US5195237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flying leads for integrated circuits
Assignee: MEDALLION TEHNOLOGY LLC
•
Filing: 1991-12-24
•
Granted: 1993-03-23
•
Expires: 2011-12-24
Abstract
Abstract A method and apparatus for interconnecting electronic circuits using nearly pure soft annealed gold mechanically compressed within through-plated holes. The invention has its application in attaching integrated circuit dice directly to circuit boards by ball bonding gold wires to the bonding pads of the integrated circuit dice in a substantially perpendicular relationship to the surfaces of the dice and inserting the gold leads into through-plated holes of circuit boards which provide an electrical and a mechanical connection once the leads are compressed within the through-plated holes. The present invention also finds its application in the interconnection of sandwiched circuit board assemblies where soft gold lead wires are inserted into axially aligned through-plated holes of the circuit boards and compressed so that the gold lead wires compress and buckle within the through-plated holes, forming an electrical connection between the circuit boards.
Inventors
- 👤 Seymour R. Cray
- 👤 Nicholas J. Krajewski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:15
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/099; H01; H01R; H01R12/00; H01R12/50; H01R12/51; H01R12/52; H01R12/523; H05; H05K; H05K3/00; H05K3/30; H05K3/306; H05K3/308; H05K3/32; H05K3/328; H05K3/36; H10W70/60; H10W70/611; H10W70/62; H10W70/63; H10W70/635; H10W90/00; H10W90/401; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/096; H05K2201/10; H05K2201/10431; H05K2201/1059; H05K2201/10613; H05K2201/10742; H05K2201/1075; H05K2201/10818; H05K2201/10825; H05K2201/10886; H05K2201/10909; H05K2201/10946; H05K2203/00; H05K2203/04; H05K2203/0495; H05K3/368; H10W46/00; H10W72/00; H10W72/01; H10W72/012; H10W72/01221; H10W72/01225; H10W72/071; H10W72/0711; H10W72/07141; H10W72/07178; H10W72/072; H10W72/07251; H10W72/075; H10W72/07551; H10W72/07554; H10W72/20; H10W72/251; H10W72/252; H10W72/50; H10W72/541; H10W72/547; H10W72/551; H10W72/552; H10W72/5522; H10W72/90; H10W72/941; H10W72/944; H10W72/9445; H10W90/20; H10W90/22; H10W90/284; H10W90/288; H10W90/297; H10W90/701; H10W90/721; H10W90/724; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49139; Y10T29/4914; Y10T29/49147; Y10T29/49149; Y10T29/49151; Y10T29/49789; Y10T29/4979
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
227 words
A method of fabricating from a length of metal wire a plurality of substantially equal length flying leads which are each attached to one of a corresponding plurality of bonding pads of an integrated circuit chip and which extend generally parallel to one another and at a predetermined angle from a surface of the integrated circuit chip, each lead being fabricated by steps comprising: forming a ball on an end of the metal wire by rapidly heating the end of the wire; forming an electrical and mechanical connection of the ball to the bonding pad by pressing the ball against the bonding pad of the chip; clamping the wire at a clamping location on the wire located above the surface of the chip; holding the chip; extending the wire substantially straight and at the predetermined angle form the surface of the chip between the connection and the clamping location; notching the connected wire at a notched location at a predetermined height above the surface of the chip and between the clamping location and the connection; applying force from the clamping location through the wire and the connection to the chip; and stretching the wire at a notched location by application of the force to server the wire at the notched location and to form the flying lead from the segment of the wire connected to the chip.
Claim 2
Independent Claim
227 words
A method of fabricating from a length of metal wire a plurality of substantially equal length flying leads which are each attached to one of a corresponding plurality of bonding pads of an integrated circuit chip and which extend generally parallel to one another and at a predetermined angle from a surface of the integrated circuit chip, each lead being fabricated by steps comprising: forming a ball on an end of the metal wire by rapidly heating the end of the wire; forming an electrical and mechanical connection of the ball to the bonding pad by pressing the ball against the bonding pad of the chip; clamping the wire at a clamping location on the wire located above the surface of the chip; holding the chip; extending the wire substantially straight and at the predetermined angle form the surface of the chip between the connection and the clamping location; notching the connected wire at a notched location at a predetermined height above the surface of the chip and between the clamping location and the connection; applying force from the clamping location through the wire and the connection to the chip; and stretching the wire at a notched location by application of the force to server the wire at the notched location and to form the flying lead from the segment of the wire connected to the chip.
Claim 3
Dependent Claim
16 words
A method as defined in claim 1 wherein the extending step occurs before the notching step.
Claim 4
Dependent Claim
16 words
A method as defined in claim 1 wherein the extending step occurs before the stretching step.
Claim 5
Dependent Claim
18 words
A method as defined in claim 1 wherein the notching step does not achieve severing of the wire.
Claim 6
Dependent Claim
14 words
A method as defined in claim 1 wherein the metal wire is substantially gold.
Claim 7
Dependent Claim
20 words
A method as defined in claim 1 wherein the predetermined angle is substantially perpendicular to the surface of the chip.
Claim 8
Dependent Claim
31 words
A method as defined in claim 1 further comprising: testing the connection of the ball to the bonding pad prior to the notching step by applying the force to the wire.
Claim 9
Dependent Claim
64 words
A method as defined in claim 1 wherein the step of forming the connection further comprises: heating the chip; heating the ball to a temperature approximating the temperature of the chip; and applying sonic energy to the point of connection of the ball and the bonding pad to scrub the ball against the bonding pad while the ball is pressed against the bonding pad.
Claim 10
Dependent Claim
21 words
A method as defined in claim 1 further comprising: forming a pointed tip on the free end of the flying lead.
Claim 11
Dependent Claim
33 words
A method as defined in claim 9 wherein the step of forming the pointed tip is achieved by notching the wire and stretching the wire to sever the wire at the notched location.
Claim 12
Independent Claim
195 words
A method of attaching a flying lead having a predetermined length to an integrated circuit chip, wherein the flying lead is manufactured from an elongated conductive wire longer than the length of the flying lead and having an end, and wherein the integrated circuit chip has a planar surface with at least one bonding pad on the planar surface, comprising: holding the integrated circuit chip; forming a ball on the end of the wire; attaching the all to the bonding pad to form an electrical and mechanical bond; clamping the wire at a clamping location along the wire that is farther from the bonding pad than the predetermined length of the flying lead; stretching the wire between the clamping location and the bond perpendicularly to the planar surface of the integrated circuit chip after the bonding and clamping steps; applying force from the clamping location through the wire and through the bond to the chip to stretch the wire; and severing the wire at a severing location along the wire between the clamping location and the bond as the wire is being stretched, said severing location corresponding to the predetermined length of the flying lead.
Claim 13
Independent Claim
195 words
A method of attaching a flying lead having a predetermined length to an integrated circuit chip, wherein the flying lead is manufactured from an elongated conductive wire longer than the length of the flying lead and having an end, and wherein the integrated circuit chip has a planar surface with at least one bonding pad on the planar surface, comprising: holding the integrated circuit chip; forming a ball on the end of the wire; attaching the all to the bonding pad to form an electrical and mechanical bond; clamping the wire at a clamping location along the wire that is farther from the bonding pad than the predetermined length of the flying lead; stretching the wire between the clamping location and the bond perpendicularly to the planar surface of the integrated circuit chip after the bonding and clamping steps; applying force from the clamping location through the wire and through the bond to the chip to stretch the wire; and severing the wire at a severing location along the wire between the clamping location and the bond as the wire is being stretched, said severing location corresponding to the predetermined length of the flying lead.
Claim 14
Dependent Claim
22 words
A method as defined in claim 11 wherein the step of forming the ball further comprises: heating the end of the wire.
Claim 15
Dependent Claim
13 words
A method as defined in claim 11 wherein the wire is substantially gold.
Claim 16
Dependent Claim
37 words
A method as defined in claim 11 further comprising: extending the wire substantially straight and at a perpendicular angle from the surface of the chip between the clamping location and the bond prior to stretching the wire.
Claim 17
Dependent Claim
65 words
A method as defined in claim 11 wherein the step of attaching the ball to the bonding pad further comprises: heating the integrated circuit chip; heating the ball; pressing the ball against the bonding pad of the integrated circuit chip to bring the ball into contact with the bonding pad; and applying sonic energy to the ball to scrub the surface of the bonding pad.
Claim 18
Dependent Claim
22 words
A method as defined in claim 15 wherein the integrated circuit chip and the ball are heated to approximately the same temperature.
Claim 19
Dependent Claim
40 words
A method as defined in claim 11 wherein the step of stretching the wire further comprises: applying the force to the wire at the clamping location; and resisting the force at the bond between the ball and the bonding pad.
Claim 20
Dependent Claim
41 words
A method as defined in claim 17 wherein the step of severing the wire as it is being stretched further comprises: notching the wire at the severing location; and breaking the wire at the severing location by application of the force.
Claim 21
Dependent Claim
19 words
A method as defined in claim 18 wherein the notching step occurs after the step of applying the force.
Claim 22
Dependent Claim
21 words
A method as defined in claim 11 further comprising: forming a pointed tip on the free end of the flying lead.
Claim 23
Dependent Claim
25 words
A method as defined in claim 20 wherein the step of forming the pointed tip is achieved by severing the wire at the severing location.
Claim 24
Dependent Claim
40 words
A method as defined in claim 21 wherein the step of severing the wire at the severing location further comprises: notching the wire at the severing location; and breaking the wire at the severing location by application of the force.
References Cited (Backward Citations)
US3258736A
Cited
US1946889A
Cited
US2694799A
Cited
US2969521A
Cited
US3022480A
Cited
US3212040A
Cited
US3125803A
Cited
US3097032A
Cited
US3371249A
Cited
US3217283A
Cited
US3357090A
Cited
US3286340A
Cited
GB1035580A
Cited
US3333225A
Cited
US3376635A
Cited
US3403438A
Cited
US3255430A
Cited
US3373481A
Cited
US3400358A
Cited
US3319217A
Cited
US3397451A
Cited
US3472443A
Cited
US3459998A
Cited
US3568001A
Cited
US3623649A
Cited
US3641660A
Cited
US3672047A
Cited
US3670409A
Cited
US3813773A
Cited
US3941298A
Cited
US3863827A
Cited
US3832603A
Cited
US3904934A
Cited
US3867759A
Cited
US3941486A
Cited
US3954217A
Cited
US4142228A
Cited
US4208080A
Cited
US4110904A
Cited
DE2742716A1
Cited
US4285002A
Cited
US4216576A
Cited
US4326663A
Cited
US4295184A
Cited
US4230925A
Cited
US4354310A
Cited
US4352553A
Cited
US4417392A
Cited
US4374457A
Cited
GB2095473A
Cited
US4542438A
Cited
EP0089778A2
Cited
US4514784A
Cited
JPS59208751A
Cited
JPS60134444A
Cited
US4550493A
Cited
US4653186A
Cited
US4661192A
Cited
US4734058A
Cited
US4700996A
Cited
US4720770A
Cited
WO1988004829A1
Cited
US4797113A
Cited
US4873764A
Cited
US4813128A
Cited
US4889496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-22 | 1996-09-21 | 1997-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-22 | 2000-09-21 | 2001-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-22 | 2004-09-21 | 2005-03-23 | $7700.00 | Window Closed / Lapsed |