Patent US5796591A successfully refreshed from Google Patents.
US5796591A
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US
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Direct chip attach circuit card
Assignee: International Business Machines Corp
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Filing: 1995-06-07
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Granted: 1998-08-18
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Expires: 2015-06-07
Abstract
Abstract A structure and a method is disclosed for making a laminated circuit carrier card for the purpose of making a Direct Chip Attached Module (DCAM) with low cost and high reliability. The carrier is made using an organic or an inorganic laminated carrier having at least one surface available for direct chip mount. The chip has at least one solder ball with a cap of low melting point metal. The surface of the carrier has electrical features that are directly connected to the low melting point metal on the solder ball of the chip to form the eutectic and this way the chip is directly attached to the carrier.
Inventors
- 👤 Hormazdyar Minocher Dalal
- 👤 Kenneth Michael Fallon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:31
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/09372; H05K2201/09472; H05K2201/095; H05K2201/09509; H05K2201/10; H05K2201/10613; H05K2201/10954; H05K2201/10992; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H10W72/01215; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/07254; H10W72/20; H10W72/221; H10W72/222; H10W72/241; H10W72/242; H10W72/251; H10W72/252; H10W72/255; H10W72/90; H10W72/941; H10W72/9415; H10W90/00; H10W90/701; H10W90/721; H10W90/724; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
79 words
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball.
Claim 2
Dependent Claim
79 words
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball.
Claim 3
Dependent Claim
16 words
The structure of claim 1, wherein said electronic card has at least one SMT secured thereto.
Claim 4
Dependent Claim
33 words
The structure of claim 1, wherein said device carrier is selected from a group consisting of flexible organic circuit carrier, flexible inorganic circuit carrier, rigid organic circuit carrier or rigid inorganic circuit carrier.
Claim 5
Dependent Claim
23 words
The structure of claim 1, wherein at least a portion of said electronic card has at least one coating of an insulator material.
Claim 6
Dependent Claim
30 words
The structure of claim 1, wherein said device carrier is selected from a group consisting of an interposer, a first level package, a second level package, or a mother board.
Claim 7
Dependent Claim
26 words
The structure of claim 1, wherein said solder ball is selected from a group consisting of high melting point solder, low melting point solder or C4.
Claim 8
Dependent Claim
30 words
The structure of claim 1, wherein said device is selected from a group consisting of organic substrate, multi-layer organic substrate, ceramic substrate, multi-layer ceramic substrate or an integrated circuit chip.
Claim 9
Dependent Claim
18 words
The structure of claim 1, wherein said solder ball is on an electrically conductive feature of said device.
Claim 10
Dependent Claim
34 words
The structure of claim 8, wherein the material for said electrically conductive feature is selected from a group consisting of Au, Co, Cr, Cu, Fe, Ni, TiW, phased Cr and Cu, and alloys thereof.
Claim 11
Dependent Claim
22 words
The structure of claim 8, wherein said electrically conductive feature is in electrical contact with at least one internal electrically conductive feature.
Claim 12
Dependent Claim
27 words
The structure of claim 1, wherein said solder ball comprises a lead-tin alloy and wherein said alloy contains between about 2 percent to about 10 percent tin.
Claim 13
Dependent Claim
27 words
The structure of claim 1, wherein said solder ball comprises a lead-tin alloy and wherein said alloy contains between about 98 percent to about 70 percent lead.
Claim 14
Dependent Claim
35 words
The structure of claim 1, wherein material for said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
Claim 15
Dependent Claim
26 words
The structure of claim 1, wherein at least a portion of said capped solder ball is secured to an electrically conductive feature on said device carrier.
Claim 16
Dependent Claim
36 words
The structure of claim 14, wherein the material for said electrically conductive feature is selected from a group consisting of Au, Co, Cr, Cu, Fe, Ni, Ta, Ti, TiW, phased Cr and Cu, and alloys thereof.
Claim 17
Dependent Claim
23 words
The structure of claim 14, wherein said device carrier is selected from a group consisting of organic circuit carrier or ceramic circuit carrier.
Claim 18
Dependent Claim
26 words
The structure of claim 16, wherein said organic circuit carrier is selected from a group consisting of rigid organic circuit carrier or flexible organic circuit carrier.
Claim 19
Dependent Claim
22 words
The structure of claim 17, wherein the material for said rigid organic circuit carrier is selected from a group consisting of epoxies.
Claim 20
Dependent Claim
28 words
The structure of claim 1, wherein said low melting point metal caps between about 20 percent to about 80 percent of the exposed surface of said solder ball.
Claim 21
Dependent Claim
28 words
The structure of claim 1, wherein said low melting point metal caps between about 30 percent to about 50 percent of the exposed surface of said solder ball.
Claim 22
Dependent Claim
31 words
The structure of claim 1, wherein said device is selected from a group consisting of an IC chip, capacitor, resistor, a circuit carrier card, a power supply or an amplifying device.
Claim 23
Dependent Claim
37 words
The structure of claim 1, where the thickness of said low melting point metal is chosen to provide a eutectic volume of between about 5 percent to about 40 percent of the volume of said solder ball.
Claim 24
Dependent Claim
23 words
The structure of claim 1, wherein the average thickness of said low melting point metal is between about 15 to about 50 micro-meters.
Claim 25
Dependent Claim
25 words
The structure of claim 1, wherein said solder ball is selected from a group consisting of alloys of Pb, Bi, In, Sn, Ag or Au.
Claim 26
Dependent Claim
37 words
The structure of claim 1, where the thickness of said low melting point metal is chosen to provide a eutectic volume of between about 10 percent to about 30 percent of the volume of said solder ball.
Claim 27
Dependent Claim
108 words
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
Claim 28
Dependent Claim
108 words
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
Claim 29
Dependent Claim
80 words
An electronic structure comprising a substrate having at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
Claim 30
Dependent Claim
80 words
An electronic structure comprising a substrate having at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |