We have found 2 software records in our database eligible for .vcf to .spb file format conversion.
You can import existing contacts in vCard format (.vcf) to Samsung Kies, add it to your contacts library for your smart phone and save it as an .spb file.
This is most likely the only way how to achieve vcf to spb conversion, but it was reported to us that this function may be lacking in some later versions of Kies. In that case you will need to download and use some older version of the program.
VCF
Files with vcf extension are almost always contacts saved in vCard format. Typically used various Personal Information Managers or e-mail clients (for example Outlook), as well as exported from mobile phones, for the purposes of sharing or migrating contacts from one device to another.
SPB
Files with spb extension is mainly known to be used for a contact backup exported by Samsung Kies management software for various Samsung smart phones.