Method for making wafer level image module
A wafer level image module includes a photo sensor for outputting an electrical signal upon receiving light, a lens set for focusing incident light onto the photo sensor, and an adjustment member disposed between the photo sensor and the lens set for controlling the distance between the photo sensor and the lens set to compensate the focus offset of the photo sensor for enabling the lens set to accurately focus the incident light onto the photo sensor in an in-focus manner so as to provide a high image quality.
1. A method for making a wafer level image module comprising the steps of:
a) providing a photo sensor made by an integrated circuit manufacturing process;
b) stacking a lens set made by an integrated circuit manufacturing process on the photo sensor;
c) measuring a focus offset of said lens set and determining in-focus or out-of-focus status of said photo sensor;
d) disposing an adjustment member between said lens set and said photo sensor to compensate the focus offset of said lens set so as to have said photo sensor be in an in-focus status, wherein said adjustment member comprises a glass ball; and
e) disposing a transparent spacer between said photo sensor and said adjustment member, wherein said transparent spacer is in direct contact with said adjustment member.
2. The method as claimed in claim 1 , wherein said step (c) comprises a sub-step of using a signal processor to check the out-of-focus status to be a far focal or near focal status when said photo sensor is in an out-of-focus status.
3. The method as claimed in claim 1 , wherein said transparent spacer has an opening corresponding to a photo sensing area of said photo sensor.
4. A method for making a wafer level image module comprising:
providing a photo sensor;
molding transparent ultraviolet polymers to form a lens set,
stacking a said lens set on said photo sensor;
measuring a focus offset of said lens set;
determining a thickness of an adjustment member according to said focus offset;
bonding said adjustment member between said lens set and said photo sensor;
confirming a second focus offset of said lens set by a probe card; and
disposing a transparent spacer between said photo sensor and said adjustment member, wherein said transparent spacer is in direct contact with said adjustment member, wherein said adjustment member comprises a glass ball.
5. The method as claimed in claim 4 , further comprising:
clamping said photo sensor, said adjustment member, and said lens set; and
placing said photo sensor, said adjustment member, and said lens set on a test table.
6. The method as claimed in claim 4 , wherein the bonding step comprises:
holding said photo sensor, said adjustment member, and said lens set together.
7. The method as claimed in claim 4 , wherein the measuring step comprises:
picking up a signal from the photo sensor upon focusing an image onto said photo sensor by the lens set; and
processing said signal to check in-focus or out-of-focus status of the image.
8. The method as claimed in claim 4 , wherein said transparent spacer has an opening corresponding to a photo sensing area of said photo sensor.