US4885841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibrational method of aligning the leads of surface-mount electronic components with the mounting pads of printed circuit boards during the molten solder mounting process
Assignee: PNC NATIONAL ASSOCIATION AS ADMINISTRATIVE AGENT
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Filing: 1989-02-21
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Granted: 1989-12-12
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Expires: 2009-02-21
Abstract
Abstract During solder-reflow attachment of surface-mount electronic components to a printed circuit board, vibrational energy sufficient to overcome the static coefficient of friction between the leads of a component and their respective connector pads is applied to the board, with the result that the surface tension of the molten solder between the leads and the pads will produce a best-fit alignment of the leads of each component on their corresponding connector pads.
Inventors
- 👤 John P. McNabb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:13
CPC Classifications
H; H05; H05K; H05K13/00; H05K13/04; H05K13/046; B; B23; B23K; B23K1/00; B23K1/06; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3421; H05K2201/00; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10689; H05K2203/00; H05K2203/02; H05K2203/0292; H05K2203/04; H05K2203/048; Y; Y02; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49133; Y10T29/49144; Y10T29/49146
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
271 words
A method of solderably attaching the leads of surface-mount electronic components to the connector pads on a printed circuit board such that the leads of each component are positioned in a best-fit centering on their corresponding mounting pads, comprising the steps of: tinning the leads of the components with solder; applying a paste comprised of flux and powdered solder to the mounting pads on the printed circuit board; creating an unsoldered component-board assembly by positioning the components on the printed circuit board such that the leads of the components are roughly aligned with their corresponding connector pads; heating the unsoldered component-board assembly, while in a substantially horizontal position, to a temperature sufficient to permit the solder tinning on the leads and the powdered solder in the paste to melt and fuse; applying vibrational energy to the component-board assembly while the solder between the leads and pads is in a fused and molten state; said vibrational energy being sufficient to overcome the static coefficient of friction between the leads of the components and their respective connector pads to a point where the surface tension of the molten solder will produce a best-fit alignment of the leads of each component on their corresponding connector pads; said vibrational energy being less than a level which would exert forces on the components greater than those exerted on the components by the surface tension of the molten solder; halting the application of said vibrational energy while the solder between the leads and pads is in a fused and molten state; and cooling the component-board assembly, thus allowing the solder between the leads and pads to solidfy.
Claim 2
Independent Claim
271 words
A method of solderably attaching the leads of surface-mount electronic components to the connector pads on a printed circuit board such that the leads of each component are positioned in a best-fit centering on their corresponding mounting pads, comprising the steps of: tinning the leads of the components with solder; applying a paste comprised of flux and powdered solder to the mounting pads on the printed circuit board; creating an unsoldered component-board assembly by positioning the components on the printed circuit board such that the leads of the components are roughly aligned with their corresponding connector pads; heating the unsoldered component-board assembly, while in a substantially horizontal position, to a temperature sufficient to permit the solder tinning on the leads and the powdered solder in the paste to melt and fuse; applying vibrational energy to the component-board assembly while the solder between the leads and pads is in a fused and molten state; said vibrational energy being sufficient to overcome the static coefficient of friction between the leads of the components and their respective connector pads to a point where the surface tension of the molten solder will produce a best-fit alignment of the leads of each component on their corresponding connector pads; said vibrational energy being less than a level which would exert forces on the components greater than those exerted on the components by the surface tension of the molten solder; halting the application of said vibrational energy while the solder between the leads and pads is in a fused and molten state; and cooling the component-board assembly, thus allowing the solder between the leads and pads to solidfy.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein said vibrational energy is in the 20 to 60 hertz range.
Claim 4
Dependent Claim
20 words
The method of claim 2, wherein said vibrational energy has an amplitude within a range of 0.04 to 0.08 mm.
Claim 5
Dependent Claim
18 words
The method of claim 3, wherein said heating of the component-board assembly is performed in an infrared oven.
Claim 6
Dependent Claim
18 words
The method of claim 4, wherein component-board assemblies are transported through said infrared oven on a track conveyer.
Claim 7
Dependent Claim
30 words
The method of claim 5, wherein the lower surface of the component-board assembly is brought into contact with a cylindrical roller, the axis of which vibrates in a vertical plane.
Claim 8
Independent Claim
256 words
A method of solderably attaching the leads of surface-mount electronic components to the connector pads on a printed circuit board such that the leads of each component are positioned in a best-fit centering on their corresponding mounting pads, comprising the steps of: coating the leads of the components and the mounting pads on the printed circuit board with solder; creating an unsoldered component-board assembly by positioning the components on the printed circuit board such that the leads of the components are roughly aligned with their corresponding connector pads; heating the unsoldered component-board assembly, while in a substantially horizontal position, to a temperature sufficient to permit the solder on the leads and pads to melt and fuse; applying vibrational energy to the component-board assembly while the solder between the leads and pads is in a fused and molten state; said vibrational energy being sufficient to overcome the static coefficient of friction between the leads of the components and their respective connector pads to a point where the surface tension of the molten solder will produce a best-fit alignment of the leads of each component on their corresponding connector pads; said vibrational energy being less than a level which would exert forces on the components greater than those exerted on the components by the surface tension of the molten solder; halting the application of said vibrational energy while the solder between the leads and pads is in a fused and molten state; and cooling the component-board assembly, thus allowing the solder between the leads and pads to solidify.
Claim 9
Independent Claim
256 words
A method of solderably attaching the leads of surface-mount electronic components to the connector pads on a printed circuit board such that the leads of each component are positioned in a best-fit centering on their corresponding mounting pads, comprising the steps of: coating the leads of the components and the mounting pads on the printed circuit board with solder; creating an unsoldered component-board assembly by positioning the components on the printed circuit board such that the leads of the components are roughly aligned with their corresponding connector pads; heating the unsoldered component-board assembly, while in a substantially horizontal position, to a temperature sufficient to permit the solder on the leads and pads to melt and fuse; applying vibrational energy to the component-board assembly while the solder between the leads and pads is in a fused and molten state; said vibrational energy being sufficient to overcome the static coefficient of friction between the leads of the components and their respective connector pads to a point where the surface tension of the molten solder will produce a best-fit alignment of the leads of each component on their corresponding connector pads; said vibrational energy being less than a level which would exert forces on the components greater than those exerted on the components by the surface tension of the molten solder; halting the application of said vibrational energy while the solder between the leads and pads is in a fused and molten state; and cooling the component-board assembly, thus allowing the solder between the leads and pads to solidify.
Claim 10
Dependent Claim
23 words
The method of claim 7, wherein the solder used to coat the leads is in a fused state at the time of application.
Claim 11
Dependent Claim
23 words
The method of claim 7, wherein the solder used to coat the leads is in a powdered state at the time of application.
Claim 12
Dependent Claim
23 words
The method of claim 7, wherein the solder used to coat the pads is in a fused state at the time of application.
Claim 13
Dependent Claim
23 words
The method of claim 7, wherein the solder used to coat the pads is in a powdered state at the time of application.
Claim 14
Dependent Claim
17 words
The method of claim 7, wherein said vibrational energy is in the 20 to 60 hertz range.
Claim 15
Dependent Claim
20 words
The method of claim 12, wherein said vibrational energy has an amplitude within a range of 0.04 to 0.08 mm.
Claim 16
Dependent Claim
18 words
The method of claim 13, wherein said heating of the component-board assembly is performed in an infrared oven.
Claim 17
Dependent Claim
18 words
The method of claim 14, wherein component-board assemblies are transported through said infrared oven on a chain conveyer.
Claim 18
Dependent Claim
30 words
The method of claim 15, wherein the lower surface of the component-board assembly is brought into contact with a cylindrical roller, the axis of which vibrates in a vertical plane.
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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) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |