Browse Prior Art Database

Method for a preprint solder paste test pad

IP.com Disclosure Number: IPCOM000130559D
Publication Date: 2005-Oct-26
Document File: 3 page(s) / 16K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a preprint solder paste test pad. Benefits include improved functionality and improved reliability.

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Method for a preprint solder paste test pad

Disclosed is a method for a preprint solder paste test pad. Benefits include improved functionality and improved reliability.

Background

              Conventionally, Organic Solderability Preservative (OSP) is a cost effective surface finish that is widely used for notebook computers. However, the OSP surface finish is typically accompanied by in-circuit testing issues. The use of lead-free solder, which requires higher processing temperatures, increases the difficulty. As a result, lead free applications on OSP boards are not widely implemented (see Figure 1).

      The passing criteria for the in-circuit test, is, 100% test-pad coverage post wave. If one test pad is uncovered, an in-circuit testing issue is created. Conventionally, ~2% to 10% of the test pads are uncovered after wave process due to OSP test pad oxidation (see Figure 2).

General description

      The disclosed method uses preprint solder paste to solve the in-circuit testing issue with OSP surface finishes. This preprint solder paste prevents the test pad oxidation that leads to the testing issues.

Advantages

              The disclosed method provides advantages, including:

•             Improved functionality due to enabling lead free implementation on OSP surfaces

•             Improved reliability due to preventing test pad oxidation and eliminating the in-circuit testing issue

Detailed description

              The disclosed method includes a preprint solder paste on an OSP surface-finished test pad by using surface mount technology (SMT) processes. The preprint solder paste prevents oxidation on the OSP test pad and enables in-circuit testi...