Abstract:
A method for manufacturing an LED module includes following steps: providing a SMT (Surface Mount Technology) apparatus having a CCD (Charge-Coupled Device) image sensor and a nozzle, and providing a PCB and fixing the PCB in the SMT apparatus; providing a plurality of LEDs and mounting the LEDs on the PCB by the SMT apparatus; providing a plurality of lenses each having a plurality of patterned portions formed on an outer face of the lens, and the CCD image sensor imaging the lens and identifying the patterned portions, and then the SMT apparatus obtaining a location of the lens relative to the LED; positioning the lens on the PCB to cover the LED by the SMT apparatus; and fixing the lens on the PCB.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The disclosure generally relates to a method for manufacturing a light emitting diode (LED) module. 
         [0003]    2. Description of Related Art 
         [0004]    In recent years, due to excellent light quality and high luminous efficiency, light emitting diodes (LEDs) have increasingly been used as substitutes for incandescent bulbs, compact fluorescent lamps and fluorescent tubes as light sources of illumination devices. 
         [0005]    A conventional backlight module includes a flat back cover and a plurality of LED modules mounted on the back cover in array. Each of the LED modules should have an illumination angle as large as possible. To achieve this objective, an optical lens is usually required to be placed above the LED. Generally, in a conventional method for manufacturing the LED module, the LEDs are firstly fixed on a PCB by SMT (Surface Mount Technology) apparatus, and then the lenses are correspondingly positioned above the LEDs, finally the lenses are fixed on the PCB. 
         [0006]    However, it is hard to position the lenses corresponding to the LEDs accurately, it may cause unsuitable light emitting effect of the LED module. 
         [0007]    What is needed, therefore, is a method for manufacturing an LED module to overcome the above described disadvantages. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0009]      FIG. 1  is a flow chart of a method for manufacturing an LED module in accordance with an embodiment of the present disclosure. 
           [0010]      FIG. 2  is a schematic view of the method of  FIG. 1 . 
           [0011]      FIG. 3  is a top view of a lens of an LED module manufactured by the method of  FIG. 1 . 
           [0012]      FIG. 4  is a flow chart of a method for manufacturing an LED module in accordance with a second embodiment of the present disclosure. 
           [0013]      FIG. 5  is a schematic view of the method of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Embodiments of a method for manufacturing a light emitting diode (LED) module will now be described in detail below and with reference to the drawings. 
         [0015]    Referring to  FIGS. 1-2 , a method for manufacturing an LED module in accordance with a first embodiment is provided. The method for manufacturing the LED module includes following steps. 
         [0016]    Step S 101 , a SMT (Surface Mount Technology) apparatus  100  is provided, and an elongated PCB  10  is positioned in the SMT apparatus  100 . The SMT apparatus  100  has a CCD (Charge-Coupled Device) image sensor  102  and a nozzle  104 . 
         [0017]    Step S 102 , a plurality of LEDs  20  are provided. The LEDs  20  are mounted on the PCB  10  by the SMT apparatus  100 . 
         [0018]    Step S 103 , a plurality of lenses  30  are provided. Referring also to  FIG. 3 , each lens  30  has a plurality of patterned portions  32  formed on an outer face of the lens  30 . Each lens  30  is imaged by the CCD image sensor  102 , the patterned portions  32  are identified by the CCD image sensor  102 , and a location of the lens  30  relative to a corresponding LED  20  is obtained by the SMT apparatus  100 . 
         [0019]    Step S 104 , the lenses  30  are correspondingly positioned on the PCB  10  and cover the LEDs  20  by the SMT apparatus  100 . 
         [0020]    Step S 105 , the lenses  30  are fixed on the PCB  10 . 
         [0021]    In detail, a manner of positioning each lens  30  on the PCB  10  by the SMT apparatus  100  includes following steps. Firstly, the PCB  10  with the LEDs  20  mounted thereon is fixed in the SMT apparatus  100 . Secondly, a corresponding lens  30  is carried by the nozzle  104  of the SMT apparatus  100 . Thirdly, the lens  30  is imaged by the CCD image sensor  102 , and the patterned portions  32  of the lens  30  are identified by the CCD image sensor  102 . Fourthly, a location variation between the lens  30  and a corresponding LED  20  on the PCB  10  is calculated by the SMT apparatus  100 . Finally, the lens  30  is positioned on the PCB  10  and covers the corresponding LED  20  by the nozzle  104  of the SMT apparatus  100 , according to the location variation. 
         [0022]    Each lens  30  is integrally made of transparent materials such as PC (polycarbonate) or PMMA (polymethyl methacrylate). A dimension of the lens  30  is about 3 mm. 
         [0023]    Each lens  30  includes a light-incident face  301  facing the LED  20 , a light-emitting face  302  opposite to the light-incident face  301 , and a lateral face  303  interconnecting the light-incident face  301  and the light-emitting face  302 . A center of a bottom portion of the lens  30  is recessed inwardly to form a receiving room  304  for accommodating the LED  20  therein. The light-emitting face  302  is convex and has a dome-like profile. The lens  30  further includes an annular flange  305  protruding outwardly form the lateral face  303  of the lens  30 . 
         [0024]    The patterned portions  32  of each lens  30  are formed on a top face of the annular flange  305 . It can be understood that, the patterned portions  32  could be formed on the light-incident face  301 , the light-emitting face  302  or the lateral face  303  of the lens  30 . A dimension of the patterned portion  32  is about 0.1 mm. In this embodiment of the disclosure, there are three patterned portions  32  evenly spaced from each other. 
         [0025]    Referring to  FIGS. 4-5 , a method for manufacturing an LED module in accordance with a second embodiment is provided. 
         [0026]    Step S 101 A, a SMT (Surface Mount Technology) apparatus  100   a  is provided, and an elongated PCB  10  is positioned in the SMT apparatus  100   a . The SMT apparatus  100   a  has a first CCD (Charge-Coupled Device) image sensor  102   a , a second CCD image sensor  102   b , and a nozzle  104 . A resolution of the second CCD image sensor  102   b  is higher than that of the first image sensor  102   a.    
         [0027]    Step S 102 A, a plurality of LEDs  20  are provided. The LEDs  20  are mounted on the PCB  10  by the SMT apparatus  100   a.    
         [0028]    Step S 103 A, a plurality of lenses  30  are provided. Each lens  30  is imaged by the first CCD image sensor  102   a , and a location of the lens  30  relative to a corresponding LED  20  is obtained by the SMT apparatus  100   a.    
         [0029]    Step S 104 A, the lenses  30  are correspondingly positioned on the PCB  10  and cover the LEDs  20  by the SMT apparatus  100   a.    
         [0030]    Step S 105 A, each lens  30  has a plurality of patterned portions  32  formed on an outer face of the lens  30 , the lens  30  is imaged by the second CCD image sensor  102   b , the patterned portions  32  are identified by the second CCD image sensor  102   b , and a position of at least a corresponding lens  30  is adjusted by the SMT apparatus  100 . 
         [0031]    Step S 106 A, the lenses  30  are fixed on the PCB  10   
         [0032]    In detail, a manner of positioning each lens  30  on the PCB  10  by the SMT apparatus  100   a  includes following steps. Firstly, the PCB  10  with the LEDs  20  mounted thereon is fixed in the SMT apparatus  100   a . Secondly, a corresponding lens  30  is carried by the nozzle  104  of the SMT apparatus  100   a . Thirdly, the lens  30  is imaged by the first CCD image sensor  102   a , a profile of the lens  30  is identified by the first CCD image sensor  102   a . Fourthly, a first location variation between the lens  30  and a corresponding LED  20  on the PCB  10  is calculated by the SMT apparatus  100   a . Fifthly, the lens  30  is positioned on the PCB  10  and covers the corresponding LED  20  by the nozzle  104  of the SMT apparatus  100   a , according to the first location variation. Sixthly, the lens  30  is imaged by the second CCD image sensor  102   b , and the patterned portions  32  (as shown in  FIG. 3 ) of the lens  30  are identified by the second CCD image sensor  102   b . Seventhly, a second location variation between the lens  30  and the corresponding LED  20  is calculated by the SMT apparatus  100   a . Finally, a position of the lens  30  covering the corresponding LED  20  is adjusted by the nozzle  104  of the SMT apparatus  100   a , according to the second location variation. 
         [0033]    Each lens  30  is integrally made of transparent materials such as PC (polycarbonate) or PMMA (polymethyl methacrylate). A dimension of the lens  30  is about 3 mm. 
         [0034]    Each lens  30  includes a light-incident face  301  facing the LED  20 , a light-emitting face  302  opposite to the light-incident face  301 , and a lateral face  303  interconnecting the light-incident face  301  and the light-emitting face  302 . A center of a bottom portion of the lens  30  is recessed inwardly to form a receiving room  304  for accommodating the LED  20  therein. The light-emitting face  302  is convex and has a dome-like profile. The lens  30  further includes an annular flange  305  protruding outwardly form the lateral face  303  of the lens  30 . 
         [0035]    Referring to  FIG. 3  again, the lens  30  of the second embodiment is the same as that of the first embodiment, the patterned portions  32  of each lens  30  are formed on a top face of the annular flange  305 . It can be understood that, the patterned portions  32  could be formed on the light-incident face  301 , the light-emitting face  302  or the lateral face  303  of the lens  30 . A dimension of the patterned portion  32  is about 0.1 mm. In this embodiment of the disclosure, there are three patterned portions  32  evenly spaced from each other. 
         [0036]    It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.