To meet the demand of high-density and memory/logic options for sophisticated electronic devices, many assemblers are evaluating package on package (PoP) technology. PoP assemblies allow for higher electronic functionality per unit circuit board area, and allows low cost product memory customization, and highly flexible manufacturing. Unlike PoP flux, ALPHA® PoP33 solder paste uses flux and solder powder, to minimize defects associated with non-planar processor/memory combinations during the reflow process. The use of paste can help reduce costly defects associated with soldering known good memory devices to known good processor packages by bridging gaps that PoP flux alone may not.
ALPHA® PoP33 was designed to minimize expensive rework and scrap by providing highly repeatable paste volumes to BGA memory packages. ALPHA® PoP33 maintains its rheology, even under frequent exposure to high shear, for 24 hours. This means highly reproducible volumes of paste pick up in normal PoP dipping applications, reducing defects, increasing yields and reducing scrap. ALPHA® POP33 is a no-clean lead-free solder paste. By optimizing ultra-fine solder powder and physical properties of flux, it is ideal for 150 to 300 μ offset BGA packages, while leaving a clear, colorless, residue with high electrical resistivity.