Patent Publication Number: US-2020304692-A1

Title: Lens module and electronic device using the lens module

Description:
FIELD 
     The subject matter herein generally relates to imaging devices. 
     BACKGROUND 
     The lens module is a core component of a camera device. The lens module has evolved to be smaller in volume and higher in performance. However, the lens module produced by a conventional process may be low in cost but large in size. On the other hand, the lens modules produced with advanced devices has a high cost and a low yield. 
     Therefore, there is room for improvement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of embodiments, with reference to the attached figures. 
         FIG. 1  is an isometric view of a lens module according to an embodiment of the present disclosure. 
         FIG. 2  is an exploded view of the lens module of  FIG. 1 . 
         FIG. 3  is an isometric view of a lens unit of the lens module of  FIG. 1 . 
         FIG. 4  is a cross-sectional view taken along line VIII-VIII of  FIG. 1 . 
         FIG. 5  is an isometric view of a lens module according to another embodiment of the present disclosure. 
         FIG. 6  is an exploded view of the lens module of  FIG. 5 . 
         FIG. 7  is an isometric view of a lens unit of the lens module of  FIG. 5 . 
         FIG. 8  is a cross-sectional view taken along line IV-IV of  FIG. 5 . 
         FIG. 9  is a perspective view of an electronic device with the lens module of  FIG. 1 or 5  installed thereon. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is made in conjunction with the accompanying drawings. Specific embodiments of the present disclosure are described. 
     In the following description, when an element is described as being “fixed to” another element, the element can be fixed to the another element with or without intermediate elements. When an element is described as “connecting” another element, the element can be connected to the other element with or without intermediate elements. 
     Without a given definition otherwise, all terms used have the same meaning as commonly understood by those skilled in the art. The term “and/or” means including any and all combinations of one or more of associated listed items. 
     Referring to  FIG. 1  to  FIG. 4 , an embodiment of the present disclosure provides a lens module  100  for use in an electronic device. The electronic device can be a smart phone, a tablet computer, or the like. In this embodiment, the electronic device is a mobile phone  300  (see  FIG. 9 ). The lens module  100  includes a circuit board  10 , a photosensitive chip  20 , a first adhesive layer  30 , a filter  40 , and a lens unit  60 . 
     The circuit board  10  can be a ceramic substrate, a soft board, a hard board, or a board combining soft and hard. In the embodiment, the circuit board  10  is a soft and hard board, and includes a first hard board portion  101 , a second hard board portion  102 , and a soft board portion connected between portions  101  and  102 . A photosensitive chip  20 , a plurality of electronic components  11 , and a plurality of metal wires  12  are mounted on a surface of the first hard board portion  101 . The electronic components  11  and the metal wires  12  surround the photosensitive chip  20 . The metal wires  12  are electrically connected to the photosensitive chip  20 . 
     The first adhesive layer  30  is disposed on the surface of the first hard board portion  101  where the photosensitive chip  20  is located. The photosensitive chip  20  is fixed to the first hard board portion  101  by a second adhesive layer  21 . The second adhesive layer  21  can be an optical adhesive. In the embodiment, the photosensitive chip  20  is a complementary metal oxide semiconductor (CMOS) chip or a charge coupled device (CCD) chip and is rectangular in shape. The metal wires  12  may be made of a metal having a high electrical conductivity, such as gold. The electronic components  11  can include passive components such as resistors, capacitors, diodes, transistors, relays, and electrically erasable programmable read only memorys (EEPROMs). 
     An electrical connection element  13  is mounted on the second hard board portion  102 . The electrical connection element  13  transmits signals between the lens module  100  and other components of the electronic device. The electrical connection element  13  can be a connector or a gold fingers. In the embodiment, the electrical connection portion  13  is a connector. 
     The first adhesive layer  30  is fixed on the first hard board portion  101 . The first adhesive layer  30  is shape of a rectangular frame, and includes a main body  31  and a through hole  32  defined on the main body  31 . Referring to  FIG. 3 , in the embodiment, the photosensitive chip  20  is located in the through hole  32 . The main body  31  surrounds the photosensitive chip  20  and covers the electronic components  11  and the metal wires  12 . The main body  31  does not extend beyond the outer periphery of the first hard board portion  101 . 
     For producing such a lens module  100 , no special molding device is required, only a glue spreading machine is needed to produce the first adhesive layer  30  on the first hard board portion  101 . Glue from the glue spreading machine is restricted from going beyond the periphery of the first hard board portion  101 , so that the first adhesive layer  30  does not go over the outer periphery of the first hard board portion  101 . At the same time, an image area of the photosensitive chip  20  is shielded to prevent the image area from being contaminated by the glue. In the embodiment, the first adhesive layer  30  can be a thermosetting adhesive or a UV adhesive. The amount of the glue and the path of the glue spreading machine are predetermined to avoid the image area of the photosensitive chip  20 , while covering the electronic components  11 , the metal wires  12 , and the periphery of the photosensitive chip  20 . The glue spread on the first hard board portion  101  when solid forms the first adhesive layer  30 . The first adhesive layer  30  is not easily cracked and deformed, and is less affected by temperature and humidity. The first adhesive layer  30  is also opaque and light-proof, thereby improving the reliability of the lens module  100 . 
     In the embodiment, the first adhesive layer  30  envelops the electronic components  11  and the metal wires  12 , and reduces the distances from the electronic components  11  to the edges of the first hard board portion  101 , thereby miniaturizing the lens module  100 . 
     In a conventional lens module, a small amount of light will reach the metal wire  12  when light is irradiated into the conventional lens module at a specific angle. The metal wire  12  reflects light and causes flashing and ghost imaging on the photosensitive chip  20 . In the lens module  100 , the first adhesive layer  30  envelops the metal wire  12 . The first adhesive layer  30  absorbs any light falling thereon and reduces flashing caused by the metal wire  12  reflecting light onto the photosensitive chip  20 . 
     The glue is effectively prevented from contaminating the image area of the photosensitive chip  20 , by adjusting the amount of the glue applied and the path of the glue spreading machine, thereby improving a yield of the lens module  100 . 
     In the embodiment, the lens unit  60  is directly bonded to the first hard board portion  101  after the glue is spread on the first hard board portion  101 . The lens unit  60  includes a lens holder  61  and a lens  62  formed in the lens holder  61 . The lens holder  61  and the lens  62  can be made of a resin. In the embodiment, the lens holder  61  can be integrally formed with the lens  62  by an injection molding process. 
     In the embodiment, the lens holder  61  is fixed to a surface of the first adhesive layer  30  away from the circuit board  10 . The lens holder  61  includes a substantially square first holder portion  611 , a substantially cylindrical second holder portion  612 , and a plurality of posts  613  extended downwardly from the first holder portion  611 . The posts  613  are fixed to the first adhesive layer  30 . In the embodiment, there are six posts  613 . In other embodiments, the number of the posts  613  can be less or greater than six. The second holder portion  612  is connected to the first holder portion  611  away from the circuit board  10 . A width of the first holder portion  611  is greater than a width of the second holder portion  612 . 
     The second holder portion  612  is opened at a side away from the first lens holder portion  611 , to expose the lens  62 . A spacer  621  is formed below the lens  62 . The spacer  621  and the first holder portion  611  cooperatively form an accommodating space (hereinafter “the first accommodating space  622 ”). The filter  40  is received in the first accommodating space  622  to face the photosensitive chip  20 . 
     In the embodiment, a third adhesive layer  41  is disposed around an edge region of the filter  40 . The third adhesive layer  41  is also frame-shaped and is square, and the third adhesive layer  41  bonds the filter  40  to the spacer  621 . The third adhesive layer  41  can be an optical glue. 
       FIG. 5  to  FIG. 8  show a lens module  200  according to a second embodiment. The lens module  200  is the same as the lens module  100  in structure excepting that the lens module  200  includes a bracket  50 . The bracket  50  is fixed on the first adhesive layer  30 . The lens unit  60  is fixed on the bracket  50  away from the circuit board  10 , and the filter  40  is also fixed on the bracket  50 . 
     In the embodiment, the bracket  50  includes six supporting posts  53  that are fixed on the first adhesive layer  30 . In other embodiments, the number of the supporting posts  53  can be less or more than six. Each supporting post  53  is configured to fix a position of the bracket  50  on the first adhesive layer  30  and prevent the glue from collapsing during solidification. 
     A through hole  51  is defined in the middle of the bracket  50 . An inner wall of the through hole  51  extends toward the central axis of the through hole  51  to form a flange  52 . The flange  52  divides the through hole  51  into two accommodating spaces (hereinafter referred as “second accommodating space  521 ” and “third accommodating space  522 ”). The second accommodating space  521  is adjacent to the circuit board  10  and the third accommodating space  522  is away from the circuit board  10 . The photosensitive chip  20  is received in the second accommodating space  521 . The filter  40  is fixed to the flange  52  through the third adhesive layer  41  and is received in the third accommodating space  522 . The filter  40  faces the photosensitive chip  20 . 
     The lens module  200  includes a fourth adhesive layer  63 . The fourth adhesive layer  63  is also frame-shaped. The body of the fourth adhesive layer  63  is disposed on an edge region of the bracket  50  away from the circuit board  10 . The first holder portion  611  of the lens unit  60  is fixed to the bracket  50  by the fourth adhesive layer  63 . The fourth adhesive layer  63  can be an optical glue. 
     In the embodiment, no post extends downwardly from the first lens holder portion  611 . 
     Referring to  FIG. 9 , the lens modules  100  and  200  can be applied in various electronic devices equipped with camera modules, such electronic devices include mobile phones, wearable devices, computer devices, vehicles, and monitoring devices. In the embodiment, the lens modules  100  and  200  are applied in a mobile phone  300 . 
     The lens module provided by the present disclosure has the following beneficial effects. First, the first adhesive layer is formed by directly spreading glue on the first hard board portion of the circuit board so as to envelop the electronic components, thereby reducing the distances from the electronic components  11  to edges of the first hard board portion  101 , and also miniaturizing the lens module. Second, the first adhesive layer envelops the metal wires, thereby preventing light on the metal wires causing flashing and thus improving image quality. Third, forming the first adhesive layer on the first hard board portion does not require special molding equipment and molds, only a glue spreading machine. This reduces the cost. Fourth, in the first embodiment, the lens unit is directly bonded to the circuit board after the glue is spread, no step of covering the circuit board is needed, thereby saving work and improving efficiency. Fifth, adjusting the amount of glue and the path of the glue spreading machine prevents the glue from contaminating the image area of the photosensitive chip, thereby improving the yield. 
     The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes can be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims.