BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a light emitting diode, and more particular to a light emitting diode with a high heat dissipating effect.
2. Description of Prior Art
Traditional light emitting diode (LED) gradually replaces traditional light bulb due to its compact size, low power consumption, and long life expectancy, and thus LEDs are used extensively in the different areas such as traffic lights, signal lights, flashlights, mobile phones, lamps and large outdoor billboards. Since the brightness of a single piece of light emitting diode is very limited, several pieces of light emitting diodes are combined to produce a high-brightness light source, but such arrangement causes more complicated manufacturing processes and incurs higher costs.
As a result, a high-power light emitting diode is introduced to the market, and the high-power light emitting diode can produce a super high brightness light source, and its application simply requires several light emitting diodes to achieve the brightness required for illuminations and displays. Since the high-power light emitting diode can produce a super high-brightness light source and its application also causes a very high heat source, therefore a heat sinking slug is usually combined with the high-power light emitting diode to guide and dissipate the heat source produced by the light emitting chip, so as to ensure a long life expectancy of the high-power light emitting diode.
U.S. Pat. No. 6,274,924 entitled “Surface mountable LED package” discloses a heat sinking slug combined with a high-power light emitting diode. In the manufacturing process of a light emitting diode in accordance with such patented technology, a metal frame is prepared first; a base filled with a plastic material is formed on the metal frame; a through hole is created at the center of the base for inserting a reflector cup on the heat sinking slug into the through hole, an insulating base is produced in the reflector cup, and a chip is mounted onto the base; a lead wire is bonded between the chip and the frame; and an optical lens is packaged onto the base.
When the light emitting chip in accordance with the foregoing patented technology is lit, the heat produced by the light emitting chip is dissipated from the heat sinking slug to achieve the heat dissipating effect, but this type of high-power light emitting diodes involves a complicated manufacturing process and many types of equipments, and thus the manufacture consumes much time, takes many steps, and incurs high costs.
SUMMARY OF THE INVENTIONIn view of the foregoing shortcomings of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct experiments and modifications, and finally developed a light emitting diode with a high heat dissipating effect by using simple equipment to overcome the shortcomings of the prior art and lower the manufacturing cost significantly.
Therefore, it is a primary objective of the present invention to provide a light emitting diode structure with high dissipating, and the structure comprises: a lead frame, a chip, two lead wires, an internal casing and an external casing. The lead frame has a first electrode and a second electrode, a carrying portion disposed on the first electrode, a cavity and a plurality of through holes disposed on the carrying portion, a lead coupled to an end of the carrying portion, a heat dissipating protrusion disposed on the back side of the carrying portion, a solder portion and a lead disposed on the second electrode, a plurality of through holes disposed on the solder portion for installing the visible or invisible light chip into a cavity of the first electrode, two lead wires electrically coupled to the chip, an end of the two lead wires respectively and electrically coupled to the lead frame, an internal casing formed on the chip, and an external casing having a base and a lens formed at the internal casing, the two lead wires and the lead frame.
BRIEF DESCRIPTION OF DRAWINGSThe features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself however may be best understood by reference to the following detailed description of the invention, which describes certain exemplary embodiments of the invention, taken in conjunction with the accompanying drawings in which:
FIG. 1 is a flow chart of a manufacturing procedure of a light emitting diode of the present invention;
FIG. 2 is a front view of a lead frame of the present invention;
FIG. 3 is a rear view of a lead frame of the present invention;
FIG. 4 is a schematic view of adhering a chip onto a lead frame of the present invention;
FIG. 5 is a schematic view of wire bonding a chip of the present invention;
FIG. 6 is a schematic view of packaging a casing of the present invention
FIG. 7 is a schematic view of applying the present invention; and
FIG. 8 is a schematic view of a light emitting diode of another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTIONThe technical characteristics, features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings. The drawings are provided for reference and illustration only, but not intended for limiting the present invention.
Referring toFIG. 1 for a flow chart of a manufacturing procedure of a light emitting diode of the present invention, the manufacturing procedure of a light emitting diode with a high heat dissipation effect comprises the steps of:
Step10: preparing a thick metal;
Step20: shaping the thick metal into a plurality of connected lead frames by an etching technology or a punching technology;
Step30: fixing a visible or invisible light chip onto the lead frame by an adhesive to complete a chip bonding process, wherein the adhesive is either non-conductive or conductive (such as a silver paste or a thermal paste);
Step40: soldering the two lead wires onto the chip, and then soldering the two lead wires with the lead frame to complete a wire bonding process;
Step50: dispensing silicon onto the chip to protect the chip, and dispensing an epoxy compound on the surface of the silicon (such as the manufacture of yellow light emitting diodes) at the chip, adhesive, lead wire and lead frame, and if it is necessary to manufacture a white light emitting diode, a fluorescent colloid is dispensed onto the chip first, and then silicon is dispensed onto the fluorescent colloid, and finally the epoxy resin is dispensed onto silicon; and
Step60: pressing the compound into cylindrical, hemispherical or square base and lens by a thermal compression technology to complete the manufacture of a light emitting diode.
Referring toFIGS. 2 and 3 for a front view and a rear view of a lead frame of the present invention respectively, a thick metal is etched and punched into afirst electrode11 and asecond electrode12, both coupled to alead frame1, and thefirst electrode11 has acarrying portion111, and thecarrying portion111 has acircular cavity112 and a plurality of throughholes113, and an end of thecarrying portion111 is coupled to alead114, and the back side of the carryingportion111 forms a circularheat dissipating protrusion115, and thesecond electrode12 forms asolder portion121 and alead122, and thesolder portion121 has a plurality of throughholes123, and the throughholes113,123 are provided for passing the compound of the casing through the throughholes113,123 and securing thelead frame11 during the thermal compressing process of the casing of the light emitting diode.
Referring toFIG. 4 for a schematic view of adhering a lead frame onto a chip, the chip bonding is performed for thelead frame1, and anadhesive2 is coated onto acavity112 of thefirst electrode11, and then the visible orinvisible light chip3 is adhered into thecavity112. Theadhesive2 is a non-conductive silver paste or thermal paste.
Referring toFIG. 5 for a schematic view of wire bonding a chip of the present invention, twolead wires31,32 are soldered onto thechip3 after a chip bonding is performed for thefirst electrode11 of thelead frame1, and the twolead wires31,32 are respectively and electrically coupled to thecarrying portion111 of thefirst electrode11 and thesolder portion121 of thesecond electrode12, such that if the twolead wires31,32 are electrically conducted, thechip3 will produce a light source. InFIG. 5, thechip3 is a light emitting diode chip.
Referring toFIG. 6 for a schematic view of packaging a casing of the present invention, silicon is dispensed onto thechip3 to form aninternal casing4 for protecting thechip3 after the chip bonding and wire bonding are performed at thelead frame1, and then anexternal casing5 is covered onto thelead frame1,chip3 andlead wire31,32 andinternal casing4, wherein theexternal casing5 is made of an epoxy compound. After abase51 and alens52 are formed integrally by a thermal compression technology, a light emitting diode with a high heat dissipating effect is completed.
Referring toFIG. 7 for a schematic view of applying the present invention, the back sides of first andsecond electrodes11,12 of thelead frame1 are exposed, after theexternal casing5 is thermally pressed. After the light emitting diodes are soldered onto analuminum board6, the back sides of the first andsecond electrodes11,12 are in full contact with thealuminum board6, so that when the light emitting diodes are lit, the heat produced by the light emitting diodes are conducted through the back sides of the first electrode11 (including a heat dissipating protrusion115) and thesecond electrode12 to thealuminum board6. Such arrangement can expedite the heat dissipation of the light emitting diodes to extend the life expectancy of the light emitting diodes.
Refer toFIG. 8 for a schematic view of a light emitting diode of another preferred embodiment of the present invention. If it is necessary to manufacture a white light emitting diode, alead frame1, alight chip3 andlead wires31,32 are produced first, and then a fluorescent colloid is dispensed onto thechip3 to form afluorescent layer7, and silicon is dispensed onto thefluorescent layer7 to form aninternal casing4 for protecting thechip3, and anexternal casing5 is covered onto thelead frame1,chip3,lead wires31,32 andinternal casing4, wherein theexternal casing5 is made of an epoxy compound, and the compound is used for integrally shaping abase51 and alens52 by a thermal compression technology, so as to complete the manufacture of a light emitting diode with a high heat dissipating effect.
In view of the manufacturing flow described above, the light emitting diode of the invention comes with a simple structure, an easy manufacturing process, and easy-to-use equipments for lowering the manufacturing cost of the light emitting diode.
The present invention is illustrated with reference to the preferred embodiment and not intended to limit the patent scope of the present invention. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.