SAC305/TYPE4/INDIUM8.9/88.5%锡膏

详情描述：

Introduction
Indium8.9 is an air or nitrogen reflow, no-clean solder paste specifically formulated to accommodate the higher processing temperatures required by the SnAgCu, SnAg, and other alloy systems favored by the electronics industry to replace conventional Pb-bearing solders. Indium8.9 offers unprecedented stencil print transfer efficiency to work in the broadest range of processes. In addition, the high probe testability of Indium8.9 minimizes false failures in ICT.
 
 
 Features
?High transfer efficiency through small apertures(≤ 0.66AR)
?xcellent wetting to all common finishes at high and low peak reflow temperatures
?lear, probe testable flux residue
?liminates head-in-pillow defects
 
Alloys
Indium Corporation manufactures low-oxide spherical powder composed of a variety of Pb-free alloys that cover a broad range of melting temperatures. Type 4 and Type 3 powder are standard offerings with SAC alloys. The metal percent is the weight percent of the solder powder in the solder paste and is dependent upon the powder type and application. Standard product offerings are detailed below.
 
Printing
Stencil Design:
Electroformed and laser cut/electropolished stencils produce the best printing characteristics among stencil types. Stencil aperture design is a crucial step in optimizing the print process. The following are a few general recommendations:
? Discrete components — A 10–20% reduction of stencil aperture has significantly reduced or eliminated the occurrence of mid-chip solder beads. The “home plate” design is a common method for achieving this reduction.
? Fine pitch components — A surface area reduction is recommended for apertures of 20 mil pitch and finer. This reduction will help minimize solder balling and bridging that can lead to electrical shorts. The amount of reduction necessary is process dependent (5–15% is common).
? For optimum transfer efficiency and release of the solder paste from the stencil apertures, industry standard aperture and aspect ratios should be adhered to.