Double Shoulder Contact and movable Ground Pin QFP Test & Burn-In Socket

Among such high density packages, the QFP has proven to be the right choice when it comes to combine high functional integration with excellent connection reliability. With its gull-wing shaped lead feet surface mount, QFP is most tolerant towards vibration, flexing, warping and other stress applied to the PCB. This mechanical reliability has been the reason why QFP is the first choice for industries that are operating in harsh conditions such as automotive.

Highest contact reliability, no lead foot touching, movable ground pin option, full auto-load capababilty – these are the major quality features of this socket family. They predestine the IC500 for use when excellent reliability and contact quality is mandatory. Like for qualifying/burn-in/testing safety relevant automotive IC devices.

Besides the connection reliability, issues like heat dissipation and RF characteristics often require test sockets to be equipped with components that can handle cooling and grounding. IC500 movable ground pin sockets are equipped with either crown shaped or flat head ground pins depending on customer requirement.

The additional exposed pad connection however has brought a new challenge to socket design: a spring loaded center pin – a common solution – mainly pushes the package away from its ideal insertion plane during loading. Possible counter measures often add technical complexity to the auto-load handler resulting in manual-load capable sockets only.

To overcome this challenge, Yamaichi Electronics has applied a new design to the ground pin in its IC500 series socket. The revolutionary design allows the center pin to actuate in conjunction with the movement of the push cover. While the push cover is being held down, the center pin retracts completely to allow the package to be guided into its position. When the push cover is released, double shoulder contacts are actuated first, holding the package firmly in its plane before the center pin comes into action. This two step actuation ensures that the IC500 series remains auto-load capable and reliable for all future test and burn-in applications.