Solder preform with internal flux core including thermochromic indicator

Abstract

A solder preform in the shape of a solder tube or washer includes: a cylindrically shaped solder alloy body including an inner surface, an outer surface, a first end, and a second end, the second end interlocking with the first end, and the first end and the second end cut along an entire height of the cylindrically shaped solder alloy body; and a flux core embedded in the cylindrically shaped solder alloy body between the inner surface and the outer surface, the flux core including a thermochromic indicator. During reflow soldering, the flux core including the thermochromic indicator is configured to flow out of the first end and the second end to coat a substrate that is soldered.

Dependencies are inferred from the claim text.