Patent Publication Number: US-2022232152-A1

Title: Camera module of reduced size and method for manufacturing the same

Description:
FIELD 
     The present disclosure relates to a camera module and a manufacturing method thereof. 
     BACKGROUND 
     Electronic products are often equipped with a camera module, but in order to realize the miniaturization of the electronic product, the camera should also be miniaturized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawn figures are to be viewed in conjunction with the embodiments described herein. 
         FIG. 1  is a cross-sectional view of a baseplate according to an embodiment of the present disclosure. 
         FIG. 2  is a cross-sectional view showing an image sensor disposed on the baseplate of  FIG. 1 . 
         FIG. 3  is a cross-sectional view showing a mounting bracket according to an embodiment of the present disclosure. 
         FIG. 4  is a cross-sectional view showing an optical filter and a lens disposed on the mounting bracket of  FIG. 3 . 
         FIG. 5  is a cross-sectional view showing a circuit board according to an embodiment of the present disclosure. 
         FIG. 6  is a cross-sectional view showing the mounting bracket of  FIG. 4  connected with the baseplate of  FIG. 2 . 
         FIG. 7  is a cross-sectional view showing the circuit board of  FIG. 5  connected with the mounting bracket of  FIG. 6 . 
         FIG. 8  is a perspective view of the mounting bracket according to an embodiment of the present disclosure. 
         FIG. 9  is a diagram of a capacitor of the mounting bracket of  FIG. 8 . 
         FIG. 10  is a diagram of coils of the mounting bracket of  FIG. 8 . 
         FIG. 11  is a cross-sectional view showing the circuit board connected with the mounting bracket according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout. 
     As used herein, when a first component is referred to as “fixed to” a second component, it is intended that the first component may be directly attached to the second component or may be indirectly attached to the second component via another component. When a first component is referred to as “connecting” to a second component, it is intended that the first component may be directly connected to the second component or may be indirectly connected to the second component via a third component between them. When a first component is referred to as “disposed to” a second component, it is intended that the first component may be directly disposed to the second component or may be disposed to the second component via a third component between them. The terms “perpendicular,” “horizontal,” “left,” “right,” and similar expressions used herein are merely intended for description. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. The term “and/or” used herein includes any suitable combination of one or more related items listed. 
     The present disclosure provides a lens module. The lens module includes a baseplate defining a receiving hole, an image sensor disposed on the baseplate and corresponding in position to the receiving hole, a mounting bracket disposed on the baseplate, an optical filter, a lens, and a circuit board. The mounting bracket defines a through hole. An inner wall of the through hole extends towards a central axis of the through hole to form a platform, and a side of the mounting bracket adjacent to the platform extends outward to form a connecting portion. A multilayer coil surrounding the through hole, a capacitor, and a resistor are formed on the mounting bracket by laser direct structuring (LDS). The multilayer coil is constituted by multiple layers of encircling coils which surround the through hole and are formed on the mounting bracket by winding from inside to outside. The number of layers in the multilayer coil is greater than 2. Layers in the multilayer coil are electrically connected with each other through via holes. The image sensor is disposed on the platform and is accommodated in the through hole. The lens is mounted in the through hole. The circuit board is connected with the mounting bracket through the connecting portion. 
     The present disclosure also provides a method for manufacturing the lens module. The method includes the following steps. The image sensor is mounted on the baseplate, the image sensor corresponding in position to the receiving hole on the baseplate. The mounting bracket is provided, the mounting bracket defining the through hole, the inner wall of the through hole extending towards a central axis of the through hole to form the platform, and the side of the mounting bracket adjacent to the platform extending outward to form the connecting portion. The multilayer coil surrounding the through hole, the capacitor, and the resistor are formed by laser direct structuring, the multilayer coil being constituted by multiple layers of encircling coils surrounding the through hole and formed on the mounting bracket wound from inside to outside, and the number of layers in the multilayer coil being greater than 2. The layers in the multilayer coil are electrically connected with each other through via holes. The optical filter is mounted on the platform, the optical filter being accommodated in the through hole. The lens is mounted in the through hole. The mounting bracket is mounted on the baseplate. The circuit board is connected with the mounting bracket through the connecting portion. 
     In the lens module and the manufacturing method of the present disclosure, the mounting bracket extends outward to form the connecting portion, and the circuit board is connected with the mounting bracket through the connecting portion, thus a height of the circuit board is reduced and a thickness of the lens module is also reduced. In addition, the multilayer coil surrounding the through hole is formed on the mounting bracket from inside to outside by laser direct structuring, the capacitor and the resistor are formed on the mounting bracket by laser direct structuring, and layers in the multilayer coil are electrically connected to each other through via holes. This achieves maximum use of line space on the mounting bracket, so as to reduce the size of the mounting bracket. 
     Referring to  FIGS. 1 to 7 , an embodiment of a lens module  100  is provided. The lens module  100  is applied to an electronic device (not shown) which may be a smart phone, a tablet computer, etc. The lens module  100  includes a baseplate  10 , an image sensor  20 , a mounting bracket  30 , an optical filter  40 , a lens  50 , and a circuit board  60 . 
     The baseplate  10  defines a receiving hole  11  penetrating the baseplate  10 . The image sensor  20  is mounted on the baseplate  10  by flip-chip bonding, and the image sensor  20  corresponds in position to the receiving hole  11 . The baseplate  10  may be a ceramic plate or a hard board. 
     The receiving hole  11  is a step-shaped hole. The receiving hole  11  includes a first receiving hole  111  and a second receiving hole  112  intercommunicating. A width of the first receiving hole  111  is less than a width of the second receiving hole  112 , to form a flange  12  on the baseplate  10 . 
     The image sensor  20  is mounted on the flange  12  by flip-chip bonding. The width of the first receiving hole  111  is less than a width of the image sensor  20  and the width of the image sensor  20  is less than or equal to the width of the second receiving hole  112 . 
     A depth of the second receiving hole  112  is less than or equal to a thickness of the image sensor  20 , so that the image sensor  20  is accommodated in the receiving hole  11 . The image sensor  20  is a complementary metal oxide semiconductor (CMOS) chip or a charge-coupled device (CCD) chip. 
     The mounting bracket  30  is fixed to the baseplate  10 . The mounting bracket  30  defines a through hole  31  penetrating the mounting bracket  30 . The through hole  31  corresponds in position to the receiving hole  11 . A part of an inner wall of the through hole  31  close to the baseplate  10  extends towards a central axis of the through hole  31  to form a platform  32 . The optical filter  40  is fixed to the platform  32  by an adhesive layer and is accommodated in the through hole  31 . In the present embodiment, a surface of the platform  32  is a surface of the mounting bracket  30  in contact with the baseplate  10 . The platform  32  may also be arranged in a structure similar to the flange  12  on the baseplate  10 . 
     A side of the mounting bracket  30  close to the baseplate  10  extends outward to form a connecting portion  33 . The connecting portion  33  is provided with a solder pad  331  for connecting with the circuit board  60  or other components. 
     A surface of the mounting bracket  30  close to the baseplate  10  is provided with a bonding pad  34  for connecting the baseplate  10  or other components. 
     In some embodiments, the mounting bracket  30  is connected with the baseplate  10  through a surface mounted technology (SMT) or an anisotropic conductive film (ACF). 
     The mounting bracket  30  is also provided with a coil  35 , a capacitor  36 , and a resistor  37 , around the through hole  31 . 
     Specifically, the mounting bracket  30  is formed by laser direct structuring (LDS). The coil  35 , the capacitor  36 , and the resistor  37  are directly formed on the mounting bracket  30  by LDS. 
     The LDS process is a three-dimensional molded interconnect device (3D-MID) production technology including injection molding, laser processing, and electroplating process. By LDS, ordinary plastic components are endowed with electrical interconnection function, so that plastic shells and structural parts not only have the functions of support and protection, but also have the functions of shielding and an antenna combined with conductive circuits, thereby forming the so-called 3D-MID, which is suitable for the production of thin local lines. 
     Referring to  FIGS. 8 to 10 , the mounting bracket  30  is made in multiple layers (more than two layers) by LDS, and a plurality of layers of encircling coils are formed on the mounting bracket  30  from inside to outside by the LDS process to form the coil  35 . Specifically, one part is formed by injection molding, then one layer of encircling coil is formed on the outer surface of the injection-molded part through laser cutting and electroplating, then another part is formed on the one injection-molded part, and another layer of encircling coil connected with the one layer of encircling coil is formed on the outer surface of the other injection-molded part, so that the coil  35  can be directly formed in the mounting bracket  30 . The number of layers of the coil  35  is greater than 2, and the layers in the multilayer coil  35  are electrically connected by via holes (not shown). The capacitor  36  is formed on the inner wall of the through hole  31 . According to requirements, the resistor  37  which controls current, such as a single-layer resistor or a multi-layer resistor, is formed at a local position of the mounting bracket  30 . 
     The optical filter  40  may be an infrared filter. The infrared filter is formed by plating optical films having a high refractive index on an optical substrate using a precision optical coating technology, the filter removes infrared light from incoming light. 
     The lens  50  is mounted in the through hole  31  of the mounting bracket  30 . The lens  50  corresponds in position to the image sensor  20 . The lens  50  may be made of resin. 
     The circuit board  60  is connected with the mounting bracket  30  through the connecting portion  33 . The circuit board  60  may be a ceramic board, a soft board, a hard board, or a rigid-flexible board. 
     The circuit board  60  may be connected with the connecting portion  33  through an anisotropic conductive film (ACF), hot bar soldering, paste soldering, or the surface mounted technology (SMT), thereby reducing a height of the entire lens module  100 . 
     The circuit board  60  is provided with a connector  61 . The connector  61  is attached to a surface of the circuit board  60  through the surface mounted technology (SMT). 
     Referring to  FIG. 11 , the baseplate  10 , the image sensor  20 , the mounting bracket  30 , the optical filter  40 , and the lens  50  can also be used as an independent component, and the circuit board  60  or other component can be connected with the connecting portion  33  by wire bonding. 
     An embodiment of a method for manufacturing the lens module  100  includes the following steps: 
     Step one, referring to  FIG. 1 , the baseplate  10  is provided. 
     Specifically, the baseplate  10  defines the receiving hole  11  penetrating the baseplate  10 . The receiving hole  11  is a step-shaped hole. The receiving hole  11  includes the first receiving hole  111  and the second receiving hole  112  which intercommunicate. A width of the first receiving hole  111  is less than a width of the second receiving hole  112  to form the flange  12  on the baseplate  10 . 
     Step two, referring to  FIG. 2 , the image sensor  20  is provided and is mounted on the baseplate  10  by flip chip bonding. 
     Specifically, the width of the first receiving hole  111  is less than the width of the image sensor  20 , the width of the image sensor  20  is less than or equal to the width of the second receiving hole  112 , and a depth of the second receiving hole  112  is less than or equal to a thickness of the image sensor  20 . When the image sensor  20  is mounted on the flange  12  by flip chip bonding, the image sensor  20  is accommodated in the receiving hole  11 . 
     Step three, referring to  FIG. 3 , the mounting bracket  30  is provided. 
     Specifically, the mounting bracket  30  with the coil  35 , the capacitor  36 , and the resistor  37  is formed through a LDS process. 
     The mounting bracket  30  defines the through hole  31  penetrating the mounting bracket  30 . A part of the inner wall on a side of the mounting bracket  30  extends towards the central axis of the through hole  31  to form the platform  32 . A side of the mounting bracket  30  close to the baseplate  10  extends outward to form the connecting portion  33 . The connecting portion  33  is provided with the solder pad  331  for connecting with the circuit board  60  or other components. A surface of the mounting bracket  30  close to the baseplate  10  is provided with the bonding pad  34  for connecting the baseplate  10  or other components. 
     The coil  35  is constituted by the plurality of layers of encircling coils formed on the mounting bracket  30  from inside to outside, surrounding the through hole  31 . The capacitor  36  is formed on the inner wall of the through hole  31 . The resistor  37  is formed at a local position of the mounting bracket  30  according to need. 
     Step four, referring to  FIG. 4 , the optical filter  40  and the lens  50  are provided and are mounted on the mounting bracket  30 . 
     Specifically, the optical filter  40  is fixed to the platform  32  by an adhesive layer and is accommodated in the through hole  31 . The lens  50  is mounted in the through hole  31  of the mounting bracket  30 . 
     Step five, referring to  FIG. 5 , the circuit board  60  is provided. 
     The connector  61  is attached to a surface of the circuit board  60  through the surface mounted technology (SMT). 
     Step six, referring to  FIG. 6 , the mounting bracket  30  is mounted on the baseplate  10 . 
     Specifically, the bonding pad  34  of the mounting bracket  30  is connected with the baseplate  10  through the surface mounted technology (SMT) or an anisotropic conductive film (ACF). 
     Step seven, referring to  FIG. 7 , the circuit board  60  is connected with the mounting bracket  30 . 
     Specifically, the solder pad  331  of the connecting portion  33  of the mounting bracket  30  is connected with the circuit board  60  through an anisotropic conductive film (ACF), hot bar soldering, paste soldering, or the surface mounted technology (SMT). 
     The above is only a preferred embodiment of the present disclosure, and is not intended to limit the scope of the present disclosure. Although embodiments of the present disclosure are described above, it is not intended to limit the present disclosure. The present disclosure may be modified or modified to equivalent variations without departing from the technical scope of the present disclosure by any person skilled in the art. Any simple modifications, equivalent changes and modifications made to the above embodiments remain within the scope of the technical solutions of the present disclosure.