A compliant interconnection device and assembly method of manufacture, and of micro interconnection casting

Claim 2

A compliant interconnection device (25a) of the type having a plurality of spaced., individual interconnections (31) extending on both sides of a plate (25), characterised in that the interconnections (31) are lockingly engaged with the plate (25).

Claim 3

The interconnection device (25a) of claim 1 characterised in that the plate (25) is of a flexible, nonelastic, dielectric material (12).

Claim 4

The interconnection device (25a) of claim 2 characterised in that the plate (25) is of a dielectric material having a dielectric strength at least equivalent to a paper (12) with clay particulate fillers.

Claim 5

The interconnection device (25a) of claim 1 characterised in that the interconnections (31) are columnar.

Claim 6

The interconnection device (25a) of claim 1 characterised in that the interconnections (31) include first * columnar portions (31a) on each side of the Plate (25) and a: vertically offset second columnar portion (31b) extending on both sides of the plate and connected to the first columnar portions (31a) by member (31e) normal to the columpar portions (31a, 31b).

Claim 7

The interconnection device (25a) cf claim 1 characterised in that the interconnections (31) include first and second vertically offset columnar portions (31a, 31b) joined by a member (31e) extending normal thereto.

Claim 8

The interconnection device (25a) of claim 1 characterised by the interconnections (31) being spaced in from the edges of the plate (25) and further a plurality of apertures (15) are provided in the plate (25) interior of the interconnections (31).

Claim 9

The interconnection device (25a) of claim 1 characterised by the interconnections (31) comprising a grid array (37) interior to the edges of the plate (25).

Claim 10

The interconnection device (25a) of claim 1, 3, 4, 5 or 6 characterised by the interconnections (31) being cast solder columns.

Claim 11

The interconnection device (25a) of claim 1 characterised in that the interconnections (31) are positioned around the periphery of the plate (25) and one or more columns (37) of heat dissipating material are positioned interior to the interconnections (31).

Claim 12

The interconnection device (25a) of claim 9 characterised by a free end (31d) of at least one solder column (31) extending beyond the free end (31d) of another solder column (31).

Claim 13

The interconnection device (25a) of claim 3 characterised by the plate (25) including electrical circuitry (61) thereon extending to and electrically interconnecting at least two interconnections (31).

Claim 14

The interconnection device (25a) of claim 1 characterised in that the plate (25) includes coregistry means (32,33a) for alignment of the interconnections (31) with circuit elements (26,27) between which the device (25a) may be positioned.

Claim 15

A method for making a compliant interconnection device (25a) of the type having a plurality of spaced, individual solder columns (31) extending through a plate (25) and as claimed in claim 1, characterised by the steps of: a. punching a plurality of apertures (15) in a dielectric plate (25); b. cast.ing through said apertures solder columns (31) lockingly engaging the plate (25); c. chilling the solder columns (31); and d. ejecting said solder columns (31) from a casting die (17).

Claim 16

The method of claim 14 characterised by the additional step of depositing solder paste on each free end (31c,31d) of each solder column (31) for soldering said solder columns (31) to circuit elements (26,27).

Claim 17

The method of claim 14 characterised by casting each of the solder columns (31) with a high temperature solder.

Claim 18

The method of claim 14 characterised by the additional step of shearing the cast solder columns (31) at the bottom (31d) thereof.

Claim 19

The method of claim 14 characterised by the additional step of shearing the cast solder columns (31) at both the top (31c) and bottom (31d) for coplanarity between each of the top and bottom surfaces (31c,31d) of the solder columns (31).

Claim 20

The method of claim 14 characterised by casting each of the solder columns (31) with a solder composition of 95 percent lead - 5 percent tin by weight.

Claim 21

A circuit element comprising a printed circuit board (27) having a plurality of circuit pads (30) on a surface thereof, and an interconnection device as claimed in claim 1 comprising a plurality of interconnections (31) soldered to the circuit pads (30), characterised in that the plurality of interconnections (31) comprise individual solder columns (31) in compliant locking securement with a plate (25) and being substantially perpendicular thereto and to each circuit pad (30) and with free ends (31c,31d) on each solder column (31) being substantially coplanar with respect to each circuit pad (30).

Claim 22

An assembly including a leadless chip carrier (26) having circuit pads (53) on one surface and an interconnection device as claimed in claim 1 comprising a plurality of interconnections (31) soldered to the circuit pads (53), characterised in that the plurality of interconnections (31) comprise individual, elongated solder columns (31) in compliant locking securement with a plate (25).

Claim 23

A microinterconnection casting method characterised by the steps of: a. maintaining a casting nozzle (17a) at a temperature in a liquidus region of a casting alloy with respect to a phase diagram thereof; b. maintaining at substantially the same temperature a plurality of conduits (50c) in the casting nozzle (17a) and from the casting nozzle (17a) to a casting die (16) comprising first and second die plates (51,17), wherein said conduits (50c) are in coregistry with a corresponding number of conduits (50c) in a first die plate (51), and wherein said first die plate (51) is movable relative to the casting nozzle (17a); c. maintaining said second die plate (17) separate and removably positioned with respect to the first die plate (51), said second die plate (17) having a corresponding number of conduits (50c) in the first die plate (51) and the casting nozzle (17a) conduits (50c). d. engaging, between the first and second die plates (51,17), a temporary die plate (25) having apertures (15) corresponding to each of the conduits (50c) in the first and second die plates (51,17). e. extruding through said conduits (50c) and apertures (15) said casting alloy to form cast interconnections (31) lockingly engaging the temporary die plate (25); f. sliding the first, second and temporary die plates (51,17,25) as a unit relative to the conduits (50c) in the casting nozzle (17a) and thereby shearing the cast interconnections (31) at the interface between the casting nozzle (17a) and first die plate (51); and g. disengaging the first die plate (51) from the second die plate (17) and ejecting therefrom the temporary die plate (25).

Claim 24

A microinterconnection casting method characterised by the steps of: a. maintaining a casting nozzle (17a) at a temperature in a liquidus region of a casting alloy with respect to a phase diagram thereof; b. maintaining at substantially the same temperature a plurality of conduits (50c) in the casting nozzle (17a) and from the casting nozzle (17a) to a casting die (16) comprising first and second die plates (51,17), wherein said conduits (50c) are in coregistry with a corresponding number of conduits (50c) in a first die plate (51), and wherein said first die plate (51) is movable relative to the casting nozzle (17a); c. maintaining said second die plate (17) separate and removably positioned with respect to the first die plate (51), said second die plate (17) having a corresponding number of conduits (50c) in the first die plate (51) and the casting nozzle (17a) conduits (50c). d. engaging, between the first and second die plates (51,17), a temporary die plate (25) having apertures (15) corresponding to each of the conduits (50c) in the first and second die plates (51,17). e. extruding through said conduits (50c) and apertures (15) said casting alloy to form cast interconnections (31) lockingly engaging the temporary die plate (25); f. sliding the first, second and temporary die plates (51,17,25) as a unit relative to the conduits (50c) in the casting nozzle (17a) and thereby shearing the cast interconnections (31) at the interface between the casting nozzle (17a) and first die plate (51); and g. disengaging the first die plate (51) from the second die plate (17) and ejecting therefrom the temporary die plate (25).

Claim 25

The method of claim 22 further characterised in that the second die plate (17) comprises first and second die sections (52,53) with the first die section (52) defining the top of the interconnections lockingly engaged to the temporary die plate (25) and wherein the second die section (53) includes heat risers relative to the first die section (52) and wherein the second die section (53) is movable relative to the first die section (52), providing the step of shearingly disengaging the heat risers from the first die section (52), and means (50) for ejecting the interconnections (31) from the first die section (52).

Claim 26

An assembly including a leadless chip carrier (26) having circuit pads (53) on one surface, a printed circuit board (27) having circuit pads (30) on one surface and an interconnection device as claimed in claim 1 comprising a plurality of interconnections (31) extending between the carrier 26 and the board 27 and electrically connecting the pads (53) on the carrier (26) to the pads (30) on the board (27), characterised in that the plurality of interconnections (31) comprise individual, elongated solder columns (31) in compliant locking securement with a plate (25) located intermediate the carrier (26) and board (27).