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US3731377A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for handling beam-lead and odd-shaped semi-conductor devices

Assignee: Individual
•
Filing: 1971-08-19
•
Granted: 1973-05-08
•
Expires: 1991-08-19
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Abstract

Abstract An apparatus and method for manipulating monolithic microelectronic dice are provided. The apparatus comprises a probe-like electromagnet which uses a variety of different shaped tips to change the configuration of the magnetic field. The magnetic field at the tip is further adjusted by reversing the polarity of the electricity in the electromagnet windings and controlling the power applied to these windings. The core of the electromagnet is maintained in a demagnetized state by switching the electrical polarity of the windings. The method comprises the steps of applying a magnetically permeable substance to the dice, attaching each of the dice to the electromagnet using the force of the magnetic field, moving the attached die to a preferred location and orientation and releasing said die. Said magnetically permeable substance may comprise a fluid adhesive with a magnetically permeable insulated powder mixed therein, a permeable metal formed in beam-leads, or a permeable metal formed into bumps on the surface of flip-chips.

Inventors

  • 👤 W Muckelroy

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 03:52
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/76; H10P72/7604; H10P72/7622; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49133

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 34 words
A methOd according to claim 1 further comprising the step of subjecting said magnetically permeable substance to an elevated temperature for a time period sufficient to cause said substance to spread over said surface.
Claim 2
Dependent Claim 30 words
A method according to claim 1 further comprising the step of demagnetizing said electromagnet by reversing the electrical polarity of said windings and controlling the electrical power to said windings.
Claim 3
Dependent Claim 38 words
A method according to claim 1 further comprising the step of adjusting the magnetic field strength at said pole by reversing the electrical polarity of said windings and controlling the amount of electrical power supplied to said windings.
Claim 4
Independent Claim 113 words
A method for manipulating monolithic microelectronic die comprising the 5. of a. applying a magnetically permeable substance to a surface of a monolithic microelectronic die; b. contacting said die with the attracting pole of an electromagnet such that when a magnetic field is generated at said pole, said field produces sufficient force to cause said dice to adhere thereto; c. moving said electromagnet with said die attached thereto to a location and decreasing said magnetic field such that said die is released from said pole; and d. removing said substance from said surface of said die by flushing with a solvent, said die having been attached to microcircuit substrate prior to this step.
Claim 5
Dependent Claim 38 words
A method according to claim 5 further comprising the step of dissolving said substance with a solvent prior to flushing said die with a solvent said die having been attached to a microcircuit substrate prior to these steps.
Claim 6
Dependent Claim 19 words
A method according to claim 2 wherein said substance is a mixture which further comprises a solidifiable adhesive fluid.
Claim 7
Dependent Claim 47 words
A method according to claim 6 wherein said electromagnet comprises a probe having a magnetically permeable core, a tip protruding from one end thereof, a plurality of conductive windings located around said core, means for supplying electric current to said windings, and means for housing said core.
Claim 8
Dependent Claim 17 words
A method according to claim 8 wherein said core comprises a paramagnetic material and a ferrimagnetic material.
Claim 9
Dependent Claim 16 words
A method according to claim 8 wherein said core comprises a diamagnetic material and a plastic.
Claim 10
Dependent Claim 25 words
A method according to claim 1 wherein said location is at least one bonding pad on a microcircuit substrate to which said die is interjoined.
Claim 11
Dependent Claim 29 words
A method according to claim 1 wherein said location is a plurality of bonding pads on a microcircuit substrate to which the electrical exits to said die are interjoined.
Claim 12
Dependent Claim 24 words
A method according to claim 8 wherein said electromagnet further comprises a plurality of interchangeable tips for changing the shape of the magnetic field.

References Cited (Backward Citations)

US1915566A Cited
US3036245A Cited
US3032363A Cited
US3341030A Cited
US3435520A Cited
US3543679A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-07 1976-11-06 1977-05-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-07 1980-11-06 1981-05-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-07 1984-11-06 1985-05-08 $7700.00 Window Closed / Lapsed

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