Lead having a solder-preform and preform-carrying finger engageable directly with a contact pad

A lead-substrate assembly, which comprises:

• a lead having an elongated stem and first and second resilient clamping fingers having opposed clamping portions extending in opposed spaced relationship from the elongated stem;
• a substrate disposed between the opposed clamping portions of the resilient clamping fingers;
• a contact pad on the substrate;
• and
• a solder mass bonded to the contact pad on the substrate;
• the first resilient clamping finger of the lead further including an essentially U-shaped connecting portion which connects the clamping portion of the first resilient clamping finger to the lead stem, the U-shaped connecting portion being reverse-bent with respect to the lead stem in a first direction extending away from the contact pad on the substrate;
• and
• the clamping portion of the first resilient clamping finger of the lead being reverse-bent with respect to the U-shaped connecting portion of the first resilient clamping finger in a second opposite direction extending toward the contact pad on the substrate, with an outer end portion of the clamping portion terminating adjacent the contact pad in firm engagement with the contact pad and being embedded in the solder mass to form an electrical and mechanical connection with the contact pad.

A solder-bearing lead, which comprises:

• an elongated stem;
• first and second resilient clamping fingers having opposed clamping portions extending in opposed spaced relationship from the elongated stem to define a gap for the reception of a substrate therebetween, the clamping portion of the first resilient clamping finger having an inner surface;
• a solder preform attached to the inner surface of the clamping portion of the first resilient clamping finger and having a surface portion in opposed relationship to the clamping portion of the second resilient clamping finger;
• the clamping portion of the first resilient clamping finger being partially wrapped about the solder preform in a direction facing toward the clamping portion of the second resilient clamping finger and having an outer end portion which is of a tapered configuration such that an outer end surface portion of the clamping finger outer end portion is essentially flush with the surface portion of the solder preform, and such that both the clamping finger outer end surface portion and the preform surface portion directly engage a contact pad on the substrate when the substrate is received between the finger clamping portions.

A solder-bearing lead, which comprises:

• an elongated stem;
• first and second resilient clamping fingers having opposed clamping portions extending in opposed spaced relationship from the elongated stem for the reception of a substrate therebetween, the clamping portion of the first resilient clamping finger having an inner surface;
• a solder preform attached to the inner surface of the clamping portion of the first resilient clamping finger and having a surface portion in opposed relationship to the clamping portion of the second resilient clamping finger;
• the clamping portion of the first resilient clamping finger being partially wrapped about the solder preform in a direction extending toward the clamping portion of the second resilient clamping finger and having an outer end portion which terminates adjacent the surface portion of the solder perform in opposed relationship to the clamping portion of the second resilient clamping finger, the outer end portion of the clamping finger being of tapered construction such that an outer end surface portion of the clamping finger outer end portion is essentially flush with the surface portion of the solder preform;
• and
• the clamping portion of the second resilient clamping finger defining a respective side of a substrate-receiving gap, and the surface portion of the solder preform and the adjacent flush outer end surface portion of the clamping portion of the first resilient clamping finger defining an opposite respective side of the substrate-receiving gap such that both the first clamping finger outer end surface portion and the preform surface portion directly engage a contact pad on the substrate when the substrate is received in the substrate-receiving gap between the finger clamping portions.