Small form factor modules using wafer level optics with bottom cavity and flip-chip assembly

Abstract

A disclosed method of manufacturing a camera module includes providing a stack of optical elements, providing an integrated circuit image capture device (ICD) having a top surface with an array of sensors, rigidly attaching the stack of optical elements to top surface of the image capture device, providing a substrate having an opening therethrough and a recess around said opening, and attaching the image capture device to the substrate such that edges of the image capture device are disposed in the recess and the stack of optical elements extends through the opening. The method further includes providing a second substrate (e.g., host PCB) and mounting the substrate on the second substrate to attach the camera module to the host device. Optionally, the substrate is mounted to the second substrate via a reflow solder process.

I claim: 
     
         1 . A method of manufacturing a camera module, said method comprising:
 providing a lens assembly;   providing an integrated circuit image capture device, said image capture device having a top surface with an array of sensors;   rigidly attaching said lens assembly to said top surface of said image capture device;   providing a substrate having an opening therethrough and a recess around said opening; and   attaching said image capture device to said substrate such that edges of said image capture device are disposed in said recess and said lens assembly extends through said opening.   
     
     
         2 . The method of  claim 1 , further comprising:
 providing a second substrate;   mounting said substrate on said second substrate.   
     
     
         3 . The method of  claim 2 , wherein:
 said second substrate is a printed circuit board of a host device; and   said substrate is mounted to said second substrate via a reflow solder process.   
     
     
         4 . The method of  claim 1 , wherein said step of rigidly attaching said lens assembly to said top surface of said image capture device includes adhering a bottom surface of said lens assembly to an area of said top surface of said image capture device surrounding said array of sensors. 
     
     
         5 . The method of  claim 1 , wherein no focusing process is carried out in said step of rigidly attaching said lens assembly to said top surface of said image capture device. 
     
     
         6 . The method of  claim 1 , wherein said step of attaching said image capture device to said substrate includes electrically connecting a set of electrical contacts on said image capture device to a complementary set of electrical contacts on said substrate. 
     
     
         7 . The method of  claim 6 , wherein said step of electrically connecting said set of electrical contacts to said complementary set of electrical contacts is accomplished via a flip-chip die attach process. 
     
     
         8 . The method of  claim 6 , wherein said substrate includes a second set of electrical contacts to facilitate connecting said substrate to a circuit board of a host device. 
     
     
         9 . The method of  claim 1 , wherein said substrate is formed prior to said step of attaching said image capture device to said substrate. 
     
     
         10 . A camera module comprising:
 a mounting substrate defining an opening therethrough and a recess around said opening;   an integrated circuit image capture device including a sensor array formed in a top surface of said image capture device, said image capture device being mounted in said recess of said mounting substrate; and   a lens assembly fixed to said top surface of said image capture device and extending through said opening in said mounting substrate.   
     
     
         11 . The camera module of  claim 10 , wherein:
 said mounting substrate includes a set of electrical contacts formed on a surface of said recess;   said image capture device includes a set of complementary electrical contacts formed on said top surface of said image capture device; and   said image capture device is mounted in said recess of said mounting substrate by forming electrical connections between associated pairs of said electrical contacts and said complementary electrical contacts.   
     
     
         12 . The camera module of  claim 10 , wherein
 said mounting substrate further includes a second set of electrical contacts for electrically connecting said mounting substrate to a circuit board of a host device; and   said second set of electrical contacts are electrically coupled to said set of electrical contacts to connect the circuitry of said image capture device with circuitry of said circuit board of said host device.   
     
     
         13 . The camera module of  claim 10 , wherein said lens assembly, said image capture device, and said mounting substrate can all withstand a solder reflow process. 
     
     
         14 . The camera module of  claim 10 , wherein said camera module is free of any focus adjustment mechanism. 
     
     
         15 . The camera module of  claim 10 , wherein:
 said lens assembly includes a bottom surface fixed to said top surface of said image capture device by adhering said bottom surface of said lens assembly to said top surface of said image capture device.   
     
     
         16 . The camera module of  claim 10 , wherein said recess is deeper than the image capture device is thick. 
     
     
         17 . The camera module of  claim 10 , wherein said mounting substrate is a pre-formed component. 
     
     
         18 . A camera module comprising:
 an integrated circuit image capture device including a sensor array formed in a top surface of said image capture device;   a lens assembly fixed to said top surface of said image capture device; and   means for attaching said integrated image capture device to a circuit board of a host device via a reflow solder process.   
     
     
         19 . A camera module comprising:
 an image capture device having a top surface with a peripheral edge and including a plurality of electrical contact pads located on the peripheral edge of the top surface;   a lens assembly affixed to the top surface of the image capture device; and   a mounting substrate having a top surface and a bottom surface, the bottom surface having a recess formed therein; the recess having the same shape as the peripheral edge of the top surface of the image capture device and the recess being sized to closely receive the image capture device therein, the mounting substrate also including an aperture therethrough that is shaped and sized to closely receive the lens assembly therethrough when the image capture device is received with the recess.   
     
     
         20 . The camera module as defined in  claim 19 , wherein the mounting substrate includes a planar top surface, the camera module further including a housing affixed to the planar top surface of the mounting substrate, the housing having an aperture defined in a top surface thereof, the housing partially enclosing the lens assembly therein and allowing light to pass through the aperture to impinge upon the lens assembly. 
     
     
         21 . A camera module as defined in  claim 19 , wherein:
 the recess includes a first set of electrical contacts on a first wall thereof to correspond with and electrically contact the electrical contacts of the image capture device;   the recess also includes a set of electrical connectors on a second wall thereof that is orthogonal to the first wall thereof, each of the set of connectors being electrically connected to a corresponding one of the first set of electrical contacts; and   the bottom surface of the mounting substrate adjacent the recess includes a second set of electrical contacts, each of the second set of electrical contacts being electrically connected to a corresponding one of the set of electrical connectors.