Microelectronic connections with solid core joining units
First Claim
1. A microelectronic assembly comprising:
- (a) a microelectronic component having electrical contacts;
(b) a plurality of terminals adjacent said component, each said terminal being connected to at least one contact of the component but movable relative to said component; and
(c) a plurality of joining units, each said unit including a solid core disposed on one said terminal and extending upwardly therefrom; and
(d) a unit bonding material having a first melting temperature securing each core to the terminal.
1 Assignment
0 Petitions
Accused Products
Abstract
A microelectronic component such as a semiconductor chip having electrical contacts is provided with terminals, the terminals being movable relative to the component. A joining unit having a solid core is disposed on each terminal and extends upwardly, away from the component. Each unit includes a bonding material such as a solder bonding the terminal and the solid core, the bonding material desirably defining a waist or narrow section spaced above the terminal, the waist having a curved surface forming a stress-relieving fillet. The joining units are bonded to contact pads of a substrate such as a circuit panel as by bonding the solder of the joining units to the terminals, or by means of a further solder on the contact pads having a lower melting point. The assembly provides substantial resistance to mechanical stress caused by thermal expansion. Preferably, the terminals are movable in vertical directions towards the component to compensate for nonplanarity during assembly.
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Citations
27 Claims
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1. A microelectronic assembly comprising:
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(a) a microelectronic component having electrical contacts; (b) a plurality of terminals adjacent said component, each said terminal being connected to at least one contact of the component but movable relative to said component; and (c) a plurality of joining units, each said unit including a solid core disposed on one said terminal and extending upwardly therefrom; and (d) a unit bonding material having a first melting temperature securing each core to the terminal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A microelectronic subassembly comprising:
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(a) a first element defining a plurality of terminals, each said terminal including a generally conical seat; (b) a plurality of joining units, each said unit including a substantially spherical solid core engaged in the conical seat of said terminal and extending upwardly therefrom, whereby the centers of center said solid cores are aligned with said conical seat, and (c) solder extending over the terminal and over the core, said cores having a solidus temperature higher than the melting temperature of said solder. - View Dependent Claims (24)
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25. A microelectronic assembly comprising:
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(a) a first element defining a plurality of terminals; (b) a plurality of joining units disposed on said terminals and extending upwardly therefrom, each said unit including a solid core; (c) a unit bonding material extending between each terminal and core, said cores having a solidus temperature higher than the melting temperature of said unit bonding material; (d) a substrate having contact pads; and (e) a pad bonding material on said contact pads, said pad bonding material having a melting temperature less than the melting temperature of said unit bonding material, said joining units being bonded to said contact pads by said pad bonding material, whereby said substrate can be removed from the assembly without disassembling said joining units from said terminals by heating the assembly to a temperature above the melting temperature of said pad bonding material but below the temperature of said unit bonding material. - View Dependent Claims (26, 27)
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Specification