Abstract:
A method for packaging a light emitting element includes a step of providing a carrier formed with an anode electrode and a cathode electrode, a step of providing a light emitting object by utilizing a light emitting diode chip having a positive and negative electrodes, a step of directly contacting the carrier and the light emitting diode chip to establish electrical communication among the anode and cathode electrodes and the positive and negative electrodes; and a step of firmly bonding the carrier and the light emitting diode chip by which to simplify assembling procedure and further to reduce manufacturing cost and enhance production efficiency.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a method for packaging a light emitting device, and particularly to a method for packaging a light emitting device having a light emitting diode chip in order to enhance production efficiency and reduce manufacturing cost and further improve light emitting efficiency of the light emitting advice. 
         [0003]    2. Related Art 
         [0004]    A conventional method for packaging a light emitting element having a light emitting diode chip includes the following steps: first, provide a light emitting diode (LED) chip and mount the LED chip on a groove of a substrate with gluing material, then dispense encapsulant material—into the groove, whereby structure of the light emitting element is created. However, to light the light emitting element, electrodes disposed on the LED chip have to be electrically connected to external circuits. Therefore, in the processes of packaging the light emitting element the electrodes of the LED chip must be preformed to have connecting points for being connected with the external circuits, but such processes of preforming the connecting points and connecting the external circuits multiply the procedure of the light emitting element package and obstacle development of the package. 
         [0005]    Moreover, for the LED chip is mounted on the substrate with gluing material, thermal conduction might be affected because of the gluing material and multiple layers which have different conduction coefficients, and such influence immediately lowers light emitting performance and lifespan of the light emitting element. In addition, light from the light emitting element is emitted through the gluing material to outside, and only a minor portion of light reflected from inner sides of the groove to the gluing material, so the illumination and light emitting performance is. significantly reduced. 
       SUMMARY OF THE INVENTION 
       [0006]    Accordingly, an object of the present invention is to provide a method for packaging a light emitting device having a light emitting diode (LED) chip, wherein the LED chip of electrodes is directly contacted with a carrier formed with electrodes without further connecting with external circuits and preforming connecting points, so that to simplify packaging procedure and reduce manufacturing cost and enhance production efficiency; Moreover, thanks to the light emitting device is produced by innovative and continuous processes, light emitting performance and illumination is greatly increased. 
         [0007]    To achieve the above-mentioned object, the method for packaging a light emitting element includes a step of providing a carrier formed with an anode electrode and a cathode electrode, a step of providing a light emitting object by utilizing a light emitting diode (LED) chip having a positive and negative electrodes, a step of directly contacting the carrier and the light emitting diode chip to establish electrical communication among the anode and cathode electrodes and the positive and negative electrodes, and a step of firmly bonding the carrier and the light emitting diode chip. 
         [0008]    According to the method mentioned above, the anode electrode and the cathode electrode of the carrier are formed by a technique of mesh print, micro etching, stamping, integrally molding, adhesion, thermo-compression, ink-jet printing, or laser activation and so on. 
         [0009]    Another object of the present invention is to further include a step of reflection defined by coating a first metal layer of high reflection coefficient after the carrier and the LED chip contacted to each other. 
         [0010]    Still another object of the present invention is to further include a step of high heat dissipation defined by coating a second metal layer of high thermal conductivity coefficient on the first metal layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a flowchart of a method for packaging a light emitting device of the present invention. 
           [0012]      FIGS. 2A to 2F  are a first embodiment of the present invention. 
           [0013]      FIGS. 3A to 3F  are a second embodiment of the present invention. 
           [0014]      FIGS. 4A to 4D  are a third embodiment of the present invention. 
           [0015]      FIG. 5  is a fourth embodiment of the present invention. 
           [0016]      FIGS. 6A and 6B  are respectively a fifth embodiment and a sixth embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Referring to  FIG. 1  illustrating a flowchart of a method  1  for packaging a light emitting device of the present invention, the method  1  includes following steps: a step  2  of providing a carrier formed with electrodes including an anode electrode and a cathode electrode, a step  3  of providing a light emitting object  81 , a step  4  of contact, a step  5  of bond, a step  6  of reflection, and a step  7  of heat dissipation, wherein the carrier can be selected from a material originally having the anode electrode and cathode electrode, or the anode electrode and cathode electrode of the carrier are formed separately by a technique of mesh print, micro etching, stamping, integrally molding, adhesion, thermo-compression, ink-jet printing, or laser activation and so on. Furthermore, the carrier is made of soft or rigid material. The step  3  of providing the light emitting object  81  is to use a light emitting diode (LED) chip having a positive electrode and a negative electrode as the light emitting object  81 , wherein the LED chip can be a Surface Mount Device Type (SMD) or a Vertical Type. The step  4  of contact is defined by directly contacting the anode electrode and the cathode electrode of the carrier with the positive electrode and the negative electrode of the light emitting diode chip to establish electrical communication, wherein the contact is performed through a technique of Ball Grid Array (BGA) package or Surface Mount Technology (SMT), or through general electric wires. The step  5  of bond is defined by firmly bonding the carrier with the light emitting diode chip, wherein the bonding is through a way of continuously compressing and heating or through an adhesive to firmly join the anode electrode and the cathode electrode of the carrier with the positive electrode and the negative electrode of the LED chip. The step  6  of reflection and step  7  of heat dissipation are performed after the step  5  of bond by coating a first metal layer of high reflection coefficient and a metal heat dissipation layer of high thermal-conduction coefficient in order, wherein the first metal layer is made of aurum (Au), argent (Ag), nickel (Ni), chromium (Cr) or materials composed thereof, and the metal heat dissipation layer is made of copper, aurum, argent, nickel, tin, titanium, platinum, palladium, tungsten, molybdenum, plumbago or materials composed thereof. The first metal layer and the second metal layer of high thermal conductivity coefficient are being rolled and compressed or stamped and are formed through steps of: dispensing negative photo-resist (PR) on the anode electrode and the cathode electrode of the carrier and then being exposed to ultraviolet radiation (UV) and developed, and finally through thin film deposition or electroplating. Accordingly, the light emitting device is produced with the aforesaid steps. 
         [0018]    Referring to  FIGS. 2A to 2F  illustrating a first embodiment of the present invention, in this preferred embodiment, the method  1  for packaging the light emitting device includes the step  2  of providing a carrier  21 , which is etched to form an anode electrode  22  and a cathode electrode  22  (as shown in  FIGS. 2A and 2B ), the carrier  21  being made of light transmittance material, the step  3  of providing a light emitting diode (LED) chip  31  of Surface Mounted Device (SMD) Type, the LED chip  31  having a positive electrode  32  and a negative electrode  33 . Then solder tin balls (not displayed) on the anode electrode  22  and the cathode electrode  23  of the carrier  21  with the technique of Ball Grid Array (BGA) package (alternatively, the tin balls can be soldered on the LED chip  31 ), and then directly contact the carrier  21  and the LED chip  31  to establish electrical communication among the anode and cathode electrodes  22 ,  23  and the positive and negative electrodes  32 ,  33  (as the step  4 , shown in  FIG. 2C ); then continuously compress and heat the carrier  21  and the LED chip  31  to bond together as the step  5  (as shown in  FIG. 2C ); After the preceding steps, dispense a negative photo-resist (PR) on the carrier  21  and the LED chip  31 , then the carrier  21  and the LED chip  31  are exposed to ultra radiation (UV) and developed to define an exposed upper portion of the LED chip  31  (as shown in  FIG. 2E ), and then through thin film deposition or electroplating to form the first metal layer  84  of high reflection coefficient and the metal heat dissipation layer  85  of high thermal-coefficient (as the steps  6  and  7 , shown in  FIG. 2F ). Consequently, the light emitting device  8  is produced, and light emitting efficiency is greatly enhanced. 
         [0019]    Referring to  FIGS. 3A to 3F  illustrating a second embodiment of the present invention, as described in the step  2 , in this embodiment, the carrier  21  is formed with the anode electrode  22  and the cathode electrode  23  by etching technique or other appropriate techniques (as shown in  FIGS. 3A and 3B ); Alternatively, the procedure of forming the anode and cathode electrodes  22 ,  23  can be omitted when the carrier  21  is replaced with a material of anode and cathode electrodes, or the carrier  21  originally has anode and cathode electrodes. Following the preceding step, providing the LED chip  31  of the SMD type having the positive and negative electrodes  32 ,  33  as the step  3 ; then solder tin balls on the carrier  21  with the technique of BGA package (alternatively, the tin balls can be soldered on the LED chip  31 ), and then directly contact the carrier  21  and the LED chip  31  to establish electrical communication among the anode and cathode electrodes  22 ,  23  and the positive and negative electrodes  32 ,  33  (as the step  4 , shown in  FIG. 3C ), furthermore, continuously compress and heat the carrier  21  and the LED chip  31  to bond together as the step  5 ; Pre-determine adhesive portions on the carrier  21  bonded with the LED chip  31  and partially dispense adhesive  50  thereon (as shown in  FIG. 3C ), wherein the adhesive, for example, is a fixing glue (or the adhesive  50  is dispensed fully as shown in  FIG. 3D ); then the carrier  21  and the LED chip  31  are further being rolled and compressed by the soft roller  90  (as shown in  FIG. 3E ), or being stamped. Finally, carry out the step  6  and the step  7  as described above that the first metal layer  84  of high reflection coefficient (served as a reflective layer), the metal heat dissipation layer  85  of high thermal-coefficient, the LED chip  31  and the carrier  21  are closely bonded to each other, whereby a light cup (not labeled) is formed (as shown in  FIG. 3F ), and the light emitting device  8  is produced. 
         [0020]    Referring to  FIGS. 4A to 4D  illustrating a third embodiment of the present invention, in this embodiment, the step  2  of providing the carrier  21  formed with the anode and cathode electrodes  22 ,  23  and the step  3  of providing the LED chip  31  of the positive and negative electrodes  32 ,  33  are the same; the LED chip  31  is reversely mounted on the carrier  21 , wherein the carrier  21  is dispensed with the adhesive  50  as shown in  FIG. 4A  (for example, the fixing glue); then contact the anode and cathode electrodes  22 ,  23  of the carrier  21  and the positive and negative electrodes  32 ,  33  of the LED chip  31  through electric wires  40  to establish electrical communication therebetween (as shown in  FIG. 4B ); then further roll and compress the combined carrier  21  and LED chip  31  through the soft roller  90  (as depicted in the  FIG. 3E  of the second embodiment); finally, carry out the step  6  and the step  7  as described above that the first metal layer  84  of high reflection coefficient (served as a reflective layer), the metal heat dissipation layer  85  of high thermal-coefficient, the LED chip  31  and the carrier  21  are closely bonded to each other, whereby a light cup (not labeled) is formed (as shown in  FIG. 3F ), and the light emitting device  8  is produced. 
         [0021]    Referring to  FIGS. 5 and 6A  to  6 B respectively illustrating a fourth, fifth, and sixth embodiments of the present invention, these three embodiments utilize a LED chip  31 ′ of vertical type, and other steps of the method for packaging the light emitting device are the same as described above in the first and the second embodiments. With reference to  FIG. 5 , after a carrier  21 ′ having an anode electrode  22 ′ and a cathode electrode  23 ′ is firmly bonded with the LED chip  31 ′ of a positive electrode  32 ′ and negative electrode  33 ′ (as the step  5  described above), appropriately dispense negative photo-resist (PR) on the carrier  21 ′ and the LED chip  31 ′, and then expose them to ultraviolet radiation (UV) and developed to define an exposed upper portion of the LED chip  31 ′, and finally through thin film deposition or electroplating to form the first metal layer  84 ′ ‘and the metal heat dissipation layer  85 ′. Accordingly, the light emitting device is produced. 
         [0022]    Referring to  FIG. 6A , the carrier  21 ′ is formed with the anode electrode  22  and the cathode electrode  23  by etching technique or other appropriate techniques; As mentioned above, the procedure of forming the anode and cathode electrodes  22 ′,  23 ′ can be omitted when the carrier  21 ′ is replaced with a material of anode and cathode electrodes, or the carrier  21 ′ originally has anode and cathode electrodes. Then solder tin balls on the carrier  21 ′ with the technique of BGA package (alternatively, the tin balls can be soldered on a positive electrode  32 ′ and negative electrode  33 ′ of the LED chip  31 ′), and directly contact the LED chip  31 ′ with the carrier  21 ′ to establish electrical communication among the anode and cathode electrodes  22 ′,  23 ′ and the positive and negative electrodes  32 ′,  33 ′. Pre-determine adhesive portions on the carrier  21 ′ bonded with the LED chip  31 ′ and partially dispense adhesive  50 ′ thereon, wherein the adhesive  50 ′, for example, is a fixing glue (or fully dispense the adhesive  50  on the carrier  21  and LED chip  31 ′ as shown in  FIG. 6B ); then the carrier  21 ′ and the LED chip  31 ′ are further being rolled and compressed by the soft roller  90  (as shown in  FIG. 3E ), or being stamped. Finally, carry out the step  6  and the step  7  as described above that the first metal layer  84 ′ of high reflection coefficient (served as a reflective layer), the metal heat dissipation layer  85 ′ of high thermal-coefficient, the LED chip  31 ′ and the carrier  21 ′ are closely bonded to each other, whereby the light cup concentrating light is formed (as shown in  FIG. 3F ), and the light emitting device  8  is produced. 
         [0023]    It is understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.