Heat exchanger and semiconductor module

Abstract

A heat exchanger suitable for cooling a heat source is provided, wherein a bypass channel formed in the heat exchanger has a width greater than a width of other channels to reduce a flow resistance of a fluid and a pumping power for driving a system. That is, under the same pumping power loss, more fluid is driven to achieve a better heat dissipation effect. By applying the heat exchanger, electronic devices are bonded to a top of the heat exchanger through a supporting substrate. In this way, heat generated when the electronic devices are is transferred to the heat exchanger through the supporting substrate and dissipated to the outside via the heat exchanger. Since the distance of heat transfer is decreased, the thermal resistance generated by an interface between the devices is reduced to improve heat transfer efficiency and heat dissipation effect.

What is claimed is: 
     
         1 . A heat exchanger, comprising:
 a base plate having a supporting surface and a back side opposite to the supporting surface, wherein the supporting surface supports a heat source;   a cover plate disposed on the back side of the base plate, the cover plate and the base plate forming a chamber, wherein the chamber has an inlet and an outlet located at the same side of the chamber;   a plurality of first dissipation fins intervally disposed between the base plate and the cover plate forming a plurality of first channels and a bypass channel in the chamber, wherein each of the first channels and the bypass channel extend from the inlet to a mixed flow area in the chamber, and a width of the bypass channel is greater than a width of each of the first channels;   a plurality of second dissipation fins intervally disposed between the base plate and the cover plate forming a plurality of second channels in the chamber, wherein each of the second channels extends from the mixed flow area to the outlet, and the width of the bypass channel is greater than a width of each of the second channels; and   a fluid flowing into the chamber through the inlet, wherein a portion of the fluid passes through the first channels, another portion of the fluid passes through the bypass channel, and the portion of the fluid and the another portion of the fluid mix in the mixed flow area, enter the second channels, and leave the chamber through the outlet.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein a flow resistance of the fluid in the first channels is greater than a flow resistance of the another portion of the fluid in the bypass channel. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the chamber has a first side and a second side opposite to each other, the inlet and the outlet are located at the first side, and the mixed flow area is located at the second side. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein each of the first dissipation fins is L-shaped, and each of the first dissipation fins comprises:
 a first portion extending from the first side to the second side along a first direction; and   a second portion connected to the first portion and extending to the mixed flow area along a second direction, wherein the first direction intersects the second direction.   
     
     
         5 . The heat exchanger according to  claim 4 , wherein each of the second dissipation fins is L-shaped, and each of the second dissipation fins comprises:
 a third portion extending from the first side to the second side along the first direction; and   a fourth portion connected to the third portion and extending to the mixed flow area along a third direction, wherein the third direction is opposite to the second direction.   
     
     
         6 . The heat exchanger according to  claim 4 , wherein each of the second dissipation fins is in a linear shape and extends from the first side to the mixed flow area along the first direction. 
     
     
         7 . The heat exchanger according to  claim 1 , further comprising a mixed flow means disposed in the mixed flow area and being separated from the first dissipation fins and the second dissipation fins 
     
     
         8 . The heat exchanger according to  claim 7 , wherein the mixed flow means comprises a partition lying in a flowing path of the fluid. 
     
     
         9 . The heat exchanger according to  claim 1 , wherein the bypass channel is located at an outermost side of the first channels and is adjacent to an inner wall of the chamber. 
     
     
         10 . The heat exchanger according to  claim 1 , wherein the base plate comprises a vapor chamber. 
     
     
         11 . The heat exchanger according to  claim 1 , wherein at least one of a surface of the first dissipation fins, a surface of the second dissipation fins and an inner wall of the chamber comprises a plurality of cavities. 
     
     
         12 . The heat exchanger according to  claim 11 , wherein the cavities correspond to a location of the heat source and penetrate through the base plate to be connected to a bottom of the heat source. 
     
     
         13 . The heat exchanger according to  claim 1 , wherein a material of the base plate comprises metals or composite materials.