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Method for a material to maintain a lead-free reflow temperature hierarchy for surface mounting pins, connectors, and other SMT components

IP.com Disclosure Number: IPCOM000007949D
Publication Date: 2002-May-07
Document File: 2 page(s) / 32K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a material to maintain a lead-free reflow temperature hierarchy for surface mounting pins, connectors and other surface-mount technology (SMT) components. Benefits include improved functionality and improved reliability.

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Method for a material to maintain a lead-free reflow temperature hierarchy for surface mounting pins, connectors, and other SMT components

Disclosed is a method for a material to maintain a lead-free reflow temperature hierarchy for surface mounting pins, connectors and other surface-mount technology (SMT) components. Benefits include improved functionality and improved reliability.

Background

      The disclosed method addresses the problem of lead-free joints reliability on both sides of a surface-mounted electronic device. The melting temperature of the solder on the secondary side of the device may impact placement accuracy of the component placed on the primary side of the device. The problem is conventionally solved by using Sn90/Sb10 solder for surface mounting components, pins, and connectors on the primary side of the device. The alloy’s higher melting temperature enables surface mounting on the secondary side of the package using lead-free solders with a reflow peak temperature of up to 240oC. With this solution, minimal impact occurs on the final placement accuracy or true position of the components, connectors, and pins.

Description

      The disclosed method attaches pins and other surface mounted components on a printed circuit board (PCB) or a printed wiring board (PWB) that already has mounted components. The method is an assembly process that enables attaching SMT components such as passives, pins, and connectors on both sides of the PCB/PWB.

              The key element is maintaining the reflow hierarchy for assembling double-side su...