Plate fin/chic heat exchanger

In an arrangement for cooling electrical devices comprising a plurality of electrical devices and means for cooling said electrical devices, the improvement comprising said means for cooling said electrical devices including a heat exchanger including thermally conductive means defining a channel having an inlet for receiving a cooling fluid and an outlet for discharging the cooling fluid to which heat has been transferred, the channel having at least two portions, one of the portions having disposed therein a jet impingement cooling mechanism comprising at least one plate having a plurality of small holes through which cooling fluid is jetted and a heat conductive member spaced from said at least one plate and upon which jets of cooling fluid exiting from said plurality of small holes impinge, and another of the portions of the channel having a non-jet impingement cooling mechanism located at said another portion of the channel for transferring heat in the non-jet impingement cooling mechanism to fluid flowing through said another portion of the channel, a first heat generating electrical device in thermal contact with the means defining the channel adjacent the one portion of the channel, heat flowing from the first heat generating electrical device to the one portion to cool the first heat generating electrical device during operation of the first heat generating electrical device when cooling fluid is flowed through the channel;

• and a second heat generating electrical device in thermal contact with the means defining the channel adjacent the another portion of the channel, heat flowing from the second heat generating electrical device to the another portion to cool the second heat generating electrical device during operation of the second heat generating electrical device when cooling fluid is flowing through the channel.