Miniature Wafer-Level Camera Modules

Abstract

In one aspect, a method includes providing a lens substrate having an array of lenses. The lens substrate includes an overflow region next to each lens of the array. Each overflow region includes an overflow lens material. The method also includes separating the lens substrate into a plurality of smaller lens substrates. Each of the smaller lens substrates has one of the single lens and the plurality of stacked lenses. Separating the lens substrate into the smaller lens substrates may include removing or substantially removing the overflow regions. In one aspect, the method may be performed as a method of making a miniature camera module. Other methods are also described, as are miniature camera modules.

1 . A method comprising:
 providing a lens substrate having an array of lenses, the lens substrate including an overflow region next to each lens of the array, each overflow region including an overflow lens material; and   separating the lens substrate into a plurality of smaller lens substrates, each of the smaller lens substrates having one of a single lens and a plurality of stacked lenses, wherein separating the lens substrate into the plurality of smaller lens substrates includes substantially removing the overflow regions.   
     
     
         2 . The method of  claim 1 , wherein separating the lens substrate into the smaller lens substrates comprises dicing the lens substrate. 
     
     
         3 . The method of  claim 1 , wherein separating the lens substrate into the smaller lens substrates comprises making a single cut between a pair of adjacent lenses to separate the lenses from one another and substantially remove overflow regions between the pair of adjacent lenses. 
     
     
         4 . The method of  claim 1 , wherein separating the lens substrate into the smaller lens substrates comprises making a first cut between a pair of adjacent lenses to separate the lenses from one another and substantially remove an overflow region for a first lens of the pair and making a second cut to substantially remove an overflow region for a second lens of the pair. 
     
     
         5 . The method of  claim 1 , wherein substantially removing the overflow regions includes removing at least 60% of the overflow regions. 
     
     
         6 . The method of  claim 5 , wherein substantially removing the overflow regions includes removing at least 80% of the overflow regions. 
     
     
         7 . The method of  claim 1 , wherein separating the lens substrate into the smaller lens substrates comprises separating the lens substrate into smaller lens substrates having lateral areas that are less than 1.2 millimeters by 1.2 millimeters. 
     
     
         8 . The method of  claim 7 , wherein the lateral areas are less than 0.9 millimeters by 0.9 millimeters. 
     
     
         9 . A method comprising:
 providing a lens substrate having an array of lenses, the lens substrate including an overflow region next to each lens of the array, each overflow region including an overflow lens material;   providing an image sensor array substrate having an array of image sensor arrays;   bonding the lenses with the image sensor array substrate; and   performing one or more sets of dicing operations to dice the lens substrate and the image sensor array substrate into individual modules each having an image sensor array and one of a single lens and a plurality of stacked lenses, wherein performing the one or more sets of dicing operations includes substantially removing the overflow regions.   
     
     
         10 . The method of  claim 9 , wherein said bonding and said performing the one or more sets of dicing operations comprises:
 wafer bonding the lens substrate having the array of lenses and the image sensor array substrate; and   dicing the bonded lens and image sensor array substrates into the individual modules, wherein the dicing substantially removes the overflow regions.   
     
     
         11 . The method of  claim 9 , wherein said bonding and said performing the one or more sets of dicing operations comprises:
 dicing the lens substrate having the array of lenses into individual lens die each having one of a single lens and a plurality of stacked lenses;   bonding each lens die to a corresponding image sensor array of the image sensor array substrate; and   dicing the image sensor array substrate having the lens die bonded thereto into the individual modules.   
     
     
         12 . The method of  claim 11 , wherein dicing the lens substrate substantially removes the overflow regions. 
     
     
         13 . The method of  claim 9 , wherein performing the one or more sets of dicing operations to dice the lens substrate and the image sensor array substrate into the individual modules comprises dicing into individual modules having lateral areas that are less than 1.2 millimeters by 1.2 millimeters. 
     
     
         14 . The method of  claim 9 , wherein providing the image sensor array substrate comprises providing an image sensor array substrate having one or more through-silicon vias. 
     
     
         15 . A miniature camera module, the miniature camera module comprising:
 an aperture operable to receive light from an external environment;   one of a single lens and a plurality of stacked lenses optically coupled to receive the light from the aperture, the one of the single lens and the plurality of stacked lenses operable to optically focus the light;   an image sensor array optically coupled to receive the focused light from the one of the single lens and the plurality of stacked lenses, the image sensor array having a lateral area that is less than 0.6 millimeters by 0.6 millimeters, and the miniature camera module having a lateral area that is less than 1.2 millimeters by 1.2 millimeters; and   interconnects electrically coupled with the image sensor array and accessible from an outside of the miniature camera module to allow electrical connection to be made to an external signaling medium,   wherein the one of the single lens and the plurality of stacked lenses is operable to optically focus the light on the active area of the image sensor array to provide a working distance that is less than 50 millimeters and a field of view that is greater than 70°.   
     
     
         16 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses has no more than three focusing surfaces. 
     
     
         17 . The miniature camera module of  claim 16 , wherein the one of the single lens and the plurality of stacked lenses has only two focusing surfaces. 
     
     
         18 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses has a lateral area of less than 0.9 millimeters by 0.9 millimeters, and wherein the image sensor array has a lateral area that of less than 0.5 millimeters by 0.5 millimeters. 
     
     
         19 . The miniature camera module of  claim 15 , wherein the working distance is less than 30 millimeters and the field of view is greater than 75°. 
     
     
         20 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses comprises one or more molded lens, and wherein the one of the single lens and the plurality of stacked lenses has a surface where an overflow region has been cut away. 
     
     
         21 . The miniature camera module of  claim 15 , wherein the interconnects comprise a ball grid array. 
     
     
         22 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses includes a first lens closest to the aperture stop and a second lens, and wherein the aperture stop is at the first lens. 
     
     
         23 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses includes a molded lens of a polymeric material capable of withstanding a solder reflow process without compromised optical properties. 
     
     
         24 . The miniature camera module of  claim 15 , wherein the one of the single lens and the plurality of stacked lenses comprises only two lenses providing only two optical focusing surfaces, wherein the lateral area of the image sensor array is no more than 0.4 millimeters by 0.4 millimeters, wherein the lateral area of the miniature camera module is no more than 0.8 millimeters by 0.8 millimeters, wherein the working distance is less than 30 millimeters, and wherein the field of view is greater than 75°. 
     
     
         25 . An endoscope comprising a housing and the miniature camera module of  claim 15  enclosed within the housing. 
     
     
         26 . A miniature camera module, the miniature camera module comprising:
 an aperture operable to receive light from an external environment;   one of a single lens and a plurality of stacked lenses optically coupled to receive the light from the aperture, the one of the single lens and the plurality of stacked lenses operable to optically focus the light, the one of the single lens and the plurality of stacked lenses having a lateral area that is less than 1.2 millimeters by 1.2 millimeters, the one of the single lens and the plurality of stacked lenses including one or more molded lens, and the one of the single lens and the plurality of stacked lenses having a surface where an overflow lens material has been cut away;   an image sensor array optically coupled to receive the focused light from the one of the single lens and the plurality of stacked lenses, the image sensor array having a lateral area that is less than 0.6 millimeters by 0.6 millimeters; and   interconnects electrically coupled with the image sensor array and accessible from an outside of the miniature camera module to allow electrical connection to be made to an external signaling medium.   
     
     
         27 . The miniature camera module of  claim 26 , wherein the one of the single lens and the plurality of stacked lenses has no more than three focusing surfaces. 
     
     
         28 . The miniature camera module of  claim 26 , wherein the one of the single lens and the plurality of stacked lenses has a lateral area of less than 0.9 millimeters by 0.9 millimeters, and wherein the image sensor array has a lateral area that of less than 0.5 millimeters by 0.5 millimeters. 
     
     
         29 . The miniature camera module of  claim 26 , wherein the one of the single lens and the plurality of stacked lenses comprises only two lenses providing only two optical focusing surfaces, wherein the lateral area of the image sensor array is no more than 0.4 millimeters by 0.4 millimeters, wherein the lateral area of the one of the single lens and the plurality of stacked lenses is no more than 0.8 millimeters by 0.8 millimeters, wherein a working distance of the miniature camera module is less than 30 millimeters, and wherein a field of view of the miniature camera module is greater than 75°. 
     
     
         30 . An endoscope comprising:
 a hermetically sealed housing, the housing having a transparent portion;   a light source enclosed within the hermetically sealed housing, the light source positioned to transmit light through the transparent portion of the housing;   a miniature wafer-level camera module enclosed within the hermetically sealed housing, the miniature camera module positioned to receive light through the transparent portion of the hermetically sealed housing, the miniature camera module including:   an aperture operable to receive the light received through the transparent portion;   one of the single lens and the plurality of stacked lenses optically coupled to receive the light from the aperture, the one of the single lens and the plurality of stacked lenses operable to optically focus the light;   an image sensor array optically coupled to receive the focused light from the one of the single lens and the plurality of stacked lenses, the image sensor array having a lateral area that is less than 0.6 millimeters by 0.6 millimeters, and the miniature camera module having a lateral area that is less than 1.2 millimeters by 1.2 millimeters; and   interconnects electrically coupled with the image sensor array and accessible from an outside of the miniature camera module to allow electrical connection to be made to an external signaling medium,   wherein the one of the single lens and the plurality of stacked lenses is operable to optically focus the light on the active area of the image sensor array to provide a working distance that is less than 50 millimeters and a field of view that is greater than 75°   
     
     
         31 . The endoscope of  claim 30 , wherein the one of the single lens and the plurality of stacked lenses comprises one or more molded lens, and wherein the one of the single lens and the plurality of stacked lenses has a surface where an overflow region has been cut away. 
     
     
         32 . The endoscope of  claim 30 , wherein the one of the single lens and the plurality of stacked lenses has no more than three focusing surfaces. 
     
     
         33 . The endoscope of  claim 30 , wherein the lateral area of the image sensor array is no more than 0.5 millimeters by 0.5 millimeters, and wherein the lateral area of the one of the single lens and the plurality of stacked lenses is no more than 0.9 millimeters by 0.9 millimeters. 
     
     
         34 . The endoscope of  claim 30 , wherein the endoscope comprises a capsular endoscope, and wherein the hermetically sealed housing has a size and a shape capable of being swallowed by a human. 
     
     
         35 . The endoscope of  claim 30 , further comprising a flexible cannula having a proximal portion and a distal portion to be introduced into a patient, and wherein the hermetically sealed housing is located at the distal portion of the flexible cannula.