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Vibrational Introduction of Fine Metallic Powder into Small Holes

IP.com Disclosure Number: IPCOM000076325D
Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Lau, JA: AUTHOR [+3]

Abstract

This is a method for filling small diameter holes in a printed-circuit board with fine metallic powder to provide an electrical interconnection medium. There is shown a modified hypodermic needle 1, having a tapered end 1a adapted to fit into a hole 2 of a printed circuit board 3. The hypodermic needle 1 is supported by an ultrasonic vibrational device 4. When the needle 1 is ultrasonically excited, the metallic powder within the needle flows through the tapered end la and into the opening 2 in the printed-circuit board 3. The amount of powder to be dispensed from the hypodermic needle 1 can be controlled by the duration of the pulsing period, as well as by the frequency of the vibration. Preferably, the operating frequency for vibration is in the range of from 1 KHz to 60 KHz.

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Vibrational Introduction of Fine Metallic Powder into Small Holes

This is a method for filling small diameter holes in a printed-circuit board with fine metallic powder to provide an electrical interconnection medium. There is shown a modified hypodermic needle 1, having a tapered end 1a adapted to fit into a hole 2 of a printed circuit board 3. The hypodermic needle 1 is supported by an ultrasonic vibrational device 4. When the needle 1 is ultrasonically excited, the metallic powder within the needle flows through the tapered end la and into the opening 2 in the printed-circuit board 3. The amount of powder to be dispensed from the hypodermic needle 1 can be controlled by the duration of the pulsing period, as well as by the frequency of the vibration. Preferably, the operating frequency for vibration is in the range of from 1 KHz to 60 KHz.

To enhance the metal powder loading operation, the printed-circuit board 3 overlies a porous block 5 and vacuum cavity 6. A filter paper 7 separates the porous block 5 and printed-circuit board 3 and prevents the powder from being introduced into the porous block 5 and vacuum cavity 6 area. Alternatively, the vacuum cavity 6 may be attached to a vibrating board 8 which can be agitated in a horizontal plane.

The combination of vibrational agitation and vacuum suction provides a unique method for filling small holes of approximately 10 mils in diameter with fine metallic powder, to produce an electrical interconnection medium...