Patent Application
20080080133
The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:
Referring to
The packaging unit further includes a first shell member 21 and a second shell member 22, which is corresponding to and oppositely joined to the first shell member 21. The first and second shell members 21, 22 are made of one of aluminum and copper in the first embodiment. Alternatively, other material with good extensibility and heat conductivity is capable of being made as the shell members 21, 22 in addition to the aluminum or copper.
The first shell member 21 has a work zone 211, a first joint part 212 and a stop part 213. The first joint part 212 surrounds the work zone 211 and is disposed at the same elevation as the work zone 211. The stop part 213 is disposed between the work zone 211 and the first joint part 212 in a way of being upright from the first shell member 21.
The stop part 213 has a elongated channel shaped cross section with an inner vertical section 217, a top horizontal section 218 and an outer vertical section 219.
The first shell member 21 is a cast integral piece in the first embodiment. Alternatively, the stop part 213 can be plated in place or attached to the position between the work zone 211 and the first joint part 212 with any other working ways.
The first joint part 212 has a first groove 214 extending to the work zone 211 and a filling pipe section 215 is inserted into the first groove 214 and welded to the first joint part 212 with the outer end of the filling pipe 215 being a closed end (detail description afterward). The first joint part 212 is a flat shaped horizontal wall in the first embodiment. Alternatively, the first joint part 212 can be shapes different from the flat shaped horizontal wall in practice.
The bonding member 5 is disposed between the first joining part 212 and the second joining part 222 for adhering both of the joining parts 212, 222. The joining member 5 is a soldering paste with flux or soldering wires without flux. Alternatively, air-tight glue or adhesives can be used for joining the joining parts 212, 222. The flux is capable of corroding oxidized layer (not shown) on the joining parts 212, 222 and resisting tin solder from being oxidized for eutectic reaction being performed completely. In this way, air-tight joint between the first shell member 21 and the second shell member 22 can be secured.
As the foregoing, the soldering wires without flux can be employed and protective gas is introduced to protect the joining parts 212, 222 from being oxidized. For instance, the protective gas containing 95% nitrogen and 5% hydrogen can be used and the nitrogen acts as the protection gas and hydrogen performs reduction reaction with oxide layer on the joining parts 212, 222 to remove the oxide layer. Hence, the protective gas replaces function of the flux.
The capillary device 3 and the work fluid 4 is disposed in a chamber 23 defined by the work zone 211 of the first shell member 21 and the shell lid 221 of the second shell member 22. The capillary device 3 is a metal net in the work fluid 4 in the instant embodiment and includes a plurality of capillary apertures 31. Alternatively, the capillary device 3 can be formed with another other way such as providing a plurality of upright capillary tubes (not shown) or being integrally joined to the work zone 211 or the shell lid part 221.
The capillary device 3 is capable of resulting in capillary phenomenon of liquid so that once a portion of the capillary device 3 contacts with liquid, the liquid can diffuse to rest of the capillary device 3 and the diffusion is independent of direction of the gravity. Hence, sizes of the capillary apertures depend on what material of the capillary device 3 is and what the work fluid 4 is.
The work fluid 4 is water in the instant embodiment but another liquid such as methyl alcohol or propyl alcohol can be employed as the work fluid too.
The packaging unit 2 further includes a heat absorption end 24 and a heat releasing end 25. Pressure in the chamber 23 is equal to saturated vapor pressure of the work fluid 4 such that the work fluid 4 is in a steadily balancing state between liquid state and gaseous state.
When the heat absorption end 24 is heated to increase temperature thereof, the steady state of balance is unable to be kept and the work fluid 4 at the heat absorption end 24 vaporizes as gaseous work fluid 4. Under this circumstance, the vapor pressure at the heat absorption end 24 is greater than that at the heat releasing end and the gaseous work fluid 4 diffuses toward the heat releasing end 25. The heat releasing end 25 is lower in temperature so that the gaseous work fluid 4 is condensed as liquid work fluid 4 and excessive liquid work fluid 4 flows back to the heat absorption end 24. In this way, a heat guiding process for heat conducting to the heat releasing end 25 from the heat absorption end is complete.
The heat guiding process results from the steady state of balance being unable to be kept so that the heat guiding process performs heat conduction continuously if and only if temperature between the heat absorption end and the heat releasing end is different. Different work fluids 4 provide different work temperatures and it is incapable of performing the heat guiding process any more while the ambient temperature is higher than the work temperature.
Referring to
Step 61 is to provide the first shell member 21 and the second shell member 22 and the filling pipe 215 is placed in the first groove 214 of the first shell member 21. Because the filling pipe 215 provides a length greater than the first groove 214, an end of the filling pipe 215 passes through the stop part 213 to communicate with work zone 211 and another end of the filling pipe 215 extends outward the first shell member 21.
Step 62 is that the bonding member 5 is provided and coated on at least one of the first joining part 212 and the second joining part 222. The bonding member 5 is the soldering paste in the instant embodiment and the first and second joining part 212, 222 are coated with the soldering paste.
Step 63 is to provide a capillary device 3, which is formed at the work zone 211 of the first shell member 21. The capillary device 3 is a metal net in the instant embodiment. It is known by the skill persons of the art that step 62 and step 63 are interchangeable in sequence of the process and it is not limited with the instant embodiment.
Step 64 is to cover the second shell member 22 on the first shell member 21 with a fixture 7 (shown in
The bonding member 5 is the soldering paste in the instant embodiment so that step 65 is to move the joined first and second shell members 21, 22 in a high temperature stove (not shown) or to heat the joined first and second shell members 21, 22 with a hot air gun (not shown) for the bonding member 5 being melted and adhered to the first joining part 212 and the second joining part 222. The joining parts 212, 222 are cooled down and joined to each other with bonding member 5 after heating process. Once the joining parts 212, 222 are attached to each other, the chamber 23 can communicate with outside by means of the filling pipe 215. The high temperature stove is a back-soldering stove (not shown). In case of the no solder tin being contained in the bonding member 5, step 65 is skipped and step 66 is processed directly.
If the first joining part 212 is not joined to the second joining part 222 tightly, it means the chamber 23 can communicate with the outside via other spots in addition to the filling pipe 215 and the flat type heat pipe is unable to work normally. Hence, step 66 is to provide a leakage test to verify if the first joining part 212 is attached to the second joining part 222 tightly. If leakage is happened during the test, the manufacturing process for the flat type heat pipe of the instant embodiment is stopped completely to avoid infective flat type pipe. If no leakage is happened during the test, it means that the first joining part 21 is attached to the second joining part tightly and step 67 can be further processed.
Step 67 is to provide an air removable filling device (not shown) and the work fluid 4 is filled in the chamber 23 with the filling device.
Step 68 is to provide the air removable filling device again for reducing pressure in the chamber 23 and the filling pipe so as to suck out residue air in the chamber 23. In this way, the pressure in the chamber 23 can be adjusted to be equal to the saturated vapor pressure of the work fluid.
Step 69 is to provide a clamp-welding for the outer end of the filling pipe 215 being sealed. A clamping device (not shown) is employed to hold outer end of the filling pipe 215 and a shear device (not shown) is employed to cut off the filling pipe 215. Further, a seam welding device (not shown) is employed to spot-weld the filling pipe 215 to allow the filling pipe 215 being completely air-tight to finish fabrication of the flat type heat pipe.
Further, the work zone 211 of the first shell member 21 can be disposed at an elevation different from the first joining part 212 other than at an elevation the same as the first joining part 212. That is, the work zone 211 can be disposed higher or lower than the first joining part 212 so that it is capable of adjusting space of the chamber 23. Referring to
Besides, in case of the soldering paste providing large particles, it is necessary to prepare a large nozzle head (not shown) for coating the soldering paste. But, the large nozzle head easily results in excessive soldering paste entering the chamber 23. Referring to
In view of above, it is appreciated that the flat type heat pipe and manufacturing process thereof and the packaging unit 2 according to the present invention provide an upright stop part 213 between the work zone 211, 211′ and the first joining part 212, 212′, 212″ to limit extent of the bonding member 5 while coating the bonding member 5 and to prevent the coated bonding member 5 from entering the chamber 23 and influencing properties and functions of the capillary device 3 and the work fluid 4 while pressingly fitting the first shell member 21 with the second shell member 22 for maintaining capability of heat dissipation of the flat type heat pipe. Further, the groove 228 at the first joining part 212″ is helpful for receiving large particles in the soldering paste and the excessively overflow soldering paste and the groove 226 at the second joining part 222″ and a seal ring 227 received in the groove 226 secure tightness between the first and second joining parts 212″, 222″ such that the flat type heat pipe device of the present invention provides advantage of the soldering paste being capable of melting without overflow.
While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.
