Packaged microelectronic imagers and methods of packaging microelectronic imagers

Abstract

A microelectronic imager comprising an imaging unit and an optics unit attached to the imaging unit, and methods for packaging microelectronic imagers. In one embodiment, the imaging unit can include (a) a microelectronic die with an image sensor and a plurality of external contacts electrically coupled to the image sensor and (b) a first referencing element fixed to the imaging unit. The optics unit can include an optic member and a second referencing element fixed to the optics unit. The second referencing element is releasably seated with the first referencing element at a preset position in which the optic member is situated at a desired location relative to the image sensor.

1 . A microelectronic imager, comprising: 
 an imaging unit including (a) a microelectronic die with an image sensor and a plurality of external contacts electrically coupled to the image sensor, and (b) a first referencing element at a set location relative to the image sensor; and    an optics unit having an optic member and a second referencing element at a set location with respect to the optics unit, the second referencing element being detachably seated with the first referencing element at a preset position in which the optic member is situated at a desired location relative to the image sensor.    
   
   
       2 . The imager of  claim 1  wherein the first referencing element further comprises a first engagement member and the second referencing element further comprises a second engagement member engaged with the first engagement member, and wherein the first and second engagement members are configured to releasably secure the first and second referencing elements together.  
   
   
       3 . The imager of  claim 1  wherein the first engagement member comprises first threads and the second engagement member comprises second threads.  
   
   
       4 . The imager of  claim 3  wherein the first referencing element further comprises a first stop component at a preset distance from the image sensor and the second referencing element further comprises a second stop component at preset distance from the optic member, and wherein the first and second stop components contact each other to position the optic member at a predetermined distance from the image sensor.  
   
   
       5 . The imager of  claim 1  wherein: 
 the first referencing element further comprises a base section attached to the imaging unit, an intermediate section mounted to the base section, and a first engagement member at the intermediate section; and    the second referencing element further comprises a second engagement member engaged with the first engagement member, and wherein the first and second engagement members are configured to releasably secure the intermediate section to the second referencing element.    
   
   
       6 . The imager of  claim 5  wherein the first engagement member comprises first threads and the second engagement member comprises second threads engaged with the first threads.  
   
   
       7 . The imager of  claim 5  wherein the first and second engagement members are a bayonet connection.  
   
   
       8 . The imager of  claim 5  wherein the base section has a base stop at a preset distance from a focal plane of the image sensor and the intermediate section has an intermediate stop in contact with the base stop to register the intermediate section to the focal plane of the image sensor.  
   
   
       9 . The imager of  claim 5  wherein: 
 the base section has a base stop at a preset distance from the image sensor;    the intermediate section has an intermediate stop and a first stop component at a preset distance from the intermediate stop, and the base stop contacts the intermediate stop to space the first stop component from the image sensor by a preset distance; and    the second referencing element further comprises a second stop component engaged with the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       10 . The imager of  claim 5  wherein the first engagement member comprises one of a slot or a tab, and the second engagement member comprises the other of the slot or the tab, and wherein the slot receives the tab.  
   
   
       11 . The imager of  claim 10  wherein the slot has a first portion and a second portion extending transverse to the first portion.  
   
   
       12 . The imager of  claim 1  wherein: 
 the first referencing element has a first interface feature at a first reference location relative to the image sensor on the die;    the second referencing element has a second interface feature at a second reference location relative to the optic member; and    the first interface feature is engaged with the second interface feature with the first reference location coinciding with the second reference location whereby the optic member is aligned with the image sensor and positioned at a desired distance from the image sensor.    
   
   
       13 . The imager of  claim 1  wherein: 
 the first referencing element comprises a first support projecting from the die, the first support having a first alignment component at a preset lateral location from the image sensor and a first stop component at a fixed, preset elevation from the image sensor; and    the second referencing element comprises a second support fixed to the optics unit, the second support having (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       14 . The imager of  claim 1  wherein: 
 the imaging unit further comprises a cover over the die;    the first referencing element comprises a first support projecting from the cover, the first support having a first alignment component at a preset lateral location from the image sensor and a first stop component at a fixed, preset elevation from the image sensor; and    the second referencing element comprises a second support projecting from the optics unit, the second support having (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       15 . The imager of  claim 1  wherein the first referencing element comprises a first support on the die around the image sensor and the second referencing element comprises a second support on the optics unit around the optic member, and the first support on the die is mated with the second support on the optics unit.  
   
   
       16 . The imager of  claim 1  wherein: 
 the imaging unit further comprises a cover over the image sensor; and    the first referencing element comprises a first support on the cover and the second referencing element comprises a second support on the optics unit around the optic member, and the first support on the cover is mated with the second support on the optics unit.    
   
   
       17 . The imager of  claim 1  wherein the first referencing element comprises a first support having a first step and the second referencing element comprises a second support having a second step mated with the first step of the first support.  
   
   
       18 . The imager of  claim 1  wherein one of the first or second referencing elements comprises a channel and the other of the first or second referencing elements comprises a projection received in the channel.  
   
   
       19 . The imager of  claim 1  wherein: 
 the imaging unit further comprises a cover over the image sensor;    the first referencing element comprises a depression in the cover; and    the second referencing element comprises a support having a distal protrusion received in the depression in the cover.    
   
   
       20 . The imager of  claim 1  wherein: 
 the imaging unit further comprises a cover over the image sensor;    the optics unit further comprises a substrate carrying the optic member;    the first referencing element comprises a support projecting from the cover and having a distal protrusion; and    the second referencing element comprises a depression in the substrate in which the distal protrusion of the support is received.    
   
   
       21 . The imager of  claim 1  wherein the first referencing element comprises a plurality of guides projecting from one of the die or a cover over the die, and the second referencing element comprises a support extending from the optics unit that has bearing surfaces juxtaposed with the guides.  
   
   
       22 . The imager of  claim 1  wherein the first referencing element comprises a first support projecting from one of the die or a cover over the die and a first radial alignment component at the support, and the second referencing element comprises a second support projecting from the optics unit and a second radial alignment component at the second support, and wherein the first and second radial alignment components are aligned to radially align the optic member with the image sensor.  
   
   
       23 . The imager of  claim 1  wherein the first referencing element comprises a first support projecting from one of the die or a cover over the die and the second referencing element comprises a second support projecting from the optics unit, the first support having a first inclined surface, and the second support having a complementary inclined surface engaging the first inclined surface.  
   
   
       24 . A microelectronic imager, comprising: 
 a microelectronic die having an image sensor and a plurality of contacts electrically coupled to the image sensor;    a first referencing element positioned relative to the die, the first referencing element having a first alignment component at a lateral distance from the image sensor and a first stop component spaced apart from the image sensor along an axis normal to the image sensor by separation distance;    an optics unit having an optic member; and    a second referencing element connected to the optics unit, the second referencing element having a second alignment component contacting the first alignment component to align the optic member with the image sensor and a second stop component contacting the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       25 . The imager of  claim 24  wherein: 
 the first referencing element comprises a first support projecting from one of the die or a cover over the die, and the first support includes the first alignment component and the first stop component; and    the second referencing element comprises a second support projecting from the optics unit, and the second support includes the second alignment component and the second stop component.    
   
   
       26 . The imager of  claim 24  wherein the first referencing element comprises a first support having a first step and the second referencing element comprises a second support having a second step mated with the first step of the first support.  
   
   
       27 . The imager of  claim 24  wherein one of the first or second referencing elements comprises a channel and the other of the first or second referencing elements comprises a projection received in the channel.  
   
   
       28 . The imager of  claim 24  wherein the first referencing element further comprises a first engagement member and the second referencing element further comprises a second engagement member engaged with the first engagement member, and wherein the first and second engagement members are configured to releasably secure the first and second referencing elements together.  
   
   
       29 . The imager of  claim 28  wherein the first engagement member comprises first threads and the second engagement member comprises second threads.  
   
   
       30 . The imager of  claim 28  wherein the first and second engagement members are configured into a bayonet connection.  
   
   
       31 . A microelectronic imager, comprising: 
 an imaging unit including (a) a microelectronic die having an image sensor and a plurality of external contacts electrically connected to the image sensor, and (b) a first referencing element fixed with respect to the image sensor; and    an optics unit including an optic member and a second referencing element fixed with respect to the optic member, the second referencing element being detachably seated with the first referencing element, and the first and second referencing elements being configured to align the optic member with the image sensor and space the optic member apart from the image sensor by a desired distance when the first and second referencing elements are seated together.    
   
   
       32 . The imager of  claim 31  wherein: 
 the first referencing element has a first interface feature at a first reference location relative to the image sensor on the die;    the second referencing element has a second interface feature at a second reference location relative to the optic member; and    the first interface feature is engaged with the second interface feature with the first reference location coinciding with the second reference location such that the optic member is aligned with the image sensor and positioned at a desired distance from the image sensor.    
   
   
       33 . The imager of  claim 31  wherein: 
 the first referencing element comprises a first support projecting from the die, the first support having a first alignment component at a preset lateral location from the image sensor and a first stop component at a set elevation from the image sensor; and    the second referencing element comprises a second support fixed to the optics unit, the second support having (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       34 . The imager of  claim 31  wherein: 
 the imaging unit further comprises a cover over the die;    the first referencing element comprises a first support projecting from the cover, the first support having a first alignment component at a preset lateral location from the image sensor and a first stop component at a fixed, preset elevation from the image sensor; and    the second referencing element comprises a second support projecting from the optics unit, the second support having (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       35 . The imager of  claim 31  wherein the first referencing element comprises a first support on the die around the image sensor and the second referencing element comprises a second support on the optics unit around the optic member, and the first support on the die is mated with the second support on the optics unit.  
   
   
       36 . The imager of  claim 31  wherein: 
 the imaging unit further comprises a cover over the die; and    the first referencing element comprises a first support on the cover and the second referencing element comprises a second support on the optics unit around the optic member, and the first support on the cover is mated with the second support on the optics unit.    
   
   
       37 . The imager of  claim 31  wherein the first referencing element comprises a first support having a first step and the second referencing element comprises a second support having a second step mated with the first step of the first support.  
   
   
       38 . The imager of  claim 31  wherein the first referencing element comprises a first support projecting from one of the die or a cover over the die and the second referencing element comprises a second support projecting from the optics unit, the first support having a first inclined surface, and the second support having a complementary inclined surface engaging the first inclined surface.  
   
   
       39 . A microelectronic imager, comprising: 
 an imaging unit including (a) a microelectronic die with an image sensor and a plurality of external contacts electrically coupled to the image sensor, and (b) a first stand-off section fixed to the imaging unit and having a first interface area at a set reference position relative to the image sensor and a first quick-release engagement member; and    an optics unit having an optic member and a second stand-off section fixed to the optics unit, the second stand-off section having a second interface area at a set reference position relative to the optic member and a second quick-release engagement member, wherein the first interface area is seated with the second interface area to position the first stand-off section with the second stand-off section in a configuration in which the optic member is at a desired location relative to the image sensor, and wherein the first and second quick-release elements are coupled together to releasably secure the first stand-off section to the second stand-off section.    
   
   
       40 . The imager of  claim 39  wherein: 
 the first stand-off section projects from the die, and the first interface area has a first alignment component at a preset lateral location from the image sensor and a first stop component at a set elevation from the image sensor; and    the second stand-off section projects from the optics unit, and the second interface area has (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       41 . The imager of  claim 39  wherein: 
 the imaging unit further comprises a cover over the die;    the first stand-off section projects from the cover, and the first interface area has a first alignment component at a preset lateral location from the image sensor and a first stop component at a fixed, preset elevation from the image sensor; and    the second stand-off section projects from the optics unit, and the second interface area has (a) a second alignment component juxtaposed to the first alignment component to align the optic member with a centerline of the image sensor, and (b) a second stop component juxtaposed to the first stop component to space the optic member apart from the image sensor by a desired distance.    
   
   
       42 . The imager of  claim 39  wherein the first stand-off section projects from the die and extends around the image sensor and the second stand-off section projects from the optics unit extends around the optic member, and the first interface area is mated with the second interface area.  
   
   
       43 . The imager of  claim 39  wherein: 
 the image sensor further comprises a cover over the image sensor; and    the first stand-off section projects from the cover and the second stand-off section projects from the optics unit, and the first interface area is mated with the second interface area.    
   
   
       44 . The imager of  claim 39  wherein the first interface area comprises a first step and the second interface area comprises a second step mated with the first step.  
   
   
       45 . The imager of  claim 39  wherein one of the first or second stand-off sections includes a channel and the other of the first or second stand-off sections includes a projection received in the channel.  
   
   
       46 . The imager of  claim 39  wherein the first stand-off section further comprises a first engagement member and the second stand-off section further comprises a second engagement member engaged with the first engagement member, and wherein the first and second engagement members are configured to releasably secure the first and second referencing elements together.  
   
   
       47 . The imager of  claim 46  wherein the first engagement member comprises first threads and the second engagement member comprises second threads.  
   
   
       48 . The imager of  claim 46  wherein the first and second engagement members are configured into a bayonet connection.  
   
   
       49 . An assembly of a plurality of imagers, comprising: 
 a microelectronic workpiece comprising a first substrate, a plurality of dies on the first substrate, and a plurality of first referencing elements on the first substrate, wherein individual dies have an image sensor and external electrical contacts electrically coupled to the image sensor, and wherein individual first referencing elements have first engagement members and are positioned at a predetermined location relative to a corresponding image sensor of a corresponding die; and    an optics workpiece comprising a second substrate, a plurality of optics units on the second substrate, and a plurality of second referencing elements on the second substrate, wherein individual optics units have an optic member and individual second referencing elements are positioned at a predetermined location relative to a corresponding optic member, and wherein the second referencing elements (a) have second engagement members detachably engaged with the first engagement members and (b) are seated with corresponding first referencing elements at predetermined positions relative to corresponding image sensors in which individual optic members are situated at a desired location relative to corresponding individual image sensors.    
   
   
       50 . A method of packaging an imager, comprising: 
 providing an imaging unit having (a) a microelectronic die with an image sensor and a plurality of external contacts electrically coupled to the image sensor, and (b) a first referencing element fixed to the imaging unit, wherein the first referencing element has a first interface feature at a reference position relative to the image sensor and a first engagement member;    providing an optics unit having an optic member and a second referencing element fixed to the optics unit, wherein the second referencing element has a second interface feature at a reference position relative to the optic member and a second engagement member; and    attaching the second referencing element to the first referencing element by seating the second interface feature with the first interface feature in a predetermined position in which the optic member is at a desired location relative to the image sensor, and wherein the first and second engagement members are releasably engaged with each other.    
   
   
       51 . The method of  claim 50  wherein attaching the second referencing element to the first referencing element comprises moving at least one of the imaging unit and the optics unit toward the other using automated equipment.  
   
   
       52 . The method of  claim 50  wherein the imaging unit is a first imaging unit of a plurality of imaging units on a microelectronic workpiece, and wherein providing the imaging unit comprises constructing the first referencing element on the workpiece at the first imaging unit before separating the first imaging unit from the workpiece.  
   
   
       53 . The method of  claim 50  wherein the first referencing element comprises a first support around the image sensor and the second referencing element comprises a second support on the optics unit around the optic member, and wherein attaching the first referencing element to the second referencing element comprises mating the first support with the second support.  
   
   
       54 . The method of  claim 50  wherein the first referencing element comprises a first support having a first step and the second referencing element comprises a second support having a second step, and wherein attaching the first referencing element to the second referencing element comprises mating the first step of the first support with the second step of the second support.  
   
   
       55 . The method of  claim 50  wherein one of the first or second referencing elements comprises a channel and the other of the first or second referencing elements comprises a projection received in the channel, and wherein attaching the first referencing element to the second referencing element comprises inserting the protrusion into the channel.  
   
   
       56 . The method of  claim 50  wherein: 
 the imaging unit further comprises a cover over the image sensor, the first referencing element comprises a depression in the cover, and the second referencing element comprises a support having a distal protrusion; and    attaching the first referencing element to the second referencing element comprises inserting the protrusion into the depression.    
   
   
       57 . The method of  claim 50  wherein: 
 the imaging unit further comprises a cover over the image sensor, the optics unit further comprises a substrate carrying the optic member, the first referencing element comprises a support having a distal protrusion, and the second referencing element comprises a depression in the substrate; and    attaching the first referencing element to the second referencing element comprises inserting the protrusion into the depression.    
   
   
       58 . The method of  claim 50  wherein the first referencing element comprises a plurality of guides projecting from one of the die or a cover over the die, and the second referencing element comprises a support extending from the optics unit that has bearing surfaces, and wherein attaching the first referencing element to the second referencing element comprises positioning the bearing surfaces next to the guides.  
   
   
       59 . The method of  claim 50  wherein the first referencing element comprises a first support projecting from one of the die or a cover over the die and a first radial alignment component at the support, and the second referencing element comprises a second support projecting from the optics unit and a second radial alignment component at the second support, and wherein attaching the first referencing element to the second referencing element comprises aligning the first radial alignment component with the second radial alignment component to radially align the optic member with the image sensor.  
   
   
       60 . The method of  claim 50  wherein the first referencing element comprises a first support projecting from one of the die or a cover over the die and the second referencing element comprises a second support projecting from the optics unit, the first support having a first inclined surface, and the second support having a complementary inclined surface, and wherein attaching the first referencing element to the second referencing element comprises engaging the first inclined surface with the second inclined surface.  
   
   
       61 . The method of  claim 50 , further comprising: 
 providing a plurality of imaging units on a microelectronic workpiece, wherein individual imaging units include (a) a microelectronic die with an image sensor and a plurality of external contacts electrically coupled to the image sensor, and (b) a first referencing element fixed to the workpiece;    providing a plurality of optics units on an optic workpiece, wherein individual optics units include an optic member and a second referencing element fixed to the optics unit; and    releasably attaching the first referencing element of individual imaging units to corresponding second referencing elements of corresponding optics units.    
   
   
       62 . The method of  claim 61 , further comprising singulating the imaging units from each other and testing the imaging units to determine known-good-units, and wherein the attaching procedure comprises attaching the first referencing elements of known-good-units to corresponding second referencing elements of corresponding optics units.  
   
   
       63 . The method of  claim 62  wherein attaching the first referencing elements of known-good-units to corresponding second referencing elements of corresponding optics units occurs before singulating the optics workpiece.  
   
   
       64 . The method of  claim 62  wherein attaching the first referencing elements of known-good-units to corresponding second referencing elements of corresponding optics units occurs after singulating the optics workpiece.  
   
   
       65 . The method of  claim 61 , further comprising singulating the optics workpiece to separate the individual optics units, and wherein the attaching procedure comprises attaching the second referencing elements of separated optics units to corresponding first referencing elements of corresponding imaging units.  
   
   
       66 . The method of  claim 65  wherein the attaching procedure comprises mating the first referencing elements with corresponding second referencing element before singulating either the microelectronic workpiece or the optics workpiece.  
   
   
       67 . The method of  claim 65  wherein providing the imaging units comprises constructing the first referencing elements on the microelectronic workpiece using stereolithography processing.  
   
   
       68 . The method of  claim 65  wherein providing the optics units comprises constructing the second referencing elements on the optics workpiece using stereolithography processing.  
   
   
       69 . The method of  claim 50  wherein the first engagement member comprises first threads and the second engagement member comprises second threads releasably engaged with the first threads.  
   
   
       70 . The method of  claim 50  wherein the first and second engagement members comprise a bayonet connection.