Browse Prior Art Database

Immersion Wave Soldering Flux

IP.com Disclosure Number: IPCOM000062661D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Rott, W: AUTHOR [+2]

Abstract

It is proposed that in lieu of a 5% b.w. Na2EDTA glycerin flux a 2 to 6% b.w. Na4EDTA glycerin flux be used. In advanced packaging, the circuit boards, fitted with contact springs, are soldered in an immersion wave soldering process. For that purpose, the boards are immersed in an about 160ŒC hot glycerin flux, activated with EDTA, which ensures that the circuit boards are uniformly heated to process temperature and that board and contact spring surfaces are free of oxides and other impurities. In lieu of the previously used Na2EDTA glycerin flux, a 2 to 6 % b.w. Na4EDTA glycerin flux bath is used.

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Immersion Wave Soldering Flux

It is proposed that in lieu of a 5% b.w. Na2EDTA glycerin flux a 2 to 6% b.w. Na4EDTA glycerin flux be used. In advanced packaging, the circuit boards, fitted with contact springs, are soldered in an immersion wave soldering process. For that purpose, the boards are immersed in an about 160OEC hot glycerin flux, activated with EDTA, which ensures that the circuit boards are uniformly heated to process temperature and that board and contact spring surfaces are free of oxides and other impurities. In lieu of the previously used Na2EDTA glycerin flux, a 2 to 6 % b.w. Na4EDTA glycerin flux bath is used. Such a bath has the following advantages over that previously used: Maturing after the bath has been newly set or after EDTA has been added is eliminated, as the bath has the desired properties, for example, with respect to wetting tin or palladium surfaces, right from the start. Eliminated, too, is the high aggressiveness of the bath with respect to the removal of the tin layer. The solderability of the tin and palladium surfaces treated in the bath is considerably improved, which is particularly conspicuous during the soldering of palladium-coated contact springs.

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