A conventional ZIF connector typically includes a housing having an elongated slot along a front surface which is sized and shaped to receive a circuit board or flexible flat cable (hereinafter called insert elements). Located within the housing are typically a plurality of terminals which are adapted to contact at least one surface of the insert element. The terminals are biased to a predetermined overlapping position and will therefore exert a controlled amount of contact force against the insert element to achieve the required electrical contact. As is well known in the art, many of the circuit boards and flat cable used today are delicate and include fragile electrical contacts, such as thin film deposition layers and high gauge wire (extremely fine). Such delicate insert elements are easily damaged during insertion into the slot of a ZIF connector even by the relatively low contact force exerted by the terminals. It is for this reason that ZIF connectors include provisions to reduce the magnitude of the contact force during insertion of the insert elements and thereafter reapply the force so that proper electrical contact may be achieved. A common technique used with prior art ZIF connectors to release or reduce the contact force of the contact terminals during insertion of the inserted elements is to mechanically displace each contact terminal from the path of insertion, during the insertion process. This displacement of terminals may be achieved using a lever arm which mechanically engages each contact terminal, or, as in the connector disclosed in U.S. Pat. No. 5,542,855 issued to Asai, the contact terminals are already positioned away from the path of insertion during the insertion process and are forced into tight engagement, as required, by inserting a key element into a second slot which effectively deforms each contact terminal in the desired manner.
A problem with the prior art ZIF connectors is that they are expensive to manufacture owing to the relatively complex internal mechanisms used to simultaneously displace the contact terminals. These prior art ZIF connectors are designed for repeated use, such as removably securing an IC chip to a circuit board for possible removal at a later time. The prior art ZIF connectors are not intended to be permanently attached (soldered) to both the inserted elements and the circuit board.
It is therefore a first object of the present invention to provide a zero-insertion-force connector which is simple in construction and inexpensive to manufacture.
It is another object of the invention to provide such a ZIF connector that includes contacts that are adapted to be soldered to corresponding electrical contacts located on the insert element.
It is another object of the invention to provide such a ZIF connector that otherwise overcomes the deficiencies of the prior art.