1. Field of the Invention
The present invention relates to a method of manufacturing an LED illuminator, in particular, to a method for directly soldering light emitting diodes on a flat heat pipe.
2. Description of Related Art
Light emitting diode; LED, has advantages such as small size, impact-endurable, long lifespan, low power consumption, cold illumination and mercury-free . . . etc. It has become the major item of research and developing recently. In the beginning is indication light, and now is LED light product. The development trend of LED is from low power to high power, and the application aspects are diversified more and more.
With the wide application of high power LED, the requirement of heat dissipation is raised gradually. If that heat is not radiated well, there will be many problems, such as the light efficiency is lowered, lifespan is shortened, light quality is changed . . . etc. Therefore, the arrangement of thermal-conduction needs an efficient heat-dissipating structure to radiate heat outside the illuminator module to avoid the aforementioned problems.
The current heat-dissipating way of LED illuminators are mostly heat sinks for increasing the thermal-conductive area. The disadvantages are lower heat-dissipating efficiency and larger occupied space. Some prior arts use a heat pipe coordinated with the heat sink to increase the heat-dissipating efficiency, however the cost is higher.
Moreover, all the aforementioned heat-dissipation ways have the common disadvantage, in which the heat of LED elements is necessarily radiated through a printed board. The printed board is a low thermal conductive material, so that the heat produced by LED elements can not be radiated efficiently and quickly to the heat pipe. To improve the high thermal resistance of the printed board, metal core PCB (MCPCB) of prior art is developed. However, the heat produced by the LED elements still need be radiated through the multi-layers of the MCPCB and thermal grease (or thermal paste) and then to the heat pipe.
Furthermore, a retention kit of complex structure is usually used to fix the LED elements to heat pipe and heat sink. The retention kit not only increases cost but also occupies space. Besides, to assemble the retention kit consumes manpower considerably.
Accordingly, in view of the aforesaid shortcomings, the present inventor not only to improve the assembly way of LED elements and heat pipe to increase thermal conductive efficiency, but also to use a concise structure for combining the heat pipe and heat sink to accomplish an LED illuminator.
In view of the aforementioned issues, the present invention provides a method of manufacturing an LED illuminator, in which a printed circuit layer is formed on a flat heat pipe, so that LED elements can be soldered directly on the flat heat pipe. Thereby, the thermal-conductive path between the LED elements and the flat heat pipe is shortened to enhance the effectiveness of heat-dissipating.
Besides, the other aspect to be solved by the present invention is to provide a method of manufacturing an LED illuminator, which a treating tool is provided to form the printed circuit layer on a plurality of flat heat pipe simultaneously, so that it can save manufacturing time and cost.
Furthermore, the present invention is to provide a method of manufacturing an LED illuminator including a concise mechanism to fix a heat-dissipating module on the flat heat pipe, for accomplishing the LED illuminator. A conventional retention kit is omitted therefore, manufacturing cost is saved, and the occupied space is reduced.
To achieve the aforementioned objectives, the present invention provides a method of manufacturing an LED illuminator, including steps as follows. First, at least one flat heat pipe is provided and a flat surface is formed thereon. Next, a treating tool is provided to fix the at least one flat heat pipe. Then, a printed circuit layer is formed on the at least one flat heat pipe. The process to form the printed circuit layer includes as follows. First, an insulated layer is applied on the flat surface of the at least one flat heat pipe. Next, a conductive layer is applied on the insulated layer to form a plurality of conducted circuits. Then, a solder-resistant layer is applied on the conductive layer to form a plurality of solder portions. After the printed circuit layer is formed, solder paste is applied on the solder portions, and a plurality of LED elements are disposed on the solder portions of the flat heat pipe. Finally, the flat heat pipe and the LED elements are passed through a reflow oven.
To achieve the aforementioned objectives, the present invention further provides a printing halftone-screen which is able to cover the flat heat pipes.
To achieve the aforementioned objectives, the treating tool, which is provided according to the method of manufacturing an LED illuminator of the present invention, includes a plurality of fixing rods. The flat heat pipe is formed with a plurality of locating holes corresponds with the fixing rods. Besides, the present invention further includes steps as follows. First, at least one heat-dissipating module is provided, in which the heat-dissipating module is formed with a plurality of assembling holes. Next, a plurality of assembling elements is provided, and the assembling elements pass through the assembling holes of the heat-dissipating module and the locating holes of the flat heat pipe. Thereby, the heat-dissipating module is fixed on the flat heat pipe.
The advantages resulted from the present invention are as follows.
In order to further understand the techniques, means and effects the present invention takes for achieving the prescribed objectives, the following detailed descriptions and appended drawings are hereby referred, such that, through which, the purposes, features and aspects of the present invention can be thoroughly and concretely appreciated; however, the appended drawings are merely provided for reference and illustration, without any intention to be used for limiting the present invention.
Referring now to
The process to form the flat surface 12 on the flat heat pipes 1a and 1b includes as follows. First, a surface of the flat heat pipes 1a and 1b are polished, and then to clean particles (not shown) which are produced by the polishing step of forming the flat surface 12. The flat surface 12 is used to directly form a printed circuit layer 2 on the flat heat pipes 1a, 1b.
Before the printed circuit layer 2 is formed, a treating tool 30 is provided by the present invention to retain the flat heat pipes 1a and 1b. Thus, the flat heat pipes 1a and 1b could be retained on the treating tool 30. The treating tool 30 has a plurality of orientating protrusions 32 to orientate the flat heat pipes 1a, 1b. The orientating protrusions 32 are against edges of the flat heat pipes 1a and 1b.
Since each of the flat heat pipes may has different size, a second retaining way is provided according to the present invention. The treating tool 30 has a plurality of fixing rods 34. The flat heat pipes 1a and 1b are formed with a plurality of locating holes 14, which are corresponded with the fixing rods 34. The locating holes 14 could be schemed out their locations according to the printed circuit layer 2 in advance, and pass through the flat heat pipe 1a. The locating holes 14 could be treated as orientating marks on the printing halftone-screen on one aspect, and to fix the heat-dissipating module on the other hand, which will be described after.
The fixing rods 34 of the treating tool 30 preferably are movable. For example, the treating tool 30 is formed with a plurality of orientating blind-holes 301, 302, 303. The fixing rods 34 could be inserted in the orientating blind-holes 301, or moved in the orientating blind-holes 302, 303. The orientating blind-holes 301, 302, 303 could be arranged in an array on the treating tool 30. Therefore, when locations of the locating holes 14 are changed according to different requirements of the flat heat pipes 1a and 1b, the fixing rods 34 of the present invention could be moved accordingly.
One characteristic of the present invention is that the printed circuit layer 2 can be once formed on the flat heat pipes 1a and 1b through the treating tool 30, so that manufacturing time can be saved. When the present invention adapts the way of screen printing, the area of one printing halftone-screen is several-folds of the flat heat pipe. Through one of the printing halftone-screen, it can work on several ones of the flat heat pipes. Therefore, the manpower can be saved. In this embodiment, only two flat heat pipes 1a, 1b are illustrated in view side. The present invention reasonably could provide the treating tool with a matched size according to the area of the printing halftone-screen. Thus several flat heat pipes can be simultaneously formed with the printed circuit layer 2.
The flat heat pipes maybe have different thickness. To print uniformly on each of the flat heat pipes when printing, the treating tool 30 further includes at least one of the level-adjusted devices 36. The level-adjusted device 36 pass through the treating tool 30 and upward against a bottom surface of the flat heat pipes 1a, 1b to adjust the top surface of the flat heat pipe 1a, 1b on the same level. In this embodiment, the level-adjusted device 36 in a simplest way is a bolt. The user can adjust the level-disposition of the level-adjusted device 36 under the treating tool 30, and the top surfaces of the flat heat pipes 1a, 1b could be adjusted to the same level.
There is another characteristic in the present invention, which the printed circuit layer 2 is formed directly on the flat surface 12 of the flat heat pipes 1a, 1b. The electronic elements on the printed circuit layer 2, such as LED elements, did not need to radiate heat through any printed board. Therefore, thermal conductive path is shortened and heat-dissipating efficiency is enhanced. The process to form the printed circuit layer 2 is described thereinafter. Since the flat heat pipes 1a and 1b are conductive metallic pieces, an insulated layer 21 is formed firstly on the flat surface 12 of the flat heat pipes 1a, 1b. Next, a conductive layer 22 is formed on the insulated layer 21 to form a plurality of conducted circuits (not shown). Finally, a solder-resistant layer 23 is formed on the conductive layer 22, so that some required portions of the conductive layer 22 could be exposed outside to form a plurality of exposed areas. The exposed areas can be treated as, for example, solder portions 222 to solder leads, or solder portions 226 to connect wires, or exposed portion 224 to contact a bottom of LED elements 4 directly to radiate heat conveniently (as shown in
The insulated layer 21 preferably is made of insulated material of low thermal resistance, and heat-conductive. For example, UV-curable resin, epoxy resin of well thermal conduction, or epoxy resin plus glass fabric, or adhesive epoxy glass fiber cloth of well thermal conduction. The conductive layer 22 could be conductive paste, such as copper paste, silver paste, silver-aluminum paste, aluminum paste, or expansive metal paste. The advantage is able to use screen printing. Alternatively, the print circuits of the conductive layer 22 could be copper tinsel formed by etching to bear a higher current. The solder-resistant layer 23 is formed by applying solder mask, which can protect parts of the conducted circuits, to avoid a short circuit between closed circuits caused by flowing solder paste when soldering electronic elements. It also can isolate the flat heat pipes 1a, 1b from reacting oxidation with moisture in air. After the solder mask is applied, it could further be treated with an anti-oxidant surface to enhance anti-oxidant ability according to requirements. According to the aforementioned way, at least the solder-resistant layer 23 could be formed by screen printing.
Referring to
The present invention after tested, the thermal conductive efficiency of the flat heat pipe is effected few by high-temperature of the reflow oven. Alternatively, to reduce the effectiveness of high-temperature of the reflow oven onto the flat heat pipe, the present invention can seal one end of the flat heat pipe and form an opening at the other end of the flat heat pipe. And, then to process the steps of forming the printed circuit layer 2. After the steps of forming the solder-resistant layer 23, filling a working liquid into the flat heat pipe through the opening, such as water, methanol, and acetone. Finally, sealing the opening of the flat heat pipe. Besides, the present invention can seal the opening temporarily by tape . . . etc. to avoid particles entering the flat heat pipe. The opening is opened before filling the working liquid.
Referring to
The present invention utilizes the assembling elements of concise structure, so that the heat-dissipating module 5 can be firmly combined with the flat heat pipe 1a without any retention kit. The manufacturing cost can be reduced, space occupied is less, and manpower of assembling the retention kit is skipped. The aforementioned construction for radiating heat could be extended with much more heat-dissipating elements, such as heat sink, fans, water-cooling module, even other flat heat pipe . . . etc.
Referring to
Referring to
Referring to
Referring to table 1 as follows, an LED illuminator according to the present invention has a contrastive data sheet with five groups of experiment. The five groups of experiment are temperatures measured the seven LEDS along a row line in
Group 1: FIN, None; medium, none; hole, none.
Group 2: FIN, 1; medium, thermal paste; hole, none.
Group 3: FIN, 1; medium, thermal grease; hole, Yes.
Group 4: FIN, 2; medium, thermal paste; hole, none.
Group 5: FIN, 2; medium, thermal grease; hole, Yes.
To contrast Groups 2 and 3, Group 3 means the LED illuminator of the present invention having four locating holes drilled, and one of the heat-dissipating module 5 with the flat heat pipe 1b through bolts, nuts and thermal grease. Comparing with Group 2, which has no locating hole and thermal paste used to combine one heat-dissipating module 5, Group 3 has a higher heat-dissipating efficiency.
To contrast Groups 4 and 5, Group 5 means the LED illuminator of the present invention having four locating holes, and one pair of the heat-dissipating modules 5 combined with the flat heat pipe 1b through bolt, nut and thermal grease. Comparing with Group 4, which has no locating holes and thermal paste is used to combine one pair of the heat-dissipating module 5, Group 5 has a higher heat-dissipating efficiency.
It is proved by the experiments that, the LED illuminator of the present invention even is drilled with four locating holes, however it has better heat-dissipating results through the concise mechanism of the assembling elements (bolt 52 and nut 54 as shown in
The method of manufacturing an LED illuminator according to the present invention includes characteristics and function as follows.
1. The present invention directly forms the printed circuit layer 2 on the flat heat pipe 1a, 1b, and the LED elements 4 are soldered on the flat heat pipe 1a directly, so that the thermal-conductive path between the LED element 4 and the flat heat pipe 1a is shortened to enhance heat-dissipating efficiency.
2. The present invention utilizes one printing halftone-screen which is able to cover the flat heat pipes 1a, 1b, and one piece of the treating tool 30 can simultaneously form the printed circuit layer 2 on a plurality of flat heat pipes 1a, 1b. Therefore, manufacturing time and cost is reduced.
3. The flat heat pipe 1a of the present invention is formed with the locating holes 14, which not only providing a retaining function when the printed circuit layer 2 is forming, but also providing a concise structure to combine the flat heat pipe 1a with the heat-dissipating module 5 through the assembling elements, such as bolt 52 and nut 54. The LED illuminator could be accomplished accordingly, and conventional retention kit is omitted. Therefore, manufacturing cost can be saved, and occupied space is reduced.
The above-mentioned descriptions represent merely the preferred embodiment of the present invention, without any intention to limit the scope of the present invention thereto. Various equivalent changes, alternations or modifications based on the claims of present invention are all consequently viewed as being embraced by the scope of the present invention.