US Patent 8974236 Low profile electrical connector

An electrical connector for electrically connecting a central processing unit (CPU) to a printed circuit board (PCB) includes a housing, a number of contacts, and a number of solder balls. The housing has a number of passageways extending passing through the housing and a number of protrusions located outside the passageways and corresponding the passageways one-to-one. A number of contacts partially are disposed in the passageways and each has a hole to match with the protrusion and secure the contacts on the housing. A number of solder balls are connected with corresponding contacts.