Electrical connector with improved contact retention

An electrical connector comprising:

• an insulative housing defining a mating face, a mounting face opposite to the mating face, and a plurality of terminal receiving channels extending from the mating face to the mounting face, each channel having at least one deformable step portion formed on an inner face thereof;
• and
• a plurality of conductive terminals each having a body portion of an elongate, rectangular shape, the body portion comprising an upper portion and a lower portion, a width of the upper portion being bigger than a width of the lower portion thereby a shoulder being formed along a longwise direction and a recessed portion being formed under the shoulder, such that the shoulder press the step portion of the channel downwardly, which lead to the step portion being depressed and collapsed, during the insertion of the terminal from the mating face of the housing into the channel, and such that part of the step portion is pressed into the recessed portion of the terminal, thereby providing a permanently engaging force between the depressed step portion of the channel and the recessed portion of the terminal, each terminal comprises a pair of spaced-apart legs projecting from the body portion and extending beyond the mating face of the housing and adapted for mating with a complementary contact, each terminal has a tail portion extending from the body portion along a direction away from the spaced-apart legs and the tail portion of each terminal has a solder pad having a circular-shaped cross section and a solder ball attached on the solder pad.