An electrical card connector (100) adapted for accepting memory cards includes an insulative housing (2), a terminal module (3) received in the housing and a metal shell (1) substantially covering the housing. The housing includes a card receiving space (24) and an upper wall (20). A row of slots (2031) are defined in inner side surface of the upper wall. The terminal module includes an insulative casing (31) and a number of first and second terminals (32a, 32). The first and second terminals respectively includes first and second mounting portions (322a, 322) fixed in the casing, first and second body portions (321a, 321) alternately held in corresponding slots of the upper wall, and first and second contacting portions (323a, 323) arranged in two lines in the card receiving space for electrically connecting with the card.

A pair of irreversible female and male connectors (2,1) fitting one in another have respectively female and male housings (22, 2), and the female housing (22) has a cavity (23) with a front opening so as to fit on the male housing (2) along an insertion direction. The female housing (22) has pin contacts (28) in placed the cavity and partitions (25) formed in it along the direction so as to separate the contacts (28) one from another. Socket contacts (42) engaging the pin contacts are placed in the male housing (2) that has cutouts (6) fitting on the partitions (25), and each partition having opposite sides (35,36) asymmetrical about a cross section center of the partition. Each cutout (6) also has asymmetrical sides (45,46) corresponding to the sides of each partition, such that the connectors are inhibited from engaging one another if one of them is reversed upside down, so that the pair of connectors are unlikely to come into wrong and upside-down connection, thus ensuring a stable and reliable mutual engagement even if they are designed thinner and smaller in size as required for the high-voltage type connectors.

Integrated stacked microchannel heat exchanger and heat spreaders for cooling integrated circuit (IC) dies and packages and cooling systems employing the same are disclosed. In one embodiment, a stacked microchannel heat exchanger is operatively and thermally coupled to an IC die or package using an interstitial solder or a solderable material in combination with solder. In another embodiment, a stacked microchannel heat exchanger is operatively and thermally coupled to an IC die or package using an adhesive. In a further embodiment, a stacked microchannel heat exchanger is operatively coupled to an IC die or package by fasteners and is thermally coupled to the IC die or package using a thermal interface material. The integrated stacked microchannel heat exchanger and heat spreaders may be employed in a closed loop cooling system including a pump and a heat rejecter. The integrated stacked microchannel heat exchanger and heat spreaders are configured to support either a two-phase or a single-phase heat transfer process using a working fluid such as water.