Abstract: A socket is provided for an IC package having a plurality of contacts. The socket includes a body mounting a plurality of terminals and having a receptacle in the top thereof for receiving the IC package with the contacts in engagement with the terminals. At least one retainer/ejector member is mounted on the socket body adjacent the receptacle for movement relative to the body from a first position retaining the IC package in the receptacle and a second position at least partially ejecting the IC package from the receptacle. An actuator member is movably mounted on the socket body. The actuator member is operatively associated with the retainer/ejector member for moving the retainer/ejector member from its first position to its second position.

Abstract: A socket for burn-in testing of an integrated circuit package having electrical leads. The socket includes an outer socket housing and an inner socket housing slidably moveable relative to the outer housing between an upper limit position and a lower limit position, the inner housing for supporting the integrated circuit package thereon and having a plurality of terminal-receiving cavities therein. The socket further includes a plurality of terminals disposed in the terminal-receiving cavities of said inner housing for contacting the leads of the integrated circuit package, a cam mechanism for raising and lowering the inner housing between the upper limit position and lower limit position relative to the outer housing, and a latch mechanism for holding and releasing the integrated circuit package relative to the inner housing.

Abstract: A spring is provided having a high durability in actual use and sagging resistance of the same level as or higher than conventional ones through improvement of the corrosion fatigue resistance. The spring uses as a material a steel including C: 0.35-0.55%, Si: 1.60-3.00%, Mn: 0.20-1.50%, S: 0.010% or less, Ni: 0.40-3.00%, Cr: 0.10-1.50%, N: 0.010-0.025%, V: 0.05-0.50% and Fe balance. The steel is heat treated to have a hardness of 50.5-55.0 HCC and shot-peened at a moderate temperature to render a residual stress of −600 MPa or more at a depth of 0.2 mm below the surface. The temperature at which the spring is shot-peened is preferably 100-300° C., and the hardness of shot particles for the shot-peening is preferably 450-600 Hv.

Abstract: A socket having a structure which is suitable for electrical connection with ball-shaped lead terminals of an IC package is shown. When a cover (12) is pushed down, a latch (70) moves away, a slide plate (40) slides toward the positive side in an X direction through levers (52) and (50) and movable shaft (58) and both arms of each contact maker (30) open. Each lead terminal (solder ball) (32a) of the BGA package (32) is freely inserted between both arms of a respective contact maker (30) when in the open state. When cover (12) rises to its highest position, slide plate (40) slides in the reverse direction by the spring force of a compression coil spring, thereby returning to the its original position and both arms of each contact (32) engage each lead terminal (32a) in such a way as to hold it from opposite sides with a result that an electrical connection based on compressive engagement is obtained between each contact element (30) and each respective terminal (32a).

Abstract: In an atomic absorption spectrophotometer utilizing the direct Zeeman's method, plural lamps are installed in the light source unit in order to enhance the versatility and enable continuous analyses. Accordingly, a plurality of low pressure discharge tubes 14 and hollow cathode lamps 16 in total are mounted on a lamp holder 12 of the light source unit, and by rotating the lamp holder 12, an arbitrary lamp may be positioned at the light source position for measurement. When the low pressure discharge tube 14 is used as the light source, in order to perform background correction by the Zeeman's method, a permanent magnet or an electromagnet 24 for operating a magnetic field on the light source is disposed, and a polarizing unit 26 is disposed on the measurement optical path, so that the direction of polarization of the measurement light to be sent to an atomizing unit 26 is changed over between the atomic absorption measurement mode and the background correction mode.

Abstract: A lighting circuit part (26) is provided for lighting a hollow cathode lamp (1), to feed a large lighting current (I1) intermittently and periodically across an anode and a cathode by a control signal from a control part (22) while feeding a boost current (Ib) across a boost electrode and the anode in a part of a period when the lighting current (I1) flows across the anode and the cathode. Absorbance including both of atomic absorption of a sample and background absorption is detected with light emitted when the large current (I1) is fed across the anode and the cathode with feeding of the boost current (Ib) while absorbance by background absorption of the sample is detected with light emitted when the large current (I1) is fed across the anode and the cathode with no feeding of the boost current (Ib) so that difference between these absorbance levels is obtained to obtain true atomic absorption corrected as to background absorption. Thus, measurement is made in a high S-N ratio with background correction.

Abstract: A flameless atomic absorption spectrophotometer including a valve controller that connects the inside of the heating tube to the inert gas source before the sample is atomized, whereby water vapor or organic vapor generated from the sample before the atomizing stage is expelled from the tube through the sampling hole. In the atomizing stage of the heating program, the valve controller connects the inside of the heating tube to the outer atmosphere, whereby the atomized sample can expand along the optical path within the heating tube.