Structure of image sensor module and a method for manufacturing of wafer level package

Abstract

The present invention discloses an image sensor module and forming method of wafer level package. The image sensor module comprises a metal alloy base, a wafer level package, a lens holder, and flexible printed circuits (F.P.C.). The wafer level package having a plurality of image sensor dice and a plurality of solder balls is attached to the metal alloy base. A plurality of lens are placed in the lens holder, and the lens holder is located on the image sensor dice. The lens holder is placed in the flexible printed circuits (F.P.C.), and the flexible printed circuits (F.P.C.) has a plurality of solder joints coupled to the solder balls for conveniently transmitting signal of the image sensor dice. Moreover, the image sensor dice may be packaged with passive components or other dice with a side by side structure or a stacking structure.

1 . A process of wafer level package, comprising the steps of:
 forming a first photo resist pattern on metal pads of a plurality of dice on a wafer to cover said metal pads;   forming a first dielectric layer on said first photo resist pattern and said plurality of dice;   removing said first photo resist pattern;   sawing said plurality of dice on said wafer to form individual dice;   selecting good said dice and attaching said good dice to a metal alloy base, wherein material of said metal alloy base comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials;   forming a material layer on said base to fill in a space among said plurality of dice on said base;   forming a second dielectric layer on said material layer;   etching a partial region of said second dielectric layer to form first openings to expose metal pads on said dice;   forming a contact conductive layer on said first openings to electrically couple with said metal pads, respectively;   forming a second photo resist layer on said second dielectric layer and said contact conductive layer;   removing a partial region of said second photo resist layer to form a second photo resist pattern to expose said contact conductive layer to form second openings;   forming conductive lines on said second photo resist pattern and said second openings being coupled with said contact conductive layer, respectively;   removing remaining said second photo resist pattern;   forming an isolation layer on said conductive lines and said second dielectric layer;   removing a partial region of said isolation layer on said conductive lines to form third openings; and   welding solder balls on said third openings.   
   
   
       2 . The process in  claim 1 , further comprising a step of sawing said base to isolate said plurality of dice after the step of said welding solder balls. 
   
   
       3 . The process in  claim 1 , further comprising a step of back lapping said wafer to get a thickness of said wafer around 100-300 cm after the step of said removing first photo resist pattern. 
   
   
       4 . The process in  claim 1 , further comprising a step of forming an epoxy layer on back surface of said base. 
   
   
       5 . The process in  claim 1 , wherein said plurality of dice comprise at least two types of dice. 
   
   
       6 . The process in  claim 1 , wherein material of said first dielectric layer is SiO2 by spin coating. 
   
   
       7 . The process in  claim 1 , wherein material of said first dielectric layer is silicon rubber based material. 
   
   
       8 . The process in  claim 1 , wherein material of said material layer is silicon rubber, epoxy, BCB, BT, polyimide (PI) or SINR(Siloxane polymer). 
   
   
       9 . The process in  claim 1 , wherein material of said second dielectric layer is silicon rubber, epoxy, SINR(Siloxane polymer), BCB or polyimide (PI). 
   
   
       10 . The process in  claim 1 , further comprising a step of forming a filtering film on said first dielectric layer, said filtering film is an IR filtering layer. 
   
   
       11 . The process in  claim 1 , wherein material of said contact conductive layer is selected from Ti, Cu and the combination thereof. 
   
   
       12 . The process in  claim 1 , wherein material of said isolation layer is selected from epoxy, resin and the combination thereof. 
   
   
       13 . The process in  claim 1 , wherein material of said conductive lines is selected from Ni, Cu, Au and the combination thereof. 
   
   
       14 . The process in  claim 1 , wherein said step of welding said solder balls comprises placing said solder balls on said third openings by a screen printing method and joining said solder balls together with surfaces of said conductive lines by an IR reflow method. 
   
   
       15 . A process of wafer level package, comprising the steps of:
 forming a first dielectric layer on a plurality of dice on a wafer by using a first photo resist pattern;   sawing said plurality of dice on said wafer to form individual dice;   selecting good said dice and attaching said good dice to a metal alloy base, wherein material of said metal alloy base comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials;   forming a material layer on said base to fill in a space among said plurality of dice on said base;   forming a second dielectric layer on said material layer;   etching a partial region of said second dielectric layer to form first openings to expose metal pads on said dice;   forming a contact conductive layer on said first openings to electrically couple with said metal pads, respectively;   forming a second photo resist pattern to expose said contact conductive layer to form second openings;   forming conductive lines on said second photo resist pattern and said second openings being coupled with said contact conductive layer, respectively;   removing remaining said second photo resist pattern;   forming an isolation layer on said conductive lines and said second dielectric layer;   removing a partial region of said isolation layer on said conductive lines to form third openings; and   welding solder balls on said third openings.   
   
   
       16 . The process in  claim 15 , further comprising a step of sawing said base to isolate said plurality of dice after the step of said welding solder balls. 
   
   
       17 . The process in  claim 15 , further comprising a step of back lapping said wafer to get a thickness of said wafer around 100-300 μm after the step of said removing said first photo resist pattern. 
   
   
       18 . The process in  claim 15 , further comprising a step of forming an epoxy layer on back surface of said base. 
   
   
       19 . The process in  claim 15 , wherein said plurality of dice comprise at least two types of dice. 
   
   
       20 . The process in  claim 15 , wherein material of said first dielectric layer is SiO2 by spin coating. 
   
   
       21 . The process in  claim 15 , wherein material of said first dielectric layer is silicon rubber based material. 
   
   
       22 . The process in  claim 15 , wherein material of said material layer is silicon rubber, epoxy, resin, BCB, BT, polyimide (PI) or SINR(Siloxane polymer). 
   
   
       23 . The process in  claim 15 , wherein material of said second dielectric layer is SINR(Siloxane polymer), BCB or polyimide (PI). 
   
   
       24 . The process in  claim 15 , further comprising a step of forming a filtering film on said first dielectric layer, said filtering film is an IR filtering layer. 
   
   
       25 . The process in  claim 15 , wherein material of said contact conductive layer is selected from Ti, Cu and the combination thereof. 
   
   
       26 . The process in  claim 15 , wherein material of said isolation layer is selected from epoxy, resin and the combination thereof. 
   
   
       27 . The process in  claim 15 , wherein material of said conductive lines is selected from Ni, Cu, Au and the combination thereof. 
   
   
       28 . The process in  claim 15 , wherein said step of welding said solder balls comprises placing said solder balls on said third openings by a screen printing method and joining said solder balls together with surfaces of said conductive lines by an IR reflow method.