Patent Publication Number: US-2020304693-A1

Title: Camera module and electronic device using same

Description:
FIELD 
     The subject matter herein generally relates to image-capturing devices. 
     BACKGROUND 
     A lens module may include lenses, a lens holder, a carrier, a filter, a photosensitive chip, and a circuit board. The lens modules are required to be reduced in size because the electronic devices that applying the lens modules are becoming thinner. Although the lens modules fabricated under the traditional COB (Chip On Board) packaging process are stable, the lens modules are large, and miniaturization is problematic. 
     Thus, there is room for improvement within the art. 
    
    
     
       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 exploded view of the lens module of  FIG. 1  from another angle. 
         FIG. 4  is a cross-sectional view along line IV-IV of  FIG. 1 . 
         FIG. 5  is a perspective view of an electronic device using a lens module according to an embodiment of the present disclosure. 
     
    
    
     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” or “connecting to” another element, the element can be connected to the other element with or without intermediate elements. 
     Without a definition otherwise, all terms given below are of 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  and  FIG. 2 , an embodiment of the present disclosure provides a lens module  100 . The lens module  100  includes a circuit board  10 , a carrier  40 , a filter  60 , and a lens holder  70 , and a lens unit  80 . 
     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  11 , a second hard board portion  12 , and a soft board portion  13  connected between portions  11  and  12 . An electrical connection element  20  is mounted on the second hard board portion  12 . When the lens module  100  is installed in an electronic device (not shown), the electrical connection element  20  transmits signals between the lens module  100  and other components of the electronic device. In the embodiment, the electrical connection element  20  can be an edge connector or a gold finger. 
     One surface of the first hard board portion  11  carries a photosensitive chip  21  and a plurality of metal wires  23 . The photosensitive chip  21 , the metal wires  23  and the electrical connection element  20  are located on a same side of the circuit board  10 . The photosensitive chip  21  is electrically connected to the first hard board portion  11  through the metal wires  23 . In the embodiment, the photosensitive chip  21  is rectangular in shape. An opposite surface of the first hard board portion  11  carries at least one electronic component  22  electrically connected to the first hard board portion  11 . The electronic component  22  can be a passive component such as a resistor, a capacitor, a diode, a transistor, a relay, or an electrically erasable programmable read only memory (EEPROM). 
     Referring to  FIG. 3  and  FIG. 4 , in the embodiment, the lens module  100  further includes a first plastic layer  30  and a second plastic layer  31 . The first plastic layer  30  is located on the surface of the first hard board portion  11  where the photosensitive chip  21  is located. In the embodiment, the first plastic layer  30  is substantially a hollow rectangular structure and includes a main body  31  and a first through hole  32  defined on the main body  31 . The photosensitive chip  21  has a photosensitive area and a non-photosensitive area not sensitive to light surrounding the photosensitive area. The metal wires  23  electrically connect the non-photosensitive area of the photosensitive chip  21  with the first hard board portion  11 . The first through hole  32  of the first plastic layer  30  is aligned with the photosensitive area of the photosensitive chip  21  and exposes the photosensitive area of the photosensitive chip  21 . The main body  31  of the first plastic layer  30  covers and encloses the non-photosensitive region of the photosensitive chip  21  and the metal wires  23 . In the embodiment, the first plastic layer  30  further includes a first recess  33  recessed toward the circuit board  10  and surrounding the first through hole  32 . The photosensitive chip  21  is received in the first recess  33 . 
     The second plastic layer  31  is located on the surface of the first hard board portion  11  where the electronic component  22  is located. In the embodiment, the second plastic layer  31  is substantially rectangular in shape. The second plastic layer  31  defines a groove (not shown) for receiving and covering the electronic component  22 , the electronic component  22  is thereby packaged on the first hard board portion  11 . In the embodiment, the first plastic layer  30  and the second plastic layer  31  are both injection molded elements. 
     In a conventional lens module, for the electronic component, the photosensitive chip and the metal wires are located on a same surface of a circuit board, and lateral gaps exist between the photosensitive chip and the metal wires. In the embodiment, lateral gaps are avoided and a lateral dimension of the lens module  100  is reduced where the electronic component  22  is located on a surface of the circuit board  10  and the photosensitive chip  21  is located on opposite surface of the circuit board  10 . Thus, the lens module  100  is miniaturized. Furthermore, the first plastic layer  30  and the second plastic layer  31  effectively prevent external contaminants reaching the photosensitive chip  21  and the electronic component  22 , thereby improving the imaging quality of the lens module  100 . The first plastic layer  30  covers the metal wires  23  and prevents reflections therefrom and flashing and ghost imaging on the photosensitive chip  20  are reduced. The second plastic layer  31  effectively shields against light leaking from the circuit board  10 , and improves the imaging quality of the lens module  100  further. The electronic component  22  is disposed on a surface of the circuit board  10  away from the photosensitive chip  21 , preventing reflections of light from the electronic component  22  and reducing flashing and ghost imaging on the photosensitive chip  20 , thereby improving the imaging quality of the lens module  100 . 
     In the embodiment, the carrier  40  is mounted on the first plastic layer  30  through a first adhesive layer  50 . The carrier  40  is substantially a hollow rectangular structure and defines a second through hole  41 . The second through hole  41  is aligned with the photosensitive area of the photosensitive chip  21  and exposes the photosensitive area of the photosensitive chip  21 . The carrier  40  defines a second recess  42  and an air venting hole  43 . The second recess  42  recesses inwardly from a surface of the carrier  40  away from the circuit board  10  and surrounds the second through hole  41 . The air venting hole  43  runs through the carrier  40  and has a central axis substantially parallel to a central axis of the second through hole  41 . The carrier  40  can be made of metal or plastic. In this embodiment, the carrier  40  is made of plastic. 
     The filter  60  is mounted in the second recess  42  of the carrier  40  through a second adhesive layer  51 . In the present embodiment, the filter  60  has a rectangular shape. 
     The lens holder  70  is mounted on the surface of the carrier  40  away from the circuit board  10  through a third adhesive layer  52 . The lens holder  70  is substantially a rectangular parallelepiped structure. A receiving hole  71  is defined in the lens holder  70 . The lens holder  70  is made of metal or plastic. In this embodiment, the lens holder  70  is made of an aluminum alloy. 
     The lens unit  80  is received in the receiving hole  71  of the lens holder  70 . The lens unit  80  and the lens holder  70  are assembled together or integrally formed. In the embodiment, the lens unit  80  and the lens holder  70  are integrally formed by an injection molding process. The lens unit  80  includes a first lens  81 , a second lens  82 , and a third lens  83 . The second lens  82  is located between the first lens  81  and the third lens  83 . The first lens  81 , the second lens  82 , and the third lens  83  are sequentially decreased in diameter. The lens unit  80  is integrally formed or can be assembled by assembling the first lens  81 , the second lens  82 , and the third lens  83  together. In the embodiment, the first lens  81 , the second lens  82 , and the third lens  83  are integrally formed to form the lens unit  80 . 
     Referring to  FIG. 5 , the lens module  100  can be applied to various electronic devices equipped with camera modules, such as mobile phones, wearable devices, computer devices, vehicles, or monitoring devices. In the embodiment, the lens module  100  is applied to a mobile phone  200 . 
     The lens module  100  provided by the present disclosure has the following beneficial effects. The electronic component  22  is located on a surface of the circuit board  10  which is not the surface on which the photosensitive chip  21  and the metal wire  23  are located, thereby avoiding lateral gaps between the electronic component  22  and the photosensitive chip  21  and the metal wire  23 , and thereby reducing a lateral dimension of the lens module  100 , and achieving better miniaturization of the lens module  100 . 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.