Liquid cooling jacket

Abstract

A liquid cooling jacket (J 1 ) transmits heat generated by a CPU ( 101 ) which is installed at a predetermined position to coolant supplied from an external heat transmission fluid supply means and flowing inside of the liquid cooling jacket. The liquid cooling jacket includes a first flow passage (A 1 ) on a side of the heat transmission fluid supply means, a second flow passage group (B 1 ) including a plurality of second flow passages (B 1 a ) branched from the first flow passage (A 1 ), and a third flow passage (C 1 ) installed at downstream side of the plurality of the second flow passages (B 1 a ), and collecting the plurality of the second flow passages (B 1 a ), wherein the CPU ( 101 ) mainly dissipates the heat to the second flow passage group (B 1 ).

1 . A liquid cooling jacket for transmitting heat generated by a heating element which is installed to a predetermined position to a heat transmission fluid supplied from an external heat transmission fluid supply means and flowing inside of the liquid cooling jacket, the liquid cooling jacket comprising:
 a first flow passage on a side of the heat transmission fluid supply means;   a second flow passage group consisting of a plurality of second flow passages branched from the first flow passage, and   a third flow passage installed at downstream side of the plurality of the second flow passages, and collecting the plurality of the second flow passages,   wherein the heating element mainly dissipates the heat to the second flow passage group.   
   
   
       2 . A liquid cooling jacket for transmitting heat generated by a heating element which is installed to a predetermined position to a heat transmission fluid supplied from an external heat transmission fluid supply means and flowing inside of the liquid cooling jacket, the liquid cooling jacket comprising:
 a first flow passage, a plurality of a second flow passage groups each of which consists of a plurality of second flow passages, and a third flow passage toward downstream in order,   wherein the heating element mainly dissipates the heat to the second flow passage groups, and the adjacent second flow passage groups are connected in series via a communication flow passage.   
   
   
       3 . The liquid cooling jacket according to  claim 2 , wherein the adjacent second flow passage groups are disposed side by side, and a lower end of one of the adjacent second flow passage groups and an upper end of the other one of the adjacent second flow passage groups are on the same side. 
   
   
       4 . The liquid cooling jacket according to  claim 1 , comprising a tube bundle formed by bundling a plurality of metallic tubes, wherein an inner hole of each of the plurality of metallic tubes is the second flow passage. 
   
   
       5 . The liquid cooling jacket according to  claim 1 , further comprising a metallic tube having a plurality of inner holes, wherein each of the inner holes is the second flow passage. 
   
   
       6 . The liquid cooling jacket according to  claim 1 , further comprising a plurality of metallic fins arranged at a predetermined interval, wherein a space between the adjacent fins is the second flow passage. 
   
   
       7 . The liquid cooling jacket according to  claim 6 , wherein a width W of the second flow passage is in the range of 0.2 to 1.1 mm. 
   
   
       8 . The liquid cooling jacket according to  claim 6 , wherein the width W of the second flow passage and a thickness T of the fins disposed between the adjacent second flow passages satisfy Formula 1.
   −0.375 ×W+ 0.875 ≦T/W≦− 1.875 ×W+ 3.275  Formula 1   
   
   
       9 . The liquid cooling jacket according to  claim 6 , wherein a depth D of the second flow passage and the width W of the second flow passage satisfy Formula 2.
   5× W+ 1 ≦D≦− 16.25 ×W+ 2.75  Formula 2   
   
   
       10 . The liquid cooling jacket according to  claim 6 , further comprising:
 a fin member comprising the plurality of metallic fins and a base from which the plurality of metallic fins are extended;   a jacket body for housing the fin member,   wherein the base is heat-exchangeably fixed to the jacket body.   
   
   
       11 . The liquid cooling jacket according to  claim 6 , further comprising:
 a first fin member comprising a first base and a plurality of first fins extended from the first base;   a second fin member comprising a second base and a plurality of second fins extended from the second base,   wherein the first fin member and the second fin member are combined such that the plurality of the first fins and the plurality of the second fins are interlocked together,   the plurality of metallic fins are composed of the first fins and the second fins, and   the second flow passage is formed between the first fin and the second fin adjacent to each other.   
   
   
       12 . The liquid cooling jacket according to  claim 11 , wherein the heating element is installed on a side of the first base,
 a protruding length of the first fin is set to be equal to or shorter than a protruding length of the second fin, and   the plurality of the second fins is thermally connected to the first base.   
   
   
       13 . The liquid cooling jacket according to  claim 6 , further comprising:
 a jacket body comprising a fin housing for housing the plurality of the metallic fins;   a sealing member for sealing the fin housing; wherein a contact area where a peripheral wall of the jacket body surrounding the fin housing and the sealing member are in contact with each other is friction stir welded, and   a start end of the area which is friction stir welded overlaps with a finish end of the area which is friction stir welded.   
   
   
       14 . The liquid cooling jacket according to  claim 13 , wherein the plurality of metallic fins is extended from the sealing member and integrally formed with the sealing member. 
   
   
       15 . The liquid cooling jacket according to  claim 13 , wherein the peripheral wall is friction stir welded with a jig holding the peripheral wall so that the peripheral wall does not protrude outward. 
   
   
       16 . The liquid cooling jacket according to  claim 13 , wherein a length of a pin of a tool to be used in the friction stir welding is less than or equal to 60% of a thickness of the sealing member. 
   
   
       17 . The liquid cooling jacket according to  claim 13 , wherein a position where the tool is pulled apart does not overlap with the contact area in the friction stir welding. 
   
   
       18 . The liquid cooling jacket according to  claim 1 , further comprising a metallic honeycomb member comprising a plurality of minute holes, wherein each of the plurality of minute holes is the second flow passage. 
   
   
       19 . The liquid cooling jacket according to  claim 1 , further comprising:
 a ripple cross-section metallic heat dissipating sheet, and   a metallic jacket body to which the heat dissipating sheet is heat-exchangeably fixed, wherein   the second flow passage is formed between the heat dissipating sheet and the jacket body.   
   
   
       20 . The liquid cooling jacket according to  claim 6 , wherein the metal is aluminum or aluminum alloy. 
   
   
       21 . The liquid cooling jacket according to  claim 1 , wherein a heat transmission fluid inlet communicating with the first flow passage and a heat transmission fluid outlet communicating with the third passage are arranged symmetric with respect to the heating element. 
   
   
       22 . The liquid cooling jacket according to  claim 21 , wherein the inlet and the outlet are arranged relatively away from each other. 
   
   
       23 . The liquid cooling jacket according to  claim 21 , wherein the inlet and the outlet are arranged such that the inlet and the outlet come closer to the heating element. 
   
   
       24 . The liquid cooling jacket according to  claim 1 , wherein the heating element is a CPU.