Chemistry: electrical and wave energy – Processes and products – Processes of treating materials by wave energy
Patent
1993-05-11
1995-06-20
Tung, T.
Chemistry: electrical and wave energy
Processes and products
Processes of treating materials by wave energy
204400, 204412, 204434, G01N 2726
Patent
active
054258596
ABSTRACT:
A sequential electrochemical reduction method and apparatus are provided for assessing and restoring solderability of electronic component leads. The method detects and quantifies the presence of metallic oxides that are detrimental to solderability by sequential electrochemical reduction in contact with an electrolyte in an inert atmosphere. A cathode having a high hydrogen overvoltage is placed in contact with the electrolyte. A solderable portion of the component to be tested is placed in contact with the cathode and the electrolyte. An inert counter electrode and a reference electrode are also placed in contact with the electrolyte. A current is passed between the cathode and inert electrode, and the voltage and current are measured as a function of time during reduction of metallic oxides on the solderable portions of the component. The measurements of voltage, current, time, and charge density may be compared with baseline data from specimens having known oxide compositions that correlate with degradation of solderability.
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Anderson Dennis P.
Tench D. Morgan
McFarren John C.
Rockwell International Corporation
Tung T.
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