OSAKA, JAPAN — Nihon Superior USA, a subsidiary of Nihon Superior Co. Ltd., an advanced soldering supplier to the worldwide market, announces that it will feature a newly expanded range of SN100C products, which includes new halogen-free solder paste, in booth 402 at the upcoming Mexitrónica exhibition, scheduled to take place October 21-23, 2008 at the Expo Guadalajara, Hotel Hilton, in Guadalajara, Jalisco, México.
With its unique tin-copper-nickel-germanium alloy SN100C now firmly established as one of the global electronics industry’s most popular lead-free wave soldering alloys, Nihon Superior announces that it is extending the range of material forms in which the alloy is available.
Although developed initially to address the need for an economical wave solder, it has since been found that its properties also make SN100C an ideal choice for reflow and hand soldering as well as spheres for the attachment of area array packages.
The fluidity of SN100C, which is comparable to that of tin-lead, is one of the factors that contributes to excellent through-hole fill and minimal shorts in wave soldering. However, that property is also an advantage in hand soldering where SN100C (040) is the newest eCore addition. It is a high-reliability, halogen-free SN100C (Sn-0.7Cu-0.05Ni+Ge) lead-free flux cored solder wire that does not contain F, Cl, Br or I. The wire features good tip separation and reduced incidents of icicles as well as reduced flux residue cracking, fewer shrinkage defects, reduced copper erosion and a stable intermetallic layer. The wire also provides significant cost advantages.
The 227°C melting point of SN100C was first thought to preclude its use in reflow soldering but when it was noted that tin-silver-copper alloys (such as SAC305 with a melting point of 217-218°C) are typically reflowed with a peak temperature around 245°C it was realized that SN100C could be a drop-in replacement. Its high fluidity and excellent wetting properties mean that SN100C can be reflowed successfully at a lower superheat above liquidus than SAC alloys. Nihon Superior now offers two types of SN100C solder paste — no-clean ePaste for general reflow purposes and ePaste, a special low voiding paste for critical applications such as die attach in which heat transfer though the joint must be maximized.
The newest ePaste offered by Nihon Superior is the SN100C P600, which is a completely halogen-free SN100C (Sn-0.7Cu-0.05Ni+Ge) lead-free solder paste that does not contain F, Cl, Br or I. It is highly reliable and suitable for high-density assemblies with stable printability, excellent wettability and non-melting reduction. P600 features excellent melting behavior with minimum incidence of solder balling and mid-chip balling, stable printability, and substantial cost advantages. The paste also reduces flux residue, is a compliant alloy for reliability and impact strength (SN100C), and allows a profile similar to that of SAC to be used due to its reflow peak temperature of approximately 240°C.
Advantages of the tin-copper system include its ruggedness in impact loading and the nickel addition provides inhibition of the intermetallic growth that can increase the susceptibility of joints to failure in shock loading, e.g. when a mobile phone is dropped. These properties are prompting the industry to evaluate SN100C in flip chip and area array packages, and Nihon Superior is supporting this new application by making a range of eBalls available.
A solution for the lead-free HASL Process, SN100CL features excellent fluidity — good drainage ensures no bridges even on fine-pitch circuitry, good penetration of small diameter holes, uniform coating thickness and a smooth, bright finish. SN100CL wets quickly and offers low copper erosion. SN100CL forms a stable intermetallic compound layer (Cu/Ni/Sn layer) in between solder and copper laminate.
