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US4396140A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of bonding electronic components

Assignee: AT&T Inc
•
Filing: 1981-01-27
•
Granted: 1983-08-02
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Expires: 2001-01-27
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Abstract

Abstract Disclosed is a method of bonding electronic components (14) to metallized substrates (21) by soldering. The solder is first deposited on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads (28, 29, 30) of the components to be bonded. The component leads are then placed on the pads and the solder is reflowed. The solder thereby adheres to the leads so that a controlled amount of solder will remain on each lead when the component is lifted from the substrate. The components can then be soldered to an appropriate metallized substrate.

Inventors

  • 👤 Donald Jaffe
  • 👤 Richard C. Kershner
  • 👤 Nicholas T. Panousis

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 18:31
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3485; H05K3/341; H05K3/3421; H05K3/3426; H05K2201/00; H05K2201/10; H05K2201/10007; H05K2201/10166; H05K2201/10613; H05K2201/10954; H05K2201/10984; H05K2203/00; H05K2203/03; H05K2203/0338; H05K2203/04; H05K2203/043; Y; Y02; Y02P; Y02P70/00; Y02P70/50

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 110 words
A method of applying solder (16, 17, 18) to the leads (28, 29, 30) of an electronic component (14) characterized in the steps of first depositing solder in the form of a paste comprising lead, tin, and a flux on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure to reflow the solder and cause the solder to adhere to each lead, removing the flux from the solder to permit removal of the component from the substrate, and removing the component from the substrate.
Claim 2
Independent Claim 110 words
A method of applying solder (16, 17, 18) to the leads (28, 29, 30) of an electronic component (14) characterized in the steps of first depositing solder in the form of a paste comprising lead, tin, and a flux on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure to reflow the solder and cause the solder to adhere to each lead, removing the flux from the solder to permit removal of the component from the substrate, and removing the component from the substrate.
Claim 3
Independent Claim 166 words
A method for bonding an electronic component (14) to bonding pads (22, 23, 24) on a metallized substrate (21) comprising the steps of applying solder (16, 17, 18) to the leads (28, 29, 30) of the component, bringing said leads into contact with corresponding bonding pads on said metallized substrate, and heating the structure to melt the solder and establish a bond between the leads and bonding pads characterized in that the solder is applied to the leads by first depositing solder in the form of a paste comprising lead, tin and a flux on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure to reflow the solder and cause the solder to adhere to each lead, removing the flux from the solder to permit removal of the component from the unmetallized substrate, and removing the component from the substrate.
Claim 4
Independent Claim 166 words
A method for bonding an electronic component (14) to bonding pads (22, 23, 24) on a metallized substrate (21) comprising the steps of applying solder (16, 17, 18) to the leads (28, 29, 30) of the component, bringing said leads into contact with corresponding bonding pads on said metallized substrate, and heating the structure to melt the solder and establish a bond between the leads and bonding pads characterized in that the solder is applied to the leads by first depositing solder in the form of a paste comprising lead, tin and a flux on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure to reflow the solder and cause the solder to adhere to each lead, removing the flux from the solder to permit removal of the component from the unmetallized substrate, and removing the component from the substrate.
Claim 5
Dependent Claim 12 words
The method according to claim 2 wherein the unmetallized substrate comprises ceramic.
Claim 6
Dependent Claim 33 words
The method according to claim 2 wherein the solder on the unmetallized substrate is reflowed by heating at a peak temperature in the range 190-250 degrees Celsius for a period of 15-60 seconds.
Claim 7
Dependent Claim 29 words
The method according to claim 2 wherein the amount of solder adhering to each lead when the component is removed from the unmetallized substrate is at least 1 mg.
Claim 8
Dependent Claim 20 words
The method according to claim 2 wherein the metallized substrate comprises ceramic with a thick film circuit (20) formed thereon.
Claim 9
Dependent Claim 13 words
The method according to claim 2 wherein the component is a soldered-on transistor.
Claim 10
Dependent Claim 24 words
The method according to claim 2 wherein the solder adhering to each lead (e.g., 18 of FIG. 6) has a flat bottom surface (28).
Claim 11
Independent Claim 178 words
A method for bonding an electronic component (14) to bonding pads (22, 23, 24) on a metallized substrate (21) comprising the steps of applying solder (16, 17, 18) to the leads (28, 29, 30) of the component, bringing said leads into contact with corresponding bonding pads on said metallized substrate, and heating the structure to melt the solder and establish a bond between the leads and bonding pads characterized in that the solder is applied to the leads by first depositing on an unmetallized substrate (10) a solder paste comprising lead, tin and a flux in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure at a peak temperature in the range 190-250 degrees Celsius to melt the solder for a period of 15-60 seconds and cause the solder to adhere to each lead while the component remains in place on the unmetallized substrate, removing the flux from the solder, and removing the component from the substrate.
Claim 12
Independent Claim 178 words
A method for bonding an electronic component (14) to bonding pads (22, 23, 24) on a metallized substrate (21) comprising the steps of applying solder (16, 17, 18) to the leads (28, 29, 30) of the component, bringing said leads into contact with corresponding bonding pads on said metallized substrate, and heating the structure to melt the solder and establish a bond between the leads and bonding pads characterized in that the solder is applied to the leads by first depositing on an unmetallized substrate (10) a solder paste comprising lead, tin and a flux in a pattern of discrete pads (11, 12, 13) corresponding to the leads of the component, bringing the leads into contact with the solder pads on the substrate, heating the structure at a peak temperature in the range 190-250 degrees Celsius to melt the solder for a period of 15-60 seconds and cause the solder to adhere to each lead while the component remains in place on the unmetallized substrate, removing the flux from the solder, and removing the component from the substrate.

References Cited (Backward Citations)

US3516155A Cited
DE2728330A1 Cited
GB2025804A Cited
US4332341A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-08-01 1987-01-31 1987-08-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-08-01 1991-01-31 1991-08-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-08-01 1995-01-31 1995-08-02 $7700.00 Window Closed / Lapsed

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