EP0147576A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for forming elongated solder connections between a semiconductor device and a supporting substrate
Assignee: International Business Machines Corp
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Filing: 1984-11-06
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Granted: —
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Expires: 2004-11-06
Abstract
Abstract A process for forming elongated solder terminals (38) to connect a plurality of pads (21) on a semiconductor device (20) to a corresponding plurality of pads (12) on a supporting substrate (10) by, forming a means (32, 42) to maintain a predetermined vertical spacing between the semiconductor (20) and the supporting substrate (10) outside area of the pads, forming and fixing solder extenders (16) to each of the solder wettable pads on the substrate or the device to be joined, positioning the semiconductor device provided with solder mounds (22) on the solder mountable pads (21) over the supporting substrate with the solder mounds in registry with the pads (12) on the substrate with the solder extenders (16) positioned therebetween, the means to maintain vertical spacing located between and in abutting relation to the device and substrate, and heating the resulting assembly to reflow the solder mounds and the solder extenders while maintaining a predetermined spacing thus forming a plurality of hour-glass shaped elongated connections (38).
Inventors
- 👤 Mark Neil Lakritz
- 👤 Jose Ordonez
- 👤 Peter Joseph Tubiola
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 15:56
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H10; H10W; H10W70/00; H10W70/099; H10W72/00; H10W72/01; H10W72/012; H10W90/00; H10W90/701; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/09654; H05K2201/09781; H05K2201/10; H05K2201/10227; H05K2201/10234; H05K2201/20; H05K2201/2036; H05K2203/00; H05K2203/04; H05K2203/0465; H10W72/071; H10W72/072; H10W72/07221; H10W72/07227; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/07253; H10W72/20; H10W72/221; H10W72/227; H10W72/231; H10W72/237; H10W72/241; H10W72/251; H10W72/252; H10W72/281; H10W72/285; H10W72/29; H10W72/90; H10W72/921; H10W72/926; H10W90/721; H10W90/724; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
181 words
A process for forming elongated solder connections (38) between a semiconductor device (20) and a supporting substrate (10) said semiconductor device and said supporting substrate each having a plurality of solder wettable pads (21, 12), characterized in that the process comprises the following steps: forming a means (32, 42) to maintain a pretermined vertical spacing between said semiconductor device (20) and said supporting substrate (10), forming and affixing a solder extender (16) to each of said solder wettable pads (12) on said substrate (20), positioning said semiconductor device (20) having solder mounds (22) on said solder wettable pads (21) over said supporting substrate (10) with said solder mounds (22) in registry and in contact with said solder extenders (16) affixed to said pads (12) on said substrate (10), said means (32, 42) to maintain vertical spacing located between and in abutting relation to said device (20) and said support substrate (10), heating the resultant assembly to reflow said solder mounds (22) and said solder extenders (16) while maintaining a predetermined spacing thus forming a plurality of hour-glass shaped elongated connections (38).
Claim 2
Dependent Claim
181 words
A process for forming elongated solder connections (38) between a semiconductor device (20) and a supporting substrate (10) said semiconductor device and said supporting substrate each having a plurality of solder wettable pads (21, 12), characterized in that the process comprises the following steps: forming a means (32, 42) to maintain a pretermined vertical spacing between said semiconductor device (20) and said supporting substrate (10), forming and affixing a solder extender (16) to each of said solder wettable pads (12) on said substrate (20), positioning said semiconductor device (20) having solder mounds (22) on said solder wettable pads (21) over said supporting substrate (10) with said solder mounds (22) in registry and in contact with said solder extenders (16) affixed to said pads (12) on said substrate (10), said means (32, 42) to maintain vertical spacing located between and in abutting relation to said device (20) and said support substrate (10), heating the resultant assembly to reflow said solder mounds (22) and said solder extenders (16) while maintaining a predetermined spacing thus forming a plurality of hour-glass shaped elongated connections (38).
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the ratio of the height of the elongated connection (38) to the width of the solder wettable pads (12, 21) is equal to or greater than 1.
Claim 4
Dependent Claim
89 words
The process of claim 1 wherein said solder extenders (16) are formed by vapor depositing a Pb-Sn solder through an apertured mask to a blank substrate (14), vapor depositing a thin low melting metal layer (18) on the top surface of each extender element assembly and positioning it over and into contact with said solder settable pads (12) on said support substrate (10), heating to melt said low metling layer (18) and subsequently cooling to fuse the extender elements to the solder wettable pads, and removing the blank substrate.
Claim 5
Dependent Claim
47 words
The process of claim 3 wherein said extender elements are formed of Pb with a melting point of 327°C, and said low melting metal layer that is deposited on the top surface of said extender elements has a melting point equal to or less than 240 C.
Claim 6
Dependent Claim
23 words
The process of claim 4 wherein said extender elements, are formed of pure Pb, and said low melting metal layer is pure Sn.
Claim 7
Dependent Claim
94 words
The process of claim 1 wherein said means to maintain a predetermined vertical spacing between the semiconductor device and the supporting is produced by forming a plurality of solder wettable standoff pads (24) on said semiconductor device (20) located outside of the area of said solder wettable pads (21), depositing a layer of solder (30) on said standoff pads, positioning metal spheres (32) of a diameter equal to the desired said vertical spacing on said standoff pads, heating to melt said layer of solder, and cooling to secure the spheres to said standoff pads.
Claim 8
Dependent Claim
34 words
The process of claim 6 wherein said standoff pads are formed by providing solder wettable pads at the desired area locations, and depositing a layer of solder (30) on the solder wettable pads (24).
Claim 9
Dependent Claim
48 words
The process of claim 7 wherein said layer of solder (30) is deposited on said solder wettable pads through a mask (26), and said spheres (32) are positioned in openings (28) in said mask and maintained in position on the device (20) during the heating and cooling operations.
Claim 10
Dependent Claim
17 words
The process of claim 8 wherein said metal spheres are of Cu with a coating of Ki.
Claim 11
Dependent Claim
18 words
The process of claim 9 wherein the diameter of said spheres is of the order of 125 µm.
Claim 12
Dependent Claim
57 words
The process of claim 1 wherein said means (38) to maintain a predetermined vertical spacing between the semiconductor device and supporting substrate is produced by screen printing a plurality of refractory metal paste standoff bumps (44) on said support substrate (10) located outside of the area of said solder wettable pads (12), and sintering said standoff bumps.
Claim 13
Dependent Claim
20 words
The process of claim 11 wherein said standoff bumps have a height of the order of 125 µm after sintering.
References Cited (Backward Citations)
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