Koki S01X7C48-M500 low silver alloy solder paste offers good melting and wetting (<0.3mm dia CSP 0603 chip) and fine-pitch, low-halide content (CL+BR<1500ppm). Is said to have excellent printability and process parameters.

Koki, http://www.ko-ki.co.jp/top.html
Christopher Associates, www.christopherweb.com