

4. The invention of claim 3 wherein the insulating ring is internal of the conductors.

5. The invention of claim 3 wherein the insulating ring is external of the conductors.

6. The method of making a header having high-density conductor arrangements for electronic assemblies comprising:

making a conductive sheet having a plurality of spaced-apart individual conductors joined at both ends by strips of the conductive sheet;

placing the conductive sheet around a metal base so that the said sheet substantially surrounds the metal base and so that the metal base is between the two said strips and close to one of them;

placing a metal ring opposite the metal base and surrounding the conductive sheet so that the conductive sheet is between the metal base and the metal ring;

sealing the conductive sheet between the metal base and the metal ring to hold the conductive sheet in position such that the strip close to the metal base is out of contact with the seal so formed and the conductive sheet is insulated from the metal base and the metal ring;

grinding off the said strip close to the metal base;

plating the conductive sheet.

7. The invention of claim 6 including:

removing the strip at the other end of the conductive sheet after plating.

8. The invention of claim 7 including before removing the strip at the other end of the conductive sheet:

placing insulating means in contact with the plurality of conductors at the said other end to form a plug.

9. The invention of claim 6 including prior to sealing;

making a second conductive sheet having a plurality of spaced apart individual conductors joined at both ends by strips of the conductive sheet;

placing the second conductive sheet around the metal ring so that the said second sheet substantially surrounds the metal ring and so that the metal ring is between the two said strips and close to one of them;

placing a second metal ring opposite the metal ring and surrounding the second conductive sheet so that the said second sheet is between the two metal rings;

sealing the combination so that the said conductive sheet is sealed between the metal base and the metal ring to be held in position such that the strip close to the metal base is out of contact with the seal and the conductive sheet is insulated from the metal base and the metal ring and so that the second conductive sheet is sealed between the metal ring and the second metal ring to be held in position such that the strip close to the metal ring is out of contact with the seal and the second conductive sheet is insulated from the metal ring and the second metal ring;

grinding off the strip of the second conductive sheet close to the metal ring;

plating the second conductive sheet.

10. The invention of claim 9 including:

removing the strip at the other end of the second conductive sheet after plating.