US5442852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating solder ball array
Assignee: Pacific Microelectronics Corp
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Filing: 1993-10-26
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Granted: 1995-08-22
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Expires: 2013-10-26
Abstract
Abstract A method for manufacturing an electronic module comprising a substrate carrying circuitry and one or more integrated circuits and having an array of closely spaced solder balls electrically connected with terminals of the circuitry to connect the module to an array of terminals, as on printed circuit board. The array of solder balls is fabricated on the substrate by preparing the substrate to include an array of terminal pads, perforating a sheet of dielectric tape to create precise and uniform holes, and thereafter fusing the tape onto the substrate so that the holes are aligned over the substrate's terminal pads. Solder balls are then placed in the holes and heated to reflow them, so that part of the solder fills a volume defined by the holes in the dielectric tape and bonds to the terminal pads on the substrate, while the solder balls remain generally spherical above the dielectric tape. The module can then be connected to an array of terminal pads on a circuit board by positioning the ball grid array on the circuit board and again reflowing the solder balls so that they bond with the terminal pads on the circuit board.
Inventors
- 👤 Paul A. Danner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:28
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3452; H10; H10W; H10W70/00; H10W70/099; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/017; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10734; H05K2203/00; H05K2203/04; H05K2203/041; H05K2203/043; H05K2203/06; H05K2203/063; H05K2203/066; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49147; Y10T29/49149
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
113 words
A method of fabricating a ball grid array on a substrate having a plurality of electrical terminal pads thereon, comprising: (a) perforating a sheet of dielectric material to create a plurality of holes therethrough; (b) fastening the sheet of dielectric material to the substrate so that two or more of the holes are positioned over two or more of the pads; (c) placing solder balls into the holes that are positioned over the pads; and (d) heating the balls until the balls reflow and bond to the pads, each solder ball being large enough that it retains a spherical surface protruding above said sheet of dielectric material when bonded to a respective pad.
Claim 2
Independent Claim
113 words
A method of fabricating a ball grid array on a substrate having a plurality of electrical terminal pads thereon, comprising: (a) perforating a sheet of dielectric material to create a plurality of holes therethrough; (b) fastening the sheet of dielectric material to the substrate so that two or more of the holes are positioned over two or more of the pads; (c) placing solder balls into the holes that are positioned over the pads; and (d) heating the balls until the balls reflow and bond to the pads, each solder ball being large enough that it retains a spherical surface protruding above said sheet of dielectric material when bonded to a respective pad.
Claim 3
Dependent Claim
27 words
The method of claim 1, including placing each ball into a respective hole so that it is in contact with and supported by a respective terminal pad.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein said step of heating comprises using surface tension to maintain the solder balls in a generally spherical shape.
Claim 5
Dependent Claim
26 words
The method of claim 3, comprising the further step of using surface tension to maintain the solder balls in a generally spherical shape while cooling them.
Claim 6
Dependent Claim
25 words
The method of claim 1, including the step of using a computer controlled laser to perform said step of perforating said sheet of dielectric material.
Claim 7
Dependent Claim
24 words
The method of claim 1, including the step of using a mechanical punch to perform said step of perforating said sheet of dielectric material.
Claim 8
Dependent Claim
129 words
The method of claim 1 wherein the sheet of dielectric material comprises inorganic materials in an organic binder on a carrier film and said step of fastening comprises: (a) laminating the sheet of dielectric material to the substrate by positioning two or more holes over two or more pads and pressing the sheet of dielectric material against the substrate and heating the sheet of dielectric material and substrate to a first temperature; (b) densifying the sheet of dielectric material by heating the sheet of dielectric material and the substrate to a second temperature to remove the organic binder; and (c) firing the sheet of dielectric material and the substrate to a third temperature, causing a part of the sheet of dielectric material to fuse and adhere to the substrate.
Claim 9
Dependent Claim
21 words
The method of claim 7, further comprising the step of removing the carrier film before densifying the sheet of dielectric material.
Claim 10
Dependent Claim
15 words
The method of claim 7 wherein the second temperature is greater than the first temperature.
Claim 11
Dependent Claim
15 words
The method of claim 7 wherein the third temperature is greater than the second temperature.
Claim 12
Independent Claim
150 words
A method of fabricating a ball grid array on a substrate having a plurality of terminal pads thereon, said method comprising: (a) perforating a sheet of dielectric material substantially free of conductive material carried thereon to create a plurality of holes therethrough, each hole having a first diameter and an interior wall; (b) fastening the sheet of dielectric material to the substrate so that two or more of the holes are positioned over respective ones of the terminal pads thus creating a plurality of open volumes each bounded by one of said terminal pads and one of said interior walls; (c) placing solder balls, each having a ball diameter greater than said first diameter, into the holes that are positioned over said respective ones of said terminal pads; and (d) heating the balls until each ball reflows and substantially fills the respective volume and bonds to the respective terminal pads.
Claim 13
Independent Claim
150 words
A method of fabricating a ball grid array on a substrate having a plurality of terminal pads thereon, said method comprising: (a) perforating a sheet of dielectric material substantially free of conductive material carried thereon to create a plurality of holes therethrough, each hole having a first diameter and an interior wall; (b) fastening the sheet of dielectric material to the substrate so that two or more of the holes are positioned over respective ones of the terminal pads thus creating a plurality of open volumes each bounded by one of said terminal pads and one of said interior walls; (c) placing solder balls, each having a ball diameter greater than said first diameter, into the holes that are positioned over said respective ones of said terminal pads; and (d) heating the balls until each ball reflows and substantially fills the respective volume and bonds to the respective terminal pads.
Claim 14
Dependent Claim
27 words
The method of claim 11 wherein said step of heating said solder balls includes using surface tension to maintain said solder balls in a generally spherical shape.
Claim 15
Dependent Claim
26 words
The method of claim 12, including the further step of using surface tension to maintain the solder balls in a generally spherical shape while cooling them.
Claim 16
Dependent Claim
25 words
The method of claim 11, including the step of using a computer controlled laser to perform said step of perforating said sheet of dielectric material.
Claim 17
Dependent Claim
24 words
The method of claim 11, including the step of using a mechanical punch to perform said step of perforating said sheet of dielectric material.
Claim 18
Dependent Claim
129 words
The method of claim 11 wherein the sheet of dielectric material comprises inorganic materials in an organic binder on a carrier film and said step of fastening comprises: (a) laminating the sheet of dielectric material to the substrate by positioning two or more holes over two or more pads, pressing the sheet of dielectric material against the substrate, and heating the sheet of dielectric material and the substrate to a first temperature; (b) densifying the sheet of dielectric material by heating the sheet of dielectric material and the substrate to a second temperature to remove the organic binder; and (c) firing the sheet of dielectric material and the substrate to a third temperature, causing a part of the sheet of dielectric material to fuse and adhere to the substrate.
Claim 19
Dependent Claim
22 words
The method of claim 1 wherein the sheet of dielectric material is substantially free of conductive material adjacent each of said holes.
Claim 20
Dependent Claim
27 words
The method of claim 1, wherein said step of perforating includes perforating holes of substantially uniform size and wherein said solder balls are of substantially uniform size.
Claim 21
Independent Claim
181 words
A method of fabricating a ball grid array on a substrate having a plurality of electrical terminal pads thereon, comprising: (a) perforating a sheet to create a plurality of holes therethrough, said sheet comprising inorganic materials in an organic binder on a carrier film; (b) fastening the sheet to the substrate so that two or more of the holes are positioned over two or more of the pads, said step of fastening including: (i) laminating the sheet to the substrate by positioning two or more holes over two or more pads and pressing the sheet against the substrate and heating the sheet and the substrate to a first temperature; (ii) densifying the sheet by heating the sheet and the substrate to a second temperature to remove the organic binder; and (iii) firing the sheet and the substrate to a third temperature, causing a part of the sheet to fuse and adhere to the substrate; (c) placing solder balls into the holes that are positioned over the pads; and (d) heating the balls until the balls reflow and bond to the pads.
Claim 22
Independent Claim
181 words
A method of fabricating a ball grid array on a substrate having a plurality of electrical terminal pads thereon, comprising: (a) perforating a sheet to create a plurality of holes therethrough, said sheet comprising inorganic materials in an organic binder on a carrier film; (b) fastening the sheet to the substrate so that two or more of the holes are positioned over two or more of the pads, said step of fastening including: (i) laminating the sheet to the substrate by positioning two or more holes over two or more pads and pressing the sheet against the substrate and heating the sheet and the substrate to a first temperature; (ii) densifying the sheet by heating the sheet and the substrate to a second temperature to remove the organic binder; and (iii) firing the sheet and the substrate to a third temperature, causing a part of the sheet to fuse and adhere to the substrate; (c) placing solder balls into the holes that are positioned over the pads; and (d) heating the balls until the balls reflow and bond to the pads.
Claim 23
Dependent Claim
18 words
The method of claim 19, further comprising the step of removing the carrier film before densifying the sheet.
Claim 24
Dependent Claim
15 words
The method of claim 19 wherein the second temperature is greater than the first temperature.
Claim 25
Dependent Claim
15 words
The method of claim 19 wherein the third temperature is greater than the second temperature.
Claim 26
Independent Claim
235 words
A method of fabricating a ball grid array on a substrate having a plurality of terminal pads thereon, said method comprising: (a) perforating a sheet to create a plurality of holes therethrough, each hole having a first diameter and an interior wall, said sheet comprising inorganic materials in an organic binder on a carrier film; (b) fastening the sheet to the substrate so that two or more of the holes are positioned over respective ones of the terminal pads thus creating a plurality of open volumes each bounded by one of said terminal pads and one of said interior walls, said step of fastening including: (i) laminating the sheet to the substrate by positioning two or more holes over two or more pads, pressing the sheet against the substrate, and heating the sheet and the substrate to a first temperature; (ii) densifying the sheet by heating the sheet and the substrate to a second temperature to remove the organic binder; and (iii) firing the sheet and the substrate to a third temperature, causing a part of the sheet to fuse and adhere to the substrate; (c) placing solder balls, each having a ball diameter greater than said first diameter, into the holes that are positioned over said respective ones of said terminal pads; and (d) heating the balls until each ball reflows and substantially fills the respective volume and bonds to the respective terminal pads.
Claim 27
Independent Claim
235 words
A method of fabricating a ball grid array on a substrate having a plurality of terminal pads thereon, said method comprising: (a) perforating a sheet to create a plurality of holes therethrough, each hole having a first diameter and an interior wall, said sheet comprising inorganic materials in an organic binder on a carrier film; (b) fastening the sheet to the substrate so that two or more of the holes are positioned over respective ones of the terminal pads thus creating a plurality of open volumes each bounded by one of said terminal pads and one of said interior walls, said step of fastening including: (i) laminating the sheet to the substrate by positioning two or more holes over two or more pads, pressing the sheet against the substrate, and heating the sheet and the substrate to a first temperature; (ii) densifying the sheet by heating the sheet and the substrate to a second temperature to remove the organic binder; and (iii) firing the sheet and the substrate to a third temperature, causing a part of the sheet to fuse and adhere to the substrate; (c) placing solder balls, each having a ball diameter greater than said first diameter, into the holes that are positioned over said respective ones of said terminal pads; and (d) heating the balls until each ball reflows and substantially fills the respective volume and bonds to the respective terminal pads.
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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) | 1998-08-21 | 1999-02-20 | 1999-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-21 | 2003-02-20 | 2003-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-21 | 2007-02-20 | 2007-08-22 | $7700.00 | Window Closed / Lapsed |