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US 4,722,470 AGranted
Method and transfer plate for applying solder to component leads
AssigneeInternational Business Machines Corporation
InventorAjay Johary
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AssigneeInternational Business Machines Corporation
InventorAjay Johary
Estimating the term…
A method and a solder transfer member for applying discrete bodies of solder of predetermined size to the leads of a component for subsequent surface mounting to a substrate. The transfer member is a plate having a non-wetted surface, for example titanium, with an array of cavities matching the component lead pattern, each having a volume corresponding to the desired amount of solder to be applied to the corresponding lead. The method includes placing solder paste on the transfer member and filling the cavities by wiping the plate surface. The component is placed on the transfer member with the leads contacting the solder paste in the cavities. Reflow of the solder paste bonds to each lead a discrete body of solder having a precisely determined size. To limit wicking of solder on the leads, selective masking may be performed by applying a water soluble mask coating to the leads and removing the mask from selected areas by placing the component against a surface charged with water before placing the component on the transfer member.
A method of applying discrete bodies of solder of predetermined size to the leads of a component for subsequent surface mount attachment by reflow to a substrate, the component leads lying in a generally planar pattern, said method comprising:
A method of forming discrete bonded solder bodies upon a substrate mountable device in a predetermined array of locations on the device, said method comprising:
A method of preparing a conductive metal lead for surface mounting to a conductive region of a substrate with a solder joint having a predetermined volume of solder, said method comprising the steps of:
A solder transfer member for use in preparing a component for surface mounting to a substrate wherein the component has a plurality of spaced electrical leads with a generally planar footprint and the substrate has a pattern of conductive regions matching the footprint, said solder transfer member comprising:
Dependencies are inferred from the claim text.