US6388336B1
Expired / Lapsed
US
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Multichip semiconductor assembly
Assignee: Texas Instruments Inc
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Filing: 1999-09-15
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Granted: 2002-05-14
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Expires: 2019-09-15
Abstract
Abstract A multichip semiconductor assembly comprising a semiconductor chip stack comprising first and second chips, each having an active surface including an integrated circuit and a plurality of input/output contact pads; a leadframe for interconnecting semiconductor integrated circuits having a plurality of leads, portions of said leads comprising undulating patterns and a surface metallurgy for promoting solder wetting, said leadframe being disposed between said first and second chips, and said active surface of said first chip positioned in front of said active surface of said second chip; and connections between each of said contact pads of said first chip to one of said leads, respectively, and between each of said contact pads of said second chip to one of said leads, respectively, said connections comprising solder balls, whereby the connections to at least one of said leads are common between said first and second chips.
Inventors
- 👤 Vaiyapuri Venkateshwaran
- 👤 Ji Cheng Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:38
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/411; H10W70/415; H10W70/421; H10W70/424; H10W90/00; H10W90/811; H10W72/00; H10W72/071; H10W72/072; H10W72/07251; H10W72/20; H10W72/251; H10W72/252; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5525; H10W72/851; H10W72/853; H10W72/865; H10W74/00; H10W90/701; H10W90/721; H10W90/726; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
74 words
A leadframe for interconnecting semiconductor circuits comprising: a plurality of leads having first and second surfaces; at least portions of said leads formed in an undulating pattern suitable for positioning solder balls; wherein said undulating pattern comprises contours for positioning solder balls concurrently on said first and second surfaces; and said first and second surfaces of said undulating lead portions metallurgically prepared such that said surfaces promote wetting during reflow of said solder balls.
Claim 2
Dependent Claim
74 words
A leadframe for interconnecting semiconductor circuits comprising: a plurality of leads having first and second surfaces; at least portions of said leads formed in an undulating pattern suitable for positioning solder balls; wherein said undulating pattern comprises contours for positioning solder balls concurrently on said first and second surfaces; and said first and second surfaces of said undulating lead portions metallurgically prepared such that said surfaces promote wetting during reflow of said solder balls.
Claim 3
Dependent Claim
24 words
The leadframe according to claim 1 wherein said undulating pattern comprises contours shaped for positioning solder balls between 0.1 and 0.5 mm in diameter.
Claim 4
Dependent Claim
23 words
The leadframe according to claim 1 wherein said undulating pattern comprises contours for positioning solder balls concurrently on said first and second surfaces.
Claim 5
Dependent Claim
25 words
The leadframe according to claim 1 wherein said metallurgical preparation comprises deposition of nickel and noble metal layers over the base metal of said leadframe.
Claim 6
Dependent Claim
12 words
The leadframe according to claim 4 wherein said noble metal is palladium.
Claim 7
Dependent Claim
144 words
A multichip semiconductor assembly comprising: a semiconductor chip stack comprising first and second chips, each having an active surface including an integrated circuit and a plurality of input/output contact pads; a leadframe for interconnecting semiconductor integrated circuits having a plurality of leads, portions of said leads comprising undulating patterns and a surface metallurgy for promoting solder wetting, said leadframe being disposed between said first and second chips, and said active surface of said first chip positioned in front of said active surface of said second chip; and connections between each of said contact pads of said first chip to one of said leads, respectively, and between each of said contact pads of said second chip to one of said leads, respectively, said connections comprising solder balls, whereby the connections to at least one of said leads are common between said first and second chips.
Claim 8
Dependent Claim
144 words
A multichip semiconductor assembly comprising: a semiconductor chip stack comprising first and second chips, each having an active surface including an integrated circuit and a plurality of input/output contact pads; a leadframe for interconnecting semiconductor integrated circuits having a plurality of leads, portions of said leads comprising undulating patterns and a surface metallurgy for promoting solder wetting, said leadframe being disposed between said first and second chips, and said active surface of said first chip positioned in front of said active surface of said second chip; and connections between each of said contact pads of said first chip to one of said leads, respectively, and between each of said contact pads of said second chip to one of said leads, respectively, said connections comprising solder balls, whereby the connections to at least one of said leads are common between said first and second chips.
Claim 9
Dependent Claim
15 words
The multichip semiconductor assembly according to claim 6 wherein said leadframe comprises solely metallic portions.
Claim 10
Dependent Claim
19 words
The multichip semiconductor assembly according to claim 6 wherein said chip stack comprises chips of different integrated circuit types.
Claim 11
Dependent Claim
31 words
The multichip semiconductor assembly according to claim 6 wherein at least one of said chips comprises silicon, silicon germanium, gallium arsenide or any other semiconductor material used in electronic device production.
Claim 12
Dependent Claim
17 words
The multichip semiconductor assembly according to claim 6 wherein said chip stack comprises chips of identical types.
Claim 13
Dependent Claim
17 words
The multichip semiconductor assembly according to claim 6 wherein said assembly is encapsulated in a molded package.
Claim 14
Dependent Claim
80 words
A semiconductor assembly comprising: a semiconductor chip having an integrated circuit including a plurality of input/output contact pads; a leadframe for interconnecting semiconductor integrated circuits having a plurality of leads, portions of said leads comprising undulating patterns and a surface metallurgy for promoting solder wetting; wherein said undulating pattern comprises contours for positioning solder balls concurrently on said first and second surfaces; and connections between each of said contact pads to one of said leads, respectively, said connections comprising solder-balls.
Claim 15
Dependent Claim
80 words
A semiconductor assembly comprising: a semiconductor chip having an integrated circuit including a plurality of input/output contact pads; a leadframe for interconnecting semiconductor integrated circuits having a plurality of leads, portions of said leads comprising undulating patterns and a surface metallurgy for promoting solder wetting; wherein said undulating pattern comprises contours for positioning solder balls concurrently on said first and second surfaces; and connections between each of said contact pads to one of said leads, respectively, said connections comprising solder-balls.
Claim 16
Dependent Claim
14 words
The semiconductor assembly according to claim 12 wherein said leadframe comprises solely metallic portions.
Claim 17
Dependent Claim
16 words
The semiconductor assembly according to claim 12 wherein said assembly is encapsulated in a molded package.
References Cited (Backward Citations)
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