Dear Qingwei, Try Quickipak.com or OSE in the bay area. My company, GDSI does wafer backgrinding and dicing and often we refer our customers to afore mentioned for packaging. Laila Collins Laila Collins Account Manager Semiconductor Tapes and Materials Inc. 925 Berryessa Road San Jose, CA 95133 408 451 2000 x103 P 408 451 2001 F Lcollins@wafergrind.com