Electrical card connector applying uniform insertion force

An electrical card connector, comprising:

• an insulating base having a bottom wall, two side walls being disposed on the bottom wall and being opposite to each other, an accommodation space and a card insertion port;
• the accommodation space and the card insertion port being defined by the bottom wall and the side walls;
• each side wall being provided with a sliding surface facing the accommodation space, and an opening far away from the card insertion port;
• wherein, the opening is adjacent to the sliding surface, and the sliding surface includes an arc surface adjacent to the opening;
• a plurality of first conductive terminals being arranged in a first row and being retained in the bottom wall;
• each first conductive terminal having a first elastic arm, which is adjacent to the card insertion port and at least a portion of which extends into the accommodation space;
• a plurality of second conductive terminals being arranged in a second row and being retained in the bottom wall;
• each second conductive terminal having a second elastic arm, which is far away from the card insertion port and at least a portion of which extends into the accommodation space;
• and
• a pair of balance terminals being retained in the side walls;
• each balance terminal including a fixed end, an elastic pressure arm and a sliding portion disposed in sequence;
• the fixed end being adjacent to the card insertion port;
• the elastic pressure arm being bent and extending along the corresponding side wall, and the elastic pressure arm at least partially extending into the accommodation space;
• wherein, the sliding portion is a protrusion toward the sliding surface;
• wherein, the elastic pressure arms of the pair of balance terminals are used to clamp two side edges of an electronic card and exert a clamping force on the electronic card when the electronic card is inserted into the accommodation space and touches the first elastic arms;
• wherein, the sliding portions of the pair of balance terminals are used to slide along the sliding surfaces of the corresponding side walls when the elastic pressure arms clamp the electronic card and the electronic card continues to be inserted;
• wherein, the sliding portions of the pair of balance terminals are capable of entering the corresponding openings and allowing the elastic pressure arms to release at least a portion of the clamping force on the electronic card when the electronic card touches the second elastic arms.