Metal treatment – Compositions – Fluxing
Patent
1994-03-22
1995-01-17
Rosenberg, Peter D.
Metal treatment
Compositions
Fluxing
420558, 420559, 420570, B23K 3534
Patent
active
053823001
ABSTRACT:
A solder paste is composed of a vehicle (or flux) system and a mixture of at least two solder powders. One component of this mixture is a eutectic or near-eutectic Sn/Pb alloy powder, while the other component comprises powders selected from at least one elemental metal powder or at least one solder alloy powder or at least one elemental metal powder and at least one solder alloy powder. Said other component is a powder or combination of powders each of which has a liquidus temperature which is lower by at least 5 degrees Centigrade (.degree.C.) than the solidus temperature of said eutectic or near-eutectic Sn/Pb alloy powder or a solidus temperature which is higher by at least 5.degree. C. than the liquidus temperature of said eutectic or near-eutectic Sn/Pb alloy powder. The eutectic or near-eutectic Sn/Pb powder makes up from 5 to 95 weight percent of the total powder mixture. Alternatively, not all powders which comprise the second component need to obey this rule so long as at least 30% by wt. of the entire powder mixture has a solidus temperature which is at least 5.degree. C. higher than the highest liquidus temperature of the eutectic or near-eutectic Sn/Pb alloy powder. This solder paste results in an uncompromised consolidation and wetting process in which all of the solder joints or balls are formed on and wetted to an appropriate contact by the solder reflow process.
REFERENCES:
patent: 4767471 (1988-08-01), McLellan
patent: 4865654 (1989-09-01), McLellan
patent: 4921550 (1989-07-01), McLellan
patent: 5211764 (1993-05-01), Degani
patent: 5229070 (1993-07-01), Melton
H. H. Manko, "Soldering Handbook for Printed Circuits and Surface Mounting," Van Nostrand Reinhold (New York) 1986, pp. 290-294.
J. S. Hwang, Ph.D, "Solder Paste in Electronics Packaging," Van Nostrand Reinhold, Chapter 4, p. 73.
Blonder Greg E.
Degani Yinon
Dudderar Thomas D.
Alber Oleg E.
AT&T Corp.
Rosenberg Peter D.
LandOfFree
Solder paste mixture does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solder paste mixture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solder paste mixture will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-745158