Flat heat pipe

Abstract

An exemplary flat heat pipe with an evaporator section and a condenser section includes a casing, and a first wick structure and a second wick structure in the casing. The casing defines a first vapor channel within the evaporator section. The first wick structure contacts an inner surface of the casing at the condenser section. The first wick structure includes a contact portion in contact with the inner surface of the casing, and an isolated portion from the inner surface of the casing. The isolated portion and the inner surface of the casing cooperatively define therebetween a second vapor channel in communication with the first vapor channel. The second wick structure contacts the inner surface of the casing at the evaporator section. The second wick structure joins the first wick structure at a joint between the evaporator section and the condenser section.

1 . A flat heat pipe with an evaporator section and a condenser section at opposite ends thereof, the flat heat pipe comprising:
 a hollow flat casing defining a first vapor channel within the evaporator section;   a first wick structure received in the casing at the condenser section, the first wick structure in contact with an inner surface of the casing at the condenser section, the first wick structure comprising at least one contact portion in contact with the inner surface of the casing, and at least one isolated portion isolated from the inner surface of the casing, the at least one isolated portion and the inner surface of the casing cooperatively defining a second vapor channel therebetween, the first and second vapor channels in communication with each other; and   a second wick structure received in the casing at the evaporator section, the second wick structure in contact with an inner surface of the casing at the evaporator section, the second wick structure joining the first wick structure at a joint between the evaporator section and the condenser section.   
     
     
         2 . The flat heat pipe of  claim 1 , wherein the first wick structure is formed by weaving a plurality of metal wires, the second wick structure is made of sintered metal powder, and the first and second wick structures are joined together by sintering. 
     
     
         3 . The flat heat pipe of  claim 2 , wherein the first wick structure is a hollow tube, and comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the first wick structure is located in the center of the casing, and the second vapor channel comprises two passages respectively defined between the sidewalls of the first wick structure and the inner surface of the casing. 
     
     
         4 . The flat heat pipe of  claim 3 , wherein the at least one contact portion comprises two contact portions, the at least one isolated portion comprises two isolated portions, the top and bottom walls of the first wick structure form the two contact portions in contact with the inner surface of the casing, respectively, and the first and second sidewalls of the first wick structure form the two isolated portions isolated from the inner surface of the casing. 
     
     
         5 . The flat heat pipe of  claim 2 , further comprising another first wick structure received in the casing at the condenser section, wherein the casing comprises opposite top and bottom plates, and two opposite side plates between the top and bottom plates, the two first wick structures are disposed at opposite inner sides of the casing at the side plates, respectively, each of the two first wick structures comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the first sidewalls of the first wick structures faces each other, and the second vapor channel is defined between the first sidewalls of the first wick structures and the inner surface of the casing. 
     
     
         6 . The flat heat pipe of  claim 5 , wherein the at least one contact portion comprises two contact portions, the at least one isolated portion comprises two isolated portions, the top wall, the bottom wall and the first sidewall of each first wick structure cooperatively form one of the contact portions in contact with the inner surface of the casing, and the second sidewall of each first wick structure forms one of the isolated portions isolated from the inner surface of the casing. 
     
     
         7 . The flat heat pipe of  claim 2 , further comprising another two first wick structures, wherein the casing comprises opposite top and bottom plates, and two opposite side plates between the top and bottom plates, the three first wick structures are spaced from each other, two of the first wick structures are disposed at opposite inner sides of the casing at the side plates, respectively, and the other first wick structure is located in the center of the casing, each of the first wick structures comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the second vapor channel comprises two passages, one of the passages is defined between the second sidewall of the first wick structure at one of the side plates of the casing, the first sidewall of the first wick structure in the center of the casing and the inner surface of the casing, and the other passage is defined between the second sidewall of the first wick structure at the other side plate of the casing, the second sidewall of the first wick structure in the center of the casing and the inner surface of the casing. 
     
     
         8 . The flat heat pipe of  claim 7 , wherein the at least one contact portion comprises four contact portions, the at least one isolated portion comprises four isolated portions, the top wall, the bottom wall and the first sidewall of each of the first wick structures at the opposite side plates of the casing cooperatively form two of the contact portions in contact with the inner surface of the casing, the top and bottom walls of the first wick structure in the center of the casing form another two of the contact portions in contact with the inner surface of the casing, respectively, the second sidewall of each of the first wick structures at the opposite side plates of the casing form two of the isolated portions isolated from the inner surface of the casing, and the first and second sidewalls of the first wick structure in the center of the casing form another two of the isolated portions isolated from the inner surface of the casing, respectively. 
     
     
         9 . The flat heat pipe of  claim 1 , wherein the second wick structure contacts a portion of the inner surface of the casing at the evaporator section which corresponds to an area of an outside of the casing designated for contacting a heat-generating electronic component. 
     
     
         10 . The flat heat pipe of  claim 1 , wherein the first wick structure is an extruded flattened shape. 
     
     
         11 . The flat heat pipe of  claim 1 , wherein a height of the casing is less than 2 millimeters. 
     
     
         12 . The flat heat pipe of  claim 1 , wherein the first wick structure is a hollow tube, and defines an inner space therein, and the inner space communicates with the first vapor channel. 
     
     
         13 . The flat heat pipe of  claim 12 , wherein the second wick structure blocks a portion of an end of the inner space of the first wick structures at the joint. 
     
     
         14 . A flat heat pipe with an evaporator section and a condenser section at opposite ends thereof, the flat heat pipe comprising:
 a hollow flat casing defining a first vapor channel within the evaporator section;   a first wick structure received in the casing at the condenser section, the first wick structure formed by weaving a plurality of metal wires, the first wick structure comprising at least one isolated portion isolated from an inner surface of the casing, the at least one isolated portion and the inner surface of the casing cooperatively defining a second vapor channel therebetween, the first and second vapor channels in communication with each other; and   a second wick structure received in the casing at the evaporator section, the second wick structure made of sintered metal powder, the second wick structure joining the first wick structure at a joint between the evaporator section and the condenser section.   
     
     
         15 . The flat heat pipe of  claim 14 , wherein the first and second wick structures are joined together by sintering. 
     
     
         16 . The flat heat pipe of  claim 14 , wherein the first wick structure is a hollow tube, and comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the first wick structure is located in the center of the casing, and the second vapor channel comprises two passages defined between the sidewalls of the first wick structure and the inner surface of the casing, respectively. 
     
     
         17 . The flat heat pipe of  claim 14 , further comprising another first wick structure, wherein the casing comprises opposite top and bottom plates, and two opposite side plates between the top and bottom plates, the two first wick structures are disposed at the opposite side plates of the casing, respectively, each of the two first wick structures comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the first sidewalls of the first wick structures face each other, and the second vapor channel is defined between the first sidewalls of the first wick structures and the inner surface of the casing. 
     
     
         18 . The flat heat pipe of  claim 14 , further comprising another two first wick structures, wherein the casing comprises opposite top and bottom plates, and two opposite side plates between the top and bottom plates, the three first wick structures are spaced from each other, two of the first wick structures are disposed at opposite side plates of the casing, respectively, the other first wick structure is located in the center of the casing, each of the first wick structures comprises a top wall, a bottom wall opposite to the top wall, and a first sidewall and a second sidewall interconnecting the top and bottom walls, the second vapor channel comprises two passages, one of the passages is defined between the second sidewall of the first wick structure at one of the side plates of the casing, the first sidewall of the first wick structure in the center of the casing and the inner surface of the casing, and the other passage is defined between the second sidewall of the first wick structure at the other side plate of the casing, the second sidewall of the first wick structure in the center of the casing and the inner surface of the casing. 
     
     
         19 . The flat heat pipe of  claim 14 , wherein the second wick structure contacts a portion of the inner surface of the casing at the evaporator section which corresponds to an area of an outside of the casing designated for contacting a heat-generating electronic component. 
     
     
         20 . The flat heat pipe of  claim 14 , wherein the first wick structure is a hollow tube, and defines an inner space therein, the second wick structure blocks a portion of an end of the inner space of the first wick structure at the joint, and the inner space of the first wick structure communicates with the first vapor channel.